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Sample records for positive-end expiratory pressure

  1. Effects of positive end-expiratory pressure on renal function.

    Science.gov (United States)

    Järnberg, P O; de Villota, E D; Eklund, J; Granberg, P O

    1978-01-01

    The effects were studied positive end-expiratory pressure (PEEP) on renal function in eight patients with acute respiratory failure, requiring mechanical ventilation. On application of PEEP + 10 cm H2O, central venous pressure increased, systolic blood pressure decreased, urine flow and PAH-clearance were reduced, while inulin clearance remained stable. There was a marked increase in fractional sodium reabsorption and a concurrent decrease in fractional osmolal excretion. Fractional free-water clearance and the ratio UOsm/POsm did change.

  2. The effect of positive end-expiratory pressure on pulse pressure ...

    African Journals Online (AJOL)

    The effect of positive end-expiratory pressure on pulse pressure variation. FJ Smith, M Geyser, I Schreuder, PJ Becker. Abstract. Objectives: To determine the effect of different levels of positive end-expiratory pressure (PEEP) on pulse pressure variation (PPV). Design: An observational study. Setting: Operating theatres of a ...

  3. Interaction between intra-abdominal pressure and positive-end expiratory pressure

    Directory of Open Access Journals (Sweden)

    Jamili Anbar Torquato

    2009-02-01

    Full Text Available OBJECTIVE: The aim of this study was to quantify the interaction between increased intra-abdominal pressure and Positive-End Expiratory Pressure. METHODS: In 30 mechanically ventilated ICU patients with a fixed tidal volume, respiratory system plateau and abdominal pressure were measured at a Positive-End Expiratory Pressure level of zero and 10 cm H2O. The measurements were repeated after placing a 5 kg weight on the patients' belly. RESULTS: After the addition of 5 kg to the patients' belly at zero Positive-End Expiratory Pressure, both intra-abdominal pressure (p<0.001 and plateau pressures (p=0.005 increased significantly. Increasing the Positive-End Expiratory Pressure levels from zero to 10 cm H2O without weight on the belly did not result in any increase in intra-abdominal pressure (p=0.165. However, plateau pressures increased significantly (p< 0.001. Increasing Positive-End Expiratory Pressure from zero to 10 cm H2O and adding 5 kg to the belly increased intra-abdominal pressure from 8.7 to 16.8 (p<0.001 and plateau pressure from 18.26 to 27.2 (p<0.001. Maintaining Positive-End Expiratory Pressure at 10 cm H2O and placing 5 kg on the belly increased intra-abdominal pressure from 12.3 +/- 1.7 to 16.8 +/- 1.7 (p<0.001 but did not increase plateau pressure (26.6+/-1.2 to 27.2 +/-1.1 -p=0.83. CONCLUSIONS: The addition of a 5kg weight onto the abdomen significantly increased both IAP and the airway plateau pressure, confirming that intra-abdominal hypertension elevates the plateau pressure. However, plateau pressure alone cannot be considered a good indicator for the detection of elevated intra-abdominal pressure in patients under mechanical ventilation using PEEP. In these patients, the intra-abdominal pressure must also be measured.

  4. Pharmacologic Interventions to Improve Splanchnic Oxygenation During Ventilation with Positive End-Expiratory Pressure

    NARCIS (Netherlands)

    Fournell, A.; Scheeren, T. W. L.; Picker, O.; Schwarte, L. A.; Wolf, M; Bucher, HU; Rudin, M; VanHuffel, S; Wolf, U; Bruley, DF; Harrison, DK

    2012-01-01

    Mechanical ventilation with positive end-expiratory pressure (PEEP) is an indispensable tool in the management of respiratory failure to preserve or improve lung function and systemic oxygenation. However, PEEP per se may also, as has been shown in experimental animals, impair regional

  5. Hyperinflation and intrinsic positive end-expiratory pressure: less room to breathe.

    Science.gov (United States)

    Krieger, Bruce P

    2009-01-01

    Clinically, the symptoms and limited exercise capabilities of patients with chronic obstructive pulmonary disease (COPD) correlate better with changes in lung volumes than with airflow measurements. The realization of the clinical importance of hyperinflation has been overshadowed for decades by the use of forced expiratory volume during 1 s (FEV(1)) and the ratio of the FEV(1) to the forced expiratory vital capacity (FEV(1)/FVC) to categorize the severity and progression of COPD. Hyperinflation is defined as an elevation in the end-expiratory lung volume or functional residual capacity. When severe hyperinflation encroaches upon inspiratory capacity and limits vital capacity, it results in elevated intrinsic positive end-expiratory pressure (PEEPi) that places the diaphragm at a mechanical disadvantage and increases the work of breathing. Severe hyperinflation is the major physiologic cause of the resulting hypercarbic respiratory failure and patients' inability to transition (i.e. wean) from mechanical ventilatory support to spontaneous breathing. This paper reviews the basic physiologic principles of hyperinflation and its clinical manifestations as demonstrated by PEEPi. Also reviewed are the adverse effects of hyperinflation and PEEPi in critically ill patients with COPD, and methods for minimizing or counterbalancing these effects. Copyright 2009 S. Karger AG, Basel.

  6. Control of positive end-expiratory pressure (PEEP for small animal ventilators

    Directory of Open Access Journals (Sweden)

    Leão Nunes Marcelo V

    2010-07-01

    Full Text Available Abstract Background The positive end-expiratory pressure (PEEP for the mechanical ventilation of small animals is frequently obtained with water seals or by using ventilators developed for human use. An alternative mechanism is the use of an on-off expiratory valve closing at the moment when the alveolar pressure is equal to the target PEEP. In this paper, a novel PEEP controller (PEEP-new and the PEEP system of a commercial small-animal ventilator, both based on switching an on-off valve, are evaluated. Methods The proposed PEEP controller is a discrete integrator monitoring the error between the target PEEP and the airways opening pressure prior to the onset of an inspiratory cycle. In vitro as well as in vivo experiments with rats were carried out and the PEEP accuracy, settling time and under/overshoot were considered as a measure of performance. Results The commercial PEEP controller did not pass the tests since it ignores the airways resistive pressure drop, resulting in a PEEP 5 cmH2O greater than the target in most conditions. The PEEP-new presented steady-state errors smaller than 0.5 cmH2O, with settling times below 10 s and under/overshoot smaller than 2 cmH2O. Conclusion The PEEP-new presented acceptable performance, considering accuracy and temporal response. This novel PEEP generator may prove useful in many applications for small animal ventilators.

  7. Effects of positive end-expiratory pressure on arthroscopic shoulder surgery under general anesthesia.

    Science.gov (United States)

    Ersoy, Ayşın; Çakırgöz, Mensure; Ervatan, Zekeriya; Kıran, Özlem; Türkmen, Aygen; Esenyel, Cem Zeki

    2016-01-01

    Our study is a prospective, randomized study on patients undergoing arthroscopic shoulder surgery in the beach-chair position to evaluate the effects of positive end-expiratory pressure (PEEP) on hemodynamic stability, providing a bloodless surgical field and surgical satisfaction. Fifty patients were divided into two groups. Group I (n=25) had zero end-expiratory pressure (ZEEP) administered under general anesthesia, and group II (n=25) had +5 PEEP administered. During surgery, intraarticular hemorrhage and surgical satisfaction were evaluated on a scale of 0-10. During surgery, at the 5th, 30th, 60th, and 90th minutes and at the end of surgery, heart rate, mean arterial pressure (MAP), and positive inspiratory pressure were recorded. At the end of the surgery, the amount of bleeding and duration of the operation were recorded. In group I, the duration of operation and amount of bleeding were found to be significantly greater than those in group II (pshoulder surgery in the beach-chair position reduces the amount of hemorrhage in the surgical field and thus increases surgical satisfaction without requiring the creation of controlled hypotension.

  8. Positive end-expiratory pressure improves gas exchange and pulmonary mechanics during partial liquid ventilation.

    Science.gov (United States)

    Kirmse, M; Fujino, Y; Hess, D; Kacmarek, R M

    1998-11-01

    Partial liquid ventilation (PLV) with perflubron (PFB) has been proposed as an adjunct to the current therapies for the acute respiratory distress syndrome (ARDS). Because PFB has been also referred to as "liquid PEEP," distributing to the most gravity-dependent regions of the lung, less attention has been paid to the amount of applied positive end-expiratory pressure (PEEP). We hypothesized that higher PEEP levels than currently applied are needed to optimize gas exchange, and that the lower inflection point (LIP) of the pressure-volume curve could be used to estimate the amount of PEEP needed when the lung is filled with PFB. Lung injury was induced in 23 sheep by repeated lung lavage with warmed saline until the PaO2/FIO2 ratio fell below 150. Five sheep were used to investigate the change of the LIP when the lung was filled with PFB in increments of 5 ml/kg/body weight to a total of 30 ml/kg/body weight. To evaluate the impact of PEEP set at LIP +1 cm H2O we randomized an additional 15 sheep to three groups with different doses (7.5 ml, 15 ml, 30 ml/kg/body weight) of PFB. In random order a PEEP of 5 cm H2O or PEEP at LIP +1 cm H2O was applied. The LIP decreased with incremental filling of PFB to a minimum at 10 ml (p PFB shifts the LIP to the left, and that setting PEEP at LIP +1 cm H2O improves gas exchange at moderate to high doses of PFB.

  9. Positive end-expiratory pressure improves survival in a rodent model of cardiopulmonary resuscitation using high-dose epinephrine.

    LENUS (Irish Health Repository)

    McCaul, Conán

    2009-10-01

    Multiple interventions have been tested in models of cardiopulmonary resuscitation (CPR) to optimize drug use, chest compressions, and ventilation. None has studied the effects of positive end-expiratory pressure (PEEP) on outcome. We hypothesized that because PEEP can reverse pulmonary atelectasis, lower pulmonary vascular resistance, and potentially improve cardiac output, its use during CPR would increase survival.

  10. Effects of recruitment maneuver and positive end-expiratory pressure on respiratory mechanics and transpulmonary pressure during laparoscopic surgery.

    Science.gov (United States)

    Cinnella, Gilda; Grasso, Salvatore; Spadaro, Savino; Rauseo, Michela; Mirabella, Lucia; Salatto, Potito; De Capraris, Antonella; Nappi, Luigi; Greco, Pantaleo; Dambrosio, Michele

    2013-01-01

    The authors tested the hypothesis that during laparoscopic surgery, Trendelenburg position and pneumoperitoneum may worsen chest wall elastance, concomitantly decreasing transpulmonary pressure, and that a protective ventilator strategy applied after pneumoperitoneum induction, by increasing transpulmonary pressure, would result in alveolar recruitment and improvement in respiratory mechanics and gas exchange. In 29 consecutive patients, a recruiting maneuver followed by positive end-expiratory pressure 5 cm H(2)O maintained until the end of surgery was applied after pneumoperitoneum induction. Respiratory mechanics, gas exchange, blood pressure, and cardiac index were measured before (T(BSL)) and after pneumoperitoneum with zero positive end-expiratory pressure (T(preOLS)), after recruitment with positive end-expiratory pressure (T(postOLS)), and after peritoneum desufflation with positive end-expiratory pressure (T(end)). Esophageal pressure was used for partitioning respiratory mechanics between lung and chest wall (data are mean ± SD): on T(preOLS), chest wall elastance (E(cw)) and elastance of the lung (E(L)) increased (8.2 ± 0.9 vs. 6.2 ± 1.2 cm H(2)O/L, respectively, on T(BSL); P = 0.00016; and 11.69 ± 1.68 vs. 9.61 ± 1.52 cm H(2)O/L on T(BSL); P = 0.0007). On T(postOLS), both chest wall elastance and E(L) decreased (5.2 ± 1.2 and 8.62 ± 1.03 cm H(2)O/L, respectively; P = 0.00015 vs. T(preOLS)), and Pao(2)/inspiratory oxygen fraction improved (491 ± 107 vs. 425 ± 97 on T(preOLS); P = 0.008) remaining stable thereafter. Recruited volume (the difference in lung volume for the same static airway pressure) was 194 ± 80 ml. Pplat(RS) remained stable while inspiratory transpulmonary pressure increased (11.65 + 1.37 cm H(2)O vs. 9.21 + 2.03 on T(preOLS); P = 0.007). All respiratory mechanics parameters remained stable after abdominal desufflation. Hemodynamic parameters remained stable throughout the study. In patients submitted to laparoscopic surgery in

  11. [Clinical research of using optimal compliance to determine positive end-expiratory pressure].

    Science.gov (United States)

    Xu, Lei; Feng, Quan-sheng; Lian, Fu; Shao, Xin-hua; Li, Zhi-bo; Wang, Zhi-yong; Li, Jun

    2012-07-01

    To observe the availability and security of optimal compliance strategy to titrate the optimal positive end-expiratory pressure (PEEP), compared with quasi-static pressure-volume curve (P-V curve) traced by low-flow method. Fourteen patients received mechanical ventilation with acute respiratory distress syndrome (ARDS) admitted in intensive care unit (ICU) of Tianjin Third Central Hospital from November 2009 to December 2010 were divided into two groups(n = 7). The quasi-static P-V curve method and the optimal compliance titration were used to set the optimal PEEP respectively, repeated 3 times in a row. The optimal PEEP and the consistency of repeated experiments were compared between groups. The hemodynamic parameters, oxygenation index (OI), lung compliance (C), cytokines and pulmonary surfactant-associated protein D (SP-D) concentration in plasma before and 2, 4, and 6 hours after the experiment were observed in each group. (1) There were no significant differences in gender, age and severity of disease between two groups. (2)The optimal PEEP [cm H(2)O, 1 cm H(2)O=0.098 kPa] had no significant difference between quasi-static P-V curve method group and the optimal compliance titration group (11.53 ± 2.07 vs. 10.57 ± 0.87, P>0.05). The consistency of repeated experiments in quasi-static P-V curve method group was poor, the slope of the quasi-static P-V curve in repeated experiments showed downward tendency. The optimal PEEP was increasing in each measure. There was significant difference between the first and the third time (10.00 ± 1.58 vs. 12.80 ± 1.92, P vs. 93.71 ± 5.38, temperature: 38.05 ± 0.73 vs. 36.99 ± 1.02, IL-6: 144.84 ± 23.89 vs. 94.73 ± 5.91, TNF-α: 151.46 ± 46.00 vs. 89.86 ± 13.13, SP-D: 33.65 ± 8.66 vs. 16.63 ± 5.61, MAP: 85.47 ± 9.24 vs. 102.43 ± 8.38, CCI: 3.00 ± 0.48 vs. 3.81 ± 0.81, OI: 62.00 ± 21.45 vs. 103.40 ± 37.27, C: 32.10 ± 2.92 vs. 49.57 ± 7.18, all P safety and usability.

  12. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model.

    Directory of Open Access Journals (Sweden)

    Laura A Cagle

    Full Text Available Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury.To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation.5-12 week-old female BALB/c mice (n = 85 were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg or high tidal volume (15 ml/kg with or without positive end-expiratory pressure and recruitment maneuvers.Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation.Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours and lung injury worsens with longer-term ventilation (4 hrs. Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points. Dynamic compliance can be used guide

  13. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model

    Science.gov (United States)

    Franzi, Lisa M.; Linderholm, Angela L.; Last, Jerold A.; Adams, Jason Y.; Harper, Richart W.

    2017-01-01

    Background Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury. Objectives To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation. Methods 5–12 week-old female BALB/c mice (n = 85) were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg) or high tidal volume (15 ml/kg) with or without positive end-expiratory pressure and recruitment maneuvers. Results Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation. Conclusions Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours) and lung injury worsens with longer-term ventilation (4 hrs). Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points

  14. Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model.

    Science.gov (United States)

    Cagle, Laura A; Franzi, Lisa M; Linderholm, Angela L; Last, Jerold A; Adams, Jason Y; Harper, Richart W; Kenyon, Nicholas J

    2017-01-01

    Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury. To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation. 5-12 week-old female BALB/c mice (n = 85) were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg) or high tidal volume (15 ml/kg) with or without positive end-expiratory pressure and recruitment maneuvers. Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation. Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours) and lung injury worsens with longer-term ventilation (4 hrs). Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points. Dynamic compliance can be used guide the frequency

  15. Respiratory System Mechanics During Low Versus High Positive End-Expiratory Pressure in Open Abdominal Surgery: A Substudy of PROVHILO Randomized Controlled Trial

    NARCIS (Netherlands)

    D'Antini, Davide; Huhle, Robert; Herrmann, Jacob; Sulemanji, Demet S.; Oto, Jun; Raimondo, Pasquale; Mirabella, Lucia; Hemmes, Sabrine N. T.; Schultz, Marcus J.; Pelosi, Paolo; Kaczka, David W.; Vidal Melo, Marcos Francisco; Gama de Abreu, Marcelo; Cinnella, Gilda

    2018-01-01

    In the 2014 PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure (PROVHILO) trial, intraoperative low tidal volume ventilation with high positive end-expiratory pressure (PEEP = 12 cm H2O) and lung recruitment maneuvers did not decrease postoperative pulmonary complications

  16. Effect of Positive End-Expiratory Pressure on Central Venous Pressure in Patients under Mechanical Ventilation.

    Science.gov (United States)

    Shojaee, Majid; Sabzghabaei, Anita; Alimohammadi, Hossein; Derakhshanfar, Hojjat; Amini, Afshin; Esmailzadeh, Bahareh

    2017-01-01

    Finding the probable governing pattern of PEEP and CVP changes is an area of interest for in-charge physicians and researchers. Therefore, the present study was designed with the aim of evaluating the relationship between the mentioned pressures. In this quasi-experimental study, patients under mechanical ventilation were evaluated with the aim of assessing the effect of PEEP change on CVP. Non-trauma patients, over 18 years of age, who were under mechanical ventilation and had stable hemodynamics, with inserted CV line were entered. After gathering demographic data, patients underwent 0, 5, and 10 cmH 2 O PEEPs and the respective CVPs of the mentioned points were recorded. The relationship of CVP and PEEP in different cut points were measured using SPSS 21.0 statistical software. 60 patients with the mean age of 73.95 ± 11.58 years were evaluated (68.3% male). The most frequent cause of ICU admission was sepsis with 45.0%. 5 cmH 2 O increase in PEEP led to 2.47 ± 1.53 mean difference in CVP level. If the PEEP baseline is 0 at the time of 5 cmH 2 O increase, it leads to a higher raise in CVP compared to when the baseline is 5 cmH 2 O (2.47 ± 1.53 vs. 1.57 ± 1.07; p = 0.039). The relationship between CVP and 5 cmH 2 O (p = 0.279), and 10 cmH 2 O (p = 0.292) PEEP changes were not dependent on the baseline level of CVP. The findings of this study revealed the direct relationship between PEEP and CVP. Approximately, a 5 cmH 2 O increase in PEEP will be associated with about 2.5 cmH 2 O raise in CVP. When applying a 5 cmH 2 O PEEP increase, if the baseline PEEP is 0, it leads to a significantly higher raise in CVP compared to when it is 5 cmH 2 O (2.5 vs. 1.6). It seems that sex, history of cardiac failure, baseline CVP level, and hypertension do not have a significant effect in this regard.

  17. Effect of Positive End-Expiratory Pressure on Central Venous Pressure in Patients under Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Majid Shojaee

    2016-12-01

    Full Text Available Introduction: Finding the probable governing pattern of PEEP and CVP changes is an area of interest for in-charge physicians and researchers. Therefore, the present study was designed with the aim of evaluating the relationship between the mentioned pressures. Methods: In this quasi-experimental study, patients under mechanical ventilation were evaluated with the aim of assessing the effect of PEEP change on CVP. Non-trauma patients, over 18 years of age, who were under mechanical ventilation and had stable hemodynamics, with inserted CV line were entered. After gathering demographic data, patients underwent 0, 5, and 10 cmH2O PEEPs and the respective CVPs of the mentioned points were recorded. The relationship of CVP and PEEP in different cut points were measured using SPSS 21.0 statistical software. Results: 60 patients with the mean age of 73.95 ± 11.58 years were evaluated (68.3% male. The most frequent cause of ICU admission was sepsis with 45.0%. 5 cmH2O increase in PEEP led to 2.47 ± 1.53 mean difference in CVP level. If the PEEP baseline is 0 at the time of 5 cmH2O increase, it leads to a higher raise in CVP compared to when the baseline is 5 cmH2O (2.47 ± 1.53 vs. 1.57 ± 1.07; p = 0.039. The relationship between CVP and 5 cmH2O (p = 0.279, and 10 cmH2O (p = 0.292 PEEP changes were not dependent on the baseline level of CVP. Conclusion: The findings of this study revealed the direct relationship between PEEP and CVP. Approximately, a 5 cmH2O increase in PEEP will be associated with about 2.5 cmH2O raise in CVP. When applying a 5 cmH2O PEEP increase, if the baseline PEEP is 0, it leads to a significantly higher raise in CVP compared to when it is 5 cmH2O (2.5 vs. 1.6. It seems that sex, history of cardiac failure, baseline CVP level, and hypertension do not have a significant effect in this regard.

  18. [A comparative study between inflation and deflation pressure-volume curve in determining the optimal positive end-expiratory pressure].

    Science.gov (United States)

    Gang, Li; Sun, Xiao-yi; Xu, Jin-quan; Zhang, Xin-li; Kou, Lu-xin; Jiang, Zhi-hong; Zhang, Lei

    2012-02-01

    To determine the optimal positive end-expiratory pressure (PEEP) according to inflation and deflation pressure-volume curve (P-V curve) in patients with acute respiratory distress syndrome (ARDS). ARDS models were reproduced in 20 dogs, and they were randomly divided into two groups. In both groups, Levenberg-Marquardt iterative algorithm was employed using software to explore parameters fitting with Boltzmann formula, by which the real inflection point of pressure (Pinf d) in deflation limb or lower inflection point pressure (PLip) in inflation limb on P-V curve were defined. For the control group (inflation curve) P-V curve of PLip + 2 cm H(2)O [1 cm H(2)O = 0.098 kPa] was applied as the best PEEP value. In the experimental group (deflation curve) the Pinf d was taken as the best PEEP value. The heart rate (HR), blood pressure (BP), fingertip pulse oxygen saturation [SpO(2)], static lung compliance (Cst), arterial partial pressure of oxygen [PaO(2)] and arterial partial pressure of carbon dioxide [PaCO(2)] were monitored at 0, 2, 6, 12, 24 and 48 hours. Oxygenation index increased significantly both in control and experimental groups. In experimental group, oxygenation index (mm Hg, 1 mm Hg = 0.133 kPa) of 12, 24 and 48 hours was respectively significantly higher than that of the control group (12 hours: 177.63 ± 8.94 vs. 165.60 ± 8.90, 24 hours: 194.19 ± 10.67 vs. 168.70 ± 10.60, 48 hours: 203.15 ± 13.21 vs. 171.26 ± 9.21, all P deflation P-V curve was better than that of inflation curve.

  19. Setting individualized positive end-expiratory pressure level with a positive end-expiratory pressure decrement trial after a recruitment maneuver improves oxygenation and lung mechanics during one-lung ventilation.

    Science.gov (United States)

    Ferrando, Carlos; Mugarra, Ana; Gutierrez, Andrea; Carbonell, Jose Antonio; García, Marisa; Soro, Marina; Tusman, Gerardo; Belda, Francisco Javier

    2014-03-01

    We investigated whether individualized positive end-expiratory pressure (PEEP) improves oxygenation, ventilation, and lung mechanics during one-lung ventilation compared with standardized PEEP. Thirty patients undergoing thoracic surgery were randomly allocated to the study or control group. Both groups received an alveolar recruitment maneuver at the beginning and end of one-lung ventilation. After the alveolar recruitment maneuver, the control group had their lungs ventilated with a 5 cm·H2O PEEP, while the study group had their lungs ventilated with an individualized PEEP level determined by a PEEP decrement trial. Arterial blood samples, lung mechanics, and volumetric capnography were recorded at multiple timepoints throughout the procedure. The individualized PEEP values in study group were higher than the standardized PEEP values (10 ± 2 vs 5 cm·H2O; P decrement trial than with a standardized 5 cm·H2O of PEEP.

  20. Differential Effects of Intraoperative Positive End-expiratory Pressure (PEEP) on Respiratory Outcome in Major Abdominal Surgery Versus Craniotomy

    DEFF Research Database (Denmark)

    de Jong, Myrthe A C; Ladha, Karim S; Melo, Marcos F Vidal

    2015-01-01

    OBJECTIVES: In this study, we examined whether (1) positive end-expiratory pressure (PEEP) has a protective effect on the risk of major postoperative respiratory complications in a cohort of patients undergoing major abdominal surgeries and craniotomies, and (2) the effect of PEEP is differed......: Within the entire study population (major abdominal surgeries and craniotomies), we found an association between application of PEEP ≥5 cmH2O and a decreased risk of postoperative respiratory complications compared with PEEP 5 cmH2O was associated with a significant lower...... undergoing major abdominal surgery. Our data suggest that default mechanical ventilator settings should include PEEP of 5-10 cmH2O during major abdominal surgery....

  1. Physiologic Evaluation of Ventilation Perfusion Mismatch and Respiratory Mechanics at Different Positive End-expiratory Pressure in Patients Undergoing Protective One-lung Ventilation.

    Science.gov (United States)

    Spadaro, Savino; Grasso, Salvatore; Karbing, Dan Stieper; Fogagnolo, Alberto; Contoli, Marco; Bollini, Giacomo; Ragazzi, Riccardo; Cinnella, Gilda; Verri, Marco; Cavallesco, Narciso Giorgio; Rees, Stephen Edward; Volta, Carlo Alberto

    2018-03-01

    Arterial oxygenation is often impaired during one-lung ventilation, due to both pulmonary shunt and atelectasis. The use of low tidal volume (VT) (5 ml/kg predicted body weight) in the context of a lung-protective approach exacerbates atelectasis. This study sought to determine the combined physiologic effects of positive end-expiratory pressure and low VT during one-lung ventilation. Data from 41 patients studied during general anesthesia for thoracic surgery were collected and analyzed. Shunt fraction, high V/Q and respiratory mechanics were measured at positive end-expiratory pressure 0 cm H2O during bilateral lung ventilation and one-lung ventilation and, subsequently, during one-lung ventilation at 5 or 10 cm H2O of positive end-expiratory pressure. Shunt fraction and high V/Q were measured using variation of inspired oxygen fraction and measurement of respiratory gas concentration and arterial blood gas. The level of positive end-expiratory pressure was applied in random order and maintained for 15 min before measurements. During one-lung ventilation, increasing positive end-expiratory pressure from 0 cm H2O to 5 cm H2O and 10 cm H2O resulted in a shunt fraction decrease of 5% (0 to 11) and 11% (5 to 16), respectively (P ventilation, high positive end-expiratory pressure levels improve pulmonary function without increasing high V/Q and reduce driving pressure.

  2. Intratidal recruitment/derecruitment persists at low and moderate positive end-expiratory pressure in paediatric patients.

    Science.gov (United States)

    Wirth, Steffen; Artner, Lisa; Broß, Tobias; Lozano-Zahonero, Sara; Spaeth, Johannes; Schumann, Stefan

    2016-12-01

    In paediatric patients positive end-expiratory pressure (PEEP) is traditionally set lower than in adults. We investigated whether moderately higher PEEP improves respiratory mechanics and regional ventilation. Therefore, 40 children were mechanically ventilated with PEEP 2 and 5cmH 2 O. Volume-dependent compliance profiles were analysed as a measure of intratidal recruitment/derecruitment. Regional ventilation was assessed using electrical impedance tomography. Mean compliance was 17.9±9.9mLcmH 2 O -1 (PEEP 2cmH 2 O), and 19.0±10.9mLcmH 2 O -1 (PEEP 5 cmH 2 O, pventilation. In conclusion, mechanically ventilated paediatric patients undergo intratidal recruitment/derecruitment which occurs more prominently in younger than in older children. A PEEP of 5cmH 2 O does not fully prevent intratidal recruitment/derecruitment but homogenizes regional ventilation in comparison to 2cmH 2 O. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Influence of Positive End-Expiratory Pressure on Myocardial Strain Assessed by Speckle Tracking Echocardiography in Mechanically Ventilated Patients

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    Federico Franchi

    2013-01-01

    Full Text Available Purpose. The effects of mechanical ventilation (MV on speckle tracking echocardiography- (STE-derived variables are not elucidated. The aim of the study was to evaluate the effects of positive end-expiratory pressure (PEEP ventilation on 4-chamber longitudinal strain (LS analysis by STE. Methods. We studied 20 patients admitted to a mixed intensive care unit who required intubation for MV and PEEP titration due to hypoxia. STE was performed at three times: (T1 PEEP = 5 cmH2O; (T2 PEEP = 10 cmH2O; and (T3 PEEP = 15 cmH2O. STE analysis was performed offline using a dedicated software (XStrain MyLab 70 Xvision, Esaote. Results. Left peak atrial-longitudinal strain (LS was significantly reduced from T1 to T2 and from T2 to T3 (. Right peak atrial-LS and right ventricular-LS showed a significant reduction only at T3 (. Left ventricular-LS did not change significantly during titration of PEEP. Cardiac chambers’ volumes showed a significant reduction at higher levels of PEEP (. Conclusions. We demonstrated for the first time that incremental PEEP affects myocardial strain values obtained with STE in intubated critically ill patients. Whenever performing STE in mechanically ventilated patients, care must be taken when PEEP is higher than 10 cmH2O to avoid misinterpreting data and making erroneous decisions.

  4. Application of dead space fraction to titrate optimal positive end-expiratory pressure in an ARDS swine model.

    Science.gov (United States)

    Bian, Weishuai; Chen, Wei; Chao, Yangong; Wang, Lan; Li, Liming; Guan, Jian; Zang, Xuefeng; Zhen, Jie; Sheng, Bo; Zhu, Xi

    2017-04-01

    This study aimed to apply the dead space fraction [ratio of dead space to tidal volume (VD/VT)] to titrate the optimal positive end-expiratory pressure (PEEP) in a swine model of acute respiratory distress syndrome (ARDS). Twelve swine models of ARDS were constructed. A lung recruitment maneuver was then conducted and the PEEP was set at 20 cm H 2 O. The PEEP was reduced by 2 cm H 2 O every 10 min until 0 cm H 2 O was reached, and VD/VT was measured after each decrement step. VD/VT was measured using single-breath analysis of CO 2 , and calculated from arterial CO 2 partial pressure (PaCO 2 ) and mixed expired CO 2 (PeCO 2 ) using the following formula: VD/VT = (PaCO 2 - PeCO 2 )/PaCO 2 . The optimal PEEP was identified by the lowest VD/VT method. Respiration and hemodynamic parameters were recorded during the periods of pre-injury and injury, and at 4 and 2 cm H 2 O below and above the optimal PEEP (Po). The optimal PEEP in this study was found to be 13.25±1.36 cm H 2 O. During the Po period, VD/VT decreased to a lower value (0.44±0.08) compared with that during the injury period (0.68±0.10) (P<0.05), while the intrapulmonary shunt fraction reached its lowest value. In addition, a significant change of dynamic tidal respiratory compliance and oxygenation index was induced by PEEP titration. These results indicate that minimal VD/VT can be used for PEEP titration in ARDS.

  5. Differing responses in right and left ventricular filling, loading and volumes during positive end-expiratory pressure

    International Nuclear Information System (INIS)

    Schulman, D.S.; Biondi, J.W.; Matthay, R.A.; Zaret, B.L.; Soufer, R.

    1989-01-01

    Using a combined hemodynamic and radionuclide technique, 20 patients with varied ventricular function were evaluated during positive end-expiratory pressure (PEEP) application. Left ventricular (LV) and right ventricular (RV) ejection fractions and cardiac output were measured, and ventricular volumes were derived. Seven patients (group 1) who had an increase in LV end-diastolic volume with PEEP and 13 patients (group 2) who had the more typical response, a decrease in LV end-diastolic volume with PEEP, were identified. Compared with group 2, group 1 patients had a higher incidence of coronary artery disease (5 of 7 vs 1 of 13, p less than 0.005) and lower cardiac output (3.9 +/- 1.6 vs 9.1 +/- 3.2 liters/min, p less than 0.005), LV ejection fraction (27 +/- 13 vs 51 +/- 21%, p less than 0.05), RV ejection fraction (15 +/- 6 vs 32 +/- 8%, p less than 0.005) and peak filling rate (1.32 +/- 0.43 vs 3.51 +/- 1.70 end-diastolic volumes/s, p less than 0.05). LV and RV volumes increased and peak filling rate decreased with PEEP in group 1, whereas in group 2 LV volume decreased and RV volume and peak filling rate remained unchanged. Using stepwise regression analysis, the change in LV volume with PEEP was related directly to baseline systemic vascular resistance and inversely to baseline blood pressure. Similarly, the change in peak filling rate with PEEP was inversely related to the change in RV end-diastolic volume. Thus, the hemodynamic response to PEEP is heterogeneous and may be related to LV ischemia

  6. Effects of Inhaled Fenoterol and Positive End-Expiratory Pressure on the Respiratory Mechanics of Patients with Chronic Obstructive Pulmonary Disease

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    Claude Guerin

    2005-01-01

    Full Text Available BACKGROUND: During acute ventilatory failure in patients with chronic obstructive pulmonary disease (COPD, applying external positive end-expiratory pressure (PEEPe will reopen small airways and, thus, may enhance peripheral deposition as well as the physiological effects of inhaled beta-2 agonists.

  7. Associations between positive end-expiratory pressure and outcome of patients without ARDS at onset of ventilation: a systematic review and meta-analysis of randomized controlled trials

    NARCIS (Netherlands)

    Serpa Neto, Ary; Filho, Roberto Rabello; Cherpanath, Thomas; Determann, Rogier; Dongelmans, Dave A.; Paulus, Frederique; Tuinman, Pieter Roel; Pelosi, Paolo; de Abreu, Marcelo Gama; Schultz, Marcus J.

    2016-01-01

    The aim of this investigation was to compare ventilation at different levels of positive end-expiratory pressure (PEEP) with regard to clinical important outcomes of intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) at onset of ventilation. Meta-analysis of

  8. Effects of positive end-expiratory pressure on intraoperative core temperature in patients undergoing posterior spine surgery: prospective randomised trial.

    Science.gov (United States)

    Seo, Hyungseok; Do Son, Je; Lee, Hyung-Chul; Oh, Hyung-Min; Jung, Chul-Woo; Park, Hee-Pyoung

    2018-03-01

    Objective Positive end-expiratory pressure (PEEP) causes carotid baroreceptor unloading, which leads to thermoregulatory peripheral vasoconstriction. However, the effects of PEEP on intraoperative thermoregulation in the prone position remain unknown. Methods Thirty-seven patients undergoing spine surgery in the prone position were assigned at random to receive either 10 cmH 2 O PEEP (Group P) or no PEEP (Group Z). The primary endpoint was core temperature 180 minutes after intubation. Secondary endpoints were delta core temperature (difference in core temperature between 180 minutes and immediately after tracheal intubation), incidence of intraoperative hypothermia (core temperature of peripheral vasoconstriction-related data. Results The median [interquartile range] core temperature 180 minutes after intubation was 36.1°C [35.9°C-36.2°C] and 36.0°C [35.9°C-36.4°C] in Groups Z and P, respectively. The delta core temperature and incidences of intraoperative hypothermia and peripheral vasoconstriction were not significantly different between the two groups. The peripheral vasoconstriction threshold (36.2°C±0.5°C vs. 36.7°C±0.6°C) was lower and the onset of peripheral vasoconstriction (66 [60-129] vs. 38 [28-70] minutes) was slower in Group Z than in Group P. Conclusions Intraoperative PEEP did not reduce the core temperature decrease in the prone position, although it resulted in an earlier onset and higher threshold of peripheral vasoconstriction.

  9. Is increased positive end-expiratory pressure the culprit? Autoresuscitation in a 44-year-old man after prolonged cardiopulmonary resuscitation: a case report

    OpenAIRE

    Hagmann, Henning; Oelmann, Katrin; Stangl, Robert; Michels, Guido

    2016-01-01

    Background The phenomenon of autoresuscitation is rare, yet it is known to most emergency physicians. However, the pathophysiology of the delayed return of spontaneous circulation remains enigmatic. Among other causes hyperinflation of the lungs and excessively high positive end-expiratory pressure have been suggested, but reports including cardiopulmonary monitoring during cardiopulmonary resuscitation are scarce to support this hypothesis. Case presentation We report a case of autoresuscita...

  10. Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers.

    Science.gov (United States)

    Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N T; Canet, Jaume; Spieth, Peter M; Rocco, Patricia R M; Schultz, Marcus J; Pelosi, Paolo; Gama de Abreu, Marcelo

    2015-09-01

    Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials.

  11. Clinical assessment of auto-positive end-expiratory pressure by diaphragmatic electrical activity during pressure support and neurally adjusted ventilatory assist.

    Science.gov (United States)

    Bellani, Giacomo; Coppadoro, Andrea; Patroniti, Nicolò; Turella, Marta; Arrigoni Marocco, Stefano; Grasselli, Giacomo; Mauri, Tommaso; Pesenti, Antonio

    2014-09-01

    Auto-positive end-expiratory pressure (auto-PEEP) may substantially increase the inspiratory effort during assisted mechanical ventilation. Purpose of this study was to assess whether the electrical activity of the diaphragm (EAdi) signal can be reliably used to estimate auto-PEEP in patients undergoing pressure support ventilation and neurally adjusted ventilatory assist (NAVA) and whether NAVA was beneficial in comparison with pressure support ventilation in patients affected by auto-PEEP. In 10 patients with a clinical suspicion of auto-PEEP, the authors simultaneously recorded EAdi, airway, esophageal pressure, and flow during pressure support and NAVA, whereas external PEEP was increased from 2 to 14 cm H2O. Tracings were analyzed to measure apparent "dynamic" auto-PEEP (decrease in esophageal pressure to generate inspiratory flow), auto-EAdi (EAdi value at the onset of inspiratory flow), and IDEAdi (inspiratory delay between the onset of EAdi and the inspiratory flow). The pressure necessary to overcome auto-PEEP, auto-EAdi, and IDEAdi was significantly lower in NAVA as compared with pressure support ventilation, decreased with increase in external PEEP, although the effect of external PEEP was less pronounced in NAVA. Both auto-EAdi and IDEAdi were tightly correlated with auto-PEEP (r = 0.94 and r = 0.75, respectively). In the presence of auto-PEEP at lower external PEEP levels, NAVA was characterized by a characteristic shape of the airway pressure. In patients with auto-PEEP, NAVA, compared with pressure support ventilation, led to a decrease in the pressure necessary to overcome auto-PEEP, which could be reliably monitored by the electrical activity of the diaphragm before inspiratory flow onset (auto-EAdi).

  12. Respiratory System Mechanics During Low Versus High Positive End-Expiratory Pressure in Open Abdominal Surgery: A Substudy of PROVHILO Randomized Controlled Trial.

    Science.gov (United States)

    D'Antini, Davide; Huhle, Robert; Herrmann, Jacob; Sulemanji, Demet S; Oto, Jun; Raimondo, Pasquale; Mirabella, Lucia; Hemmes, Sabrine N T; Schultz, Marcus J; Pelosi, Paolo; Kaczka, David W; Vidal Melo, Marcos Francisco; Gama de Abreu, Marcelo; Cinnella, Gilda

    2018-01-01

    In the 2014 PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure (PROVHILO) trial, intraoperative low tidal volume ventilation with high positive end-expiratory pressure (PEEP = 12 cm H2O) and lung recruitment maneuvers did not decrease postoperative pulmonary complications when compared to low PEEP (0-2 cm H2O) approach without recruitment breaths. However, effects of intraoperative PEEP on lung compliance remain poorly understood. We hypothesized that higher PEEP leads to a dominance of intratidal overdistension, whereas lower PEEP results in intratidal recruitment/derecruitment (R/D). To test our hypothesis, we used the volume-dependent elastance index %E2, a respiratory parameter that allows for noninvasive and radiation-free assessment of dominant overdistension and intratidal R/D. We compared the incidence of intratidal R/D, linear expansion, and overdistension by means of %E2 in a subset of the PROVHILO cohort. In 36 patients from 2 participating centers of the PROVHILO trial, we calculated respiratory system elastance (E), resistance (R), and %E2, a surrogate parameter for intratidal overdistension (%E2 > 30%) and R/D (%E2 mechanical ventilation with protective tidal volumes in patients undergoing open abdominal surgery, lung recruitment followed by PEEP of 12 cm H2O decreased the incidence of intratidal R/D and did not worsen overdistension, when compared to PEEP ≤2 cm H2O.

  13. Positive end-expiratory pressure increases pulmonary clearance of inhaled 99mTc-DTPA in nonsmokers but not in healthy smokers

    International Nuclear Information System (INIS)

    Nolop, K.B.; Braude, S.; Royston, D.; Maxwell, D.L.; Hughes, J.M.B.

    1987-01-01

    Positive end-expiratory pressure (PEEP) is widely used in the treatment of severe pulmonary oedema, although its effects on the clearance of water and small solutes from alveolus to blood are not well characterized. We studied the effect of the application of 10 cmH 2 O of PEEP on the flux of inhaled 99 mTc-diethylene-triamine-penta-acetic acid (DTPA) from lung to blood in six healthy smoking and six nonsmoking subjects. The rate of flux was corrected for possible changes in pulmonary blood volume during PEEP by use of an intravenous injection of 99m Tc-DTPA. The baseline clearance rate (K,%.min -1 ) for nonsmokers was 1.48±0.12 (mean±SE) and increased to 2.40±0.29 during PEEP (p<0.05). In contrast, the mean clearance rate for smokers was 3.26±0.82 at baseline and 3.03±0.82 during PEEP (p=NS). The application of positive end-expiratory pressure appears to increase alveolar solute flux in nonsmokers but not in smokers, suggesting that the pathway for solute clearance in smokers is governed by different rate-limiting steps to those of nonsmokers

  14. Effects of respiratory rate, plateau pressure, and positive end-expiratory pressure on PaO2 oscillations after saline lavage.

    Science.gov (United States)

    Baumgardner, James E; Markstaller, Klaus; Pfeiffer, Birgit; Doebrich, Marcus; Otto, Cynthia M

    2002-12-15

    One of the proposed mechanisms of ventilator-associated lung injury is cyclic recruitment of atelectasis. Collapse of dependent lung regions with every breath should lead to large oscillations in PaO2 as shunt varies throughout the respiratory cycle. We placed a fluorescence-quenching PO2 probe in the brachiocephalic artery of six anesthetized rabbits after saline lavage. Using pressure-controlled ventilation with oxygen, ventilator settings were varied in random order over three levels of positive end-expiratory pressure (PEEP), respiratory rate (RR), and plateau pressure minus PEEP (Delta). Dependence of the amplitude of PaO2 oscillations on PEEP, RR, and Delta was modeled by multiple linear regression. Before lavage, arterial PO2 oscillations varied from 3 to 22 mm Hg. After lavage, arterial PO2 oscillations varied from 5 to 439 mm Hg. Response surfaces showed markedly nonlinear dependence of amplitude on PEEP, RR, and Delta. The large PaO2 oscillations observed provide evidence for cyclic recruitment in this model of lung injury. The important effect of RR on the magnitude of PaO2 oscillations suggests that the static behavior of atelectasis cannot be accurately extrapolated to predict dynamic behavior at realistic breathing frequencies.

  15. Intraoperative and postoperative evaluation of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients

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    Ye-Qiu Li

    2016-01-01

    Full Text Available Objective: To evaluate intraoperative and postoperative condition of low tidal volume combined with low-level positive end-expiratory pressure ventilation in laparoscopic surgery in elderly patients. Methods: A total of 176 cases of elderly patients (more than 60 years old receiving laparoscopic surgery in our hospital from July 2013 to July 2015 were selected as research subjects and randomly divided into observation group and control group, each group included 88 cases, control group received conventional ventilation strategy, observation group received low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy, and then levels of hemodynamic indexes, respiratory mechanical indexes, serology indexes and cerebral vessel related indexes, etc of two groups were compared. Results: Intraoperative and postoperative heart rate and mean arterial pressure levels of observation group were lower than those of control group, arterial partial pressure of oxygen and oxygenation index levels were higher than those of control group and differences had statistical significance (P<0.05; intraoperative APIP and Pplat values of observation group were lower than those of control group, Cs value was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative serum IL-8 and TNF-α levels of observation group were lower than those of control group, IL-10 level was higher than that of control group and differences had statistical significance (P<0.05; intraoperative and postoperative PjvO2, SjvO2 and CjvO2 levels of observation group were higher than those of control group, Da-jvO2 level was lower than that of control group and differences had statistical significance (P<0.05. Conclusions: When elderly patients receive laparoscopic surgery, the use of low tidal volume combined with low-level positive end-expiratory pressure ventilation strategy can stabilize hemodynamic

  16. Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

    International Nuclear Information System (INIS)

    Schumann, Stefan; Schließmann, Stephan J; Wagner, Giskard; Goebel, Ulrich; Priebe, Hans-Joachim; Guttmann, Josef; Kirschbaum, Andreas

    2010-01-01

    Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH 2 O) or high (8 cmH 2 O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

  17. Surfactant impairment after mechanical ventilation with large alveolar surface area changes and effects of positive end-expiratory pressure

    NARCIS (Netherlands)

    S.J.C. Verbrugge (Serge); S.H. Bohm; D.A.M.P.J. Gommers (Diederik); L.J.I. Zimmermann (Luc); B.F. Lachmann (Burkhard)

    1998-01-01

    textabstractWe have assessed the effects of overinflation on surfactant function and composition in rats undergoing ventilation for 20 min with 100% oxygen at a peak inspiratory pressure of 45 cm H2O, with or without PEEP 10 cm H2O (groups 45/10 and 45/0, respectively).

  18. Lung-protective ventilation in intensive care unit and operation room : Tidal volume size, level of positive end-expiratory pressure and driving pressure

    NARCIS (Netherlands)

    Serpa Neto, A.

    2017-01-01

    Several investigations have shown independent associations between three ventilator settings – tidal volume size, positive end–expiratory pressure (PEEP) and driving pressure – and outcomes in patients with the acute respiratory distress syndrome (ARDS). There is an increasing notion that similar

  19. Lung recruitability is better estimated according to the Berlin definition of acute respiratory distress syndrome at standard 5 cm H2O rather than higher positive end-expiratory pressure: a retrospective cohort study.

    Science.gov (United States)

    Caironi, Pietro; Carlesso, Eleonora; Cressoni, Massimo; Chiumello, Davide; Moerer, Onner; Chiurazzi, Chiara; Brioni, Matteo; Bottino, Nicola; Lazzerini, Marco; Bugedo, Guillermo; Quintel, Michael; Ranieri, V Marco; Gattinoni, Luciano

    2015-04-01

    The Berlin definition of acute respiratory distress syndrome has introduced three classes of severity according to PaO2/FIO2 thresholds. The level of positive end-expiratory pressure applied may greatly affect PaO2/FIO2, thereby masking acute respiratory distress syndrome severity, which should reflect the underlying lung injury (lung edema and recruitability). We hypothesized that the assessment of acute respiratory distress syndrome severity at standardized low positive end-expiratory pressure may improve the association between the underlying lung injury, as detected by CT, and PaO2/FIO2-derived severity. Retrospective analysis. Four university hospitals (Italy, Germany, and Chile). One hundred forty-eight patients with acute lung injury or acute respiratory distress syndrome according to the American-European Consensus Conference criteria. Patients underwent a three-step ventilator protocol (at clinical, 5 cm H2O, or 15 cm H2O positive end-expiratory pressure). Whole-lung CT scans were obtained at 5 and 45 cm H2O airway pressure. Nine patients did not fulfill acute respiratory distress syndrome criteria of the novel Berlin definition. Patients were then classified according to PaO2/FIO2 assessed at clinical, 5 cm H2O, or 15 cm H2O positive end-expiratory pressure. At clinical positive end-expiratory pressure (11±3 cm H2O), patients with severe acute respiratory distress syndrome had a greater lung tissue weight and recruitability than patients with mild or moderate acute respiratory distress syndrome (pBerlin definition of acute respiratory distress syndrome assessed at 5 cm H2O allows a better evaluation of lung recruitability and edema than at higher positive end-expiratory pressure clinically set.

  20. Effects of positive end expiratory pressure administration during non-invasive ventilation in patients affected by amyotrophic lateral sclerosis: A randomized crossover study.

    Science.gov (United States)

    Crescimanno, Grazia; Greco, Francesca; Arrisicato, Salvo; Morana, Noemi; Marrone, Oreste

    2016-10-01

    No studies have evaluated the impact of different settings of non-invasive ventilation (NIV) in patients affected by amyotrophic lateral sclerosis (ALS). We explored consequences of positive end-expiratory pressure (PEEP) application on effectiveness of ventilation, sleep architecture and heart rate variability (HRV) in patients with ALS naïve to ventilatory treatment. In two consecutive nights, 25 patients received in random order 0 or 4 cm H2 0 of PEEP during nocturnal NIV administration (Idea Ultra ResMed) with the same level of total positive inspiratory pressure. Polysomnographies were performed to evaluate sleep and NIV quality, as well as HRV. HRV was analyzed on 4-h periods and on 5-min segments of stable NREM sleep. We did not observe differences in gas exchanges during NIV with and without PEEP. Conversely, during PEEP application increases in leaks (41.4 ± 29.3% vs 31.0 ± 25.7%, P = 0.0007) and in autotriggerings (4.2 (IQR 1.3-10.0) vs 0.9 (IQR 0.0-3.0) events/h, P NIV was associated with worse NIV and sleep quality and with higher sympathetic activity. © 2016 Asian Pacific Society of Respirology.

  1. Intrinsic positive end-expiratory pressure during one-lung ventilation of patients with pulmonary hyperinflation. Influence of low respiratory rate with unchanged minute volume.

    Science.gov (United States)

    Szegedi, L L; Barvais, L; Sokolow, Y; Yernault, J C; d'Hollander, A A

    2002-01-01

    We measured lung mechanics and gas exchange during one-lung ventilation (OLV) of patients with chronic obstructive pulmonary disease, using three respiratory rates (RR) and unchanged minute volume. We studied 15 patients about to undergo lung surgery, during anaesthesia, and placed in the lateral position. Ventilation was with constant minute volume, inspiratory flow and FIO2. For periods of 15 min, RR of 5, 10, and 15 bpm were applied in a random sequence and recordings were made of lung mechanics and an arterial blood gas sample was taken. Data were analysed with the repeated measures ANOVA and paired t-test with Bonferroni correction. PaO2 changes were not significant. At the lowest RR, PaCO2 decreased (from 42 (SD 4) mm Hg at RR 15-41 (4) mm Hg at RR 10 and 39 (4) mm Hg at RR 5, P<0.01), and end-tidal carbon dioxide increased (from 33 (5) mm Hg at RR 15 to 35 (5) mm Hg at RR 10 and 36 (6) mm Hg at RR 5, P<0.01). Intrinsic positive end-expiratory pressure (PEEPi) was reduced even with larger tidal volumes (from 6 (4) cm H2O at RR 15-5 (4) cm H2O at RR 10, and 3 (3) cm H2O at RR 5, P<0.01), most probably caused by increased expiratory time at the lowest RR. A reduction in RR reduces PEEPi and hypercapnia during OLV in anaesthetized patients with chronic obstructive lung disease.

  2. Is increased positive end-expiratory pressure the culprit? Autoresuscitation in a 44-year-old man after prolonged cardiopulmonary resuscitation: a case report.

    Science.gov (United States)

    Hagmann, Henning; Oelmann, Katrin; Stangl, Robert; Michels, Guido

    2016-12-20

    The phenomenon of autoresuscitation is rare, yet it is known to most emergency physicians. However, the pathophysiology of the delayed return of spontaneous circulation remains enigmatic. Among other causes hyperinflation of the lungs and excessively high positive end-expiratory pressure have been suggested, but reports including cardiopulmonary monitoring during cardiopulmonary resuscitation are scarce to support this hypothesis. We report a case of autoresuscitation in a 44-year-old white man after 80 minutes of advanced cardiac life support accompanied by continuous capnometry and repeated evaluation by ultrasound and echocardiography. After prolonged cardiopulmonary resuscitation, refractory electromechanical dissociation on electrocardiogram and ventricular akinesis were recorded. In addition, a precipitous drop in end-tidal partial pressure of carbon dioxide was noted and cardiopulmonary resuscitation was discontinued. Five minutes after withdrawal of all supportive measures his breathing resumed and a perfusing rhythm ensued. Understanding the underlying pathophysiology of autoresuscitation is hampered by a lack of reports including extensive cardiopulmonary monitoring during cardiopulmonary resuscitation in a preclinical setting. In this case, continuous capnometry was combined with repetitive ultrasound evaluation, which ruled out most assumed causes of autoresuscitation. Our observation of a rapid decline in end-tidal partial pressure of carbon dioxide supports the hypothesis of increased intrathoracic pressure. Continuous capnometry can be performed easily during cardiopulmonary resuscitation, also in a preclinical setting. Knowledge of the pathophysiologic mechanisms may lead to facile interventions to be incorporated into cardiopulmonary resuscitation algorithms. A drop in end-tidal partial pressure of carbon dioxide, for example, might prompt disconnection of the ventilation to allow left ventricular filling. Further reports and research on this topic

  3. FCT (functional computed tomography) evaluation of the lung volumes at different PEEP (positive-end expiratory pressure) ventilation pattern, in mechanical ventilated patients

    International Nuclear Information System (INIS)

    Papi, M.G.; Di Segni, R.; Mazzetti, G.; Staffa, F.; Conforto, F.; Calimici, R.; Salvi, A.; Matteucci, G.

    2007-01-01

    Purpose To evaluate with FCT (functional computed tomography) total lung volume and fractional lung volumes at different PEEP (positive end expiratory pressure) values in acute mechanically ventilated patients. Methods Nine ICU (intensive care unity) patients (1 lung pneumonia, 2 polytrauma, 2 sepsis, 3 brain surgery, 1 pulmonary embolism); mean age 48 ± 15 years, 6 male, 3 female; GE 16 MDCT scan was performed with acquisition from apex to diaphragma in seven seca at different PEEP values. Raw CT data were analysed by an advantage workstation to obtain volume density masks and histograms of both lungs and each lung and these density ranges were applied: - 1000 - 950 hyper-ventilated lung, -900 - 650 well aerated lung, -950 - 500 all aerated lung, -500 + 200 lung tissue. Total and fractional lung volumes, Hounsfield unit (HU) were calculated and compared at different PEEP values (0, 5, 10, 15 cm H 2 O). In four patients lung volumes were compared between the more and the less involved lung at increased PEEP. Statistic analysis: comparison means-medians tests. Results Data calculated at five PEEP showed unexpected decrease of total lung volume and increase of lung density (HU); proportionally no significant improvement of oxigenation. (orig.)

  4. FCT (functional computed tomography) evaluation of the lung volumes at different PEEP (positive-end expiratory pressure) ventilation pattern, in mechanical ventilated patients

    Energy Technology Data Exchange (ETDEWEB)

    Papi, M.G.; Di Segni, R.; Mazzetti, G.; Staffa, F. [Dept. of Radiology, S. Giovanni HS, Rome (Italy); Conforto, F.; Calimici, R.; Salvi, A. [Dept. of Anesthesiology, S. Giovanni HS, Rome (Italy); Matteucci, G. [Dept. of Pneumology, S. Giovanni HS, Rome (Italy)

    2007-06-15

    Purpose To evaluate with FCT (functional computed tomography) total lung volume and fractional lung volumes at different PEEP (positive end expiratory pressure) values in acute mechanically ventilated patients. Methods Nine ICU (intensive care unity) patients (1 lung pneumonia, 2 polytrauma, 2 sepsis, 3 brain surgery, 1 pulmonary embolism); mean age 48 {+-} 15 years, 6 male, 3 female; GE 16 MDCT scan was performed with acquisition from apex to diaphragma in seven seca at different PEEP values. Raw CT data were analysed by an advantage workstation to obtain volume density masks and histograms of both lungs and each lung and these density ranges were applied: - 1000 - 950 = hyper-ventilated lung, -900 - 650 well aerated lung, -950 - 500 all aerated lung, -500 + 200 lung tissue. Total and fractional lung volumes, Hounsfield unit (HU) were calculated and compared at different PEEP values (0, 5, 10, 15 cm H{sub 2}O). In four patients lung volumes were compared between the more and the less involved lung at increased PEEP. Statistic analysis: comparison means-medians tests. Results Data calculated at five PEEP showed unexpected decrease of total lung volume and increase of lung density (HU); proportionally no significant improvement of oxigenation. (orig.)

  5. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents pulmonary inflammation in patients without preexisting lung injury.

    Science.gov (United States)

    Wolthuis, Esther K; Choi, Goda; Dessing, Mark C; Bresser, Paul; Lutter, Rene; Dzoljic, Misa; van der Poll, Tom; Vroom, Margreeth B; Hollmann, Markus; Schultz, Marcus J

    2008-01-01

    Mechanical ventilation with high tidal volumes aggravates lung injury in patients with acute lung injury or acute respiratory distress syndrome. The authors sought to determine the effects of short-term mechanical ventilation on local inflammatory responses in patients without preexisting lung injury. Patients scheduled to undergo an elective surgical procedure (lasting > or = 5 h) were randomly assigned to mechanical ventilation with either higher tidal volumes of 12 ml/kg ideal body weight and no positive end-expiratory pressure (PEEP) or lower tidal volumes of 6 ml/kg and 10 cm H2O PEEP. After induction of anesthesia and 5 h thereafter, bronchoalveolar lavage fluid and/or blood was investigated for polymorphonuclear cell influx, changes in levels of inflammatory markers, and nucleosomes. Mechanical ventilation with lower tidal volumes and PEEP (n = 21) attenuated the increase of pulmonary levels of interleukin (IL)-8, myeloperoxidase, and elastase as seen with higher tidal volumes and no PEEP (n = 19). Only for myeloperoxidase, a difference was found between the two ventilation strategies after 5 h of mechanical ventilation (P volumes and PEEP may limit pulmonary inflammation in mechanically ventilated patients without preexisting lung injury. The specific contribution of both lower tidal volumes and PEEP on the protective effects of the lung should be further investigated.

  6. Pulmonary lesion induced by low and high positive end-expiratory pressure levels during protective ventilation in experimental acute lung injury.

    Science.gov (United States)

    Pássaro, Caroline P; Silva, Pedro L; Rzezinski, Andréia F; Abrantes, Simone; Santiago, Viviane R; Nardelli, Liliane; Santos, Raquel S; Barbosa, Carolina M L; Morales, Marcelo M; Zin, Walter A; Amato, Marcelo B P; Capelozzi, Vera L; Pelosi, Paolo; Rocco, Patricia R M

    2009-03-01

    To investigate the effects of low and high levels of positive end-expiratory pressure (PEEP), without recruitment maneuvers, during lung protective ventilation in an experimental model of acute lung injury (ALI). Prospective, randomized, and controlled experimental study. University research laboratory. Wistar rats were randomly assigned to control (C) [saline (0.1 mL), intraperitoneally] and ALI [paraquat (15 mg/kg), intraperitoneally] groups. After 24 hours, each group was further randomized into four groups (six rats each) at different PEEP levels = 1.5, 3, 4.5, or 6 cm H2O and ventilated with a constant tidal volume (6 mL/kg) and open thorax. Lung mechanics [static elastance (Est, L) and viscoelastic pressure (DeltaP2, L)] and arterial blood gases were measured before (Pre) and at the end of 1-hour mechanical ventilation (Post). Pulmonary histology (light and electron microscopy) and type III procollagen (PCIII) messenger RNA (mRNA) expression were measured after 1 hour of mechanical ventilation. In ALI group, low and high PEEP levels induced a greater percentage of increase in Est, L (44% and 50%) and DeltaP2, L (56% and 36%) in Post values related to Pre. Low PEEP yielded alveolar collapse whereas high PEEP caused overdistension and atelectasis, with both levels worsening oxygenation and increasing PCIII mRNA expression. In the present nonrecruited ALI model, protective mechanical ventilation with lower and higher PEEP levels than required for better oxygenation increased Est, L and DeltaP2, L, the amount of atelectasis, and PCIII mRNA expression. PEEP selection titrated for a minimum elastance and maximum oxygenation may prevent lung injury while deviation from these settings may be harmful.

  7. Combined Effects of Ventilation Mode and Positive End-Expiratory Pressure on Mechanics, Gas Exchange and the Epithelium in Mice with Acute Lung Injury

    Science.gov (United States)

    Thammanomai, Apiradee; Hamakawa, Hiroshi; Bartolák-Suki, Erzsébet; Suki, Béla

    2013-01-01

    The accepted protocol to ventilate patients with acute lung injury is to use low tidal volume (VT) in combination with recruitment maneuvers or positive end-expiratory pressure (PEEP). However, an important aspect of mechanical ventilation has not been considered: the combined effects of PEEP and ventilation modes on the integrity of the epithelium. Additionally, it is implicitly assumed that the best PEEP-VT combination also protects the epithelium. We aimed to investigate the effects of ventilation mode and PEEP on respiratory mechanics, peak airway pressures and gas exchange as well as on lung surfactant and epithelial cell integrity in mice with acute lung injury. HCl-injured mice were ventilated at PEEPs of 3 and 6 cmH2O with conventional ventilation (CV), CV with intermittent large breaths (CVLB) to promote recruitment, and a new mode, variable ventilation, optimized for mice (VVN). Mechanics and gas exchange were measured during ventilation and surfactant protein (SP)-B, proSP-B and E-cadherin levels were determined from lavage and lung homogenate. PEEP had a significant effect on mechanics, gas exchange and the epithelium. The higher PEEP reduced lung collapse and improved mechanics and gas exchange but it also down regulated surfactant release and production and increased epithelial cell injury. While CVLB was better than CV, VVN outperformed CVLB in recruitment, reduced epithelial injury and, via a dynamic mechanotransduction, it also triggered increased release and production of surfactant. For long-term outcome, selection of optimal PEEP and ventilation mode may be based on balancing lung physiology with epithelial injury. PMID:23326543

  8. Low tidal volume and high positive end-expiratory pressure mechanical ventilation results in increased inflammation and ventilator-associated lung injury in normal lungs.

    Science.gov (United States)

    Hong, Caron M; Xu, Da-Zhong; Lu, Qi; Cheng, Yunhui; Pisarenko, Vadim; Doucet, Danielle; Brown, Margaret; Aisner, Seena; Zhang, Chunxiang; Deitch, Edwin A; Delphin, Ellise

    2010-06-01

    Protective mechanical ventilation with low tidal volume (Vt) and low plateau pressure reduces mortality and decreases the length of mechanical ventilation in patients with acute respiratory distress syndrome. Mechanical ventilation that will protect normal lungs during major surgical procedures of long duration may improve postoperative outcomes. We performed an animal study comparing 3 ventilation strategies used in the operating room in normal lungs. We compared the effects on pulmonary mechanics, inflammatory mediators, and lung tissue injury. Female pigs were randomized into 3 groups. Group H-Vt/3 (n = 6) was ventilated with a Vt of 15 mL/kg predicted body weight (PBW)/positive end-expiratory pressure (PEEP) of 3 cm H(2)O, group L-Vt/3 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 3 cm H(2)O, and group L-Vt/10 (n = 6) with a Vt of 6 mL/kg PBW/PEEP of 10 cm H(2)O, for 8 hours. Hemodynamics, airway mechanics, arterial blood gases, and inflammatory markers were monitored. Bronchoalveolar lavage (BAL) was analyzed for inflammatory markers and protein concentration. The right lower lobe was assayed for mRNA of specific cytokines. The right lower lobe and right upper lobe were evaluated histologically. In contrast to groups H-Vt/3 and L-Vt/3, group L-Vt/10 exhibited a 6-fold increase in inflammatory mediators in BAL (P ventilation with high PEEP resulted in increased production of inflammatory markers. Low PEEP resulted in lower levels of inflammatory markers. High Vt/low PEEP resulted in less histologic lung injury.

  9. Effects of positive end-expiratory pressure titration and recruitment maneuver on lung inflammation and hyperinflation in experimental acid aspiration-induced lung injury.

    Science.gov (United States)

    Ambrosio, Aline M; Luo, Rubin; Fantoni, Denise T; Gutierres, Claudia; Lu, Qin; Gu, Wen-Jie; Otsuki, Denise A; Malbouisson, Luiz M S; Auler, Jose O C; Rouby, Jean-Jacques

    2012-12-01

    In acute lung injury positive end-expiratory pressure (PEEP) and recruitment maneuver are proposed to optimize arterial oxygenation. The aim of the study was to evaluate the impact of such a strategy on lung histological inflammation and hyperinflation in pigs with acid aspiration-induced lung injury. Forty-seven pigs were randomly allocated in seven groups: (1) controls spontaneously breathing; (2) without lung injury, PEEP 5 cm H2O; (3) without lung injury, PEEP titration; (4) without lung injury, PEEP titration + recruitment maneuver; (5) with lung injury, PEEP 5 cm H2O; (6) with lung injury, PEEP titration; and (7) with lung injury, PEEP titration + recruitment maneuver. Acute lung injury was induced by intratracheal instillation of hydrochloric acid. PEEP titration was performed by incremental and decremental PEEP from 5 to 20 cm H2O for optimizing arterial oxygenation. Three recruitment maneuvers (pressure of 40 cm H2O maintained for 20 s) were applied to the assigned groups at each PEEP level. Proportion of lung inflammation, hemorrhage, edema, and alveolar wall disruption were recorded on each histological field. Mean alveolar area was measured in the aerated lung regions. Acid aspiration increased mean alveolar area and produced alveolar wall disruption, lung edema, alveolar hemorrhage, and lung inflammation. PEEP titration significantly improved arterial oxygenation but simultaneously increased lung inflammation in juxta-diaphragmatic lung regions. Recruitment maneuver during PEEP titration did not induce additional increase in lung inflammation and alveolar hyperinflation. In a porcine model of acid aspiration-induced lung injury, PEEP titration aimed at optimizing arterial oxygenation, substantially increased lung inflammation. Recruitment maneuvers further improved arterial oxygenation without additional effects on inflammation and hyperinflation.

  10. Positive end expiratory pressure during one-lung ventilation: Selecting ideal patients and ventilator settings with the aim of improving arterial oxygenation

    Directory of Open Access Journals (Sweden)

    Hoftman Nir

    2011-01-01

    Full Text Available The efficacy of positive end-expiratory pressure (PEEP in treating intraoperative hypoxemia during one-lung ventilation (OLV remains in question given conflicting results of prior studies. This study aims to (1 evaluate the efficacy of PEEP during OLV, (2 assess the utility of preoperative predictors of response to PEEP, and (3 explore optimal intraoperative settings that would maximize the effects of PEEP on oxygenation. Forty-one thoracic surgery patients from a single tertiary care university center were prospectively enrolled in this observational study. After induction of general anesthesia, a double-lumen endotracheal tube was fiberoptically positioned and OLV initiated. Intraoperatively, PEEP = 5 and 10 cmH 2 O were sequentially applied to the ventilated lung during OLV. Arterial oxygenation, cardiovascular performance parameters, and proposed perioperative variables that could predict or enhance response to PEEP were analysed. T-test and c2 tests were utilized for continuous and categorical variables, respectively. Multivariate analyses were carried out using a classification tree model of binary recursive partitioning. PEEP improved arterial oxygenation by ≥20% in 29% of patients (n = 12 and failed to do so in 71% (n = 29; however, no cardiovascular impact was noted. Among the proposed clinical predictors, only intraoperative tidal volume per kilogram differed significantly between responders to PEEP and non-responders (mean 6.6 vs. 5.7 ml/kg, P = 0.013; no preoperative variable predicted response to PEEP. A multivariate analysis did not yield a clinically significant model for predicting PEEP responsiveness. PEEP improved oxygenation in a subset of patients; larger, although still protective tidal volumes favored a positive response to PEEP. No preoperative variables, however, could be identified as reliable predictors for PEEP responders.

  11. Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bluth, T; Teichmann, R; Kiss, T; Bobek, I; Canet, J; Cinnella, G; De Baerdemaeker, L; Gregoretti, C; Hedenstierna, G; Hemmes, S N; Hiesmayr, M; Hollmann, M W; Jaber, S; Laffey, J G; Licker, M J; Markstaller, K; Matot, I; Müller, G; Mills, G H; Mulier, J P; Putensen, C; Rossaint, R; Schmitt, J; Senturk, M; Serpa Neto, A; Severgnini, P; Sprung, J; Vidal Melo, M F; Wrigge, H; Schultz, M J; Pelosi, P; Gama de Abreu, M

    2017-04-28

    Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m 2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH 2 O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH 2 O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016.

  12. Hemodynamic responses to external counterbalancing of auto-positive end-expiratory pressure in mechanically ventilated patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Baigorri, F; de Monte, A; Blanch, L; Fernández, R; Vallés, J; Mestre, J; Saura, P; Artigas, A

    1994-11-01

    To study the effect of positive end-expiratory pressure (PEEP) on right ventricular hemodynamics and ejection fraction in patients with chronic obstructive pulmonary disease and positive alveolar pressure throughout expiration by dynamic hyperinflation (auto-PEEP). Open, prospective, controlled trial. General intensive care unit of a community hospital. Ten patients sedated and paralyzed with an acute exacerbation of chronic obstructive pulmonary disease undergoing mechanical ventilation. Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. PEEP was then increased from 0 (PEEP 0) to auto-PEEP level (PEEP = auto-PEEP) and 5 cm H2O above that (PEEP = auto-PEEP +5). At each level of PEEP, airway pressures, flow and volume, hemodynamic variables (including right ventricular ejection fraction by thermodilution technique), and blood gas analyses were recorded. The mean auto-PEEP was 6.6 +/- 2.8 cm H2O and the total PEEP reached was 12.2 +/- 2.4 cm H2O. The degree of lung inflation induced by PEEP averaged 145 +/- 87 mL with PEEP = auto-PEEP and 495 +/- 133 mL with PEEP = auto-PEEP + 5. The PEEP = auto-PEEP caused a right ventricular end-diastolic pressure increase, but there was no other significant hemodynamic change. With PEEP = auto-PEEP + 5, there was a significant increase in intravascular pressures; this amount of PEEP reduced cardiac output (from 4.40 +/- 1.38 L/min at PEEP 0 to 4.13 +/- 1.48 L/min; p 10% in only five cases and this group of patients had significantly lower right ventricular volumes than the group with less cardiac output variation (right ventricular end-diastolic volume: 64 +/- 9 vs. 96 +/- 26 mL/m2; right ventricular end-systolic volume: 38 +/- 6 vs. 65 +/- 21 mL/m2; p < .05) without significant difference in the other variables that were measured. Neither right ventricular ejection fraction nor right ventricle volumes changed as PEEP increased, but there were marked interpatient

  13. Respiratory effects of low versus high tidal volume with or without positive end-expiratory pressure in anesthetized dogs with healthy lungs.

    Science.gov (United States)

    De Monte, Valentina; Bufalari, Antonello; Grasso, Salvatore; Ferrulli, Fabienne; Crovace, Alberto Maria; Lacitignola, Luca; Staffieri, Francesco

    2018-05-01

    OBJECTIVE To evaluate the impact of 2 tidal volumes (T V s) with or without positive end-expiratory pressure (PEEP) on lung mechanics, aeration, and gas exchange in healthy anesthetized dogs. ANIMALS 40 mixed-breed dogs with healthy lungs. PROCEDURES Anesthetized dogs were randomly assigned to 4 groups (n = 10/group) with different ventilatory settings: T V of 8 mL/kg and PEEP of 0 cm H 2 O (low T V group), T V of 8 mL/kg and PEEP of 5 cm H 2 O (low T V plus PEEP group), T V of 15 mL/kg and PEEP of 0 cm H 2 O (high T V group), or T V of 15 mL/kg and PEEP of 5 cm H 2 O (high T V plus PEEP group). Expired CO 2 and respiratory rate were titrated on the basis of a predetermined stepwise protocol. Gas exchange, respiratory mechanics, and pulmonary aeration were evaluated by means of CT 30 minutes after starting mechanical ventilation at the assigned setting. RESULTS Partial pressures of arterial and expired CO 2 were higher in the low T V and low T V plus PEEP groups than in the high T V and high T V plus PEEP groups. Peak and plateau airway pressures were higher in the PEEP group than in the other groups. Static lung compliance was higher in the high T V plus PEEP group than in the low T V group. Relative percentages of atelectatic and poorly aerated lung were lower in the high T V plus PEEP group than in the other groups. Oxygenation was similar among groups. CONCLUSIONS AND CLINICAL RELEVANCE Differences in T V and PEEP application during mechanical ventilation may affect respiratory function in anesthetized dogs with healthy lungs. Ventilation with a T V of 15 mL/kg and PEEP of 5 cm H 2 O significantly improved lung compliance and reduced the amount of atelectatic and poorly aerated lung.

  14. [The influence of positive end-expiratory pressure on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome].

    Science.gov (United States)

    Yang, Chunli; Chen, Zhi; Lu, Yuanhua; He, Huiwei; Zeng, Weihua

    2014-05-01

    To explore the influence of different positive end-expiratory pressure (PEEP) levels on cerebral blood flow (CBF) and cerebrovascular autoregulation in patients with acute respiratory distress syndrome(ARDS). A prospective study was conducted. Moderate or severe ARDS patients admitted to Department of Critical Care Medicine of Jiangxi Provincial People's Hospital from January 1st, 2013 to October 1st, 2013 were enrolled. The changes in hemodynamics, respiratory mechanics and gas exchange under different levels of PEEP were observed. CBF velocity of middle cerebral artery (MCA) was measured using transcranial Doppler (TCD), and breath-holding index (BHI) was also calculated. 35 patients with ARDS were included. The oxygenation index (OI), peak inspiratory pressure (PIP), plat pressure (Pplat) and central venous pressure (CVP) were markedly elevated (OI: 324.7±117.2 mmHg vs. 173.4±95.8 mmHg, t=5.913, P=0.000; PIP: 34.7±9.1 cmH2O vs. 26.1±7.9 cmH2O,t=4.222, P=0.000; Pplat: 30.5±8.4 cmH2O vs. 22.2±7.1 cmH2O, t=4.465, P=0.000; CVP: 12.1±3.5 mmHg vs. 8.8±2.2 mmHg, t=4.723, P=0.000) when PEEP was increased from (6.4±1.0) cmH2O to (14.5±2.0) cmH2O (1 cmH2O=0.098 kPa). But no significant difference in the heart rate (85.5±19.1 beats/min vs. 82.7±17.3 beats/min, t=0.643, P=0.523), mean arterial pressure (73.5±12.4 mmHg vs. 76.4±15.1 mmHg, t=0.878, P=0.383) and CBF velocity of MCA [peak systolic flow velocity (Vmax): 91.26±17.57 cm/s vs. 96.64±18.71 cm/s, t=1.240, P=0.219; diastolic flow velocity (Vmin): 31.54±7.71 cm/s vs. 33.87±8.53 cm/s, t=1.199, P=0.235; mean velocity (Vmean): 51.19±12.05 cm/s vs. 54.27±13.36 cm/s, t=1.013, P=0.315] was found. 18 patients with BHI<0.1 at baseline demonstrated that cerebral vasomotor reactivity was poor. BHI was slightly decreased with increase in PEEP (0.78±0.16 vs. 0.86±0.19, t=1.905, P=0.061). Some of moderate or severe ARDS patients without central nervous system disease have independent of preexisting cerebral

  15. OPTIMUM LEVEL OF POSITIVE END-EXPIRATORY PRESSURE IN ACUTE RESPIRATORY DISTRESS SYNDROME CAUSED BY INFLUENZA A(H1NI)PDM09: BALANCE BETWEEN MAXIMAL END-EXPIRATORY VOLUME AND MINIMAL ALVEOLAR OVERDISTENSION.

    Science.gov (United States)

    Yaroshetskiym A I; Protsenko, D N; Boytsov, P V; Chentsov, V B; Nistratov, S L; Kudlyakov, O N; Solov'ev, V V; Banova, Zh I; Shkuratova, N V; Rezenov, N A; Gel'fand, B R

    2016-11-01

    to determine optimum level ofpositive end-expiratory pressure (PEEP) according to balance between maxi- mal end-expiratory lung volume (EEL V)(more than predicted) and minimal decrease in exhaled carbon dioxide volume (VCO) and then to develop the algorithm of gas exchange correction based on prognostic values of EEL K; alveolar recruitability, PA/FiO2, static compliance (C,,,) and VCO2. 27 mechanically ventilatedpatients with acute respiratory distress syndrome (ARDS) caused by influenza A (HINJ)pdm09 in Moscow Municipal Clinics ICU's from January to March 2016 were included in the trial. At the beginning of the study patients had the following characteristic: duration offlu symptoms 5 (3-10) days, p.0/FiO2 120 (70-50) mmHg. SOFA 7 (5-9), body mass index 30.1 (26.4-33.8) kg/m², static compliance of respiratory system 35 (30-40) ml/mbar: Under sedation and paralysis we measured EELV, C VCO and end-tidal carbon dioxide concentration (EtCO) (for CO₂ measurements we fixed short-term values after 2 min after PEEP level change) at PEEP 8, 11,13,15,18, 20 mbar consequently, and incase of good recruitability, at 22 and 24 mbar. After analyses of obtained data we determined PEEP value in which increase in EELV was maximal (more than predicted) and depression of VCO₂ was less than 20%, change in mean blood pressure and heart rate were both less than 20% (measured at PEEP 8 mbar). After that we set thus determined level of PEEP and didn't change it for 5 days. Comparision of predicted and measured EELV revealed two typical points of alveloar recruiment: the first at PEEP 11-15 mbar, the second at PEEP 20-22 mbar. EELV measured at PEEP 18 mbar appeared to be higher than predicted at PEEP 8 mbar by 400 ml (approx.), which was the sign of alveolar recruitment-1536 (1020-1845) ml vs 1955 (1360-2320) ml, p=0,001, Friedman test). we didn't found significant changes of VCO₂ when increased PEEP in the range from 8 to 15 mbar (p>0.05, Friedman test). PEEP increase from 15 to

  16. The effects of intraoperative lung protective ventilation with positive end-expiratory pressure on blood loss during hepatic resection surgery: A secondary analysis of data from a published randomised control trial (IMPROVE).

    Science.gov (United States)

    Neuschwander, Arthur; Futier, Emmanuel; Jaber, Samir; Pereira, Bruno; Eurin, Mathilde; Marret, Emmanuel; Szymkewicz, Olga; Beaussier, Marc; Paugam-Burtz, Catherine

    2016-04-01

    During high-risk abdominal surgery the use of a multi-faceted lung protective ventilation strategy composed of low tidal volumes, positive end-expiratory pressure (PEEP) and recruitment manoeuvres, has been shown to improve clinical outcomes. It has been speculated, however, that mechanical ventilation using PEEP might increase intraoperative bleeding during liver resection. To study the impact of mechanical ventilation with PEEP on bleeding during hepatectomy. Post-hoc analysis of a randomised controlled trial. Seven French university teaching hospitals from January 2011 to August 2012. Patients scheduled for liver resection surgery. In the Intraoperative Protective Ventilation trial, patients scheduled for major abdominal surgery were randomly assigned to mechanical ventilation using low tidal volume, PEEP between 6 and 8  cmH2O and recruitment manoeuvres (lung protective ventilation strategy) or higher tidal volume, zero PEEP and no recruitment manoeuvres (non-protective ventilation strategy). The primary endpoint was intraoperative blood loss volume. A total of 79 (19.8%) patients underwent liver resections (41 in the lung protective and 38 in the non-protective group). The median (interquartile range) amount of intraoperative blood loss was 500 (200 to 800)  ml and 275 (125 to 800)  ml in the non-protective and lung protective ventilation groups, respectively (P = 0.47). Fourteen (35.0%) and eight (21.5%) patients were transfused in the non-protective and lung protective groups, respectively (P = 0.17), without a statistically significant difference in the median (interquartile range) number of red blood cells units transfused [2.5 (2 to 4) units and 3 (2 to 6) units in the two groups, respectively; P = 0.54]. During hepatic surgery, mechanical ventilation using PEEP within a multi-faceted lung protective strategy was not associated with increased bleeding compared with non-protective ventilation using zero PEEP. The current study was not

  17. Efeitos de diferentes volumes correntes e da pressão expiratória final positiva sobre a troca gasosa na fístula broncopleural experimental Effects of different tidal volumes and positive end expiratory pressure on gas exchange in experimental bronchopleural fistula

    Directory of Open Access Journals (Sweden)

    Maria Gabriela Cavicchia Toneloto

    2008-09-01

    melhora e o débito da fístula é reduzido quando comparado ao volume corrente de 10ml/Kg. Um baixo volume resulta em hipercapnia e grave dessaturação. Finalmente, em qualquer volume corrente, PEEP aumenta o débito da fístula e diminui a ventilação alveolar.OBJECTIVES: The present study was designed to identify the effect of positive end expiratory pressure (PEEP and the ideal pulmonary tidal volume to ventilate animals with a surgically produced bronchopleural fistula, aiming to reduce fistula output without affecting gas exchange. METHODS: Hemodynamic and respiratory assessment of gas exchange was obtained in five, healthy, young, mechanically ventilated Large White pigs under volume controlled ventilation with FiO2 of 0.4 and an inspiration:expiration ratio of 1:2, keeping respiratory rate at 22 cpm. A bronchopleural fistula was produced by resection of the lingula. Underwater seal drainage was installed and the thorax was hermetically closed. Gas exchange and fistula output were measured with the animals ventilated sequentially with tidal volumes of 4 ml/kg, 7 ml/kg and 10 ml/Kg alternating zero of positive end expiratory pressure (ZEEP and PEEP of 10 cmH2O, always in the same order. RESULTS: These findings are attributed to reduced alveolar ventilation and ventilation/perfusion abnormalities and were attenuated with larger tidal volumes. PEEP increases air leak, even with low volume (of 2.0 ± 2.8mL to 31 ± 20.7mL; p= 0.006 and decreases alveolar ventilation in all tidal volumes. Alveolar ventilation improved with larger tidal volumes, but increased fistula output (10 mL/kg - 25.8 ± 18.3mL to 80.2 ± 43.9mL; p=0.0010. Low tidal volumes result in hypercapnia (ZEEP - Toneloto MGC, Terzi RGG, Silva WA, Moraes AC, Moreira MM 83.7± 6.9 mmHg and with PEEP 10 - 93 ± 10.1mmHg and severely decreased arterial oxygen saturation, about of 84%. CONCLUSIONS: The tidal volume of 7 ml/Kg with ZEEP was considered the best tidal volume because, despite moderate hypercapnia

  18. Avaliação da função pulmonar de recém-nascidos com síndrome do desconforto respiratório em diferentes pressões finais expiratórias positivas Assessment of pulmonary function of preterm newborn infants with respiratory distress syndrome at different positive end expiratory pressure levels

    Directory of Open Access Journals (Sweden)

    Luiz C.T. Consolo

    2002-09-01

    Full Text Available RESUMO\tABSTRACT \t Objetivo: verificar as alterações da função pulmonar: complacência dinâmica (Cdyn, volume corrente inspiratório (V Tinsp, pressão arterial de dióxido de carbono (PaCO2, em recém-nascidos pré-termo com síndrome do desconforto respiratório. Pacientes e Métodos: estudo de caso controle, incluindo 11 pré-termos com idade gestacional Objective: to verify the alterations of pulmonary function in preterm newborn infants with respiratory distress syndrome (RDS. The parameters analyzed were Dynamic Compliance (Cdyn, Inspiratory Tidal Volume (TVinsp, partial arterial pressure of carbon dioxide (PaCO2. Methods: eleven preterm newborn infants, with gestational age < 35 weeks, and birth weight < 2.500 g, were include in a control case study. All infants presented RDS and were treated with 120 mg/Kg of porcine surfactant. The initial positive end expiratory pressure (PEEP was 3 cm H2O. A pneumotachograph with a graphical monitor was used to assess the pulmonary function. After each increase in the PEEP (4 and 6 cm H2O, there was an interval of 20 minutes before measuring the arterial data of pulmonary function and arterial gases. Results: there were three males and eight females (1:2,7 among the infants with RDS. The mean gestational age was 30.78. 2.05 weeks, ranging from 26 to 34 weeks. The increase in the PEEP from 3 to 6 cm H2O caused significant decrease in the TVinsp (6.46 ±3.43 to 4.20 ±2.35, P=0.0262. With the increase in the PEEP from 4 to 6 cm H2O, there was also a decrease in the TVinsp (5.98.± 3.33 to 4.20.± 2.35, (P=0.0044. Regarding the Cdyn, when there was an increase in the PEEP from 3 to 6 cm H2O, the reduction was statistically significant (0.58.± 0.27 to 0.46± 0.25, P=0.0408 and from 4 to 6 cm H2O, the reduction in the Cdyn was also important (0.77± 0.27 to 0.46± 0.25, (P=0.0164. Increases in the PEEP from 4 to 6 cm H2O caused increases in the PaCO2 (52.81± 15.49 to 64.90± 12.69, (P= 0,0141. A

  19. Effect of Training Frequency on Maximum Expiratory Pressure

    Science.gov (United States)

    Anand, Supraja; El-Bashiti, Nour; Sapienza, Christine

    2012-01-01

    Purpose: To determine the effects of expiratory muscle strength training (EMST) frequency on maximum expiratory pressure (MEP). Method: We assigned 12 healthy participants to 2 groups of training frequency (3 days per week and 5 days per week). They completed a 4-week training program on an EMST trainer (Aspire Products, LLC). MEP was the primary…

  20. High positive end-expiratory pressure levels promote bacterial translocation in experimental pneumonia

    NARCIS (Netherlands)

    Lachmann, Robert A.; van Kaam, Anton H.; Haitsma, Jack J.; Lachmann, Burkhard

    2007-01-01

    A previous study in piglets with experimental pneumonia showed that reducing atelectasis by means of open lung ventilation attenuated bacterial translocation compared to conventional ventilation settings. This study examined the effect of open lung ventilation with higher than necessary positive

  1. Positive expiratory pressure - Common clinical applications and physiological effects.

    Science.gov (United States)

    Fagevik Olsén, Monika; Lannefors, Louise; Westerdahl, Elisabeth

    2015-03-01

    Breathing out against resistance, in order to achieve positive expiratory pressure (PEP), is applied by many patient groups. Pursed lips breathing and a variety of devices can be used to create the resistance giving the increased expiratory pressure. Effects on pulmonary outcomes have been discussed in several publications, but the expected underlying physiology of the effect is seldom discussed. The aim of this article is to describe the purpose, performance, clinical application and underlying physiology of PEP when it is used to increase lung volumes, decrease hyperinflation or improve airway clearance. In clinical practice, the instruction how to use an expiratory resistance is of major importance since it varies. Different breathing patterns during PEP increase or reduce expiratory flow, result in movement of EPP centrally or peripherally and can increase or decrease lung volume. It is therefore necessary to give the right instructions to obtain the desired effects. As the different PEP techniques are being used by diverse patient groups it is not possible to give standard instructions. Based on the information given in this article the instructions have to be adjusted to give the optimal effect. There is no consensus regarding optimal treatment frequency and number of cycles included in each treatment session and must also be individualized. In future research, more precise descriptions are needed about physiological aims and specific instructions of how the treatments have been performed to assure as good treatment quality as possible and to be able to evaluate and compare treatment effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Relationship of end-expiratory pressure, lung volume, and /sup 99m/Tc-DTPA clearance

    International Nuclear Information System (INIS)

    Cooper, J.A.; van der Zee, H.; Line, B.R.; Malik, A.B.

    1987-01-01

    We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH 2 O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH 2 O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P less than 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH 2 O PEEP. At 2.5 cmH 2 O PEEP, the clearance rate was not different from that at base line (P less than 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH 2 O (P less than 0.05). Between 15 and 20 cmH 2 O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized /sup 99m/Tc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation

  3. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents alveolar coagulation in patients without lung injury

    NARCIS (Netherlands)

    Choi, Goda; Wolthuis, Esther K.; Bresser, Paul; Levi, Marcel; van der Poll, Tom; Dzoljic, Misa; Vroom, Margreeth B.; Schultz, Marcus J.

    2006-01-01

    BACKGROUND: Alveolar fibrin deposition is a hallmark of acute lung injury, resulting from activation of coagulation and inhibition of fibrinolysis. Previous studies have shown that mechanical ventilation with high tidal volumes may aggravate lung injury in patients with sepsis and acute lung injury.

  4. Evaluation of Pressure Generated by Resistors From Different Positive Expiratory Pressure Devices.

    Science.gov (United States)

    Fagevik Olsén, Monika; Carlsson, Maria; Olsén, Erik; Westerdahl, Elisabeth

    2015-10-01

    Breathing exercises with positive expiratory pressure (PEP) are used to improve pulmonary function and airway clearance. Different PEP devices are available, but there have been no studies that describe the pressure generated by different resistors. The purpose of this study was to compare pressures generated from the proprietary resistor components of 4 commercial flow-dependent PEP valves with all other parameters kept constant. Resistors from 4 flow-regulated PEP devices (Pep/Rmt system, Wellspect HealthCare; Pipe P breathing exerciser, Koo Medical Equipment; Mini-PEP, Philips Respironics [including resistors by Rüsch]; and 15-mm endo-adapter, VBM Medizintechnik) were tested randomly by a blinded tester at constant flows of 10 and 18 L/min from an external gas system. All resistors were tested 3 times. Resistors with a similar diameter produced statistically significant different pressures at the same flow. The differences were smaller when the flow was 10 L/min compared with 18 L/min. The differences were also smaller when the diameter of the resistor was increased. The pressures produced by the 4 resistors of the same size were all significantly different when measuring 1.5- and 2.0-mm resistors at a flow of 10 L/min and 2.0-mm resistors at a flow of 18 L/min (P < .001). There were no significant differences between any of the resistors when testing sizes of 4.5 and 5.0 mm at either flow. The Mini-PEP and adapter resistors gave the highest pressures. Pressures generated by the different proprietary resistor components of 4 commercial PEP devices were not comparable, even though the diameter of the resistors is reported to be the same. The pressures generated were significantly different, particularly when using small-diameter resistors at a high flow. Therefore, the resistors may not be interchangeable. This is important information for clinicians, particularly when considering PEP for patients who do not tolerate higher pressures. Copyright © 2015 by

  5. Short-term effects of positive expiratory airway pressure in patients being weaned from mechanical ventilation

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    Marcelo de Mello Rieder

    2009-05-01

    Full Text Available OBJECTIVE: To investigate the feasibility and the cardiorespiratory effects of using positive expiratory airway pressure, a physiotherapeutic tool, in comparison with a T-tube, to wean patients from mechanical ventilation. METHODS/DESIGN: A prospective, randomized, cross-over study. SETTING: Two intensive care units. PATIENTS AND INTERVENTIONS: We evaluated forty patients who met weaning criteria and had been mechanically-ventilated for more than 48 hours, mean age 59 years, including 23 males. All patients were submitted to the T-tube and Expiratory Positive Airway Pressure devices, at 7 cm H2O, during a 30-minute period. Cardiorespiratory variables including work of breathing, respiratory rate (rr, peripheral oxygen saturation (SpO2, heart rate (hr, systolic, diastolic and mean arterial pressures (SAP, DAP, MAP were measured in the first and thirtieth minutes. The condition was analyzed as an entire sample set (n=40 and was also divided into subconditions: chronic obstructive pulmonary disease (n=14 and non-chronic obstructive pulmonary disease (non- chronic obstructive pulmonary disease (n=26 categories. Comparisons were made using a t-test and Analysis of Variance. The level of significance was p < 0.05. RESULTS: Our data showed an increase in work of breathing in the first and thirtieth minutes in the EPAP condition (0.86+ 0.43 and 1.02+1.3 as compared with the T-tube condition (0.25+0.26 and 0.26+0.35 (p<0.05, verified by the flow-sensor monitor (values in J/L. No statistical differences were observed when comparing the Expiratory Positive Airway Pressure and T-tube conditions with regard to cardiorespiratory measurements. The same result was observed for both chronic obstructive pulmonary disease and non- chronic obstructive pulmonary disease subconditions. CONCLUSIONS: Our study demonstrated that, in weaning patients from mechanical ventilation, the use of a fixed level of Expiratory Positive Airway Pressure caused an increase in work of

  6. "THE EVALUATION OF THE POSSIBLE EFFECT OF POSITIVE END EXPIRATORY PRESSURE (PEEP) ON PHARMACOKINETICS OF PHENYTOIN IN PATIENTS WITH ACUTE BRAIN INJURY UNDER MECHANICAL VENTILATION."

    OpenAIRE

    "Elham Hadidi; Mojtaba Mojtahedzadeh; Mohammad Reza Rouini; Behzad Eftekhar; Mohammad Abdollahi; Atabak Najafi; Mohammad R. Khajavi; Saeed Rezaee; Reza Ghaffari; Minoo Afshar"

    2005-01-01

    Positive ventilation has shown to have an influence on pharmacokinetic and disposition of some drugs.Beacause phenytoin with a narrow therapautic range, is the most commonly used drug for prophylaxis and treatment of early seizures after acute brain injuries, in the present study the effect of short term PEEP (5-10 cm H2O for at least 8 hours) on phenytoin serum concentration and pharmacokinetic parameters such as Vmax and clearance in brain injured patients under mechanical ventilation was e...

  7. "THE EVALUATION OF THE POSSIBLE EFFECT OF POSITIVE END EXPIRATORY PRESSURE (PEEP ON PHARMACOKINETICS OF PHENYTOIN IN PATIENTS WITH ACUTE BRAIN INJURY UNDER MECHANICAL VENTILATION."

    Directory of Open Access Journals (Sweden)

    "Elham Hadidi

    2005-04-01

    Full Text Available Positive ventilation has shown to have an influence on pharmacokinetic and disposition of some drugs.Beacause phenytoin with a narrow therapautic range, is the most commonly used drug for prophylaxis and treatment of early seizures after acute brain injuries, in the present study the effect of short term PEEP (5-10 cm H2O for at least 8 hours on phenytoin serum concentration and pharmacokinetic parameters such as Vmax and clearance in brain injured patients under mechanical ventilation was examined. Ten patients with moderate to severe acute brain injury who were placed on mechanical ventilation with an initial PEEP level of 0-5 cm H2O were included in the study. Patients received phenytoin loading dose of 15 mg/kg followed by a maintenance daily dose of 3-7 mg/kg initiated within 12 hours of loading dose. Sampels were taken on two different occasions before and after PEEP elevation. Total phenytoin serum concentrations were determined by HPLC method. A time invarient Michaelis-Menten pharmacokinetic model was used to calculate Vmax and clearance for each patient.Derrived variables were calculated as follows: Vmax, 3.5-6.8 and 3.7-8.2 mg/kg/day; Clearance, 0.1-0.7 and 0.1-1.2 l/kg/day (before and after PEEP elevation, respectively. Our data have shown a wide range of variability (2.6-32.5 mg/l in phenytoin serum concentrations. There were no statistically significant differences in the measured total concentrations (p=0.721 and calculated Vmax and clearance (p=0.285before and after PEEP elevation. Administration of fluid and inotropic agents, limitation in application of higher levels of PEEP and drug interactions, shall be considered as possible explanations for these findings.

  8. Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents pulmonary inflammation in patients without preexisting lung injury

    NARCIS (Netherlands)

    Wolthuis, Esther K.; Choi, Goda; Dessing, Mark C.; Bresser, Paul; Lutter, Rene; Dzoljic, Misa; van der Poll, Tom; Vroom, Margreeth B.; Hollmann, Markus; Schultz, Marcus J.

    2008-01-01

    Background: Mechanical ventilation with high tidal volumes aggravates lung injury in patients with acute lung injury or acute respiratory distress syndrome. The authors sought to determine the effects of short-term mechanical ventilation on local inflammatory responses in patients without

  9. Intraoperative Protective Mechanical Ventilation for Prevention of Postoperative Pulmonary Complications A Comprehensive Review of the Role of Tidal Volume, Positive End-expiratory Pressure, and Lung Recruitment Maneuvers

    NARCIS (Netherlands)

    Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N. T.; Canet, Jaume; Spieth, Peter M.; Rocco, Patricia R. M.; Schultz, Marcus J.; Pelosi, Paolo; Gama de Abreu, Marcelo

    2015-01-01

    Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses

  10. Influence of posture and positive end-tidal expiratory pressure (PEEP) on clearance of Tc99m-DTPA from the lungs

    International Nuclear Information System (INIS)

    Mason, G.R.; Maublant, J.; Sietsema, K.; Effros, R.M.; Mena, I.

    1984-01-01

    The clearance of Tc99m-DTPA aerosols from the lung has been used to detect and quantitate alterations in the permeability of the pulmonary epithelium. Clearance of the radionuclide is accelerated by both chronic and acute injuries to the lung and by smoking. Several laboratories have reported that Tc99m-DTPA clearance from upper lobes exceeded that from lower lobes in upright subjects. To investigate this phenomenon further the authors studied subjects with simultaneous anterior and posterior cameras in upright and supine positions. In the upright position, clearance from both the anterior and posterior upper regions of interest (ROI's) exceeded the lower regions (-1.64 +- .42 S.D. vs. -0.75 +- .41, anterior, p < .05, n=6), -1.04 +- .23 vs. -0.50 +- .36, posterior. All units = %/min. This difference was not observed in the supine subjects. Clearance from the anterior chest exceeded that from the posterior chest in the supine subjects (-1.28 +- .45 vs. -0.05 +- 1.08) and a small increase in radio-activity was observed in at least one ROI of 5 of 6 subjects from the posterior camera. An increase in activity is likely to be secondary to labeling of blood pool, which would have greatest affect where pulmonary blood volume is largest. Computer processing of the entire lung without observer bias in ROI placement showed similar effects of posture over non-peripheral ROI's. Five subjects breathed on PEEP to cause airspace distention, causing clearance to double. Both dependency and airspace distention appear to influence clearance of aerosolized DTPA, the latter may occur by stretching of epithelial pores

  11. Deep breathing exercises with positive expiratory pressure in patients with multiple sclerosis - a randomized controlled trial.

    Science.gov (United States)

    Westerdahl, Elisabeth; Wittrin, Anna; Kånåhols, Margareta; Gunnarsson, Martin; Nilsagård, Ylva

    2016-11-01

    Breathing exercises with positive expiratory pressure are often recommended to patients with advanced neurological deficits, but the potential benefit in multiple sclerosis (MS) patients with mild and moderate symptoms has not yet been investigated in randomized controlled trials. To study the effects of 2 months of home-based breathing exercises for patients with mild to moderate MS on respiratory muscle strength, lung function, and subjective breathing and health status outcomes. Forty-eight patients with MS according to the revised McDonald criteria were enrolled in a randomized controlled trial. Patients performing breathing exercises (n = 23) were compared with a control group (n = 25) performing no breathing exercises. The breathing exercises were performed with a positive expiratory pressure device (10-15 cmH 2 O) and consisted of 30 slow deep breaths performed twice a day for 2 months. Respiratory muscle strength (maximal inspiratory and expiratory pressure at the mouth), spirometry, oxygenation, thoracic excursion, subjective perceptions of breathing and self-reported health status were evaluated before and after the intervention period. Following the intervention, there was a significant difference between the breathing group and the control group regarding the relative change in lung function, favoring the breathing group (vital capacity: P < 0.043; forced vital capacity: P < 0.025). There were no other significant differences between the groups. Breathing exercises may be beneficial in patients with mild to moderate stages of MS. However, the clinical significance needs to be clarified, and it remains to be seen whether a sustainable effect in delaying the development of respiratory dysfunction in MS can be obtained. © 2015 The Authors. The Clinical Respiratory Journal published by John Wiley & Sons Ltd.

  12. Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway.

    Directory of Open Access Journals (Sweden)

    Samantha Torres Grams

    Full Text Available Maximal Inspiratory Pressure (MIP is considered an effective method to estimate strength of inspiratory muscles, but still leads to false positive diagnosis. Although MIP assessment with unidirectional expiratory valve method has been used in patients undergoing mechanical ventilation, no previous studies investigated the application of this method in subjects without artificial airway.This study aimed to compare the MIP values assessed by standard method (MIPsta and by unidirectional expiratory valve method (MIPuni in subjects with spontaneous breathing without artificial airway. MIPuni reproducibility was also evaluated.This was a crossover design study, and 31 subjects performed MIPsta and MIPuni in a random order. MIPsta measured MIP maintaining negative pressure for at least one second after forceful expiration. MIPuni evaluated MIP using a unidirectional expiratory valve attached to a face mask and was conducted by two evaluators (A and B at two moments (Tests 1 and 2 to determine interobserver and intraobserver reproducibility of MIP values. Intraclass correlation coefficient (ICC[2,1] was used to determine intraobserver and interobserver reproducibility.The mean values for MIPuni were 14.3% higher (-117.3 ± 24.8 cmH2O than the mean values for MIPsta (-102.5 ± 23.9 cmH2O (p<0.001. Interobserver reproducibility assessment showed very high correlation for Test 1 (ICC[2,1] = 0.91, and high correlation for Test 2 (ICC[2,1] = 0.88. The assessment of the intraobserver reproducibility showed high correlation for evaluator A (ICC[2,1] = 0.86 and evaluator B (ICC[2,1] = 0.77.MIPuni presented higher values when compared with MIPsta and proved to be reproducible in subjects with spontaneous breathing without artificial airway.

  13. Positive expiratory pressure in patients with chronic obstructive pulmonary disease--a systematic review.

    Science.gov (United States)

    Fagevik Olsén, Monika; Westerdahl, Elisabeth

    2009-01-01

    Breathing exercises against a resistance during expiration are often used as treatment for patients with chronic obstructive pulmonary disease (COPD). Controversy still exists regarding the clinical application and efficacy. The aim of this systematic review was to determine the effects of chest physiotherapy techniques with positive expiratory pressure (PEP) for the prevention and treatment of pulmonary impairment in adults with COPD. The review was conducted on randomised, controlled clinical trials in which breathing exercises with positive expiratory pressure were compared with other chest physical therapy techniques or with no treatment, in adult patients with COPD. A computer-assisted literature search of available databases from 1970 to January 2008 was performed. Two reviewers extracted data independently and assessed the trials systematically with an instrument for measuring methodological quality. In total, 11 trials met the inclusion criteria, of which 5 reached an adequate level of internal validity. Several kinds of PEP techniques with a diversity of intensities and durations of treatment have been evaluated with different outcome measures and follow-up periods. Benefits of PEP were found in isolated outcome measures in separate studies with a follow-up period <1 month. Concerning long-term effects, the results are contradictory. Prior to widespread prescription of long-term PEP treatment, more research is required to establish the benefit of the technique in patients with COPD. (c) 2008 S. Karger AG, Basel.

  14. Using an expiratory resistor, arterial pulse pressure variations predict fluid responsiveness during spontaneous breathing: an experimental porcine study.

    Science.gov (United States)

    Dahl, Michael K; Vistisen, Simon T; Koefoed-Nielsen, Jacob; Larsson, Anders

    2009-01-01

    Fluid responsiveness prediction is difficult in spontaneously breathing patients. Because the swings in intrathoracic pressure are minor during spontaneous breathing, dynamic parameters like pulse pressure variation (PPV) and systolic pressure variation (SPV) are usually small. We hypothesized that during spontaneous breathing, inspiratory and/or expiratory resistors could induce high arterial pressure variations at hypovolemia and low variations at normovolemia and hypervolemia. Furthermore, we hypothesized that SPV and PPV could predict fluid responsiveness under these conditions. Eight prone, anesthetized and spontaneously breathing pigs (20 to 25 kg) were subjected to a sequence of 30% hypovolemia, normovolemia, and 20% and 40% hypervolemia. At each volemic level, the pigs breathed in a randomized order either through an inspiratory and/or an expiratory threshold resistor (7.5 cmH2O) or only through the tracheal tube without any resistor. Hemodynamic and respiratory variables were measured during the breathing modes. Fluid responsiveness was defined as a 15% increase in stroke volume (DeltaSV) following fluid loading. Stroke volume was significantly lower at hypovolemia compared with normovolemia, but no differences were found between normovolemia and 20% or 40% hypervolemia. Compared with breathing through no resistor, SPV was magnified by all resistors at hypovolemia whereas there were no changes at normovolemia and hypervolemia. PPV was magnified by the inspiratory resistor and the combined inspiratory and expiratory resistor. Regression analysis of SPV or PPV versus DeltaSV showed the highest R2 (0.83 for SPV and 0.52 for PPV) when the expiratory resistor was applied. The corresponding sensitivity and specificity for prediction of fluid responsiveness were 100% and 100%, respectively, for SPV and 100% and 81%, respectively, for PPV. Inspiratory and/or expiratory threshold resistors magnified SPV and PPV in spontaneously breathing pigs during hypovolemia

  15. Nebulized hypertonic saline via positive expiratory pressure versus via jet nebulizer in patients with severe cystic fibrosis.

    LENUS (Irish Health Repository)

    O'Connell, Oisin J

    2011-06-01

    Nebulized hypertonic saline is a highly effective therapy for patients with cystic fibrosis (CF), yet 10% of patients are intolerant of hypertonic saline administered via jet nebulizer. Positive expiratory pressure (PEP) nebulizers splint open the airways and offers a more controlled rate of nebulization.

  16. Chest physiotherapy with positive expiratory pressure breathing after abdominal and thoracic surgery: a systematic review.

    Science.gov (United States)

    Orman, J; Westerdahl, E

    2010-03-01

    A variety of chest physiotherapy techniques are used following abdominal and thoracic surgery to prevent or reduce post-operative complications. Breathing techniques with a positive expiratory pressure (PEP) are used to increase airway pressure and improve pulmonary function. No systematic review of the effects of PEP in surgery patients has been performed previously. The purpose of this systematic review was to determine the effect of PEP breathing after an open upper abdominal or thoracic surgery. A literature search of randomised-controlled trials (RCT) was performed in five databases. The trials included were systematically reviewed by two independent observers and critically assessed for methodological quality. We selected six RCT evaluating the PEP technique performed with a mechanical device in spontaneously breathing adult patients after abdominal or thoracic surgery via thoracotomy. The methodological quality score varied between 4 and 6 on the Physiotherapy Evidence Database score. The studies were published between 1979 and 1993. Only one of the included trials showed any positive effects of PEP compared to other breathing techniques. Today, there is scarce scientific evidence that PEP treatment is better than other physiotherapy breathing techniques in patients undergoing abdominal or thoracic surgery. There is a lack of studies investigating the effect of PEP over placebo or no physiotherapy treatment.

  17. Dangerous Pressurization and Inappropriate Alarms during Water Occlusion of the Expiratory Circuit of Commonly Used Infant Ventilators.

    Directory of Open Access Journals (Sweden)

    Murray Hinder

    Full Text Available Non-invasive continuous positive airways pressure is commonly a primary respiratory therapy delivered via multi-purpose ventilators in premature newborns. Expiratory limb occlusion due to water accumulation or 'rainout' from gas humidification is a frequent issue. A case of expiratory limb occlusion due to rainout causing unexpected and excessive repetitive airway pressurisation in a Draeger VN500 prompted a systematic bench test examination of currently available ventilators.To assess neonatal ventilator response to partial or complete expiratory limb occlusion when set to non-invasive continuous positive airway pressure mode.Seven commercially available neonatal ventilators connected to a test lung using a standard infant humidifier circuit with partial and/or complete expiratory limb occlusion were examined in a bench test study. Each ventilator was set to deliver 6 cmH2O in non-invasive mode and respiratory mechanics data for 75%, 80% and 100% occlusion were collected.Several ventilators responded inappropriately with complete occlusion by cyclical pressurisation/depressurisation to peak pressures of between 19·4 and 64·6 cm H2O at rates varying between 2 to 77 inflations per minute. Tidal volumes varied between 10·1 and 24·3mL. Alarm responses varied from 'specific' (tube occluded to 'ambiguous' (Safety valve open. Carefusion Avea responded by continuing to provide the set distending pressure and displaying an appropriate alarm message. Draeger Babylog 8000 did not alarm with partial occlusions and incorrectly displayed airways pressure at 6·1cmH2O compared to the measured values of 13cmH2O.This study found a potential for significant adverse ventilator response due to complete or near complete expiratory limb occlusion in CPAP mode.

  18. Validation of a protocol to evaluate maximal expiratory pressure using a pressure transducer and a signal conditioner

    Directory of Open Access Journals (Sweden)

    Viviane Soares

    2011-09-01

    Full Text Available The respiratory muscles can present fatigue and even chronic inability to generate force. So, reliable devices are necessary to their evaluation. The aim of this study is to evaluate the MEP (Maximal Expiratory Pressure values of individuals between 20 and 25 years old and to validate a protocol using a pressure transducer and a signal conditioner comparing it with the digital manometer. We evaluated the MEP of 10 participants. They remained seated and made six respiratory maneuvers from Total Lung Capacity (TLC to Residual Volume (RV. The results in the study showed no statistically significant differences when compared to values reported in the literature, and that the pressure transducer provides reliable values for MEP.Os músculos respiratórios podem apresentar fadiga e até mesmo a incapacidade crônica na geração de força, sendo necessários dispositivos confiáveis para sua avaliação. O objetivo deste estudo foi avaliar a pressão expiratória máxima (PeMáx de indivíduos entre 20 e 25 anos e validar um protocolo que utiliza um transdutor de pressão e um condicionador de sinais comparando-o com a manovacuometria. Foram avaliadas a PeMáx de 10 participantes. Estes permaneceram sentados e realizaram seis manobras respiratórias a partir da capacidade pulmonar total (CPT até o volume residual (VR. Os resultados do estudo não apresentaram diferenças estatisticamente significativas quando comparados com os valores de normalidade descritos na literatura e mostraram que o transdutor de pressão fornece valores confiáveis para Pe máx.

  19. Comparison of intermittent positive pressure breathing and temporary positive expiratory pressure in patients with severe chronic obstructive pulmonary disease.

    Science.gov (United States)

    Nicolini, Antonello; Mollar, Elena; Grecchi, Bruna; Landucci, Norma

    2014-01-01

    Results supporting the use and the effectiveness of positive expiratory, pressure devices in chronic obstructive pulmonary disease (COPD) patients are still controversial, We have tested the hypothesis that adding TPEP or IPPB to standard pharmacological therapy may provide additional clinical benefit over, pharmacological therapy only in patients with severe COPD. Fourty-five patients were randomized in three groups: a group was treated; with IPPB,a group was treated with TPEP and a group with pharmacological; therapy alone (control group). Primary outcome measures included the measurement of scale or, questionnaire concerning dyspnea (MRC scale),dyspnea,cough, and, sputum (BCSS) and quality of life (COPD assessment test) (CAT). Secondary, outcome measures were respiratory function testing,arterial blood gas,analysis,and hematological examinations. Both patients in the IPPB group and in the TPEP group showed a significant, improvement in two of three tests (MRC,CAT) compared to the control, group.However,in the group comparison analysis for, the same variables between IPPB group and TPEP group we observed a, significant improvement in the IPPB group (P≤.05 for MRC and P≤.01 for, CAT). The difference of action of the two techniques are evident in the results of, pulmonary function testing: IPPB increases FVC, FEV1, and MIP; this reflects, its capacity to increase lung volume. Also TPEP increases FVC and FEV1 (less, than IPPB), but increases MEP, while decreasing total lung capacity and, residual volume. The two techniques (IPPB and TPEP) improves significantly dyspnea; quality of; life tools and lung function in patients with severe COPD. IPPB demonstrated a greater effectiveness to improve dyspnea and quality of life tools (MRC, CAT) than TPEP. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  20. Improved oxygenation during standing performance of deep breathing exercises with positive expiratory pressure after cardiac surgery: A randomized controlled trial.

    Science.gov (United States)

    Pettersson, Henrik; Faager, Gun; Westerdahl, Elisabeth

    2015-09-01

    Breathing exercises after cardiac surgery are often performed in a sitting position. It is unknown whether oxygenation would be better in the standing position. The aim of this study was to evaluate oxygenation and subjective breathing ability during sitting vs standing performance of deep breathing exercises on the second day after cardiac surgery. Patients undergoing coronary artery bypass grafting (n = 189) were randomized to sitting (controls) or standing. Both groups performed 3 × 10 deep breaths with a positive expiratory pressure device. Peripheral oxygen saturation was measured before, directly after, and 15 min after the intervention. Subjective breathing ability, blood pressure, heart rate, and pain were assessed. Oxygenation improved significantly in the standing group compared with controls directly after the breathing exercises (p < 0.001) and after 15 min rest (p = 0.027). The standing group reported better deep breathing ability compared with controls (p = 0.004). A slightly increased heart rate was found in the standing group (p = 0.047). After cardiac surgery, breathing exercises with positive expiratory pressure, performed in a standing position, significantly improved oxygenation and subjective breathing ability compared with sitting performance. Performance of breathing exercises in the standing position is feasible and could be a valuable treatment for patients with postoperative hypoxaemia.

  1. Positive expiratory pressure therapy versus other airway clearance techniques for bronchiectasis.

    Science.gov (United States)

    Lee, Annemarie L; Burge, Angela T; Holland, Anne E

    2017-09-27

    People with bronchiectasis experience chronic cough and sputum production and require the prescription of airway clearance techniques (ACTs). A common type of ACT prescribed is positive expiratory pressure (PEP) therapy. A previous review has suggested that ACTs including PEP therapy are beneficial compared to no treatment in people with bronchiectasis. However, the efficacy of PEP therapy in a stable clinical state or during an acute exacerbation compared to other ACTs in bronchiectasis is unknown. The primary aim of this review was to determine the effects of PEP therapy compared with other ACTs on health-related quality of life (HRQOL), rate of acute exacerbations, and incidence of hospitalisation in individuals with stable or an acute exacerbation of bronchiectasis.Secondary aims included determining the effects of PEP therapy upon physiological outcomes and clinical signs and symptoms compared with other ACTs in individuals with stable or an acute exacerbation of bronchiectasis. We searched the Cochrane Airways Group Specialised Register of Trials, PEDro and clinical trials registries from inception to February 2017 and we handsearched relevant journals. Randomised controlled parallel and cross-over trials that compared PEP therapy versus other ACTs in participants with bronchiectasis. We used standard methodological procedures as outlined by Cochrane. Nine studies involving 213 participants met the inclusion criteria, of which seven were cross-over in design. All studies included adults with bronchiectasis, with eight including participants in a stable clinical state and one including participants experiencing an acute exacerbation. Eight studies used oscillatory PEP therapy, using either a Flutter or Acapella device and one study used Minimal PEP therapy. The comparison intervention differed between studies. The methodological quality of studies was poor, with cross-over studies including suboptimal or no washout period, and a lack of blinding of

  2. Effects of nasal positive expiratory pressure on dynamic hyperinflation and 6-minute walk test in patients with COPD.

    Science.gov (United States)

    Wibmer, Thomas; Rüdiger, Stefan; Heitner, Claudia; Kropf-Sanchen, Cornelia; Blanta, Ioanna; Stoiber, Kathrin M; Rottbauer, Wolfgang; Schumann, Christian

    2014-05-01

    Dynamic hyperinflation is an important target in the treatment of COPD. There is increasing evidence that positive expiratory pressure (PEP) could reduce dynamic hyperinflation during exercise. PEP application through a nasal mask and a flow resistance device might have the potential to be used during daily physical activities as an auxiliary strategy of ventilatory assistance. The aim of this study was to determine the effects of nasal PEP on lung volumes during physical exercise in patients with COPD. Twenty subjects (mean ± SD age 69.4 ± 6.4 years) with stable mild-to-severe COPD were randomized to undergo physical exercise with nasal PEP breathing, followed by physical exercise with habitual breathing, or vice versa. Physical exercise was induced by a standard 6-min walk test (6 MWT) protocol. PEP was applied by means of a silicone nasal mask loaded with a fixed-orifice flow resistor. Body plethysmography was performed immediately pre-exercise and post-exercise. Differences in mean pre- to post-exercise changes in total lung capacity (-0.63 ± 0.80 L, P = .002), functional residual capacity (-0.48 ± 0.86 L, P = .021), residual volume (-0.56 ± 0.75 L, P = .004), S(pO2) (-1.7 ± 3.4%, P = .041), and 6 MWT distance (-30.8 ± 30.0 m, P = .001) were statistically significant between the experimental and the control interventions. The use of flow-dependent expiratory pressure, applied with a nasal mask and a PEP device, might promote significant reduction of dynamic hyperinflation during walking exercise. Further studies are warranted addressing improvements in endurance performance under regular application of nasal PEP during physical activities.

  3. Alveolar Tidal recruitment/derecruitment and Overdistension During Four Levels of End-Expiratory Pressure with Protective Tidal Volume During Anesthesia in a Murine Lung-Healthy Model.

    Science.gov (United States)

    Soares, Joao Henrique Neves; Carvalho, Alysson Roncally; Bergamini, Bruno Curty; Gress, Maria Alice Kuster; Jandre, Frederico Caetano; Zin, Walter Araujo; Giannella-Neto, Antonio

    2018-06-01

    We compared respiratory mechanics between the positive end-expiratory pressure of minimal respiratory system elastance (PEEP minErs ) and three levels of PEEP during low-tidal-volume (6 mL/kg) ventilation in rats. Twenty-four rats were anesthetized, paralyzed, and mechanically ventilated. Airway pressure (P aw ), flow (F), and volume (V) were fitted by a linear single compartment model (LSCM) P aw (t) = E rs  × V(t) + R rs  × F(t) + PEEP or a volume- and flow-dependent SCM (VFDSCM) P aw (t) = (E 1  + E 2  × V(t)) × V(t) + (K 1  + K 2  × |F(t)|) × F(t) + PEEP, where E rs and R rs are respiratory system elastance and resistance, respectively; E 1 and E 2 × V are volume-independent and volume-dependent E rs , respectively; and K 1 and K 2  × F are flow-independent and flow-dependent R rs , respectively. Animals were ventilated for 1 h at PEEP 0 cmH 2 O (ZEEP); PEEP minErs ; 2 cmH 2 O above PEEP minErs (PEEP minErs+2 ); or 4 cmH 2 O above PEEP minErs (PEEP minErs+4 ). Alveolar tidal recruitment/derecruitment and overdistension were assessed by the index %E 2  = 100 × [(E 2  × V T )/(E 1  + |E 2 | × V T )], and alveolar stability by the slope of E rs (t). %E 2 varied between 0 and 30% at PEEP minErs in most respiratory cycles. Alveolar Tidal recruitment/derecruitment (%E 2   30) were predominant in the absence of PEEP and in PEEP levels higher than PEEP minErs , respectively. The slope of E rs (t) was different from zero in all groups besides PEEP minErs+4 . PEEP minErs presented the best compromise between alveolar tidal recruitment/derecruitment and overdistension, during 1 h of low-V T mechanical ventilation.

  4. Value and limitations of transpulmonary pressure calculations during intra-abdominal hypertension.

    Science.gov (United States)

    Cortes-Puentes, Gustavo A; Gard, Kenneth E; Adams, Alexander B; Faltesek, Katherine A; Anderson, Christopher P; Dries, David J; Marini, John J

    2013-08-01

    To clarify the effect of progressively increasing intra-abdominal pressure on esophageal pressure, transpulmonary pressure, and functional residual capacity. Controlled application of increased intra-abdominal pressure at two positive end-expiratory pressure levels (1 and 10 cm H2O) in an anesthetized porcine model of controlled ventilation. Large animal laboratory of a university-affiliated hospital. Eleven deeply anesthetized swine (weight 46.2 ± 6.2 kg). Air-regulated intra-abdominal hypertension (0-25 mm Hg). Esophageal pressure, tidal compliance, bladder pressure, and end-expiratory lung aeration by gas dilution. Functional residual capacity was significantly reduced by increasing intra-abdominal pressure at both positive end-expiratory pressure levels (p ≤ 0.0001) without corresponding changes of end-expiratory esophageal pressure. Above intra-abdominal pressure 5 mm Hg, plateau airway pressure increased linearly by ~ 50% of the applied intra-abdominal pressure value, associated with commensurate changes of esophageal pressure. With tidal volume held constant, negligible changes occurred in transpulmonary pressure due to intra-abdominal pressure. Driving pressures calculated from airway pressures alone (plateau airway pressure--positive end-expiratory pressure) did not equate to those computed from transpulmonary pressure (tidal changes in transpulmonary pressure). Increasing positive end-expiratory pressure shifted the predominantly negative end-expiratory transpulmonary pressure at positive end-expiratory pressure 1 cm H2O (mean -3.5 ± 0.4 cm H2O) into the positive range at positive end-expiratory pressure 10 cm H2O (mean 0.58 ± 1.2 cm H2O). Despite its insensitivity to changes in functional residual capacity, measuring transpulmonary pressure may be helpful in explaining how different levels of positive end-expiratory pressure influence recruitment and collapse during tidal ventilation in the presence of increased intra-abdominal pressure and in

  5. Is there an optimal level of positive expiratory pressure (PEP) to improve walking tolerance in patients with severe COPD?

    Science.gov (United States)

    Russo, Davide; Simonelli, Carla; Paneroni, Mara; Saleri, Manuela; Piroddi, Ines Maria Grazia; Cardinale, Francesco; Vitacca, Michele; Nicolini, Antonello

    2016-07-01

    The application of positive expiratory pressure (PEP) devices during exercise had been proposed in order to counteract the pulmonary hyperinflation, reduce the dyspnea and thus increase the exercise tolerance in patients with severe chronic obstructive pulmonary disease (COPD). This randomized controlled crossover trial investigated the effect of two different levels of PEP (1 cmH2O and 10 cmH2O) on distance covered at 6minute walk test (6MWT) in patients with severe COPD. Secondary outcomes were the evaluation of PEP effects on physiological and pulmonary function variables. Seventy-two severe COPD patients, referred to our hospitals as in and out patients, were recruited. A basal 6MWT without devices was performed on the first day, and then repeated with PEP 1 cmH2O (PEP1) and 10 cmH2O (PEP10), with a randomized crossover design. Slow and forced spirometries, including the inspiratory capacity measure, were repeated before and after each 6MWT. 50 patients (average age 69,92 year, mean FEV1 41,42% of predicted) concluded the trial. The 6MWT improved significantly among both PEP levels and baseline (323,8 mt at baseline vs. 337,8 PEP1 and 341,8 PEP10; p<.002 and p<.018, respectively). The difference between PEP10 and PEP1 did not reach the significance. No improvements were found in pulmonary function, symptoms and physiological variables after the 6MWT. In patients with severe COPD, the application of 1 cmH2O of PEP seems to improve the exercise tolerance as 10 cmH2O, with similar dyspnea. Further studies should investigate the effects of low levels of PEP on aerobic training programs. Copyright © 2016 SEPAR. Published by Elsevier Espana. All rights reserved.

  6. Effects of positive expiratory pressure on pulmonary clearance of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid in healthy individuals

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    Isabella Martins de Albuquerque

    Full Text Available ABSTRACT Objective: To evaluate the effects of positive expiratory pressure (PEP on pulmonary epithelial membrane permeability in healthy subjects. Methods: We evaluated a cohort of 30 healthy subjects (15 males and 15 females with a mean age of 28.3 ± 5.4 years, a mean FEV1/FVC ratio of 0.89 ± 0.14, and a mean FEV1 of 98.5 ± 13.1% of predicted. Subjects underwent technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA radioaerosol inhalation lung scintigraphy in two stages: during spontaneous breathing; and while breathing through a PEP mask at one of three PEP levels-10 cmH2O (n = 10, 15 cmH2O (n = 10, and 20 cmH2O (n = 10. The 99mTc-DTPA was nebulized for 3 min, and its clearance was recorded by scintigraphy over a 30-min period during spontaneous breathing and over a 30-min period during breathing through a PEP mask. Results: The pulmonary clearance of 99mTc-DTPA was significantly shorter when PEP was applied-at 10 cmH2O (p = 0.044, 15 cmH2O (p = 0.044, and 20 cmH2O (p = 0.004-in comparison with that observed during spontaneous breathing. Conclusions: Our findings indicate that PEP, at the levels tested, is able to induce an increase in pulmonary epithelial membrane permeability and lung volume in healthy subjects.

  7. Sensitivity and specificity of hypopnoea detection using nasal pressure in the presence of a nasal expiratory resistive device (Provent®)

    International Nuclear Information System (INIS)

    Milne, Stephen; Amis, Terence C; Wheatley, John R; Kairaitis, Kristina

    2014-01-01

    Nasal expiratory resistive valves (Provent ® ) have been proposed as novel therapy for obstructive sleep apnea. We compared pressure measurements from a standard nasal pressure catheter used to assess nasal airflow during sleep with those from nasal expiratory resistive device with attached proprietary nasal pressure cannula. Nasal pressure cannula or Provent ® + proprietary nasal pressure cannula were attached to a bench model of human anterior nares and nasal passages, and pressure measured (P). Respiratory airflows generated by a subject breathing were applied to rear of model and airflow ( V-dot ) measured via pneumotachograph. Airflow amplitude (Δ V-dot ) was plotted against pressure amplitude (ΔP). Hypopnoea detection (<50% Δ V-dot ) sensitivity and specificity was tested by expressing ΔP in terms of two reference breaths: reference breath 1, Δ V-dot 0.55 L s −1  = 100%; and reference breath 2, Δ V-dot 0.45 L s −1  = 100%. ΔP/Δ V-dot relationships were linear for Δ V-dot  ≤ 0.55 L s −1 ; ΔP = 0.37ΔV + 0.16 (nasal pressure cannula), ΔP = 2.7ΔV + 0.12 (Provent ® + proprietary nasal pressure cannula); both R 2  > 0.65, p < 0.0001; p < 0.0001 for between slope difference). For nasal pressure cannula, specificity of hypopnoea detection differed between reference breaths one and two (80.2% and 40.0%, respectively), and Provent ® + proprietary nasal pressure cannula (30.3% and 74.2%, respectively). Quantification of airflow obstruction in the presence of Provent ® + proprietary nasal pressure cannula is greatly influenced by the reference breath chosen to determine a reduction in nasal airflow. Reported variability in therapeutic response to nasal expiratory resistive devices may relate to differences in measurement technique specificity used to quantify the severity of sleep disordered breathing. (paper)

  8. High altitude pulmonary edema and exercise at 4,400 meters on Mount McKinley. Effect of expiratory positive airway pressure.

    Science.gov (United States)

    Schoene, R B; Roach, R C; Hackett, P H; Harrison, G; Mills, W J

    1985-03-01

    Breathing against positive expiratory pressure has been used to improve gas exchange in many forms of pulmonary edema, and forced expiration against resistance during exercise has been advocated for climbing at high altitude as a method to optimize performance. To evaluate the effect of expiratory positive airway pressure (EPAP) on climbers with high altitude pulmonary edema (HAPE) and on exercise at high altitude, we studied four climbers with HAPE at rest and 13 healthy climbers during exercise on a bicycle ergometer at 4400 m. We measured minute ventilation (VI, L/min), arterial oxygen saturation (SaO2 percent), end-tidal carbon dioxide (PACO2, mm Hg), respiratory rate (RR), and heart rate (HR) during the last minute of a five minute interval at rest in the climbers with HAPE, and at rest, 300, and 600 kpm/minute workloads on a bicycle ergometer in the healthy subjects. The HAPE subjects demonstrated an increased SaO2 percent, no change in HR or VI, and a decrease in RR on EPAP as compared to control. In normal subjects, SaO2 percent, VI, and heart rate were significantly higher on EPAP 10 cm H2O than 0 cm H2O control (p less than 0.01, 0.01, and 0.05, respectively). The RR and PaCO2 were not significantly different. In summary, EPAP improves gas exchange in HAPE subjects at rest. The EPAP in normal subjects at high altitude resulted in a higher SaO2 percent at the expense of a higher VI and higher HR. These results suggest that the work of breathing is higher and the stroke volume lower on EPAP. The positive pressure mask may be an effective temporizing measure for victims of HAPE who cannot immediately go to a lower altitude.

  9. Deep breathing exercises with positive expiratory pressure at a higher rate improve oxygenation in the early period after cardiac surgery--a randomised controlled trial.

    Science.gov (United States)

    Urell, Charlotte; Emtner, Margareta; Hedenström, Hans; Tenling, Arne; Breidenskog, Marie; Westerdahl, Elisabeth

    2011-07-01

    In addition to early mobilisation, a variety of breathing exercises are used to prevent postoperative pulmonary complications after cardiac surgery. The optimal duration of the treatment is not well evaluated. The aim of this study was to determine the effect of 30 versus 10 deep breaths hourly, while awake, with positive expiratory pressure on oxygenation and pulmonary function the first days after cardiac surgery. A total of 181 patients, undergoing cardiac surgery, were randomised into a treatment group, performing 30 deep breaths hourly the first postoperative days, or into a control group performing 10 deep breaths hourly. The main outcome measurement arterial blood gases and the secondary outcome pulmonary function, evaluated with spirometry, were determined on the second postoperative day. Preoperatively, both study groups were similar in terms of age, SpO(2), forced expiratory volume in 1s and New York Heart Association classification. On the second postoperative day, arterial oxygen tension (PaO(2)) was 8.9 ± 1.7 kPa in the treatment group and 8.1 ± 1.4 kPa in the control group (p = 0.004). Arterial oxygen saturation (SaO(2)) was 92.7 ± 3.7% in the treatment group and 91.1 ± 3.8% in the control group (p = 0.016). There were no differences in measured lung function between the groups or in compliance to the breathing exercises. Compliance was 65% of possible breathing sessions. A significantly increased oxygenation was found in patients performing 30 deep breaths the first two postoperative days compared with control patients performing 10 deep breaths hourly. These results support the implementation of a higher rate of deep breathing exercises in the initial phase after cardiac surgery. Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

  10. Influência da técnica de pressão expiratória positiva oscilante utilizando pressões expiratórias pré-determinadas na viscosidade e na transportabilidade do escarro em pacientes com bronquiectasia Influence that oscillating positive expiratory pressure using predetermined expiratory pressures has on the viscosity and transportability of sputum in patients with bronchiectasis

    Directory of Open Access Journals (Sweden)

    Ercy Mara Cipulo Ramos

    2009-12-01

    Full Text Available OBJETIVO: Verificar a efetividade da técnica de pressão expiratória positiva oscilante (PEPO utilizando pressões expiratórias pré-determinadas sobre a viscosidade e a transportabilidade do escarro em pacientes com bronquiectasia. MÉTODOS: Foram incluídos no estudo 15 pacientes estáveis com bronquiectasia (7 homens; média de idade = 53 ± 16 anos, submetidos a duas intervenções PEPO consecutivas, com 24 h de intervalo entre si, utilizando pressões expiratórias de 15 cmH2O (P15 e 25 cmH2O (P25. O protocolo consistiu de tosse voluntária; nova expectoração voluntária após 20 min, denominado tempo zero (T0; repouso de 10 min; e utilização da técnica em duas séries de 10 min (S1 e S2 de PEPO em P15 e P25, com intervalo de 10 min entre si. A viscosidade e transportabilidade do escarro foram avaliadas pela viscosimetria, velocidade relativa de transporte no palato de rã, deslocamento em máquina simuladora de tosse e ângulo de adesão. As amostras de escarro foram coletadas em T0, após S1 e após S2. Testes estatísticos específicos foram aplicados de acordo com a distribuição dos dados. RESULTADOS: Houve diminuição significante da viscosidade do escarro após S1 em P15 e após S2 em P25. Não houve diferenças significantes entre todas as amostras para a transportabilidade. CONCLUSÕES: Houve diminuição da viscosidade do escarro quando a PEPO foi realizada em P15 e P25, o que sugere que não seja necessário gerar alta pressão expiratória para obter o resultado desejado.OBJECTIVE: To determine the effectiveness of oscillating positive expiratory pressure (OPEP using predetermined expiratory pressures on the viscosity and transportability of sputum in patients with bronchiectasis. METHODS: The study involved 15 stable patients with bronchiectasis (7 males; mean age = 53 ± 16 years, submitted to two consecutive OPEP interventions, with a 24-h interval between the two, using positive expiratory pressures set at 15 cmH2O

  11. Effects of positive expiratory pressure on pulmonary clearance of aerosolized technetium-{sup 99m}-labeled diethylenetriaminepentaacetic acid in healthy individuals

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Isabella Martins de, E-mail: albuisa@gmail.com [Universidade Federal de Santa Maria (UFSM), Santa Maria, RS (Brazil). Departamento de Fisioterapia e Reabilitacao; Cardoso, Dannuey Machado; Paiva, Dulciane Nunes [Universidade de Santa Cruz do Sul, RS (Brazil); Masiero, Paulo Ricardo; Menna-Barreto, Sergio Saldanha [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil); Resqueti, Vanessa Regiane; Fregonezi, Guilherme Augusto de Freitas [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2016-11-15

    Objective: To evaluate the effects of positive expiratory pressure (PEP) on pulmonary epithelial membrane permeability in healthy subjects. Methods: We evaluated a cohort of 30 healthy subjects (15 males and 15 females) with a mean age of 28.3 ± 5.4 years, a mean FEV{sub 1}/FVC ratio of 0.89 ± 0.14, and a mean FEV{sub 1} of 98.5 ± 13.1% of predicted. Subjects underwent technetium-99m labeled diethylenetriaminepentaacetic acid ({sup 99m}TcDTPA) radio aerosol inhalation lung scintigraphy in two stages: during spontaneous breathing; and while breathing through a PEP mask at one of three PEP levels—10 cmH{sub 2}O (n = 10), 15 cmH{sub 2}O (n = 10), and 20 cmH{sub 2}O (n = 10). The {sup 99m}Tc-DTPA was nebulized for 3 min, and its clearance was recorded by scintigraphy over a 30-min period during spontaneous breathing and over a 30-min period during breathing through a PEP mask. Results: The pulmonary clearance of {sup 99m}Tc-DTPA was significantly shorter when PEP was applied—at 10 cmH{sub 2}O (p = 0.044), 15 cmH{sub 2}O (p = 0.044), and 20 cmH{sub 2}O (p = 0.004) - in comparison with that observed during spontaneous breathing. Conclusions: Our findings indicate that PEP, at the levels tested, is able to induce an increase in pulmonary epithelial membrane permeability and lung volume in healthy subjects. (author)

  12. Use of positive pressure in preoperative and intraoperative of bariatric surgery and its effect on the time of extubation

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    Letícia Baltieri

    2015-04-01

    Full Text Available BACKGROUND AND OBJECTIVE: To investigate the influence of intraoperative and preoperative positive pressure in the time of extubation in patients undergoing bariatric surgery. METHOD: Randomized clinical trial, in which 40 individuals with a body mass index between 40 and 55 kg/m2, age between 25 and 55 years, nonsmokers, underwent bariatric surgery type Roux-en-Y gastric bypass by laparotomy and with normal preoperative pulmonary function were randomized into the following groups: G-pre (n = 10: individuals who received treatment with noninvasive positive pressure before surgery for 1 h; G-intra (n = 10: individuals who received positive end-expiratory pressure of 10 cm H2O throughout the surgical procedure; and G-control (n = 20: not received any preoperative or intraoperative intervention. Following were recorded: time between induction of anesthesia and extubation, between the end of anesthesia and extubation, duration of mechanical ventilation, and time between extubation and discharge from the post-anesthetic recovery. RESULTS: There was no statistical difference between groups. However, when applied to the Cohen coefficient, the use of positive end-expiratory pressure of 10 cm H2O during surgery showed a large effect on the time between the end of anesthesia and extubation. About this same time, the treatment performed preoperatively showed moderate effect. CONCLUSION: The use of positive end-expiratory pressure of 10 cm H2O in the intraoperative and positive pressure preoperatively, influenced the time of extubation of patients undergoing bariatric surgery.

  13. Physiological techniques for detecting expiratory flow limitation during tidal breathing

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    N.G. Koulouris

    2011-09-01

    Full Text Available Patients with severe chronic obstructive pulmonary disease (COPD often exhale along the same flow–volume curve during quiet breathing as they do during the forced expiratory vital capacity manoeuvre, and this has been taken as an indicator of expiratory flow limitation at rest (EFLT. Therefore, EFLT, namely attainment of maximal expiratory flow during tidal expiration, occurs when an increase in transpulmonary pressure causes no increase in expiratory flow. EFLT leads to small airway injury and promotes dynamic pulmonary hyperinflation, with concurrent dyspnoea and exercise limitation. In fact, EFLT occurs commonly in COPD patients (mainly in Global Initiative for Chronic Obstructive Lung Disease III and IV stage, in whom the latter symptoms are common, but is not exclusive to COPD, since it can also be detected in other pulmonary and nonpulmonary diseases like asthma, acute respiratory distress syndrome, heart failure and obesity, etc. The existing up to date physiological techniques of assessing EFLT are reviewed in the present work. Among the currently available techniques, the negative expiratory pressure has been validated in a wide variety of settings and disorders. Consequently, it should be regarded as a simple, noninvasive, practical and accurate new technique.

  14. The effect of positive expiratory pressure (PEP) therapy on symptoms, quality of life and incidence of re-exacerbation in patients with acute exacerbations of chronic obstructive pulmonary disease: a multicentre, randomised controlled trial.

    Science.gov (United States)

    Osadnik, Christian R; McDonald, Christine F; Miller, Belinda R; Hill, Catherine J; Tarrant, Ben; Steward, Ranjana; Chao, Caroline; Stodden, Nicole; Oliveira, Cristino C; Gagliardi, Nadia; Holland, Anne E

    2014-02-01

    Positive expiratory pressure (PEP) is a technique used to enhance sputum clearance during acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The impact of PEP therapy during acute exacerbations on clinically important outcomes is not clear. This study sought to determine the effect of PEP therapy on symptoms, quality of life and future exacerbations in patients with AECOPD. 90 inpatients (58 men; mean age 68.6 years, FEV(1) 40.8% predicted) with AECOPD and sputum expectoration were randomised to receive usual care (including physical exercise)±PEP therapy. The Breathlessness, Cough and Sputum Scale (BCSS), St George's Respiratory Questionnaire (SGRQ) and BODE index (Body mass index, airflow Obstruction, Dyspnoea, Exercise tolerance) were measured at discharge, 8 weeks and 6 months following discharge, and analysed via linear mixed models. Exacerbations and hospitalisations were recorded using home diaries. There were no significant between-group differences over time for BCSS score [mean (SE) at discharge 5.2 (0.4) vs 5.0 (0.4) for PEP and control group, respectively; p=0.978] or SGRQ total score [41.6 (2.6) vs 40.8 (2.8) at 8 weeks, p=0.872]. Dyspnoea improved more rapidly in the PEP group over the first 8 weeks (p=0.006), however these benefits were not observed at 6 months. Exacerbations (p=0.986) and hospitalisations (p=0.359) did not differ between groups. We found no evidence that PEP therapy during AECOPD improves important short-term or long-term outcomes. There does not appear to be a routine role for PEP therapy in the management of such individuals.

  15. Efeitos da aplicação da EPAP (Expiratory Positive Airway Pressure sobre a tolerância ao esforço em pacientes portadores de insuficiência cardíaca

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    Claudia Thofehrn

    2013-04-01

    Full Text Available INTRODUÇÃO: Novas abordagens terapêuticas que objetivam melhorar a sensação de dispneia e fadiga em pacientes com insuficiência cardíaca, como a aplicação de pressão positiva expiratória nas vias aéreas (EPAP, podem ser aplicadas na tentativa de melhorar a capacidade funcional e a qualidade de vida. OBJETIVO: Avaliar os efeitos da utilização da EPAP ( Expiratory Positive Airway Pressure durante o esforço em indivíduos portadores de IC classe funcional II e III (NYHA. MÉTODOS: Dos 390 pacientes, foram selecionados 28 com FEVE < 40%. O Teste de Caminhada de seis minutos (TC6' foi realizado três vezes: o primeiro para a familiarização, um com a máscara e o outro sem a máscara de EPAP, sendo válido os dois últimos. A comparação entre os dados obtidos foi realizada por meio de teste t de Student pareado ou teste de Wilcoxon, conforme a normalidade dos dados. RESULTADOS: a percepção de esforço foi maior após a caminhada com a utilização da máscara quando comparado na ausência da máscara. Houve elevação significativa na saturação de oxigênio quando os pacientes estavam usando a máscara de EPAP. CONCLUSÃO: O uso da máscara de EPAP aumenta a percepção de esforço e o trabalho ventilatório, porém, não aumentou a distância percorrida no TC6, sendo sua aplicabilidade questionável em programas de reabilitação cardiovascular.

  16. Diagnostic methods to assess inspiratory and expiratory muscle strength

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    Pedro Caruso

    2015-04-01

    Full Text Available Impairment of (inspiratory and expiratory respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation; and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.

  17. Static end-expiratory and dynamic forced expiratory tracheal collapse in COPD

    International Nuclear Information System (INIS)

    O'Donnell, C.R.; Bankier, A.A.; O'Donnell, D.H.; Loring, S.H.; Boiselle, P.M.

    2014-01-01

    Aim: To determine the range of tracheal collapse at end-expiration among chronic obstructive pulmonary disease (COPD) patients and to compare the extent of tracheal collapse between static end-expiratory and dynamic forced-expiratory multidetector-row computed tomography (MDCT). Materials and methods: After institutional review board approval and obtaining informed consent, 67 patients meeting the National Heart, Lung, and Blood Institute (NHLBI)/World Health Organization (WHO) Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for COPD were sequentially imaged using a 64-detector-row CT machine at end-inspiration, during forced expiration, and at end-expiration. Standardized respiratory coaching and spirometric monitoring were employed. Mean percentage tracheal collapse at end-expiration and forced expiration were compared using correlation analysis, and the power of end-expiratory cross-sectional area to predict excessive forced-expiratory tracheal collapse was computed following construction of receiver operating characteristic (ROC) curves. Results: Mean percentage expiratory collapse among COPD patients was 17 ± 18% at end-expiration compared to 62 ± 16% during forced expiration. Over the observed range of end-expiratory tracheal collapse (approximately 10–50%), the positive predictive value of end-expiratory collapse to predict excessive (≥80%) forced expiratory tracheal collapse was <0.3. Conclusion: COPD patients demonstrate a wide range of end-expiratory tracheal collapse. The magnitude of static end-expiratory tracheal collapse does not predict excessive dynamic expiratory tracheal collapse

  18. Utilization of the lower inflection point of the pressure-volume curve results in protective conventional ventilation comparable to high frequency oscillatory ventilation in an animal model of acute respiratory distress syndrome

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    Felipe S. Rossi

    2008-01-01

    Full Text Available INTRODUCTION: Studies comparing high frequency oscillatory and conventional ventilation in acute respiratory distress syndrome have used low values of positive end-expiratory pressure and identified a need for better recruitment and pulmonary stability with high frequency. OBJECTIVE: To compare conventional and high frequency ventilation using the lower inflection point of the pressure-volume curve as the determinant of positive end-expiratory pressure to obtain similar levels of recruitment and alveolar stability. METHODS: After lung lavage of adult rabbits and lower inflection point determination, two groups were randomized: conventional (positive end-expiratory pressure = lower inflection point; tidal volume=6 ml/kg and high frequency ventilation (mean airway pressures= lower inflection point +4 cmH2O. Blood gas and hemodynamic data were recorded over 4 h. After sacrifice, protein analysis from lung lavage and histologic evaluation were performed. RESULTS: The oxygenation parameters, protein and histological data were similar, except for the fact that significantly more normal alveoli were observed upon protective ventilation. High frequency ventilation led to lower PaCO2 levels. DISCUSSION: Determination of the lower inflection point of the pressure-volume curve is important for setting the minimum end expiratory pressure needed to keep the airways opened. This is useful when comparing different strategies to treat severe respiratory insufficiency, optimizing conventional ventilation, improving oxygenation and reducing lung injury. CONCLUSIONS: Utilization of the lower inflection point of the pressure-volume curve in the ventilation strategies considered in this study resulted in comparable efficacy with regards to oxygenation and hemodynamics, a high PaCO2 level and a lower pH. In addition, a greater number of normal alveoli were found after protective conventional ventilation in an animal model of acute respiratory distress syndrome.

  19. Impact of expiratory strength training in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Plowman, Emily K; Watts, Stephanie A; Tabor, Lauren; Robison, Raele; Gaziano, Joy; Domer, Amanda S; Richter, Joel; Vu, Tuan; Gooch, Clifton

    2016-06-01

    We evaluated the feasibility and impact of expiratory muscle strength training (EMST) on respiratory and bulbar function in persons with amyotrophic lateral sclerosis (ALS). Twenty-five ALS patients participated in this delayed intervention open-label clinical trial. Following a lead-in period, patients completed a 5-week EMST protocol. Outcome measures included: maximum expiratory pressure (MEP); physiologic measures of swallow and cough; and penetration-aspiration scale (PAS) scores. Of participants who entered the active phase of the study (n = 15), EMST was well tolerated and led to significant increases in MEPs and maximum hyoid displacement during swallowing post-EMST (P < 0.05). No significant differences were observed for PAS scores or cough spirometry measures. EMST was feasible and well tolerated in this small cohort of ALS patients and led to improvements in expiratory force-generating pressures and swallow kinematics. Further investigation is warranted to confirm these preliminary findings. Muscle Nerve 54: 48-53, 2016. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  20. The SWAN Captures Variance at the Negative and Positive Ends of the ADHD Symptom Dimension

    Science.gov (United States)

    Arnett, Anne B.; Pennington, Bruce F.; Friend, Angela; Willcutt, Erik G.; Byrne, Brian; Samuelsson, Stefan; Olson, Richard K.

    2013-01-01

    Objective: The Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) Rating Scale differs from previous parent reports of ADHD in that it was designed to also measure variability at the positive end of the symptom spectrum. Method: The psychometric properties of the SWAN were tested and compared with an established measure of ADHD,…

  1. Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Reijane Oliveira Lima

    2015-08-01

    Full Text Available Abstract Introduction After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological. Objective: The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting. Methods: A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH2O (n=32; Group B, 8 cmH2O (n=26; and Group C, 10 cmH2O (n=20. Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05. Results Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization. Conclusion: In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

  2. Gadolinium prevents high airway pressure-induced permeability increases in isolated rat lungs.

    Science.gov (United States)

    Parker, J C; Ivey, C L; Tucker, J A

    1998-04-01

    To determine the initial signaling event in the vascular permeability increase after high airway pressure injury, we compared groups of lungs ventilated at different peak inflation pressures (PIPs) with (gadolinium group) and without (control group) infusion of 20 microM gadolinium chloride, an inhibitor of endothelial stretch-activated cation channels. Microvascular permeability was assessed by using the capillary filtration coefficient (Kfc), a measure of capillary hydraulic conductivity. Kfc was measured after ventilation for 30-min periods with 7, 20, and 30 cmH2O PIP with 3 cmH2O positive end-expiratory pressure and with 35 cmH2O PIP with 8 cmH2O positive end-expiratory pressure. In control lungs, Kfc increased significantly to 1.8 and 3.7 times baseline after 30 and 35 cmH2O PIP, respectively. In the gadolinium group, Kfc was unchanged from baseline (0.060 +/- 0.010 ml . min-1 . cmH2O-1 . 100 g-1) after any PIP ventilation period. Pulmonary vascular resistance increased significantly from baseline in both groups before the last Kfc measurement but was not different between groups. These results suggest that microvascular permeability is actively modulated by a cellular response to mechanical injury and that stretch-activated cation channels may initiate this response through increases in intracellular calcium concentration.

  3. Expiratory timing in obstructive sleep apnoeas.

    Science.gov (United States)

    Cibella, F; Marrone, O; Sanci, S; Bellia, V; Bonsignore, G

    1990-03-01

    Diaphragmatic electromyogram was recorded during NREM sleep in 4 patients affected by obstructive sleep apnoea (OSA) syndrome in order to evaluate the behaviour of expiratory time (TE) in the course of the obstructive apnoea-ventilation cycle. The two components of TE, i.e. time of post-inspiratory inspiratory activity (TPIIA) and time of expiratory phase 2 (TE2) were separately analysed. TPIIA showed a short duration, with only minor variations, within the apnoea, while its duration was more variable and longer in the interapnoeic periods: the longest TPIIA values were associated with the highest inspiratory volumes in the same breaths. This behaviour seemed regulated according to the need of a more or less effective expiratory flow braking, probably as a result of pulmonary stretch receptors discharge. Conversely TE2 showed a continuous gradual modulation, progressively increasing in the pre-apnoeic period, decreasing during the apnoea and increasing in the post-apnoeic period: these TE2 variations seemed related to oscillations in chemical drive. These data show that TE in the obstructive apnoea-ventilation cycle results from a different modulation in its two components and suggest that both mechanical and chemical influences play a role in its overall duration.

  4. A new design for high stability pressure-controlled ventilation for small animal lung imaging

    International Nuclear Information System (INIS)

    Kitchen, M J; Habib, A; Lewis, R A; Fouras, A; Dubsky, S; Wallace, M J; Hooper, S B

    2010-01-01

    We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

  5. Functional Magnetic Stimulation of Inspiratory and Expiratory Muscles in Subjects With Tetraplegia.

    Science.gov (United States)

    Zhang, Xiaoming; Plow, Ela; Ranganthan, Vinoth; Huang, Honglian; Schmitt, Melissa; Nemunaitis, Gregory; Kelly, Clay; Frost, Frederick; Lin, Vernon

    2016-07-01

    Respiratory complications are major causes of morbidity and mortality in persons with a spinal cord injury, partly because of respiratory muscle paralysis. Earlier investigation has demonstrated that functional magnetic stimulation (FMS) can be used as a noninvasive technology for activating expiratory muscles, thus producing useful expiratory functions (simulated cough) in subjects with spinal cord injury. To evaluate the effectiveness of FMS for conditioning inspiratory and expiratory muscles in persons with tetraplegia. A prospective before and after trial. FMS Laboratory, Louis Stokes Cleveland VA Medical Center, Cleveland, OH. Six persons with tetraplegia. Each subject participated in a 6-week FMS protocol for conditioning the inspiratory and expiratory muscles. A magnetic stimulator was used with the center of a magnetic coil placed at the C7-T1 and T9-T10 spinous processes, respectively. Pulmonary function tests were performed before, during, and after the protocol. Respiratory variables included maximal inspiratory pressure (MIP), inspiratory reserve volume (IRV), peak inspiratory flow (PIF), maximal expiratory pressure (MEP), expiratory reserve volume (ERV), and peak expiratory flow (PEF). After 6 weeks of conditioning, the main outcome measurements (mean ± standard error) were as follows: MIP, 89.6 ± 7.3 cm H2O; IRV, 1.90 ± 0.34 L; PIF, 302.4 ± 36.3 L/min; MEP, 67.4 ± 11.1 cm H2O; ERV, 0.40 ± 0.06 L; and PEF, 372.4 ± 31.9 L/min. These values corresponded to 117%, 107%, 136%, 109%, 130%, and 124% of pre-FMS conditioning values, respectively. Significant improvements were observed in MIP (P = .022), PIF (P = .0001), and PEF (P = .0006), respectively. When FMS was discontinued for 4 weeks, these values showed decreases from their values at the end of the conditioning protocol, which suggests that continual FMS may be necessary to maintain improved respiratory functions. FMS conditioning of the inspiratory and expiratory muscles improved

  6. Effect of simultaneous application of postural techniques and expiratory muscle strength training on the enhancement of the swallowing function of patients with dysphagia caused by parkinson's disease.

    Science.gov (United States)

    Byeon, Haewon

    2016-06-01

    [Purpose] This study aimed to investigate the effect of simultaneous application of postural techniques and expiratory muscle strength training on the enhancement of the swallowing function of patients with dysphagia caused by Parkinson's disease. [Subjects and Methods] The subjects of this study were 18 patients who received simultaneous application of postural techniques and expiratory muscle strength training and 15 patients who received expiratory muscle strength training only. Postural techniques were conducted in the order of chin tucking, head rotation, head tilting, bending head back, and lying down, while expiratory muscle strength training was conducted at a resistance level of about 70% of the maximal expiratory pressure. Swallowing recovery was assessed by using the Functional Dysphagia Scale based on videofluoroscopic studies. [Results] The mean value obtained in the videofluoroscopic studies for both groups decreased after the treatment. In the postural techniques plus expiratory muscle strength training group, the decrease was significantly greater than that in the expiratory muscle strength training-only group. [Conclusion] The results imply that simultaneous performance of postural techniques and expiratory muscle strength training is more effective than expiratory muscle strength training alone when applied in the swallowing rehabilitation for patients with dysphagia caused by Parkinson's disease.

  7. Volumetric expiratory high-resolution CT of the lung

    International Nuclear Information System (INIS)

    Nishino, Mizuki; Hatabu, Hiroto

    2004-01-01

    We developed a volumetric expiratory high-resolution CT (HRCT) protocol that provides combined inspiratory and expiratory volumetric imaging of the lung without increasing radiation exposure, and conducted a preliminary feasibility assessment of this protocol to evaluate diffuse lung disease with small airway abnormalities. The volumetric expiratory high-resolution CT increased the detectability of the conducting airway to the areas of air trapping (P<0.0001), and added significant information about extent and distribution of air trapping (P<0.0001)

  8. Performance characteristics of seven bilevel mechanical ventilators in pressure-support mode with different cycling criteria: a comparative bench study.

    Science.gov (United States)

    Chen, Yuqing; Cheng, Kewen; Zhou, Xin

    2015-01-26

    Pressure support ventilation from a bilevel device is a standard technique for non-invasive home ventilation. A bench study was designed to compare the performance and patient-ventilator synchronization of 7 bilevel ventilators, in the presence of system leaks. Ventilators were connected to a Hans Rudolph Series 1101 lung simulator (compliance, 50 mL/cmH2O; expiratory resistance, 20 cmH2O/L/s; respiratory rate, 15 breaths/min; inspiratory time, 1.0 s). All ventilators were set at 15 cmH2O pressure support and 5 cmH2O positive end-expiratory pressure. Tests were conducted at 2 system leaks (12-15 and 25-28 L/min). The performance characteristics and patient-ventilator asynchrony were assessed, including flow, airway pressure, time, and workload. The Breas Vivo30 could not synchronize with the simulator (frequent auto-triggering) at a leak of 25-28 L/min, but provided stable assisted ventilation when the leak was 12-15 L/min. Missed efforts and back-up ventilation occurred for the Weinmann VENTImotion and Airox Smartair Plus, requiring adjustment of trigger effort. All ventilators had a short trigger delay time (ventilators, possibly due to software algorithm differences. Adjusting the cycling criteria settings can alter the shape of the inspiratory phase and peak expiratory flow, and improve patient-ventilator synchrony.

  9. Comparação entre inspirometria de incentivo e pressão positiva expiratória na função pulmonar após cirurgia bariátrica Comparison between incentive spirometry and expiratory positive airway pressure on pulmonary function after bariatric surgery

    Directory of Open Access Journals (Sweden)

    Marcela C. Barbalho-Moulim

    2009-06-01

    Full Text Available O objetivo deste estudo foi comparar o efeito da pressão positiva expiratória (EPAP, na sigla em inglês e da inspirometria de incentivo a fluxo sobre a função pulmonar após o bypass gástrico em Y de Roux por videolaparoscopia. Participaram 28 mulheres, não-tabagistas e não-pneumopatas, com índice de massa corporal entre 35 e 50 kg/m², submetidas à cirurgia bariátrica. Todas foram avaliadas por espirometria, cirtometria toracoabdominal e quanto à mobilidade diafragmática no pré e segundo dia de pós-operatório (o tempo de internação foi de 2 dias. Foram divididas em dois grupos, GI - grupo inspirômetro (n=13 e GE, grupo EPAP (n=15. A fisioterapia foi iniciada no dia da cirurgia, cada técnica, inspirometria ou EPAP, com duração de 15 minutos; a fisioterapia motora foi padronizada para ambos os grupos. No pós-operatório, houve redução similar nos dois grupos das variáveis: capacidade vital, volume de reserva inspiratório, capacidade vital forçada e ventilação voluntária máxima. Não houve alteração nos valores do volume corrente no GI e volume de reserva expiratório no GE. A mobilidade diafragmática e a mobilidade toracoabdominal foram menos prejudicadas no GI. No pós-operatório da cirurgia bariátrica por videolaparoscopia, a inspirometria de incentivo a fluxo exerceu melhores efeitos na manutenção do volume corente, na mobilidade diafragmática e toracoabdominal, enquanto a EPAP foi mais eficaz no restabelecimento do volume de reserva expiratório.The aim of this study was to compare the effect of expiratory positive airway pressure (EPAP and flow-oriented incentive spirometry on pulmonary function after laparoscopic Roux-en-Y gastric bypass surgery. Twenty-eight non-smoking women, with no lung disease and body mass index of 35 to 50 kg/m², undergoing laparoscopic gastric bypass surgery (hospitalized for two days were assessed by spirometry, thoracoabdominal cirtometry and as to diaphragmatic motion

  10. Expiratory muscle control during vomiting - Role of brain stem expiratory neurons

    Science.gov (United States)

    Miller, A. D.; Tan, L. K.

    1987-01-01

    The neural mechanisms controlling the muscles involved during vomiting were examined using decerebrated cats. In one experiment, the activity of the ventral respiratory group (VRG) expiratory (E) neurons was recorded during induced 'fictive vomiting' (i.e., a series of bursts of coactivation of abdominal and phrenic nerves that would be expected to produce expulsion in unparalyzed animals) and vomiting. In a second, abdominal muscle electromyographic and nerve activity were compared before and after sectioning the axons of descending VRG E neurons as they cross the midline between C1 and the obex (the procedure that is known to abolish expiratory modulation of internal intercostal muscle activity). The results of the study indicate that the abdominal muscles are controlled differently during respiration and vomiting.

  11. Role of bronchodilation and pattern of breathing in increasing tidal expiratory flow with progressive induced hypercapnia in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Finucane, Kevin E; Singh, Bhajan

    2018-01-01

    Hypercapnia (HC) in vitro relaxes airway smooth muscle; in vivo, it increases respiratory effort, tidal expiratory flows (V̇ exp ), and, by decreasing inspiratory duration (Ti), increases elastic recoil pressure (Pel) via lung viscoelasticity; however, its effect on airway resistance is uncertain. We examined the contributions of bronchodilation, Ti, and expiratory effort to increasing V̇ exp with progressive HC in 10 subjects with chronic obstructive pulmonary disease (COPD): mean forced expiratory volume in 1 s (FEV 1 ) 53% predicted. Lung volumes (Vl), V̇ exp , esophageal pressure (Pes), Ti, and end-tidal Pco 2 ([Formula: see text]) were measured during six tidal breaths followed by an inspiratory capacity (IC), breathing air, and at three levels of HC. V̇ exp and V̇ with submaximal forced vital capacities breathing air (V̇ sFVC ) were compared. Pulmonary resistance ( Rl) was measured from the Pes-V̇ relationship. V̇ exp and Pes at end-expiratory lung volume (EELV) + 0.3 tidal volume [V̇ (0.3Vt) and Pes (0.3Vt) , respectively], Ti, and Rl correlated with [Formula: see text] ( P pulmonary disease (COPD), progressive HC increases tidal expiratory flows by inducing bronchodilation and via an increased rate of inspiration and lung viscoelasticity, a probable increase in lung elastic recoil pressure, both changes increasing expiratory flows, promoting lung emptying and a stable end-expiratory volume. Bronchodilation with HC occurred despite optimal standard bronchodilator therapy, suggesting that in COPD further bronchodilation is possible.

  12. Peak Expiratory Flow Rate In Cigarette Smokers | Ukoli | Highland ...

    African Journals Online (AJOL)

    Objective: To compare lung function between smokers and non-smokers using Peak Expiratory Flow Rate (PEFR). Methods: This study examines the peak expiratory flow rate (PEFR) of three hundred and forty cigarette smokers, age and sex-matched with PEFR of equal number of non-smokers. Results: The mean PEFR of ...

  13. Effects of dorsal and lateral decubitus on peak expiratory flow in healthy subjects

    Directory of Open Access Journals (Sweden)

    Heloisa H. Gianinis

    2013-10-01

    Full Text Available BACKGROUND: One of the measures of the pulmonary function is the peak expiratory flow (PEF that can be defined as the major flow obtained in an expiratory pressure after a complete inspiration to the level of the total lung capacity. This measure depends on the effort and strength of expiratory muscles, the airway diameter and the lung volume. OBJECTIVE: To compare the results of the peak expiratory flow in healthy male and female obtained in a seated position and dorsal decubitus (DD, right lateral decubitus (RLD and left lateral decubitus (LLD. METHOD: Thirty young subjects with mean age 22.7 years, healthy and non-smokers were included at the study, 15 of male sex. They did spirometry and IPAQ questionnaire to check the normal pulmonary function and physical activity level. The measures of PEF were performed in four positions, being performed 3 measures in which position, in a random order. Statistical analysis was performed according to Student's t test, with significance level set at 5%. RESULTS: There was a difference between the values obtained in sitting position(481±117.1 L/min with DD(453.2±116.3 L/min and RLD (454±112.9 L/min (p<0.05, however, did not find a significant difference between the sitting position and LLD (469±83 L/min. CONCLUSIONS: Body position affects the values of PEF, with decreasing values in DD and RLD. The LLD can be an alternative to optimize the expiratory flow in situations of constraint to the sitting position.

  14. Association between driving pressure and development of postoperative pulmonary complications in patients undergoing mechanical ventilation for general anaesthesia: a meta-analysis of individual patient data.

    Science.gov (United States)

    Neto, Ary Serpa; Hemmes, Sabrine N T; Barbas, Carmen S V; Beiderlinden, Martin; Fernandez-Bustamante, Ana; Futier, Emmanuel; Gajic, Ognjen; El-Tahan, Mohamed R; Ghamdi, Abdulmohsin A Al; Günay, Ersin; Jaber, Samir; Kokulu, Serdar; Kozian, Alf; Licker, Marc; Lin, Wen-Qian; Maslow, Andrew D; Memtsoudis, Stavros G; Reis Miranda, Dinis; Moine, Pierre; Ng, Thomas; Paparella, Domenico; Ranieri, V Marco; Scavonetto, Federica; Schilling, Thomas; Selmo, Gabriele; Severgnini, Paolo; Sprung, Juraj; Sundar, Sugantha; Talmor, Daniel; Treschan, Tanja; Unzueta, Carmen; Weingarten, Toby N; Wolthuis, Esther K; Wrigge, Hermann; Amato, Marcelo B P; Costa, Eduardo L V; de Abreu, Marcelo Gama; Pelosi, Paolo; Schultz, Marcus J

    2016-04-01

    Protective mechanical ventilation strategies using low tidal volume or high levels of positive end-expiratory pressure (PEEP) improve outcomes for patients who have had surgery. The role of the driving pressure, which is the difference between the plateau pressure and the level of positive end-expiratory pressure is not known. We investigated the association of tidal volume, the level of PEEP, and driving pressure during intraoperative ventilation with the development of postoperative pulmonary complications. We did a meta-analysis of individual patient data from randomised controlled trials of protective ventilation during general anesthaesia for surgery published up to July 30, 2015. The main outcome was development of postoperative pulmonary complications (postoperative lung injury, pulmonary infection, or barotrauma). We included data from 17 randomised controlled trials, including 2250 patients. Multivariate analysis suggested that driving pressure was associated with the development of postoperative pulmonary complications (odds ratio [OR] for one unit increase of driving pressure 1·16, 95% CI 1·13-1·19; pprotective ventilation on development of pulmonary complications (p=0·027). In two studies that compared low with high PEEP during low tidal volume ventilation, an increase in the level of PEEP that resulted in an increase in driving pressure was associated with more postoperative pulmonary complications (OR 3·11, 95% CI 1·39-6·96; p=0·006). In patients having surgery, intraoperative high driving pressure and changes in the level of PEEP that result in an increase of driving pressure are associated with more postoperative pulmonary complications. However, a randomised controlled trial comparing ventilation based on driving pressure with usual care is needed to confirm these findings. None. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Pressão expiratória positiva na via aérea por máscara facial na hemodinâmica de pós-operatórios cardíacos Expiratory positive airway pressure in postoperative cardiac hemodynamics

    Directory of Open Access Journals (Sweden)

    Ana Claudia Borges dos Santos Sena

    2010-10-01

    Full Text Available FUNDAMENTOS: A pressão expiratória positiva na via aérea por máscara facial (EPAP é utilizada no pós-operatório de cirurgias cardíacas, entretanto, seus efeitos hemodinâmicos não foram claramente estudados. OBJETIVO: Avaliar as alterações hemodinâmicas causadas pela EPAP em pacientes pós-cirurgia cardíaca monitorados por cateter de Swan-Ganz. MÉTODOS: Foram incluídos no estudo, pacientes no primeiro ou segundo pós-operatório de cirurgia cardíaca, estáveis hemodinamicamente e com cateter de Swan-Ganz. Eles foram avaliados em repouso e após o uso de 10 cmH2O de EPAP, de forma randomizada. As variáveis estudadas foram: saturação de oxigênio, frequências cardíaca e respiratória, pressões arteriais médias sistêmica e pulmonar (PAM e PAMP, pressões venosa central (PVC e de oclusão da atéria pulmonar (POAP, débito e índice cardíacos, e resistências vasculares sistêmica e pulmonar. Os pacientes foram divididos em subgrupos (com fração de ejeção 50% e os dados foram comparados por teste t e ANOVA. RESULTADOS: Vinte e oito pacientes foram estudados (22 homens, idade média 68 ± 11 anos. Comparando o período de repouso versus EPAP, as alterações observadas foram: POAP (11,9 ± 3,8 para 17,1 ± 4,9 mmHg, p BACKGROND: Expiratory positive airway pressure (EPAP is used in after cardiac surgeries. However, its hemodynamic effects have not been clearly studied. OBJECTIVE: To evaluate the hemodynamic changes caused by EPAP in patients after cardiac surgery monitored by Swan-Ganz. METHODS: Patients at the first or second cardiac surgery postoperative period hemodynamically stable with a Swan-Ganz catheter were included in the study. They were assessed at rest and after using 10 cmH2O EPAP at random. The variables studied were: oxygen saturation, heart rate and respiratory rate, mean artery pressures and pulmonary artery mean pressures (MAP and PAMP, central venous pressure (CVP and pulmonary capillary wedge pressure

  16. Avaliação da frequência cardíaca à medida de pressão expiratória máxima estática e à manobra de Valsalva em jovens saudáveis Heart rate assessment during maximal static expiratory pressure and Valsalva maneuver in healthy young men

    Directory of Open Access Journals (Sweden)

    Vinicius Minatel

    2012-10-01

    Full Text Available CONTEXTUALIZAÇÃO: A medida de pressão expiratória máxima (PEmáx possui algumas contraindicações, pois acredita-se que as respostas obtidas nessa medida são similares às respostas encontradas na manobra de Valsalva (MV. OBJETIVOS: O objetivo principal é avaliar a resposta da frequência cardíaca (FC durante a medida da PEmáx e da MV em jovens saudáveis, em diferentes posturas, para identificar se e em qual condição a PEmáx reproduz as respostas obtidas na MV e, adicionalmente, estimar o trabalho realizado nas manobras. MÉTODO: Doze jovens saudáveis foram avaliados, orientados e familiarizados com as manobras. A MV foi composta por um esforço expiratório (40 mmHg durante 15 segundos contra um manômetro. A PEmáx foi executada segundo a American Thoracic Society. Ambas as medidas foram realizadas nas posturas supino e sentado. Para a análise da variação da frequência cardíaca (∆FC, índice de Valsalva (IV, índice da PEmáx (IPEmáx e o trabalho estimado das manobras (Wtotal, Wisotime, Wtotal/∆FCtotal e Wisotime/∆FCisotime , utilizou-se ANOVA two-way com post-hoc de Holm-Sidak (pBACKGROUND: The measure of the maximal expiratory pressure (MEP has some contraindications, as it is believed that the responses obtained in this measure are similar to the Valsalva maneuver (VM. OBJECTIVE: The main purpose of this study was to evaluate the heart rate responses (HR during the MEP and the VM measures in healthy young men into different postures aiming to identify whether and in which situation the MEP reproduces the responses obtained in the VM. Additionally we aim to estimate the workload realized during the maneuvers. METHOD: Twelve healthy young men were evaluated, instructed and familiarized with the maneuvers. The VM was characterized by an expiratory effort (40 mmHg against a manometer for 15 seconds. The MEP measure has been performed according to the American Thoracic Society. Both measures were performed at sitting

  17. Multi-detector CT evaluation in patients suspected of tracheobronchomalacia: Comparison of end-expiratory with dynamic expiratory volumetric acquisitions

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, Gilbert R. [Department of Radiology (France)], E-mail: gferretti@chu-grenoble.fr; Jankowski, Adrien [Department of Radiology (France)], E-mail: ajankowski@chu-grenoble.fr; Perrin, Marie Amelie [Department of Radiology (France)], E-mail: maperrin@chu-grenoble.fr; Chouri, Nathalie [Department of Respiratory Diseases (France)], E-mail: nchouri@chu-grenoble.fr; Arnol, Nathalie [Sleep Laboratory and EFCR, University Hospital, Grenoble (France); HP2 Laboratory, INSERM ERI 0017 (Hypoxia: Pathophysiology), Joseph Fourier University, Grenoble (France)], E-mail: narnold@chu-grenoble.fr; Aubaud, Laurent [Department of Radiology (France)], E-mail: laubaud@chu-grenoble.fr; Pepin, Jean-Louis [Sleep Laboratory and EFCR, University Hospital, Grenoble (France); HP2 Laboratory, INSERM ERI 0017 (Hypoxia: Pathophysiology), Joseph Fourier University, Grenoble (France)], E-mail: jlpepin@chu-grenoble.fr

    2008-11-15

    Purpose: The aim of this study was to compare dynamic expiratory imaging and end-expiratory imaging using multi-detector CT (MDCT) of the central airways in patients suspected of tracheobronchomalacia (TBM). Methods: This study had local ethical committee approval. Seventy patients suspected of TBM were prospectively included. All patients underwent evaluation of central airways by three different low-dose MDCT acquisitions: end inspiration, end expiration, and dynamic expiration. Degree of airway collapse was measured by calculating the percentage change in the area and diameter of the airways between inspiratory and the two expiratory techniques at three levels of the trachea and in the sagittal diameter of the right and left main bronchi. Three threshold levels of percentage reduction in diameter or area (30%, 50%, and 70%) for defining TBM were evaluated. Results: In the entire population, the mean percentage of airway collapse was significantly greater with dynamic expiratory imaging than with the end-expiratory imaging at three different levels: lower thoracic trachea (26% vs. 16.6%, p < 0.009), right (25.2% vs. 14%, p < 0.01) and left main (24.7% vs. 13.3%, p < 0.01) bronchus. Whatever the threshold value for defining TBM, dynamic expiratory imaging always resulted in diagnosing TBM in more patients than end-expiratory imaging. Conclusions: Dynamic expiratory imaging shows a significantly greater degree and a significantly greater extent of airway collapse than standard end-expiratory imaging in patients suspected of TBM. Further evaluation of the clinical relevance of such findings is warranted.

  18. What's in a name? Expiratory tracheal narrowing in adults explained

    International Nuclear Information System (INIS)

    Leong, P.; Bardin, P.G.; Lau, K.K.

    2013-01-01

    Tracheomalacia, tracheobronchomalacia, and excessive dynamic airway collapse are all terms used to describe tracheal narrowing in expiration. The first two describe luminal reduction from cartilage softening and the latter refers to luminal reduction from exaggerated posterior membrane movement. Expiratory tracheal narrowing is a frequent occurrence that can cause symptoms of airway obstruction, such as dyspnoea, wheeze, and exercise intolerance. The accurate diagnosis and quantification of expiratory tracheal narrowing has important aetiological, therapeutic, and prognostic implications. The reference standard for diagnosis has traditionally been bronchoscopy; however, this method has significant limitations. Expiratory tracheal disorders are readily detected by four-dimensional dynamic volume multidetector computed tomography (4D-CT), an emerging, non-invasive method that will potentially enable detection and quantification of these conditions. This review discusses the morphological forms of expiratory tracheal narrowing and demonstrates the utility of 4D-CT in the diagnosis, quantification, and treatment of these important conditions

  19. Impact of humidification and nebulization during expiratory limb protection: an experimental bench study.

    Science.gov (United States)

    Tonnelier, Alexandre; Lellouche, François; Bouchard, Pierre Alexandre; L'Her, Erwan

    2013-08-01

    Different filtering devices are used during mechanical ventilation to avoid dysfunction of flow and pressure transducers or for airborne microorganisms containment. Water condensates, resulting from the use of humidifiers, but also residual nebulization particles may have a major influence on expiratory limb resistance. To evaluate the influence of nebulization and active humidification on the resistance of expiratory filters. A respiratory system analog was constructed using a test lung, an ICU ventilator, heated humidifiers, and a piezoelectric nebulizer. Humidifiers were connected to different types of circuits (unheated, mono-heated, new-generation and old-generation bi-heated). Five filter types were evaluated: electrostatic, heat-and-moisture exchanger, standard, specific, and internal heated high-efficiency particulate air [HEPA] filter. Baseline characteristics were obtained from each dry filter. Differential pressure measurements were carried out after 24 hours of continuous in vitro use for each condition, and after 24 hours of use with an old-generation bi-heated circuit without nebulization. While using unheated circuits, measurements had to be interrupted before 24 hours for all the filtering devices except the internal heated HEPA filter. The heat-and-moisture exchangers occluded before 24 hours with the unheated and mono-heated circuits. The circuit type, nebulization practice, and duration of use did not influence the internal heated HEPA filter resistance. Expiratory limb filtration is likely to induce several major adverse events. Expiratory filter resistance increase is due mainly to the humidification circuit type, rather than to nebulization. If filtration is mandatory while using an unheated circuit, a dedicated filter should be used for ≤ 24 hours, or a heated HEPA for a longer duration.

  20. Hemodynamic differences between continual positive and two types of negative pressure ventilation.

    Science.gov (United States)

    Lockhat, D; Langleben, D; Zidulka, A

    1992-09-01

    In seven anesthetized dogs, ventilated with matching lung volumes, tidal volumes, and respiratory rates, we compared the effects on cardiac output (CO), arterial venous oxygen saturation difference (SaO2 - SVO2), and femoral and inferior vena cava pressure (1) intermittent positive pressure ventilation with positive end-expiratory pressure (CPPV); (2) iron-lung ventilation with negative end-expiratory pressure (ILV-NEEP); (3) grid and wrap ventilation with NEEP applied to the thorax and upper abdomen (G&W-NEEP). The values of CO and SaO2 - SVO2 with ILV-NEEP were similar to those with CPPV. However, with G&W-NEEP as compared with ILV-NEEP, mean CO was greater (2.9 versus 2.6 L/min, p = 0.02) and mean (SaO2 - SVO2) was lower (26.6% versus 28.3%, p = NS). Mean PFEM-IVC was higher with G&W-NEEP than with the other types of ventilation. We conclude that (1) ILV-NEEP is hemodynamically equivalent to CPPV and (2) G&W-NEEP has less adverse hemodynamic consequences. has less adverse hemodynamic consequences.

  1. Superoxide dismutase levels and peak expiratory flow in asthmatic children

    Directory of Open Access Journals (Sweden)

    Arie Kurniasih

    2016-11-01

    Full Text Available Background Asthma is a chronic inflammatory process which involve variety of cells such as inflammatory mediators, reactive oxygen species (ROS, and cytokines. The inflammatory process would be exacerbated in the presence of oxidative stress. Superoxide dismutase (SOD is the first important enzyme to protect the respiratory tract against oxidative stress. The decreased of SOD has a correlation with increased of airway obstruction and bronchospasm. Objective To assess for a correlation between superoxide dismutase (SOD levels and peak expiratory flow, as well as to determine the impact of SOD levels for predicting asthma attacks. Methods We conducted a prospective cohort study at Dr. Sardjito Hospital, Yogyakarta, between February and April 2011 involving asthmatic children aged 5-18 years. Subjects’ serum SOD levels and peak expiratory flow were measured at the same time point. We then performed a prospective study following up on the same subjects to find out if they had a recurrent asthma attack within one month of the tests. We also reassessed their peak expiratory flow one month after blood specimens were obtained. Results Thirty-nine patients were enrolled in this study. There was no significant correlation between SOD level and peak expiratory flow [r=0.289; 95%CI -0.025 to 0.47; P=0.074]. However, older age was significantly associated with higher peak expiratory flow (=0.5; 95%CI 3.10 to 11.57; P=0.01. Lower levels of SOD increased the risk of asthma attacks in a month following the initial measurements (RR=5.5; 95%CI 1.6 to 18.9; P=0.009. Conclusion Superoxide dismutase (SOD level is not significantly associated with peak expiratory flow. However, we find a relationship between older age and higher peak expiratory flow and a relationship between lower SOD levels and risk of asthma attacks within one month following the tests.

  2. Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation

    OpenAIRE

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-01-01

    [Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects ...

  3. Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation.

    Science.gov (United States)

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-07-01

    [Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects were positioned in a 30° lateral recumbent position, and a 2-kgf compression was applied. For expiratory rib cage compression, the rib cage was compressed unilaterally; for expiratory abdominal compression, the area directly above the navel was compressed. Tidal volume values were the actual measured values divided by body weight. [Results] Tidal volume values were as follows: at rest, 7.2 ± 1.7 mL/kg; during expiratory rib cage compression, 8.3 ± 2.1 mL/kg; during expiratory abdominal compression, 9.1 ± 2.2 mL/kg. There was a significant difference between the tidal volume during expiratory abdominal compression and that at rest. The tidal volume in expiratory rib cage compression was strongly correlated with that in expiratory abdominal compression. [Conclusion] These results indicate that expiratory abdominal compression may be an effective alternative to the manual breathing assist procedure.

  4. Mechanical breath profile of airway pressure release ventilation: the effect on alveolar recruitment and microstrain in acute lung injury.

    Science.gov (United States)

    Kollisch-Singule, Michaela; Emr, Bryanna; Smith, Bradford; Roy, Shreyas; Jain, Sumeet; Satalin, Joshua; Snyder, Kathy; Andrews, Penny; Habashi, Nader; Bates, Jason; Marx, William; Nieman, Gary; Gatto, Louis A

    2014-11-01

    Improper mechanical ventilation settings can exacerbate acute lung injury by causing a secondary ventilator-induced lung injury. It is therefore important to establish the mechanism by which the ventilator induces lung injury to develop protective ventilation strategies. It has been postulated that the mechanism of ventilator-induced lung injury is the result of heterogeneous, elevated strain on the pulmonary parenchyma. Acute lung injury has been associated with increases in whole-lung macrostrain, which is correlated with increased pathology. However, the effect of mechanical ventilation on alveolar microstrain remains unknown. To examine whether the mechanical breath profile of airway pressure release ventilation (APRV), consisting of a prolonged pressure-time profile and brief expiratory release phase, reduces microstrain. In a randomized, nonblinded laboratory animal study, rats were randomized into a controlled mandatory ventilation group (n = 3) and an APRV group (n = 3). Lung injury was induced by polysorbate lavage. A thoracotomy was performed and an in vivo microscope was placed on the lungs to measure alveolar mechanics. In the controlled mandatory ventilation group, multiple levels of positive end-expiratory pressure (PEEP; 5, 10, 16, 20, and 24 cm H2O) were tested. In the APRV group, decreasing durations of expiratory release (time at low pressure [T(low)]) were tested. The T(low) was set to achieve ratios of termination of peak expiratory flow rate (T-PEFR) to peak expiratory flow rate (PEFR) of 10%, 25%, 50%, and 75% (the smaller this ratio is [ie, 10%], the more time the lung is exposed to low pressure during the release phase, which decreases end-expiratory lung volume and potentiates derecruitment). Alveolar perimeters were measured at peak inspiration and end expiration using digital image analysis, and strain was calculated by normalizing the change in alveolar perimeter length to the original length. Macrostrain was measured by volume

  5. Inspiratory and expiratory HRCT findings in healthy smokers' lung

    International Nuclear Information System (INIS)

    Park, Hyeon Seon; Kwak, Byung Kook; Choi, Chi Hoon; Yang, Keun Mung; Lee, Chang Joon; Joo, Dong Il; Kim, Yang Soo

    1998-01-01

    The purpose of this study is to evaluate the lung changes in healthy smokers, as seen on inspiratory and expiratory high-resolution computed tomography (HRCT). Twenty-seven healthy smokers (light smokers, below 20 pack-years, n=16; heavy smokers, above 20 pack-years, n=11) and 25 nonsmokers underwent inspiratory and expiratory HRCT. All healthy smokers had normal pulmonary function and chest radiography. Parenchymal and subpleural micronodules, ground-glass attenuation, centrilobular and paraseptal emphysema, bronchial wall thickening, bronchiectasis and septal line were evaluated on inspiratory scan and by air-trapping on expiratory scan. According to the findings of HRCT, heavy smokers and higher frequency of parenchymal micronodules, ground-glass attenuation, centrilobular and paraseptal emphysema, and air-trapping than nonsmokers and light smokers. (author). 13 refs., 1 tab., 4 figs

  6. Lung function in North American Indian children: reference standards for spirometry, maximal expiratory flow volume curves, and peak expiratory flow.

    Science.gov (United States)

    Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S

    1982-02-01

    Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.

  7. Prospective randomized crossover study of a new closed-loop control system versus pressure support during weaning from mechanical ventilation.

    Science.gov (United States)

    Clavieras, Noémie; Wysocki, Marc; Coisel, Yannael; Galia, Fabrice; Conseil, Matthieu; Chanques, Gerald; Jung, Boris; Arnal, Jean-Michel; Matecki, Stefan; Molinari, Nicolas; Jaber, Samir

    2013-09-01

    Intellivent is a new full closed-loop controlled ventilation that automatically adjusts both ventilation and oxygenation parameters. The authors compared gas exchange and breathing pattern variability of Intellivent and pressure support ventilation (PSV). In a prospective, randomized, single-blind design crossover study, 14 patients were ventilated during the weaning phase, with Intellivent or PSV, for two periods of 24 h in a randomized order. Arterial blood gases were obtained after 1, 8, 16, and 24 h with each mode. Ventilatory parameters were recorded continuously in a breath-by-breath basis during the two study periods. The primary endpoint was oxygenation, estimated by the calculation of the difference between the PaO2/FIO2 ratio obtained after 24 h of ventilation and the PaO2/FIO2 ratio obtained at baseline in each mode. The variability in the ventilatory parameters was also evaluated by the coefficient of variation (SD to mean ratio). There were no adverse events or safety issues requiring premature interruption of both modes. The PaO2/FIO2 (mean ± SD) ratio improved significantly from 245 ± 75 at baseline to 294 ± 123 (P = 0.03) after 24 h of Intellivent. The coefficient of variation of inspiratory pressure and positive end-expiratory pressure (median [interquartile range]) were significantly higher with Intellivent, 16 [11-21] and 15 [7-23]%, compared with 6 [5-7] and 7 [5-10]% in PSV. Inspiratory pressure, positive end-expiratory pressure, and FIO2 changes were adjusted significantly more often with Intellivent compared with PSV. Compared with PSV, Intellivent during a 24-h period improved the PaO2/FIO2 ratio in parallel with more variability in the ventilatory support and more changes in ventilation settings.

  8. predicted peak expiratory flow in human and the clinical implication ...

    African Journals Online (AJOL)

    DR. AMINU

    predicted PEF varied widely across formulae and choice of a particular formula may alter guideline- base care. This work has therefore accepted a recently published population-base equation proposed as the reference standard for future asthma guidelines. Keywords: Peak expiratory flow, Asthma, Practice guidelines, ...

  9. Knowledge, attitude and practice of nurses toward peak expiratory ...

    African Journals Online (AJOL)

    Background: Peak expiratory flow meter (PEFM) is an easy to use, relatively cheap device that can be used for guiding management of bronchial asthma by the patients at home according to a preset plan by health care workers. Objective: The aim of the study is to reveal the extent of knowledge and perception of nurses ...

  10. Factors influencing peak expiratory flow in teenage boys | van ...

    African Journals Online (AJOL)

    Background. Peak expiratory flow (PEF) is a useful measure of pulmonary health status and is frequently utilised in asthm, management. Reduction in PEF is usually indicative of onset (of asthma symptoms. However, use can be made of PEF values only if normal values are known. The definition of normal range is always ...

  11. An expiratory assist during spontaneous breathing can compensate for endotracheal tube resistance.

    Science.gov (United States)

    Uchiyama, Akinori; Chang, Cheng; Suzuki, Shinya; Mashimo, Takashi; Fujino, Yuji

    2009-08-01

    Although inspiratory assist of spontaneous breathing in intubated patients is common, expiratory assist functions have rarely been reported. Effective expiratory support (ES) could be used to compensate for endotracheal tube (ETT) resistance during spontaneous breathing. In this study, we examined the performance of a new system designed to provide both inspiratory support (IS) and ES during spontaneous breathing with the goal of reducing the effective resistance of the ETT. The ES system consisted of a ventilator demand valve and a computer-controlled piston cylinder, which aspirated gas from the respiratory circuit during the expiratory phase. The movement of the piston was synchronized with spontaneous breathing. We compared the pressures at the tip of the ETT and in the breathing circuit during spontaneous breathing through an ETT of internal diameter (ID) 5 mm with that of an ETT with ID 8 mm in nine healthy adult male volunteers. The ventilatory mode was set to maintain a continuous airway pressure of 0 cm H(2)O. Three ventilator settings (no support, IS only, and IS plus ES) were compared using ID 5 mm ETT. We monitored pressure in the breathing circuit (P(aw)), ETT tip pressure (P(tip)), and respiratory flow. The P(tip) of the ID 5 mm ETT showed a large negative deflection during inspiration and a positive deflection during expiration without support. IS alone did not improve the respiratory pattern through the small ETT. However, IS plus ES resulted in negative P(aw) during expiration in addition to positive deflection of P(aw) during inspiration, making the pressure characteristics of P(tip) similar to those of ID 8 mm ETT. Moreover, IS plus ES produced a respiratory pattern through the ID 5 mm ETT that was similar to that through the ID 8 mm ETT. In this study of healthy volunteers, IS plus ES compensated for the airway resistance imposed by a ID 5.0 mm ETT to create pressure changes at the tip of the ETT similar to those of an ID 8.0 mm ETT.

  12. Neopuff T-piece resuscitator mask ventilation: Does mask leak vary with different peak inspiratory pressures in a manikin model?

    Science.gov (United States)

    Maheshwari, Rajesh; Tracy, Mark; Hinder, Murray; Wright, Audrey

    2017-08-01

    The aim of this study was to compare mask leak with three different peak inspiratory pressure (PIP) settings during T-piece resuscitator (TPR; Neopuff) mask ventilation on a neonatal manikin model. Participants were neonatal unit staff members. They were instructed to provide mask ventilation with a TPR with three PIP settings (20, 30, 40 cm H 2 O) chosen in a random order. Each episode was for 2 min with 2-min rest period. Flow rate and positive end-expiratory pressure (PEEP) were kept constant. Airway pressure, inspiratory and expiratory tidal volumes, mask leak, respiratory rate and inspiratory time were recorded. Repeated measures analysis of variance was used for statistical analysis. A total of 12 749 inflations delivered by 40 participants were analysed. There were no statistically significant differences (P > 0.05) in the mask leak with the three PIP settings. No statistically significant differences were seen in respiratory rate and inspiratory time with the three PIP settings. There was a significant rise in PEEP as the PIP increased. Failure to achieve the desired PIP was observed especially at the higher settings. In a neonatal manikin model, the mask leak does not vary as a function of the PIP when the flow rate is constant. With a fixed rate and inspiratory time, there seems to be a rise in PEEP with increasing PIP. © 2017 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).

  13. Influence of Changing the Diameter of the Bubble Generator Bottle and Expiratory Limb on Bubble CPAP: An in vitro Study

    Directory of Open Access Journals (Sweden)

    Chun-Shan Wu

    2012-12-01

    Conclusion: The size and submergence depth of an expiratory limb of a CPAP circuit, the diameter of the bubble generator bottle, and the compliance of the model lung all influence the magnitude and frequency of the transmitted pressure waveform. Therefore, these factors may affect lung volume recruitment and breathing efficiency in bubble CPAP.

  14. Model-based setting of inspiratory pressure and respiratory rate in pressure-controlled ventilation

    International Nuclear Information System (INIS)

    Schranz, C; Möller, K; Becher, T; Schädler, D; Weiler, N

    2014-01-01

    Mechanical ventilation carries the risk of ventilator-induced-lung-injury (VILI). To minimize the risk of VILI, ventilator settings should be adapted to the individual patient properties. Mathematical models of respiratory mechanics are able to capture the individual physiological condition and can be used to derive personalized ventilator settings. This paper presents model-based calculations of inspiration pressure (p I ), inspiration and expiration time (t I , t E ) in pressure-controlled ventilation (PCV) and a retrospective evaluation of its results in a group of mechanically ventilated patients. Incorporating the identified first order model of respiratory mechanics in the basic equation of alveolar ventilation yielded a nonlinear relation between ventilation parameters during PCV. Given this patient-specific relation, optimized settings in terms of minimal p I and adequate t E can be obtained. We then retrospectively analyzed data from 16 ICU patients with mixed pathologies, whose ventilation had been previously optimized by ICU physicians with the goal of minimization of inspiration pressure, and compared the algorithm's ‘optimized’ settings to the settings that had been chosen by the physicians. The presented algorithm visualizes the patient-specific relations between inspiration pressure and inspiration time. The algorithm's calculated results highly correlate to the physician's ventilation settings with r = 0.975 for the inspiration pressure, and r = 0.902 for the inspiration time. The nonlinear patient-specific relations of ventilation parameters become transparent and support the determination of individualized ventilator settings according to therapeutic goals. Thus, the algorithm is feasible for a variety of ventilated ICU patients and has the potential of improving lung-protective ventilation by minimizing inspiratory pressures and by helping to avoid the build-up of clinically significant intrinsic positive end-expiratory

  15. Model-based setting of inspiratory pressure and respiratory rate in pressure-controlled ventilation.

    Science.gov (United States)

    Schranz, C; Becher, T; Schädler, D; Weiler, N; Möller, K

    2014-03-01

    Mechanical ventilation carries the risk of ventilator-induced-lung-injury (VILI). To minimize the risk of VILI, ventilator settings should be adapted to the individual patient properties. Mathematical models of respiratory mechanics are able to capture the individual physiological condition and can be used to derive personalized ventilator settings. This paper presents model-based calculations of inspiration pressure (pI), inspiration and expiration time (tI, tE) in pressure-controlled ventilation (PCV) and a retrospective evaluation of its results in a group of mechanically ventilated patients. Incorporating the identified first order model of respiratory mechanics in the basic equation of alveolar ventilation yielded a nonlinear relation between ventilation parameters during PCV. Given this patient-specific relation, optimized settings in terms of minimal pI and adequate tE can be obtained. We then retrospectively analyzed data from 16 ICU patients with mixed pathologies, whose ventilation had been previously optimized by ICU physicians with the goal of minimization of inspiration pressure, and compared the algorithm's 'optimized' settings to the settings that had been chosen by the physicians. The presented algorithm visualizes the patient-specific relations between inspiration pressure and inspiration time. The algorithm's calculated results highly correlate to the physician's ventilation settings with r = 0.975 for the inspiration pressure, and r = 0.902 for the inspiration time. The nonlinear patient-specific relations of ventilation parameters become transparent and support the determination of individualized ventilator settings according to therapeutic goals. Thus, the algorithm is feasible for a variety of ventilated ICU patients and has the potential of improving lung-protective ventilation by minimizing inspiratory pressures and by helping to avoid the build-up of clinically significant intrinsic positive end-expiratory pressure.

  16. Severe bronchopulmonary dysplasia improved by noninvasive positive pressure ventilation: a case report

    Directory of Open Access Journals (Sweden)

    Mann Christian

    2011-09-01

    Full Text Available Abstract Introduction This is the first report to describe the feasibility and effectiveness of noninvasive positive pressure ventilation in the secondary treatment of bronchopulmonary dysplasia. Case presentation A former male preterm of Caucasian ethnicity delivered at 29 weeks gestation developed severe bronchopulmonary dysplasia. At the age of six months he was in permanent tachypnea and dyspnea and in need of 100% oxygen with a flow of 2.0 L/minute via a nasal cannula. Intermittent nocturnal noninvasive positive pressure ventilation was then administered for seven hours daily. The ventilator was set at a positive end-expiratory pressure of 6 cmH2O, with pressure support of 4 cmH2O, trigger at 1.4 mL/second, and a maximum inspiratory time of 0.7 seconds. Over the course of seven weeks, the patient's maximum daytime fraction of inspired oxygen via nasal cannula decreased from 1.0 to 0.75, his respiratory rate from 64 breaths/minute to 50 breaths/minute and carbon dioxide from 58 mmHg to 44 mmHg. Conclusion Noninvasive positive pressure ventilation may be a novel therapeutic option for established severe bronchopulmonary dysplasia. In the case presented, noninvasive positive pressure ventilation achieved sustained improvement in ventilation and thus prepared our patient for safe home oxygen therapy.

  17. Effects of short-term pressure-controlled ventilation on gas exchange, airway pressures, and gas distribution in patients with acute lung injury/ARDS: comparison with volume-controlled ventilation.

    Science.gov (United States)

    Prella, Maura; Feihl, François; Domenighetti, Guido

    2002-10-01

    The potential clinical benefits of pressure-controlled ventilation (PCV) over volume-controlled ventilation (VCV) in patients with acute lung injury (ALI) or ARDS still remain debated. We compared PCV with VCV in patients with ALI/ARDS with respect to the following physiologic end points: (1) gas exchange and airway pressures, and (2) CT scan intrapulmonary gas distribution at end-expiration. Prospective, observational study. A multidisciplinary ICU in a nonuniversity, acute-care hospital. Ten patients with ALI or ARDS (9 men and 1 woman; age range, 17 to 80 years). Sequential ventilation in PCV and VCV with a constant inspiratory/expiratory ratio, tidal volume, respiratory rate, and total positive end-expiratory pressure; measurement of gas exchange and airway pressures; and achievement of CT sections at lung base, hilum, and apex for the quantitative analysis of lung densities and of aerated vs nonaerated zones. PaO(2), PaCO(2), and PaO(2)/fraction of inspired oxygen ratio levels did not differ between PCV and VCV. Peak airway pressure (Ppeak) was significantly lower in PCV compared with VCV (26 +/- 2 cm H(2)O vs 31 +/- 2 cm H(2)O; p mean +/- SEM). The surface areas of the nonaerated zones as well as the total areas at each section level were unchanged in PCV compared with VCV, except at the apex level, where there was a significantly greater nonaerated area in VCV (11 +/- 2 cm(2) vs 9 +/- 2 cm(2); p mean CT number of each lung (20 lungs from 10 patients) was similar in the two modes, as were the density values at the basal and apical levels; the hilum mean CT number was - 442 +/- 28 Hounsfield units (HU) in VCV and - 430 +/- 26 HU in PCV (p lower Ppeaks through the precise titration of the lung distending pressure, and might be applied to avoid regional overdistension by means of a more homogeneous gas distribution.

  18. Spontaneous breathing during lung-protective ventilation in an experimental acute lung injury model: high transpulmonary pressure associated with strong spontaneous breathing effort may worsen lung injury.

    Science.gov (United States)

    Yoshida, Takeshi; Uchiyama, Akinori; Matsuura, Nariaki; Mashimo, Takashi; Fujino, Yuji

    2012-05-01

    We investigated whether potentially injurious transpulmonary pressure could be generated by strong spontaneous breathing and exacerbate lung injury even when plateau pressure is limited to ventilation, each combined with weak or strong spontaneous breathing effort. Inspiratory pressure for low tidal volume ventilation was set at 10 cm H2O and tidal volume at 6 mL/kg. For moderate tidal volume ventilation, the values were 20 cm H2O and 7-9 mL/kg. The groups were: low tidal volume ventilation+spontaneous breathingweak, low tidal volume ventilation+spontaneous breathingstrong, moderate tidal volume ventilation+spontaneous breathingweak, and moderate tidal volume ventilation+spontaneous breathingstrong. Each group had the same settings for positive end-expiratory pressure of 8 cm H2O. Respiratory variables were measured every 60 mins. Distribution of lung aeration and alveolar collapse were histologically evaluated. Low tidal volume ventilation+spontaneous breathingstrong showed the most favorable oxygenation and compliance of respiratory system, and the best lung aeration. By contrast, in moderate tidal volume ventilation+spontaneous breathingstrong, the greatest atelectasis with numerous neutrophils was observed. While we applied settings to maintain plateau pressure at ventilation+spontaneous breathingstrong, transpulmonary pressure rose >33 cm H2O. Both minute ventilation and respiratory rate were higher in the strong spontaneous breathing groups. Even when plateau pressure is limited to mechanical ventilation, transpulmonary pressure and tidal volume should be strictly controlled to prevent further lung injury.

  19. Parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation.

    Science.gov (United States)

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-07-01

    [Purpose] The aim of this study was to clarify physical parameters affecting the tidal volume during expiratory abdominal compression in patients with prolonged tracheostomy mechanical ventilation. [Methods] Eighteen patients with prolonged mechanical ventilation were included in this study. Expiratory abdominal compression was performed on patients lying in a supine position. The abdomen above the navel was vertically compressed in synchronization with expiration and released with inspiration. We measured the tidal volume during expiratory abdominal compression. [Results] The mean tidal volume during expiratory abdominal compression was higher than that at rest (430.6 ± 127.1 mL vs. 344.0 ± 94.3 mL). The tidal volume during expiratory abdominal compression was correlated with weight, days of ventilator support, dynamic compliance and abdominal expansion. Stepwise multiple regression analysis revealed that weight (β = 0.499), dynamic compliance (β = 0.387), and abdominal expansion (β = 0.365) were factors contributing to the tidal volume during expiratory abdominal compression. [Conclusion] Expiratory abdominal compression increased the tidal volume in patients with prolonged tracheostomy mechanical ventilation. The tidal volume during expiratory abdominal compression was influenced by each of the pulmonary conditions and the physical characteristics.

  20. First characterization of the expiratory flow increase technique: method development and results analysis

    International Nuclear Information System (INIS)

    Maréchal, L; Barthod, C; Jeulin, J C

    2009-01-01

    This study provides an important contribution to the definition of the expiratory flow increase technique (EFIT). So far, no measuring means were suited to assess the manual EFIT performed on infants. The proposed method aims at objectively defining the EFIT based on the quantification of pertinent cognitive parameters used by physiotherapists when practicing. We designed and realized customized instrumented gloves endowed with pressure and displacement sensors, and the associated electronics and software. This new system is specific to the manoeuvre, to the user and innocuous for the patient. Data were collected and analysed on infants with bronchiolitis managed by an expert physiotherapist. The analysis presented is realized on a group of seven subjects (mean age: 6.1 months, SD: 1.1; mean chest circumference: 44.8 cm, SD: 1.9). The results are consistent with the physiotherapist's tactility. In spite of inevitable variability due to measurements on infants, repeatable quantitative data could be reported regarding the manoeuvre characteristics: the magnitudes of displacements do not exceed 10 mm on both hands; the movement of the thoracic hand is more vertical than the movement of the abdominal hand; the maximum applied pressure with the thoracic hand is about twice higher than with the abdominal hand; the thrust of the manual compression lasts (590 ± 62) ms. Inter-operators measurements are in progress in order to generalize these results

  1. Liquid- and air-filled catheters without balloon as an alternative to the air-filled balloon catheter for measurement of esophageal pressure.

    Science.gov (United States)

    Beda, Alessandro; Güldner, Andreas; Carvalho, Alysson R; Zin, Walter Araujo; Carvalho, Nadja C; Huhle, Robert; Giannella-Neto, Antonio; Koch, Thea; de Abreu, Marcelo Gama

    2014-01-01

    Measuring esophageal pressure (Pes) using an air-filled balloon catheter (BC) is the common approach to estimate pleural pressure and related parameters. However, Pes is not routinely measured in mechanically ventilated patients, partly due to technical and practical limitations and difficulties. This study aimed at comparing the conventional BC with two alternative methods for Pes measurement, liquid-filled and air-filled catheters without balloon (LFC and AFC), during mechanical ventilation with and without spontaneous breathing activity. Seven female juvenile pigs (32-42 kg) were anesthetized, orotracheally intubated, and a bundle of an AFC, LFC, and BC was inserted in the esophagus. Controlled and assisted mechanical ventilation were applied with positive end-expiratory pressures of 5 and 15 cmH2O, and driving pressures of 10 and 20 cmH2O, in supine and lateral decubitus. Cardiogenic noise in BC tracings was much larger (up to 25% of total power of Pes signal) than in AFC and LFC (<3%). Lung and chest wall elastance, pressure-time product, inspiratory work of breathing, inspiratory change and end-expiratory value of transpulmonary pressure were estimated. The three catheters allowed detecting similar changes in these parameters between different ventilation settings. However, a non-negligible and significant bias between estimates from BC and those from AFC and LFC was observed in several instances. In anesthetized and mechanically ventilated pigs, the three catheters are equivalent when the aim is to detect changes in Pes and related parameters between different conditions, but possibly not when the absolute value of the estimated parameters is of paramount importance. Due to a better signal-to-noise ratio, and considering its practical advantages in terms of easier calibration and simpler acquisition setup, LFC may prove interesting for clinical use.

  2. Liquid- and air-filled catheters without balloon as an alternative to the air-filled balloon catheter for measurement of esophageal pressure.

    Directory of Open Access Journals (Sweden)

    Alessandro Beda

    Full Text Available BACKGROUND: Measuring esophageal pressure (Pes using an air-filled balloon catheter (BC is the common approach to estimate pleural pressure and related parameters. However, Pes is not routinely measured in mechanically ventilated patients, partly due to technical and practical limitations and difficulties. This study aimed at comparing the conventional BC with two alternative methods for Pes measurement, liquid-filled and air-filled catheters without balloon (LFC and AFC, during mechanical ventilation with and without spontaneous breathing activity. Seven female juvenile pigs (32-42 kg were anesthetized, orotracheally intubated, and a bundle of an AFC, LFC, and BC was inserted in the esophagus. Controlled and assisted mechanical ventilation were applied with positive end-expiratory pressures of 5 and 15 cmH2O, and driving pressures of 10 and 20 cmH2O, in supine and lateral decubitus. MAIN RESULTS: Cardiogenic noise in BC tracings was much larger (up to 25% of total power of Pes signal than in AFC and LFC (<3%. Lung and chest wall elastance, pressure-time product, inspiratory work of breathing, inspiratory change and end-expiratory value of transpulmonary pressure were estimated. The three catheters allowed detecting similar changes in these parameters between different ventilation settings. However, a non-negligible and significant bias between estimates from BC and those from AFC and LFC was observed in several instances. CONCLUSIONS: In anesthetized and mechanically ventilated pigs, the three catheters are equivalent when the aim is to detect changes in Pes and related parameters between different conditions, but possibly not when the absolute value of the estimated parameters is of paramount importance. Due to a better signal-to-noise ratio, and considering its practical advantages in terms of easier calibration and simpler acquisition setup, LFC may prove interesting for clinical use.

  3. Transport of expiratory droplets in an aircraft cabin.

    Science.gov (United States)

    Gupta, Jitendra K; Lin, Chao-Hsin; Chen, Qingyan

    2011-02-01

    The droplets exhaled by an index patient with infectious disease such as influenza or tuberculosis may be the carriers of contagious agents. Indoor environments such as the airliner cabins may be susceptible to infection from such airborne contagious agents. The present investigation computed the transport of the droplets exhaled by the index patient seated in the middle of a seven-row, twin-aisle, fully occupied cabin using the CFD simulations. The droplets exhaled were from a single cough, a single breath, and a 15-s talk of the index patient. The expiratory droplets were tracked by using Lagrangian method, and their evaporation was modeled. It was found that the bulk airflow pattern in the cabin played the most important role on the droplet transport. The droplets were contained in the row before, at, and after the index patient within 30 s and dispersed uniformly to all the seven rows in 4 minutes. The total airborne droplet fraction reduced to 48, 32, 20, and 12% after they entered the cabin for 1, 2, 3, and 4 min, respectively, because of the ventilation from the environmental control system. It is critical to predict the risk of airborne infection to take appropriate measures to control and mitigate the risk. Most of the studies in past either assume a homogenous distribution of contaminants or use steady-state conditions. The present study instead provides information on the transient movement of the droplets exhaled by an index passenger in an aircraft cabin. These droplets may contain active contagious agents and can be potent enough to cause infection. The findings can be used by medical professionals to estimate the spatial and temporal distribution of risk of infection to various passengers in the cabin. © 2010 John Wiley & Sons A/S.

  4. Successful use of non-invasive positive pressure ventilation in a complicated flail chest

    International Nuclear Information System (INIS)

    Al-Ansari, Mariam A.

    2006-01-01

    The current advanced trauma life support manual states that patients with significant hypoxia (namely, SaO2<90% on room air) as a result of pulmonary contusion should be intubated and ventilated within the first hour of injury. Recently, several researchers have shown improved outcomes when patients with acute respiratory failure are managed with noninvasive positive pressure ventilation (NIPPV). Trauma patients may also benefit from this therapy. We report a case of 15-year-old boy who isolated flail chest and pulmonary contusion, who was intubated in the emergency room, and was managed successfully with the NIPPV in the intensive care unit (ICU) despite, having had aspiration pneumonia early in the course of her stay. After initial stabilization, he failed a spontaneous breathing trial. Due to absence of contraindications to the use of NIPPV, the patient was extubated on day 7 (from pressure ventilation of 15 cmH2O and positive end expiratory pressure of 8 cm H2O) to immediate NIPPV use. Three days later (after a total of 50 hours of NIPPV use in the ICU) the patient was successfully discharged home. (author)

  5. Cardiorespiratory effects of balancing PEEP with intra-abdominal pressures during laparoscopic cholecystectomy.

    Science.gov (United States)

    Kundra, Pankaj; Subramani, Yamini; Ravishankar, M; Sistla, Sarath C; Nagappa, Mahesh; Sivashanmugam, T

    2014-06-01

    Applying appropriate positive end-expiratory pressure (PEEP) to corresponding intra-abdominal pressure (IAP) can improve gas exchange during capnoperitoneum without any hemodynamic effects. A total of 75 patients were randomly allocated to group 0PEEP (n=25), group 5PEEP (n=25), and group 10PEEP (n=25) according to the level of PEEP, in whom capnoperitoneum was created with IAP of 14, 8, and 14 mm Hg, respectively. Hemodynamic and respiratory parameters were recorded up to 30 minutes after capnoperitoneum. In 0PEEP group, mean end-tidal carbon dioxide demonstrated significant rise 2 minutes after capnoperitoneum and plateaued at about 15 minutes but remained at high level for up to 30 minutes when compared with the 5PEEP and 10PEEP groups (Phigher at 30 minutes when compared with 5PEEP (37.8±2.7 mm Hg) and 10PEEP (37.2±3.9 mm Hg) groups. The oxygenation was better preserved in 5PEEP and 10PEEP groups with significantly higher PaO2/Fio2 ratio. Heart rate, mean arterial pressure, and cardiac output remained stable throughout the study in all the 3 groups. Application of appropriate PEEP corresponding to the IAP helped maintain CO2 elimination and improved oxygenation without any hemodynamic disturbance in patients undergoing laparoscopic cholecystectomy.

  6. Ventilation distribution measured with EIT at varying levels of pressure support and Neurally Adjusted Ventilatory Assist in patients with ALI.

    Science.gov (United States)

    Blankman, Paul; Hasan, Djo; van Mourik, Martijn S; Gommers, Diederik

    2013-06-01

    The purpose of this study was to compare the effect of varying levels of assist during pressure support (PSV) and Neurally Adjusted Ventilatory Assist (NAVA) on the aeration of the dependent and non-dependent lung regions by means of Electrical Impedance Tomography (EIT). We studied ten mechanically ventilated patients with Acute Lung Injury (ALI). Positive-End Expiratory Pressure (PEEP) and PSV levels were both 10 cm H₂O during the initial PSV step. Thereafter, we changed the inspiratory pressure to 15 and 5 cm H₂O during PSV. The electrical activity of the diaphragm (EAdi) during pressure support ten was used to define the initial NAVA gain (100 %). Thereafter, we changed NAVA gain to 150 and 50 %, respectively. After each step the assist level was switched back to PSV 10 cm H₂O or NAVA 100 % to get a new baseline. The EIT registration was performed continuously. Tidal impedance variation significantly decreased during descending PSV levels within patients, whereas not during NAVA. The dorsal-to-ventral impedance distribution, expressed according to the center of gravity index, was lower during PSV compared to NAVA. Ventilation contribution of the dependent lung region was equally in balance with the non-dependent lung region during PSV 5 cm H₂O, NAVA 50 and 100 %. Neurally Adjusted Ventilatory Assist ventilation had a beneficial effect on the ventilation of the dependent lung region and showed less over-assistance compared to PSV in patients with ALI.

  7. Physiological and morphological determinants of maximal expiratory flow in chronic obstructive lung disease

    NARCIS (Netherlands)

    H.A.W.M. Tiddens (Harm); J.M. Bogaard (Jan); J.C. de Jongste (Johan); W.C.J. Hop (Wim); H.O. Coxson (Harvey); P.D. Pare

    1996-01-01

    textabstractMaximal expiratory flow in chronic obstructive pulmonary disease (COPD) could be reduced by three different mechanisms; loss of lung elastic recoil, decreased airway conductance upstream of flow-limiting segments; and increased collapsibility of airways.

  8. Evaluation of Peak Expiratory Flow Rates (PEFR) of Workers in a ...

    African Journals Online (AJOL)

    DATONYE ALASIA

    and knowledge of occupational health associated with the ... the respiratory system with significant. 5 ... Peak Expiratory Flow Rates (PEFR) of workers in a cement factory — Douglas K. E, Alasia D. D. ... history of cigarette smoking and chronic.

  9. Peak expiratory flow variability, bronchial responsiveness, and susceptibility to ambient air pollution in adults

    NARCIS (Netherlands)

    Boezen, M; Schouten, Jan; Rijcken, B; Vonk, J; Gerritsen, J; Hoek, G; Brunekreef, B; Postma, D

    1998-01-01

    Bronchial hyperresponsiveness (BHR) and peak expiratory flow (PEF) variability are associated expressions of airway lability, yet probably reflect different underlying pathophysiologic mechanisms. We investigated whether both measures can be used interchangeably to identify subjects who are

  10. Use of tidal breathing curves for evaluating expiratory airway obstruction in infants.

    Science.gov (United States)

    Hevroni, Avigdor; Goldman, Aliza; Blank-Brachfeld, Miriam; Abu Ahmad, Wiessam; Ben-Dov, Lior; Springer, Chaim

    2018-01-15

    To evaluate tidal breathing (TB) flow-volume and flow-time curves for identification of expiratory airway obstruction in infants. Pulmonary function tests were analyzed retrospectively in 156 infants aged 3-24 months with persistent or recurrent respiratory complaints. Parameters derived from TB curves were compared to maximal expiratory flow at functional residual capacity ([Formula: see text]maxFRC) measured by rapid thoracoabdominal compression technique. Analyzed parameters were: inspiratory time (t I ), expiratory time (t E ), tidal volume, peak tidal expiratory flow (PTEF), time to peak tidal expiratory flow (t PTEF ), expiratory flow when 50% and 25% of tidal volume remains in the lungs (FEF 50 , FEF 25 , respectively), and the ratios t PTEF /t E , t I /t E , FEF 50 /PTEF, and FEF 25 /PTEF. Statistical comparisons between flow indices and TB parameters were performed using mean squared error and Pearson's sample correlation coefficient. The study population was also divided into two groups based on severity of expiratory obstruction (above or below z-score for [Formula: see text]maxFRC of -2) to generate receiver operating characteristic (ROC) curves and calculate discriminatory values between the groups. TB parameters that were best correlated to [Formula: see text]maxFRC were: t PTEF /t E , FEF 50 /PTEF, and FEF 25 /PTEF, with r = 0.61, 0.67, 0.65, respectively (p < 0.0001 for all). ROC curves for FEF 50 /PTEF, FEF 25 /PTEF and t PTEF /t E showed areas under the curve of 0.813, 0.797, and 0.796, respectively. Cutoff value z-scores of -0.35, -0.34, and -0.43 for these three parameters, respectively, showed an 86% negative predictive value for severe airway obstructions. TB curves can assist in ruling out severe expiratory airway obstruction in infants.

  11. Decreased peak expiratory flow in pediatric passive smokers

    Directory of Open Access Journals (Sweden)

    Fitri Yanti

    2011-08-01

    Full Text Available Background Indonesia ranks fifth among countries with the highest aggregate levels of tobacco consumption in the world. Infants and children exposed to environmental tobacco smoke have increased rates of asthma, respiratory and ear infections, as well as reduced lung function. The effects of tobacco smoke exposure on lung function in children have been reported to be dependent on the source of smoke and the length and dose of exposure. Lung function may also be affected by a child’s gender and asthma status. Objective To compare peak expiratory flow (PEF in pediatric passive smokers to that of children not exposed to second hand smoke, and to define factors that may affect PEF in passive smokers. Methods In August 2009 we conducted a cross-sectional study at an elementary school in the Langkat district. Subjects were aged 6 to 12 years, and divided into two groups: passive smokers and those not exposed to secondhand smoke. Subjects’ PEFs were measured with a Mini-Wright peak flow meter. Measurements were performed in triplicate with the highest value recorded as the PEF. Demographic data including age, sex, weight, height, family income, parental education levels and occupations were obtained through questionnaires. Results Of the 170 participants, 100 were passive smokers and 70 were not exposed to secondhand smoke. Age distribution, weight and height were similar in both groups. We observed a significant difference in PEFs between the group of passive smokers and the group not exposed to secondhand smoke, 211.3 L/minute (SD 61.08 and 242.7 L/minute (SD 77.09, respectively (P < 0.005. The number of years of exposure to smoke (P = 0.079 and the number of cigarettes smoked daily in the household (P = 0.098 did not significantly influence PEF. Conclusion The PEF in pediatric passive smokers was significantly lower than that of children not exposed to secondhand smoke. PEF in passive smokers was not influenced by the number of years of smoke

  12. Espirometria de incentivo com pressão positiva expiratória é benéfica após revascularização miocardio Espirometría incentivada con presión positiva espiratoria es beneficiosa después de revascularización de miocardio Incentive spirometry with expiratory positive airway pressure brings benefits after myocardial revascularization

    Directory of Open Access Journals (Sweden)

    Glória Menz Ferreira

    2010-02-01

    protocolo de EI+EPAP se realizó en el período postoperatorio inmediato y durante 4 semanas más en domicilio. Dieciocho meses después de la CRM se evaluaron la fuerza de la musculatura respiratoria, la capacidad funcional, la función pulmonar, la calidad de vida y el nivel de actividad física. RESULTADOS: Después del test de caminata de seis minutos (TC6, el score para disnea (1,6 ± 0,6 vs 0,6 ± 0,3, P BACKGROUND: Patients undergoing coronary artery bypass graft (CABG surgery have higher risk to develop pulmonary complications (PCs such as atelectasis, pneumonia and pleural effusion. These complications could increase the length of hospital stay, resources utilization and also are associated with reduced quality of life and functional capacity a long term. OBJECTIVE: To test if the use of incentive spirometry (IS associated with expiratory positive airway pressure (EPAP, after CABG surgery improves dyspnea, effort perceived and quality of life 18 months after CABG. METHODS: Sixteen patients submitted to a CABG, were randomized to a control group (n=8 or IS+EPAP group (n=8. The protocol of IS+EPAP was applied in the immediate postoperative period and following for more 4 weeks in the patient's home. Eighteen months after CABG, the strength of the respiratory muscle, the functional capacity, the lung function, the quality of life and the level of physical activity were evaluated. RESULTS: After six minute walk test (6-MWT, the score of the dyspnea (1.6±0.6 vs 0.6±0.3, P<0.05 and the perceived effort (13.4±1.2 vs 9.1±0.7, P<0.05 were higher in the control group, when compared with the IS+EPAP group. In quality of life evaluation, the domain related to the physical aspects limitations was better in IS+EPAP group (93.7±4.1 vs 50±17, P<0.02. CONCLUSION: Patients that were submitted to IS+EPAP present reduction of dyspnea and lower effort sensation after the 6-MWT, and also a better quality of life 18 months after CABG.

  13. Effect of patient position and PEEP on hepatic, portal and central venous pressures during liver resection.

    Science.gov (United States)

    Sand, L; Rizell, M; Houltz, E; Karlsen, K; Wiklund, J; Odenstedt Hergès, H; Stenqvist, O; Lundin, S

    2011-10-01

    It has been suggested that blood loss during liver resection may be reduced if central venous pressure (CVP) is kept at a low level. This can be achieved by changing patient position but it is not known how position changes affect portal (PVP) and hepatic (HVP) venous pressures. The aim of the study was to assess if changes in body position result in clinically significant changes in these pressures. We studied 10 patients undergoing liver resection. Mean arterial pressure (MAP) and CVP were measured using fluid-filled catheters, PVP and HVP with tip manometers. Measurements were performed in the horizontal, head up and head down tilt position with two positive end expiratory pressure (PEEP) levels. A 10° head down tilt at PEEP 5 cm H(2) O significantly increased CVP (11 ± 3 to 15 ± 3 mmHg) and MAP (72 ± 8 to 76 ± 8 mmHg) while head up tilt at PEEP 5 cm H(2) O decreased CVP (11 ± 3 to 6 ± 4 mmHg) and MAP (72 ± 8 to 63 ± 7 mmHg) with minimal changes in transhepatic venous pressures. Increasing PEEP from 5 to 10 resulted in small increases, around 1 mmHg in CVP, PVP and HVP. There was no significant correlation between changes in CVP vs. PVP and HVP during head up tilt and only a weak correlation between CVP and HVP by head down tilt. Changes of body position resulted in marked changes in CVP but not in HVPs. Head down or head up tilt to reduce venous pressures in the liver may therefore not be effective measures to reduce blood loss during liver surgery. 2011 The Authors Acta Anaesthesiologica Scandinavica, 2011 The Acta Anaesthesiologica Scandinavica Foundation.

  14. Right ventricular function during one-lung ventilation: effects of pressure-controlled and volume-controlled ventilation.

    Science.gov (United States)

    Al Shehri, Abdullah M; El-Tahan, Mohamed R; Al Metwally, Roshdi; Qutub, Hatem; El Ghoneimy, Yasser F; Regal, Mohamed A; Zien, Haytham

    2014-08-01

    To test the effects of pressure-controlled (PCV) and volume-controlled (VCV) ventilation during one-lung ventilation (OLV) for thoracic surgery on right ventricular (RV) function. A prospective, randomized, double-blind, controlled, crossover study. A single university hospital. Fourteen pairs of consecutive patients scheduled for elective thoracotomy. Patients were assigned randomly to ventilate the dependent lung with PCV or VCV mode, each in a randomized crossover order using tidal volume of 6 mL/kg, I: E ratio 1: 2.5, positive end-expiratory pressure (PEEP) of 5 cm H2O and respiratory rate adjusted to maintain normocapnia. Intraoperative changes in RV function (systolic and early diastolic tricuspid annular velocity (TAV), end-systolic volume (ESV), end-diastolic volume (EDV) and fractional area changes (FAC)), airway pressures, compliance and oxygenation index were recorded. The use of PCV during OLV resulted in faster systolic (10.1±2.39 vs. 5.8±1.67 cm/s, respectively), diastolic TAV (9.2±1.99 vs. 4.6±1.42 cm/s, respectively) (prights reserved.

  15. Cystic lung disease: a comparison of cystic size, as seen on expiratory and inspiratory HRCT scans

    International Nuclear Information System (INIS)

    Lee, Ki Nam; Yoon, Seong Kuk; Nam, Kyung Jin; Choi, Seok Jin; Goo, Jin Mo

    2000-01-01

    To determine the effects of respiration on the size of lung cysts by comparing inspiratory and expiratory high-resolution CT (HRCT) scans. The authors evaluated the size of cystic lesions, as seen on paired inspiratory and expiratory HRCT scans, in 54 patients with Langerhans cell histiocytosis (n = 3), pulmonary lymphangiomyomatosis (n = 4), confluent centrilobular emphysema (n = 9), paraseptal emphysema and bullae (n = 16), cystic bronchiectasis (n = 13), and honeycombing (n = 9). Using paired inspiratory and expiratory HRCT scans obtained at the corresponding anatomic level, a total of 270 cystic lesions were selected simultaneously on the basis of five lesions per lung disease. Changes in lung cyst size observed during respiration were assessed by two radiologists. In a limited number of cases (n = 11), pathologic specimens were obtained by open lung biopsy or lobectomy. All cystic lesions in patients with Langerhans cell histiocytosis, lymphangiomyomatosis, cystic bronchiectasis, honeycombing, and confluent centrilobular emphysema became smaller on expiration, but in two cases of paraseptal emphysema and bullae there was no change. In cases in which expiratory CT scans indicate that cysts have become smaller, cystic lesions may communicate with the airways. To determine whether, for cysts and cystic lesions, this connection does in fact exist, paired inspiratory and expiratory HRCT scans are necessary

  16. Cystic lung disease: a comparison of cystic size, as seen on expiratory and inspiratory HRCT scans

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki Nam; Yoon, Seong Kuk; Nam, Kyung Jin [Donga University College of Medicine, Pusan (Korea, Republic of); Choi, Seok Jin [Inje University College of Medicine, Gimhae (Korea, Republic of); Goo, Jin Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2000-06-01

    To determine the effects of respiration on the size of lung cysts by comparing inspiratory and expiratory high-resolution CT (HRCT) scans. The authors evaluated the size of cystic lesions, as seen on paired inspiratory and expiratory HRCT scans, in 54 patients with Langerhans cell histiocytosis (n = 3), pulmonary lymphangiomyomatosis (n = 4), confluent centrilobular emphysema (n = 9), paraseptal emphysema and bullae (n = 16), cystic bronchiectasis (n = 13), and honeycombing (n = 9). Using paired inspiratory and expiratory HRCT scans obtained at the corresponding anatomic level, a total of 270 cystic lesions were selected simultaneously on the basis of five lesions per lung disease. Changes in lung cyst size observed during respiration were assessed by two radiologists. In a limited number of cases (n = 11), pathologic specimens were obtained by open lung biopsy or lobectomy. All cystic lesions in patients with Langerhans cell histiocytosis, lymphangiomyomatosis, cystic bronchiectasis, honeycombing, and confluent centrilobular emphysema became smaller on expiration, but in two cases of paraseptal emphysema and bullae there was no change. In cases in which expiratory CT scans indicate that cysts have become smaller, cystic lesions may communicate with the airways. To determine whether, for cysts and cystic lesions, this connection does in fact exist, paired inspiratory and expiratory HRCT scans are necessary.

  17. Lung volume and expiratory flow rates from pre- to post-puberty.

    Science.gov (United States)

    Smith, Joshua R; Emerson, Sam R; Kurti, Stephanie P; Gandhi, Kirti; Harms, Craig A

    2015-08-01

    The purpose was to determine if the airways and lungs grow disproportionately from pre- to post-puberty in boys and girls. We hypothesized that the airways grow at a slower rate than lung volume (i.e. dysanapsis growth) during puberty and boys would exhibit more dysanaptic growth compared to girls. Twenty-one pre-pubescent children [11 boys (pre 10.1 ± 0.5 years, post 15.3 ± 0.5 years); 10 girls (pre 9.4 ± 1.0 years, post 14.1 ± 1.0 years)] performed pulmonary function tests (PFTs) ~5 years ago from an original cohort of 40 children. These 21 children performed PFTs, which included forced vital capacity (FVC) and forced expiratory flow at 50 % FVC (FEF50). Static pressure at 50 % of FVC [Pst(L)50 %] was estimated based on age. Dysanapsis ratio (DR) was calculated [FEF50 × FVC(-1) × Pst(L) 50 % (-1) ]. Maturation status was determined via Tanner stages. Stage of maturation was not different (p > 0.05) between boys and girls (4.2 ± 0.6 stage vs. 3.7 ± 0.7 stage, respectively). FVC and FEF50 increased (p 0.05) from pre- to post-puberty. FEF50 and FVC significantly increased and DR decreased (p puberty for both sexes. Post-puberty, boys had a significantly larger FVC, but FEF50, DR, and FEF50/FVC were not different (p > 0.05) compared to girls. These data suggest that dysanaptic growth occurs during puberty and that it is not different between boys and girls.

  18. Experimental intra-abdominal hypertension influences airway pressure limits for lung protective mechanical ventilation.

    Science.gov (United States)

    Cortes-Puentes, Gustavo A; Cortes-Puentes, Luis A; Adams, Alexander B; Anderson, Christopher P; Marini, John J; Dries, David J

    2013-06-01

    Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) may complicate monitoring of pulmonary mechanics owing to their impact on the respiratory system. However, recommendations for mechanical ventilation of patients with IAH/ACS and the interpretation of thoracoabdominal interactions remain unclear. Our study aimed to characterize the influence of elevated intra-abdominal pressure (IAP) and positive end-expiratory pressure (PEEP) on airway plateau pressure (PPLAT) and bladder pressure (PBLAD). Nine deeply anesthetized swine were mechanically ventilated via tracheostomy: volume-controlled mode at tidal volume (VT) of 10 mL/kg, frequency of 15, inspiratory-expiratory ratio of 1:2, and PEEP of 1 and 10 cm H2O (PEEP1 and PEEP10, respectively). A tracheostomy tube was placed in the peritoneal cavity, and IAP levels of 5, 10, 15, 20, and 25 mm Hg were applied, using a continuous positive airway pressure system. At each IAP level, PBLAD and airway pressure measurements were performed during both PEEP1 and PEEP10. PBLAD increased as experimental IAP rose (y = 0.83x + 0.5; R = 0.98; p < 0.001 at PEEP1). Minimal underestimation of IAP by PBLAD was observed (-2.5 ± 0.8 mm Hg at an IAP of 10-25 mm Hg). Applying PEEP10 did not significantly affect the correlation between experimental IAP and PBLAD. Approximately 50% of the PBLAD (in cm H2O) was reflected by changes in PPLAT, regardless of the PEEP level applied. Increasing IAP did not influence hemodynamics at any level of IAP generated. With minimal underestimation, PBLAD measurements closely correlated with experimentally regulated IAP, independent of the PEEP level applied. For each PEEP level applied, a constant proportion (approximately 50%) of measured PBLAD (in cm H2O) was reflected in PPLAT. A higher safety threshold for PPLAT should be considered in the setting of IAH/ACS as the clinician considers changes in VT. A strategy of reducing VT to cap PPLAT at widely recommended values may not be

  19. Changes in forced expiratory volume in 1 second over time in COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Edwards, Lisa D; Scanlon, Paul D

    2011-01-01

    A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce.......A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce....

  20. Work of breathing using different interfaces in spontaneous positive pressure ventilation: helmet, face-mask, and endotracheal tube.

    Science.gov (United States)

    Oda, Shinya; Otaki, Kei; Yashima, Nozomi; Kurota, Misato; Matsushita, Sachiko; Kumasaka, Airi; Kurihara, Hutaba; Kawamae, Kaneyuki

    2016-08-01

    Noninvasive positive pressure ventilation (NPPV) using a helmet is expected to cause inspiratory trigger delay due to the large collapsible and compliant chamber. We compared the work of breathing (WOB) of NPPV using a helmet or a full face-mask with that of invasive ventilation by tracheal intubation. We used a lung model capable of simulating spontaneous breathing (LUNGOO; Air Water Inc., Japan). LUNGOO was set at compliance (C) = 50 mL/cmH2O and resistance (R) = 5 cmH2O/L/s for normal lung simulation, C = 20 mL/cmH2O and R = 5 cmH2O/L/s for restrictive lung, and C = 50 mL/cmH2O and R = 20 cmH2O/L/s for obstructive lung. Muscle pressure was fixed at 25 cmH2O and respiratory rate at 20 bpm. Pressure support ventilation and continuous positive airway pressure were performed with each interface placed on a dummy head made of reinforced plastic that was connected to LUNGOO. We tested the inspiratory WOB difference between the interfaces with various combinations of ventilator settings (positive end-expiratory pressure 5 cmH2O; pressure support 0, 5, and 10 cmH2O). In the normal lung and restrictive lung models, WOB decreased more with the face-mask than the helmet, especially when accompanied by the level of pressure support. In the obstructive lung model, WOB with the helmet decreased compared with the other two interfaces. In the mixed lung model, there were no significant differences in WOB between the three interfaces. NPPV using a helmet is more effective than the other interfaces for WOB in obstructive lung disease.

  1. THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY

    Science.gov (United States)

    THE EFFECT OF SUBMAXIMAL INHALATION ON MEASURES DERIVED FROM FORCED EXPIRATORY SPIROMETRY. William F. McDonnell Human Studies Division, NHEERL, U.S. Environmental Protection Agency, RTP, NC 27711. Short-term exposure to ozone results in a neurally-mediated decrease in the ab...

  2. Exogenous stimuli and circadian peak expiratory flow variation in allergic asthmatic children

    NARCIS (Netherlands)

    Meijer, G. G.; Postma, D. S.; van der Heide, S.; de Reus, D. M.; Roorda, R. J.; Koëter, G. H.; van Aalderen, W. M.

    1996-01-01

    The influence of exogenous factors in the home on the circadian variation of airway obstruction has not been fully assessed in children with asthma. The aim of the present study was to investigate the contribution of exogenous stimuli to the degree of peak expiratory flow (PEF) variability during 24

  3. Seasonal variations in house dust mite influence the circadian peak expiratory flow amplitude

    NARCIS (Netherlands)

    Postma, DS; vanderHeide, S; deReus, DM; Koeter, GH; vanAalderen, WMC; Meijer, G.

    1996-01-01

    The aim of the study was to investigate whether seasonal differences in house dust mite (HDM) allergen exposure influence the circadian peak expiratory flow (PEF) amplitude in asthmatic children. Asthmatic children (n = 25) with a solitary allergy to HDM were studied in spring and in autumn. All

  4. Exogenous stimuli and circadian peak expiratory flow variation in allergic asthmatic children

    NARCIS (Netherlands)

    Postma, DS; VanderHeide, S; DeReus, DM; Koeter, GH; VanAalderen, WMC; Meijer, G.

    The influence of exogenous factors in the home on the circadian variation of airway obstruction has not been fully assessed in children with asthma. The aim of the present study was to investigate the contribution of exogenous stimuli to the degree of peak expiratory flow (PEF) variability during 24

  5. Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

    NARCIS (Netherlands)

    A.H. Kars (Alice); J.M. Bogaard (Jan); Th. Stijnen (Theo); J. de Vries; A.F.M. Verbraak (Anton); C. Hilvering

    1997-01-01

    textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate

  6. Changes in forced expiratory volume in 1 second over time in COPD

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Edwards, Lisa D; Scanlon, Paul D

    2011-01-01

    A key feature of chronic obstructive pulmonary disease (COPD) is an accelerated rate of decline in forced expiratory volume in 1 second (FEV(1)), but data on the variability and determinants of this change in patients who have established disease are scarce....

  7. Dynamic airway pressure-time curve profile (Stress Index): a systematic review.

    Science.gov (United States)

    Terragni, Pierpaolo; Bussone, Guido; Mascia, Luciana

    2016-01-01

    The assessment of respiratory mechanics at the bedside is necessary in order to identify the most protective ventilatory strategy. Indeed in the last 20 years, adverse effects of positive ventilation to the lung structures have led to a reappraisal of the objectives of mechanical ventilation. The ventilator setting requires repeated readjustment over the period of mechanical ventilation dependency and careful respiratory monitoring to minimize the risks, preventing further injury and permitting the lung and airways healing. Among the different methods that have been proposed and validated, the analysis of dynamic P-t curve (named Stress Index, SI) represents an adequate tool available at the bedside, repeatable and, therefore, able to identify the amount of overdistension occurring in the daily clinical practice, when modifying positive end-expiratory pressure. In this review we will analyze the evidence that supports respiratory mechanics assessment at the bedside and the application of the dynamic P/t curve profile (SI) to optimize protective ventilation in patients with acute respiratory failure.

  8. compliance of the respiratory system as a predictor for successful

    African Journals Online (AJOL)

    clinical, ventilatory and blood gas criteria were studied. ... pressure (PIP) and positive end-expiratory pressure (PEEP) represented ... criteria for extubation, we found that bedside measurement of total ... position in neutral head-neck posture.

  9. Age group classification and gender detection based on forced expiratory spirometry.

    Science.gov (United States)

    Cosgun, Sema; Ozbek, I Yucel

    2015-08-01

    This paper investigates the utility of forced expiratory spirometry (FES) test with efficient machine learning algorithms for the purpose of gender detection and age group classification. The proposed method has three main stages: feature extraction, training of the models and detection. In the first stage, some features are extracted from volume-time curve and expiratory flow-volume loop obtained from FES test. In the second stage, the probabilistic models for each gender and age group are constructed by training Gaussian mixture models (GMMs) and Support vector machine (SVM) algorithm. In the final stage, the gender (or age group) of test subject is estimated by using the trained GMM (or SVM) model. Experiments have been evaluated on a large database from 4571 subjects. The experimental results show that average correct classification rate performance of both GMM and SVM methods based on the FES test is more than 99.3 % and 96.8 % for gender and age group classification, respectively.

  10. Abdominal wall reconstruction for large incisional hernia restores expiratory lung function

    DEFF Research Database (Denmark)

    Jensen, Kristian K; Backer, Vibeke; Jorgensen, Lars N

    2017-01-01

    BACKGROUND: Respiratory complications secondary to intermittent intra-abdominal hypertension and/or atelectasis are common after abdominal wall reconstruction for large incisional hernias. It is unknown if the respiratory function of this patient group is affected long term or impairs activities...... of daily living. We hypothesized that abdominal wall reconstruction for large incisional hernia would not lead to improved, long-term pulmonary function or respiratory quality of life. METHODS: Eighteen patients undergoing open abdominal wall reconstruction with mesh for a large incisional hernia...... (horizontal fascial defect width >10 cm) were compared with 18 patients with an intact abdominal wall who underwent colorectal resection. Patients were examined pre- and 1-year postoperatively. Examined measures included forced vital capacity, forced expiratory volume in first second, peak expiratory flow...

  11. Segmentation of expiratory and inspiratory sounds in baby cry audio recordings using hidden Markov models.

    Science.gov (United States)

    Aucouturier, Jean-Julien; Nonaka, Yulri; Katahira, Kentaro; Okanoya, Kazuo

    2011-11-01

    The paper describes an application of machine learning techniques to identify expiratory and inspiration phases from the audio recording of human baby cries. Crying episodes were recorded from 14 infants, spanning four vocalization contexts in their first 12 months of age; recordings from three individuals were annotated manually to identify expiratory and inspiratory sounds and used as training examples to segment automatically the recordings of the other 11 individuals. The proposed algorithm uses a hidden Markov model architecture, in which state likelihoods are estimated either with Gaussian mixture models or by converting the classification decisions of a support vector machine. The algorithm yields up to 95% classification precision (86% average), and its ability generalizes over different babies, different ages, and vocalization contexts. The technique offers an opportunity to quantify expiration duration, count the crying rate, and other time-related characteristics of baby crying for screening, diagnosis, and research purposes over large populations of infants.

  12. Focal airtrapping at expiratory high-resolution CT: comparison with pulmonary function tests

    International Nuclear Information System (INIS)

    Kauczor, H.U.; Hast, J.; Heussel, C.P.; Mildenberger, P.; Thelen, M.; Schlegel, J.

    2000-01-01

    This study was undertaken to determine prevalence, extent, and severity of focal airtrapping at expiratory high-resolution CT, and to compare focal airtrapping with age, gender, pulmonary function tests, and blood gas analysis. Two-hundred seventeen patients with and without pulmonary disease underwent paired inspiratory/expiratory high-resolution CT. Six scan pairs with corresponding scan levels were visually assessed for focal - not diffuse - airtrapping using a four-point scale. Pulmonary function tests and blood gas analysis were available for correlation in all patients (mean interval 5 days). Focal airtrapping with lower lung predominance was observed in 80 % of patients. Twenty-six of 26 patients with restrictive lung function impairment exhibited focal airtrapping (mean score 2.4), whereas only 72 of 98 (74 %) patients with obstruction did (mean score 1.5; p < 0.05). Fifty-eight of 70 (83 %) patients with normal lung function (mean score 1.8) and 19 of 23 (83 %) patients with mixed impairment (mean score 1.8) had focal airtrapping. Focal airtrapping showed negative correlations with static lung volumes (-0.27 to -0.37; p < 0.001) in all patients and moderate positive correlations with dynamic parameters (0.3-0.4; p < 0.001) in patients with obstruction. No significant correlations were found with age, gender, and blood gas analysis. Visual assessment of focal - not diffuse - airtrapping at expiratory high-resolution CT does not correlate with physiological evidence of obstruction as derived from pulmonary function tests since the perception of focal airtrapping requires an adequate expiratory increase in lung density. (orig.)

  13. Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

    OpenAIRE

    Kars, Alice; Bogaard, Jan; Stijnen, Theo; Vries, J.; Verbraak, Anton; Hilvering, C.

    1997-01-01

    textabstractThe slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate (PIE), were investigated in 28 healthy control subjects, 12 asthma and 29 emphysema patients (20 severely obstructed and nine moderately obstructed) with the aim to establish diagnostic value. Because breath volume and frequenc...

  14. Thoracoabdominal mobility evaluation by photogrammetry in newborns after expiratory flow increase technique

    Directory of Open Access Journals (Sweden)

    Júlia Isabel de Araújo Guerra

    Full Text Available Abstract Introduction: Expiratory flow increase is a maneuver of respiratory physical therapy that promotes flow direction to the upper airways however, when applied in newborns, it may result in changes of thoracoabdominal mobility. Objective: To evaluate the thoracoabdominal mobility by photogrammetry in newborns after expiratory flow increase technique. Methods: Experimental blind study performed with newborns in supine position on a support table with upper limbs flexed, abducted and externally rotated and hip flexed at 110°. Adhesive markers were allocated for geometric delimitation of the thoracoabdominal compartment and expiratory flow increase technique was performed for 5 minutes with the therapist’s hands on the thorax and abdomen. Newborns were filmed before and after the maneuver and the frames were analyzed in AutoCAD® software by a blinded investigator at the time of the procedure. The largest and the smallest thoracoabdominal area were expressed in cm2 and the mean values were compared between two moments (pre and post maneuver by paired t test. Results: Twenty newborns with a mean age of 39 weeks were included. Before the maneuver, thoracoabdominal area was 56.1 cm2 during expiration and 59.7 cm2 during inspiration, and after the maneuver the value was 56.2 cm2 during expiration and 59.8 cm2 during inspiration, with no statistical difference between before and after (p = 0.97, p = 0.92, respectively. Conclusion: Results demonstrate that expiratory flow increase technique does not seem to change thoracoabdominal mobility of healthy newborns.

  15. Regional specific mean expiratory gas flow from Slmsub(Kr) equilibrium inhalation data

    International Nuclear Information System (INIS)

    Hamilton, D.; Causer, D.A.; McIntosh, J.A.; Godfrey, K.R.

    1985-01-01

    A new method of analysing the data available from routine sup(81m) Kr equilibrium inhalation investigations has been developed. The data for analysis are acquired from a gamma camera in the form of a sequential series of images from which multiple breath activity-time curves are generated for eight regions in the lung. The method is based on a description of the behaviour of the radioactive gas in the lung using a mathematical model. Values of specific mean expiratory gas flow, that is mean expiratory gas flow per unit lung volume, are calculated from the application of the model to the expiratory phase only only of a single breath activity-time curve which is generated from the multiple breath activity-time curve using post-acquisition gating. This method overcomes the problem of non-uniform inspiratory concentration of tracer gas experienced in previously reported techniques of analysing inhalation data obtained using poorly soluble radioactive gases. The model is shown, in simulation studies, to be an adequate description of the behaviour of radioactive gas in the lung and the analysis technique is shown, in clinical studies, to be both reproducible and sensitive to disease state. (orig.)

  16. High resolution CT in cystic fibrosis--the contribution of expiratory scans

    International Nuclear Information System (INIS)

    Dorloechter, Ludger; Nes, Harald; Fluge, Gjermund; Rosendahl, Karen

    2003-01-01

    Introduction: The use of high-resolution computed tomography (HRCT) is well accepted as an accurate method for evaluation of lung parenchyma in cystic fibrosis (CF). Several scoring methods exist and, in common, all are based on HRCT findings during inspiration alone. Objective: To examine whether expiratory HRCT scans could add information about the degree of mosaic perfusion in patients with CF. Methods and patients: Pulmonary HRCT was performed in 17 CF patients (median age of 12 years) with 1-mm thin sections and 10-mm intervals during inspiration, followed by 1-mm thin sections with 20-mm intervals during expiration. HRCT was scored by using a modified Bhalla method. Results: The mean HRCT score was 8.2. Out of 17 patients, 11 (65%) demonstrated a pathological mosaic perfusion in expiration, while only three patients showed mosaic perfusion in inspiration. The degree of expiratory mosaic perfusion was graded as severe in nine patients and moderate in two patients. There was a significant correlation between our modified HRCT score and lung function, as measured by forced expiratory volume in 1 s (FEV1% predicted, P<0.01). Conclusion: Mosaic perfusion in expiration was a common pathological HRCT finding in our study group. The clinical significance of this finding needs further evaluation

  17. Inspiratory and expiratory computed tomographic volumetry for lung volume reduction surgery.

    Science.gov (United States)

    Morimura, Yuki; Chen, Fengshi; Sonobe, Makoto; Date, Hiroshi

    2013-06-01

    Three-dimensional (3D) computed tomographic (CT) volumetry has been introduced into the field of thoracic surgery, and a combination of inspiratory and expiratory 3D-CT volumetry provides useful data on regional pulmonary function as well as the volume of individual lung lobes. We report herein a case of a 62-year-old man with severe emphysema who had undergone lung volume reduction surgery (LVRS) to assess this technique as a tool for the evaluation of regional lung function and volume before and after LVRS. His postoperative pulmonary function was maintained in good condition despite a gradual slight decrease 2 years after LVRS. This trend was also confirmed by a combination of inspiratory and expiratory 3D-CT volumetry. We confirm that a combination of inspiratory and expiratory 3D-CT volumetry might be effective for the preoperative assessment of LVRS in order to determine the amount of lung tissue to be resected as well as for postoperative evaluation. This novel technique could, therefore, be used more widely to assess local lung function.

  18. Effects of non-fatiguing respiratory muscle loading induced by expiratory flow limitation during strenuous incremental cycle exercise on metabolic stress and circulating natural killer cells.

    Science.gov (United States)

    Rolland-Debord, Camille; Morelot-Panzini, Capucine; Similowski, Thomas; Duranti, Roberto; Laveneziana, Pierantonio

    2017-12-01

    Exercise induces release of cytokines and increase of circulating natural killers (NK) lymphocyte during strong activation of respiratory muscles. We hypothesised that non-fatiguing respiratory muscle loading during exercise causes an increase in NK cells and in metabolic stress indices. Heart rate (HR), ventilation (VE), oesophageal pressure (Pes), oxygen consumption (VO 2 ), dyspnoea and leg effort were measured in eight healthy humans (five men and three women, average age of 31 ± 4 years and body weight of 68 ± 10 kg), performing an incremental exercise testing on a cycle ergometer under control condition and expiratory flow limitation (FL) achieved by putting a Starling resistor. Blood samples were obtained at baseline, at peak of exercise and at iso-workload corresponding to that reached at the peak of FL exercise during control exercise. Diaphragmatic fatigue was evaluated by measuring the tension time index of the diaphragm. Respiratory muscle overloading caused an earlier interruption of exercise. Diaphragmatic fatigue did not occur in the two conditions. At peak of flow-limited exercise compared to iso-workload, HR, peak inspiratory and expiratory Pes, NK cells and norepinephrine were significantly higher. The number of NK cells was significantly related to ΔPes (i.e. difference between the most and the less negative Pes) and plasmatic catecholamines. Loading of respiratory muscles is able to cause an increase of NK cells provided that activation of respiratory muscles is intense enough to induce a significant metabolic stress.

  19. Experimental Study of Dispersion and Deposition of Expiratory Aerosols in Aircraft Cabins and Impact on Infectious Disease Transmission

    DEFF Research Database (Denmark)

    To, G.N.S.; Wan, M.P.; Chao, C.Y.H.

    2009-01-01

    The dispersion and deposition characteristics of polydispersed expiratory aerosols were investigated in an aircraft cabin mockup to study the transmission of infectious diseases. The airflow was characterized by particle image velocimetry (PIV) measurements. Aerosol dispersionwas measured...

  20. Open-lung protective ventilation with pressure control ventilation, high-frequency oscillation, and intratracheal pulmonary ventilation results in similar gas exchange, hemodynamics, and lung mechanics.

    Science.gov (United States)

    Sedeek, Khaled A; Takeuchi, Muneyuki; Suchodolski, Klaudiusz; Vargas, Sara O; Shimaoka, Motomu; Schnitzer, Jay J; Kacmarek, Robert M

    2003-11-01

    Pressure control ventilation (PCV), high-frequency oscillation (HFO), and intratracheal pulmonary ventilation (ITPV) may all be used to provide lung protective ventilation in acute respiratory distress syndrome, but the specific approach that is optimal remains controversial. Saline lavage was used to produce acute respiratory distress syndrome in 21 sheep randomly assigned to receive PCV, HFO, or ITPV as follows: positive end-expiratory pressure (PCV and ITPV) and mean airway pressure (HFO) were set in a pressure-decreasing manner after lung recruitment that achieved a ratio of Pao2/Fio2 > 400 mmHg. Respiratory rates were 30 breaths/min, 120 breaths/min, and 8 Hz, respectively, for PCV, ITPV, and HFO. Eucapnia was targeted with peak carinal pressure of no more than 35 cm H2O. Animals were then ventilated for 4 h. There were no differences among groups in gas exchange, lung mechanics, or hemodynamics. Tidal volume (PCV, 8.9 +/- 2.1 ml/kg; ITPV, 2.7 +/- 0.8 ml/kg; HFO, approximately 2.0 ml/kg) and peak carinal pressure (PCV, 30.6 +/- 2.6 cm H2O; ITPV, 22.3 +/- 4.8 cm H2O; HFO, approximately 24.3 cm H2O) were higher in PCV. Pilot histologic data showed greater interstitial hemorrhage and alveolar septal expansion in PCV than in HFO or ITPV. These data indicate that HFO, ITPV, and PCV when applied with an open-lung protective ventilatory strategy results in the same gas exchange, lung mechanics, and hemodynamic response, but pilot data indicate that lung injury may be greater with PCV.

  1. Endotracheal tube resistance and inertance in a model of mechanical ventilation of newborns and small infants—the impact of ventilator settings on tracheal pressure swings

    International Nuclear Information System (INIS)

    Hentschel, Roland; Buntzel, Julia; Guttmann, Josef; Schumann, Stefan

    2011-01-01

    Resistive properties of endotracheal tubes (ETTs) are particularly relevant in newborns and small infants who are generally ventilated through ETTs with a small inner diameter. The ventilation rate is also high and the inspiratory time (ti) is short. These conditions effectuate high airway flows with excessive flow acceleration, so airway resistance and inertance play an important role. We carried out a model study to investigate the impact of varying ETT size, lung compliance and ventilator settings, such as peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP) and inspiratory time (ti) on the pressure–flow characteristics with respect to the resistive and inertive properties of the ETT. Pressure at the Y piece was compared to direct measurement of intratracheal pressure (P trach ) at the tip of the ETT, and pressure drop (ΔP ETT ) was calculated. Applying published tube coefficients (Rohrer's constants and inertance), P trach was calculated from ventilator readings and compared to measured P trach using the root-mean-square error. The most relevant for ΔP ETT was the ETT size, followed by (in descending order) PIP, compliance, ti and PEEP, with gas flow velocity being the principle in common for all these parameters. Depending on the ventilator settings ΔP ETT exceeded 8 mbar in the smallest 2.0 mm ETT. Consideration of inertance as an additional effect in this setting yielded a better agreement of calculated versus measured P trach than Rohrer's constants alone. We speculate that exact tracheal pressure tracings calculated from ventilator readings by applying Rohrer's equation and the inertance determination to small size ETTs would be helpful. As an integral part of ventilator software this would (1) allow an estimate of work of breathing and implementation of an automatic tube compensation, and (2) be important for gentle ventilation in respiratory care, especially of small infants, since it enables the physician to

  2. Hand grip strength and maximum peak expiratory flow: determinants of bone mineral density of adolescent students.

    Science.gov (United States)

    Cossio-Bolaños, Marco; Lee-Andruske, Cynthia; de Arruda, Miguel; Luarte-Rocha, Cristian; Almonacid-Fierro, Alejandro; Gómez-Campos, Rossana

    2018-03-02

    Maintaining and building healthy bones during the lifetime requires a complicated interaction between a number of physiological and lifestyle factors. Our goal of this study was to analyze the association between hand grip strength and the maximum peak expiratory flow with bone mineral density and content in adolescent students. The research team studied 1427 adolescent students of both sexes (750 males and 677 females) between the ages of 11.0 and 18.9 years in the Maule Region of Talca (Chile). Weight, standing height, sitting height, hand grip strength (HGS), and maximum peak expiratory flow (PEF) were measured. Furthermore, bone mineral density (BMD) and total body bone mineral content (BMC) were determined by using the Dual-Energy X-Ray Absorptiometry (DXA). Hand grip strength and PEF were categorized in tertiles (lowest, middle, and highest). Linear regression was performed in steps to analyze the relationship between the variables. Differences between categories were determined through ANOVA. In males, the hand grip strength explained 18-19% of the BMD and 20-23% of the BMC. For the females, the percentage of variation occurred between 12 and 13% of the BMD and 17-18% of the BMC. The variation of PEF for the males was observed as 33% of the BMD and 36% of the BMC. For the females, both the BMD and BMC showed a variation of 19%. The HGS and PEF were divided into three categories (lowest, middle, and highest). In both cases, significant differences occurred in bone density health between the three categories. In conclusion, the HGS and the PEF related positively to the bone density health of both sexes of adolescent students. The adolescents with poor values for hand grip strength and expiratory flow showed reduced values of BMD and BMC for the total body. Furthermore, the PEF had a greater influence on bone density health with respect to the HGS of the adolescents of both sexes.

  3. Effect of pilates method on inspiratory and expiratory muscle strength in the elderly

    Directory of Open Access Journals (Sweden)

    Beatriz Mendes Tozim

    2018-03-01

    Full Text Available With aging, the respiratory muscle strength decreases and the pilates method is a technique that uses respiration as one of its principles. The present study has the aim of analyzing the influence of the pilates method on respiratory muscle strength in older women. For the evaluation of respiratory muscle strength (inspiratory and expiratory, manovacuometer was used. Thirty-one older women were divided into two groups: 14 participated in the pilates group and 17 in the control group. Participants of the pilates group performed 16 sessions of pilates method with an hour of training, twice week for eight weeks. The control group participated in four educational lectures for eight weeks. For statistical analysis, Shapiro-Wilk, ANOVA for repeated measures (p <0.05 and Cohen’s D index were performed. The results showed significant difference and the mean effect for the Cohen’s D index expiratory muscle strength of the pilates group when comparing before (69.71 ± 25.48 and after (85.23 ± 22.21 training (p<0.05 with an increase of 23%. The results of inspiratory muscle strength were not significant but presented an average effect for the Cohen’s D index for the pilates group before (69.71 ± 35.46 and after (88.00 ± 34.87 training, with an increase of 27%. The control group did not present significant differences for the variables evaluated. It could be concluded that the pilates method is effective in improving expiratory muscle strength and provides positive effects on the increase in inspiratory muscle strength.

  4. Modeling the Fate of Expiratory Aerosols and the Associated Infection Risk in an Aircraft Cabin Environment

    DEFF Research Database (Denmark)

    Wan, M.P.; To, G.N.S.; Chao, C.Y.H.

    2009-01-01

    to estimate the risk of infection by contact. The environmental control system (ECS) in a cabin creates air circulation mainly in the lateral direction, making lateral dispersions of aerosols much faster than longitudinal dispersions. Aerosols with initial sizes under 28 m in diameter can stay airborne......The transport and deposition of polydispersed expiratory aerosols in an aircraft cabin were simulated using a Lagrangian-based model validated by experiments conducted in an aircraft cabin mockup. Infection risk by inhalation was estimated using the aerosol dispersion data and a model was developed...

  5. Effect of the radiofrequency volumetric tissue reduction of inferior turbinate on expiratory nasal sound frequency.

    Science.gov (United States)

    Seren, Erdal

    2009-01-01

    We sought to evaluate the short-term efficacy of radiofrequency volumetric tissue reduction (RFVTR) in treatment of inferior turbinate hypertrophy (TH) as measured by expiratory nasal sound spectra. In our study, we aimed to investigate the Odiosoft-rhino (OR) as a new diagnostic method to evaluate the nasal airflow of patients before and after RFVTR. In this study, we have analyzed and recorded the expiratory nasal sound in patients with inferior TH before and after RFVTR. This analysis includes the time expanded waveform, the spectral analysis with time averaged fast Fourier transform (FFT), and the waveform analysis of nasal sound. We found an increase in sound intensity at high frequency (Hf) in the sound analyses of the patients before RFVTR and a decrease in sound intensity at Hf was found in patients after RFVTR. This study indicates that RFVTR is an effective procedure to improve nasal airflow in the patients with nasal obstruction with inferior TH. We found significant decreases in the sound intensity level at Hf in the sound spectra after RFVTR. The OR results from the 2000- to 4000-Hz frequency (Hf) interval may be more useful in assessing patients with nasal obstruction than other frequency intervals. OR may be used as a noninvasive diagnostic tool to evaluate the nasal airflow.

  6. Airborne spread of expiratory droplet nuclei between the occupants of indoor environments: A review.

    Science.gov (United States)

    Ai, Z T; Melikov, A K

    2018-07-01

    This article reviews past studies of airborne transmission between occupants in indoor environments, focusing on the spread of expiratory droplet nuclei from mouth/nose to mouth/nose for non-specific diseases. Special attention is paid to summarizing what is known about the influential factors, the inappropriate simplifications of the thermofluid boundary conditions of thermal manikins, the challenges facing the available experimental techniques, and the limitations of available evaluation methods. Secondary issues are highlighted, and some new ways to improve our understanding of airborne transmission indoors are provided. The characteristics of airborne spread of expiratory droplet nuclei between occupants, which are influenced correlatively by both environmental and personal factors, were widely revealed under steady-state conditions. Owing to the different boundary conditions used, some inconsistent findings on specific influential factors have been published. The available instrumentation was too slow to provide accurate concentration profiles for time-dependent evaluations of events with obvious time characteristics, while computational fluid dynamics (CFD) studies were mainly performed in the framework of inherently steady Reynolds-averaged Navier-Stokes modeling. Future research needs in 3 areas are identified: the importance of the direction of indoor airflow patterns, the dynamics of airborne transmission, and the application of CFD simulations. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Cystic Fibrosis: Are Volumetric Ultra-Low-Dose Expiratory CT Scans Sufficient for Monitoring Related Lung Disease?

    DEFF Research Database (Denmark)

    Loeve, Martine; Lequin, Maarten H; Bruijne, Marleen de

    2009-01-01

    Purpose: To assess whether chest computed tomography (CT) scores from ultra-low-dose end-expiratory scans alone could suffice for assessment of all cystic fibrosis (CF)-related structural lung abnormalities. Materials and Methods: In this institutional review board–approved study, 20 patients...... with CF aged 6–20 years (eight males, 12 females) underwent low-dose end-inspiratory CT and ultra-low-dose end-expiratory CT. Informed consent was obtained. Scans were randomized and scored by using the Brody-II CT scoring system to assess bronchiectasis, airway wall thickening, mucus plugging......-Altman plots. Results: Median age was 12.6 years (range, 6.3–20.3 years), median forced expiratory volume in 1 second was 100% (range, 46%–127%) of the predicted value, and median forced vital capacity was 99% (range, 61%–123%) of the predicted value. Very good agreement was observed between end...

  8. TU-CD-BRA-11: Application of Bone Suppression Technique to Inspiratory/expiratory Chest Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, R; Sanada, S [Kanazawa University, Kanazawa, Ishikawa (Japan); Sakuta, K; Kawashima, H [Kanazawa University Hospital, Kanazawa, Ishikawa (Japan); Kishitani, Y [TOYO Corporation, Chuoh-ku, Tokyo (Japan)

    2015-06-15

    Purpose: The bone suppression technique based on advanced image processing can suppress the conspicuity of bones on chest radiographs, creating soft tissue images normally obtained by the dual-energy subtraction technique. This study was performed to investigate the usefulness of bone suppression technique in quantitative analysis of pulmonary function in inspiratory/expiratory chest radiography. Methods: Commercial bone suppression image processing software (ClearRead; Riverain Technologies) was applied to paired inspiratory/expiratory chest radiographs of 107 patients (normal, 33; abnormal, 74) to create corresponding bone suppression images. The abnormal subjects had been diagnosed with pulmonary diseases, such as pneumothorax, pneumonia, emphysema, asthma, and lung cancer. After recognition of the lung area, the vectors of respiratory displacement were measured in all local lung areas using a cross-correlation technique. The measured displacement in each area was visualized as displacement color maps. The distribution pattern of respiratory displacement was assessed by comparison with the findings of lung scintigraphy. Results: Respiratory displacement of pulmonary markings (soft tissues) was able to be quantified separately from the rib movements on bone suppression images. The resulting displacement map showed a left-right symmetric distribution increasing from the lung apex to the bottom region of the lung in many cases. However, patients with ventilatory impairments showed a nonuniform distribution caused by decreased displacement of pulmonary markings, which were confirmed to correspond to area with ventilatory impairments found on the lung scintigrams. Conclusion: The bone suppression technique was useful for quantitative analysis of respiratory displacement of pulmonary markings without any interruption of the rib shadows. Abnormal areas could be detected as decreased displacement of pulmonary markings. Inspiratory/expiratory chest radiography combined

  9. Peak expiratory flow rate in healthy children aged 6-17 years

    DEFF Research Database (Denmark)

    Høst, A; Høst, A H; Ibsen, T

    1994-01-01

    Peak expiratory flow rate (PEFR) was measured in a cross-sectional study in 861 healthy Danish schoolchildren aged 6-17 years using a Mini Wright peak flowmeter. We found a strong correlation between PEFR and height, age and sex. The results were comparable with those from previous studies using...... a Wright peak flowmeter. The equation for prediction of PEFR in boys was calculated as (3.8 x height) + (10.6 x age) - 313.2 (p age) - 143.9 (p ... coefficient in this large sample. Among healthy children without previous asthma, earlier episodes of recurrent wheezing were reported in 8.8% and a significantly lower PEFR was found in this group....

  10. Validity of peak expiratory flow measurement in assessing reversibility of airflow obstruction.

    Science.gov (United States)

    Dekker, F W; Schrier, A C; Sterk, P J; Dijkman, J H

    1992-01-01

    BACKGROUND: Assessing the reversibility of airflow obstruction by peak expiratory (PEF) measurements would be practicable in general practice, but its usefulness has not been investigated. METHODS: PEF measurements were performed (miniWright peak flow meter) in 73 general practice patients (aged 40 to 84) with a history of asthma or chronic obstructive lung disease before and after 400 micrograms inhaled sulbutamol. The change in PEF was compared with the change in forced expiratory volume in one second (FEV1). Reversible airflow obstruction was analysed in two ways according to previous criteria. When defined as a 9% or greater increase in FEV1 expressed as a percentage of predicted values reversibility was observed in 42% of patients. Relative operating characteristic analysis showed that an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (the sensitivity and specificity of an increase of 60 l/min in detecting a 9% or more increase in FEV1 as a percentage of predicted values were 68% and 93% respectively, with a positive predictive value of 87%). When defined as an increase of 190 ml or more in FEV1, reversible airflow obstruction was observed in 53% of patients. Again an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (sensitivity 56%, specificity 94%, and positive predictive value 92%). CONCLUSION: Absolute changes in PEF can be used as a simple technique to diagnose reversible airflow obstruction in patients from general practice. PMID:1519192

  11. Pulmonary emphysema quantitation with Computed Tomography. Comparison between the visual score with high resolution CT, expiratory density mask with spiral CT and lung function studies

    International Nuclear Information System (INIS)

    Zompatori, Maurizio; Battaglia, Milva; Rimondi, Maria Rita; Vivacqua, Donatella; Biscarini, Manuela; Fasano, Luca; Pacilli, Angela Maria Grazia; Guerrieri, Aldo; Fabbri, Mario; Cavina, Mauro

    1997-01-01

    CT is the most accurate method to detect pulmonary emphysema in vivo. They compared prospectively two different methods for emphysema quantitation in 5 normal volunteers and 20 consecutive patients with chronic obstructive pulmonary disease (COPD). All subjects were submitted to function tests and HRCT; three scans were acquired at preselected levels during inspiration. The type and extent of pulmonary emphysema were defined by two independent observers under blind conditions. Disagreements were subsequently settled by consent. All subjects were also examined with expiratory spiral CT using a density mask program, at two different cut-off levels (-850,-900 HU). Visual score and expiratory spiral density mask values (-850 HU) were significantly correlated (r = 0.86), but the visual extent of emphysema was always higher than shown by expiratory spiral CT. The emphysema extent assessed with both CT methods correlated with the function result of expiratory airflow obstruction and gas diffusion impairment (visual score versus forced expiratory volume in one second: r = -0.81, versus single breath carbon monoxide diffusion: r = -0.78. Spiral expiratory density mask -850 HU versus forced expiratory volume in one second: r = -0.85 versus single breath carbon monoxide diffusion: r = -0.77). When -900 HU was used as the cut-off value for the expiratory density mask, the correlation with single breath carbon monoxide diffusion worsened (r = -0.56). Visual score and expiratory density mask -850 HU gave similar results and permitted COPD patients to be clearly distinguished from normal controls (p < 0.01). They believe the true residual volume should lie somewhere in between the CT value and the function results with the helium dilution technique and conclude that the extent of pulmonary emphysema can be confidently assessed with CT methods. Finally, the simple visual score may be as reliable as such highly sophisticated new methods as the spiral expiratory density mask

  12. Moderately high frequency ventilation with a conventional ventilator allows reduction of tidal volume without increasing mean airway pressure.

    Science.gov (United States)

    Cordioli, Ricardo Luiz; Park, Marcelo; Costa, Eduardo Leite Vieira; Gomes, Susimeire; Brochard, Laurent; Amato, Marcelo Britto Passos; Azevedo, Luciano Cesar Pontes

    2014-12-01

    The aim of this study was to explore if positive-pressure ventilation delivered by a conventional ICU ventilator at a moderately high frequency (HFPPV) allows a safe reduction of tidal volume (V T) below 6 mL/kg in a porcine model of severe acute respiratory distress syndrome (ARDS) and at a lower mean airway pressure than high-frequency oscillatory ventilation (HFOV). This is a prospective study. In eight pigs (median weight 34 [29,36] kg), ARDS was induced by pulmonary lavage and injurious ventilation. The animals were ventilated with a randomized sequence of respiratory rates: 30, 60, 90, 120, 150, followed by HFOV at 5 Hz. At each step, V T was adjusted to allow partial pressure of arterial carbon dioxide (PaCO2) to stabilize between 57 and 63 mmHg. Data are shown as median [P25th,P75th]. After lung injury, the PaO2/FiO2 (P/F) ratio was 92 [63,118] mmHg, pulmonary shunt 26 [17,31]%, and static compliance 11 [8,14] mL/cmH2O. Positive end-expiratory pressure (PEEP) was 14 [10,17] cmH2O. At 30 breaths/min, V T was higher than 6 (7.5 [6.8,10.2]) mL/kg, but at all higher frequencies, V T could be reduced and PaCO2 maintained, leading to reductions in plateau pressures and driving pressures. For frequencies of 60 to 150/min, V T progressively fell from 5.2 [5.1,5.9] to 3.8 [3.7,4.2] mL/kg (p mechanics, auto-PEEP generation, hemodynamics, or gas exchange. Mean airway pressure was maintained constant and was increased only during HFOV. During protective mechanical ventilation, HFPPV delivered by a conventional ventilator in a severe ARDS swine model safely allows further tidal volume reductions. This strategy also allowed decreasing airway pressures while maintaining stable PaCO2 levels.

  13. Comparisons of different mean airway pressure settings during high-frequency oscillation in inflammatory response to oleic acid-induced lung injury in rabbits

    Directory of Open Access Journals (Sweden)

    Koichi Ono

    2009-03-01

    Full Text Available Koichi Ono1, Tomonobu Koizumi2, Rikimaru Nakagawa1, Sumiko Yoshikawa2, Tetsutarou Otagiri11Department of Anesthesiology and Resuscitation; 2First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, JapanPurpose: The present study was designed to examine effects of different mean airway pressure (MAP settings during high-frequency oscillation (HFO on oxygenation and inflammatory responses to acute lung injury (ALI in rabbits.Methods: Anesthetized rabbits were mechanically ventilated with a conventional mechanical ventilation (CMV mode (tidal volume 6 ml/kg, inspired oxygen fraction [FIo2] of 1.0, respiratory rate [RR] of 30/min, positive end-expiratory pressure [PEEP] of 5 cmH2O. ALI was induced by intravenous administration of oleic acid (0.08 ml/kg and the animals were randomly allocated to the following three experimental groups; animals (n = 6 ventilated using the same mode of CMV, or animals ventilated with standard MAP (MAP 10 cmH2O, n = 7, and high MAP (15 cmH2O, n = 6 settings of HFO (Hz 15. The MAP settings were calculated by the inflation limb of the pressure-volume curve during CMV.Results: HFO with a high MAP setting significantly improved the deteriorated oxygenation during oleic acid-induced ALI and reduced wet/dry ratios, neutrophil counts and interleukin-8 concentration in bronchoalveolar lavage fluid, compared to those parameters in CMV and standard MAP-HFO.Conclusions: These findings suggest that only high MAP setting during HFO could contribute to decreased lung inflammation as well as improved oxygenation during the development of ALI.Keywords: lung protective ventilation, open lung ventilation, IL-8, neutrophil

  14. Early warning and prevention of pneumonia in acute leukemia by patient education, spirometry, and positive expiratory pressure

    DEFF Research Database (Denmark)

    Møller, Tom; Moser, Claus; Adamsen, Lis

    2016-01-01

    Long-lasting neutropenia associated with acute myeloid leukemia (AML) and its treatment gives rise to a high risk of pneumonia. The use of broad-spectrum antibiotic prophylaxis during outpatient management has not completely protected patients against admission due to infections and neutropenic...... in their continuous daily measurement of FEV1 and use of PEP. Daily measures of FEV1 may be an important early warning tool for assessment of pulmonary deterioration during critical phases of neutropenia. We suggest that strategic patient education in the use of spirometry and PEP should be part of standard of care...

  15. PROGRESSIVE MUSCLE RELAXATION INCREASE PEAK EXPIRATORY FLOW RATE ON CHRONIC OBSTRUCTIVE PULMONARY DISEASE PATIENTS

    Directory of Open Access Journals (Sweden)

    Tintin Sukartini

    2017-07-01

    Full Text Available Introduction: Limited progressive air flow in Chronic Obstructive Pulmonary Disease (COPD can caused by small airway disease (bronchiolitis obstructive and loss of elasticity of the lung (emphysema. Further it can be decreasing the quality of life in COPD patients because dyspnea and uncomfortable in activity. Progressive muscle relaxation (PMR is one of the relaxation technique that can repair pulmonary ventilation by decreasing chronic constriction of the respiratory muscles. The objective of this study was to analyze the effect of progressive muscle relaxation on raised peak expiratory flow rate (PEFR. Method: A pre-experimental one group pre-post test design was used in this study. Population was all of the COPD patients at Pulmonary Specialist Polyclinic Dr Mohamad Soewandhie Surabaya. There were 8 respondents taken by using purposive sampling. PEFR was counted by using peak flow meter every six day. Data were analyzed by using Paired t-Test with significance level  p≤0.05. Result: The result showed that PMR had significance level on increasing of PEFR (p=0.012. Discussion: It can be concluded that PMR has an effect on raise PEFR. Further studies are recommended to measure the effect of PMR on respiratory rate (RR, heart rate (HR subjective dyspnoe symptoms, forced expiration volume on the first minute (FEV1 and mid maximum flow rate (MMFR in COPD patients.

  16. Peak expiratory flow rate (PEFR) among Nuclear Fuel Complex (NFC) employees

    International Nuclear Information System (INIS)

    Vijay Rao, J.; Venkaiah, K.; Mohan Rao, N.

    2010-01-01

    At Nuclear Fuel Complex (NFC), employees are exposed to ammonia, hydrofluoric acid, acetone, etc., which are respiratory toxicants and inhalation of these pollutants may produce irritation and obstruction in airways. Due to nature of their occupation, tradesman working in plants are having longer duration of exposure (LDE) and others, such as supervisors, scientific officers, helpers, etc., that occasionally visit plants are having shorter duration of exposure (SDE) to these pollutants. The peak expiratory flow rate (PEFR) is an index to diagnose obstruction in larger airways and this is metered with mini peak flow meter among 835 NFC employees. Using ANOVA test, PEFR value was compared according to age and smoking. The value was compared between LDE and SDE employees according to smoking and duration of employment. The multiple regression equation for prediction of PEFR was developed. Age, smokers and higher duration of LDE employees demonstrated significantly lower PEFR value. In comparison to 10 year duration, 30 and above year duration of employment, LDE employees showed a higher decline in PEFR, that is 95 L (17.6%) and in SDE employees, that is 41L (7.8%). This may be due to longer duration of employment of LD employees smoking prevention and follow up study is suggested. (author)

  17. Peak expiratory flow as a predictor for the effectiveness of sport for patients with COPD.

    Science.gov (United States)

    Jungblut, S; Frickmann, H; Klingler, J; Zimmermann, B; Bargon, Joachim

    2006-01-31

    This study intended to find simple parameters that were able to determine the increase in physical performance as a result of sport in a group of patients with COPD (lung sport). We regularly investigated pulse, oxygenation and peak expiratory flow in participants with COPD of a "lung sport group", who participated in a structured weekly training program under professional supervision. Ten volunteers (7 females, 3 males, median of age = 69) with COPD (grade II-III) took part in the study. - The relative changes after 3 and 6 months were compared with the values of the first month of exercise. Measurements were carried out before exercise, after stamina training and at the end of the program. - Pulse and oxygenation did not show any changes. However, there was a significant improvement of peak flow after 6 months. - These peak flow changes represent further evidence of positive effects of sport in COPD and provide a parameter which allows the patients themselves to measure and evaluate the success of their physical activity.

  18. Prediction of Spirometric Forced Expiratory Volume (FEV1) Data Using Support Vector Regression

    Science.gov (United States)

    Kavitha, A.; Sujatha, C. M.; Ramakrishnan, S.

    2010-01-01

    In this work, prediction of forced expiratory volume in 1 second (FEV1) in pulmonary function test is carried out using the spirometer and support vector regression analysis. Pulmonary function data are measured with flow volume spirometer from volunteers (N=175) using a standard data acquisition protocol. The acquired data are then used to predict FEV1. Support vector machines with polynomial kernel function with four different orders were employed to predict the values of FEV1. The performance is evaluated by computing the average prediction accuracy for normal and abnormal cases. Results show that support vector machines are capable of predicting FEV1 in both normal and abnormal cases and the average prediction accuracy for normal subjects was higher than that of abnormal subjects. Accuracy in prediction was found to be high for a regularization constant of C=10. Since FEV1 is the most significant parameter in the analysis of spirometric data, it appears that this method of assessment is useful in diagnosing the pulmonary abnormalities with incomplete data and data with poor recording.

  19. Breath-by-breath analysis of expiratory gas concentration in chickens.

    Science.gov (United States)

    Itabisashi, T

    1981-01-01

    Expiratory oxygen and carbon-dioxide concentration were analysed breath by breath in order to examine their wave forms in adult awake hens restrained in various postural positions, including supine, prone and sitting positions. Expired gas was collected at the nostril in almost all the hens. In the sitting position free from vocalization, feeding, drinking, panting, and restlessness, hens showed various forms of stable pattern of oxygen-gas curves. These forms were classified into three types, or the ascending, flat and descending types, with respect to the plateau inclination. The waves of carbon-dioxide were not always a mirror image of those of oxygen. The rate of occurrence of each type varied with the hen's postural position. The wave form was altered with the experimental body-rotation of the hen. When placed between the deflections of stable pattern, the episodes of wave deformation resembling that seen at the time of uneven pulmonary ventilation in mammals could frequently be observed in any hen's posture examined. Cardiogenic oscillation appeared on the plateau of expired-gas curves.

  20. The effects of smokeless cookstoves on peak expiratory flow rates in rural Honduras.

    Science.gov (United States)

    Rennert, W P; Porras Blanco, R M; Muniz, G B

    2015-09-01

    The use of biomass fuel for cooking in traditional cookstove designs negatively affects respiratory health of communities in developing countries. Indoor pollution affects particularly women and children, who are participating in food preparation. The effects of smokeless cookstove designs on indoor pollution are well documented, but few studies exist to assess the effects of improved stove designs on the respiratory health of community members. This study uses peak expiratory flow rate (PEFR) measurements in a before-and-after format to assess respiratory function of inhabitants of all 30 houses of Buenas Noches in central Honduras. PEFRs are measured before and 6 months after the installation of Justa stoves in people's homes. Health behaviors, respiratory symptoms and fire wood use are evaluated in a door-to-door survey format. A total of 137 eligible women and children between 6 and 14 years participated in the study. PEFR improved by 9.9-18.5% (P < 0.001) depending on the participants' exposure to indoor pollution. Health complaints like cough and behaviors like clinic visits did not change with the introduction of smokeless cookstove technology. Smokeless stoves improve respiratory health in an environment of high levels of indoor pollution. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. The longitudinal relationship of work stress with peak expiratory flow: a cohort study.

    Science.gov (United States)

    Loerbroks, Adrian; Karrasch, Stefan; Lunau, Thorsten

    2017-10-01

    Research has suggested that psychological stress is associated with reduced lung function and with the development of respiratory disease. Among the major potential sources of stress in adulthood are working conditions. We aimed to examine the relationship of work stress with lung function. We drew on 4-year prospective data from the Survey of Health, Ageing and Retirement in Europe. The analyzed sample comprised 2627 workers aged 50 years or older who were anamnestically free of respiratory disease. Work stress at baseline was operationalized by abbreviated instruments measuring the well-established effort-reward imbalance model (seven items) and the control component of the job-demand control (two items). Peak expiratory flow (PEF) was determined at baseline and at follow-up. Continuous and categorized (i.e., by the tertile) work stress variables were employed in multivariable linear regression models to predict PEF change. Work stress did not show statistically significant associations with PEF change. For instance, the unstandardized regression coefficient for PEF decline according to high versus low effort-reward imbalance was -1.41 (95% confidence interval = -3.75, 0.94). Our study is the first to examine prospective relationships between work stress and PEF. Overall, we did not observe meaningful associations. Future studies should consider a broader spectrum of spirometric parameters and should expand research to younger and possibly less-selected working populations (i.e., aged <50 years).

  2. Expiratory flow limitation and operating lung volumes during exercise in older and younger adults.

    Science.gov (United States)

    Smith, Joshua R; Kurti, Stephanie P; Meskimen, Kayla; Harms, Craig A

    2017-06-01

    We determined the effect of aging on expiratory flow limitation (EFL) and operating lung volumes when matched for lung size. We hypothesized that older adults will exhibit greater EFL and increases in EELV during exercise compared to younger controls. Ten older (5M/5W; >60years old) and nineteen height-matched young adults (10M/9W) were recruited. Young adults were matched for%predicted forced vital capacity (FVC) (Y-matched%Pred FVC; n=10) and absolute FVC (Y-matched FVC; n=10). Tidal flow-volume loops were recorded during the incremental exercise test with maximal flow-volume loops measured pre- and post-exercise. Compared to younger controls, older adults exhibited more EFL at ventilations of 26, 35, 51, and 80L/min. The older group had higher end-inspiratory lung volume compared to Y-matched%Pred FVC group during submaximal ventilations. The older group increased EELV during exercise, while EELV stayed below resting in the Y-matched%Pred FVC group. These data suggest older adults exhibit more EFL and increase EELV earlier during exercise compared to younger adults. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Can Preoperative Peak Expiratory Flow Predict Postoperative Pulmonary Complications in Lung Cancer Patients Undergoing Lobectomy?

    Directory of Open Access Journals (Sweden)

    Kun ZHOU

    2017-09-01

    Full Text Available Background and objective Postoperative pulmonary complications (PPCs, especially postoperative pneumonia (POP, directly affect the rapid recovery of lung cancer patients after surgery. Peak expiratory flow (PEF can reflect airway patency and cough efficiency. Moreover, cough impairment may lead to accumulation of pulmonary secretions which can increase the risk of PPCs. The aim of this study is to investigate the effect of preoperative PEF on PPCs in patients with lung cancer. Methods Retrospective research was conducted on 433 lung cancer patients who underwent lobectomy at the West China Hospital of Sichuan University from January 2014 to December 2015. The associations between preoperative PEF and PPCs were analyzed based on patients’ basic characteristics and clinical data in hospital. Results Preoperative PEF value in PPCs group (280.93±88.99 L/min was significantly lower than that in non-PPCs group (358.38±93.69 L/min (P320 L/min group (9.4%(P<0.001. Conclusion Preoperative PEF and PPCs are correlated, and PEF may be used as a predictor of PPCs.

  4. Analysis of the static pressure volume curve of the lung in experimentally induced pulmonary damage by CT-densitometry

    International Nuclear Information System (INIS)

    David, M.; Karmrodt, J.; Herwelling, A.; Bletz, C.; David, S.; Heussel, C.P.; Markstaller, K.

    2005-01-01

    Purpose: To study quantitative changes of lung density distributions when recording in- and expiratory static pressure-volume curves by single slice computed tomography (CT). Materials and Methods: Static in- and expiratory pressure volume curves (0 to 1000 ml, increments of 100 ml) were obtained in random order in 10 pigs after induction of lung damage by saline lavage. Simultaneously, CT acquisitions (slice thickness 1 mm, temporal increment 2 s) were performed in a single slice (3 cm below the carina). In each CT image lung segmentation and planimetry of defined density ranges were achieved. The lung density ranges were defined as: hyperinflated (-1024 to -910 HU), normal aerated (-910 to -600 HU), poorly aerated (-600 to -300 HU), and non aerated (-300 to 200 HU) lung. Fractional areas of defined density ranges in percentage of total lung area were compared to recorded volume increments and airway pressures (atmospheric pressure, lower inflection point (LIP), LIP*0.5, LIP*1.5, peak airway pressure) of in- and expiratory pressure-volume curves. Results: Quantitative analysis of defined density ranges showed no differences between in- and expiratory pressure-volume curves. The amount of poorly aerated lung decreased and normal aerated lung increased constantly when airway pressure and volume were increased during inspiratory pressure-volume curves and vice versa during expiratory pressure-volume loops. Conclusion: Recruitment and derecruitment of lung atelectasis during registration of static in- and expiratory pressure-volume loops occurred constantly, but not in a stepwise manner. CT was shown to be an appropriate method to analyse these recruitment process. (orig.)

  5. A study of diurnal variation in peak expiratory flow rates in healthy adult female subjects in South India

    Directory of Open Access Journals (Sweden)

    Jenny Jayapal

    2014-01-01

    Full Text Available Background: Peak Expiratory Flow Rate (PEFR reflects the strength and condition of respiratory muscles and the degree of airflow limitation in large airways. PEFR shows hour to hour variation that follows a specific pattern in asthmatics and healthy individuals. Adequate data is not available for the diurnal variation in normal individuals who are students in professional courses and had a sedentary life style. Hence, this study was undertaken to study the diurnal variation in peak expiratory flow rates in healthy adult female subjects in South India. Materials and Methods: Peak expiratory flow rate was recorded in 50 adult healthy female students aged 18-23 years and studying in professional courses. Mini Wright′s peak flow meter was used to measure the peak expiratory flow rate. PEFR were recorded at 7-8 a.m., 10-11 a.m., 1-2 p.m., 4-5 p.m., and 7-8 p.m. for two consecutive days. Results: On analysis of PEFR records of individual subjects, it was seen that there was an overall dip in the morning at 7-8 h PEFR, which increased in the daytime, peaking in the afternoon at 1-2 p.m. and eventually decreased in the night. Subjects did not show the peak PEFR values at the same time point, 10% of subjects had a rise in PEFR in the early morning, afternoon (1-2 p.m. peak was observed in 48% subjects and evening (4-5 p.m. peak was observed in 16% subjects. 14% subjects showed a peak in the night time (7-8 p.m. PEFR values. Conclusion: This study provided the preliminary reference data of diurnal variation of peak expiratory flow rate in healthy adults. Since, there is a variation in the peak expiratory flow rate recorded during different time points of the day; hence, to compare the PEFR between individuals it is advisable to record the PEFR at the same time point.

  6. Volume-monitored chest CT: a simplified method for obtaining motion-free images near full inspiratory and end expiratory lung volumes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Kathryn S. [The Ohio State University College of Medicine, Columbus, OH (United States); Long, Frederick R. [Nationwide Children' s Hospital, The Children' s Radiological Institute, Columbus, OH (United States); Flucke, Robert L. [Nationwide Children' s Hospital, Department of Pulmonary Medicine, Columbus, OH (United States); Castile, Robert G. [The Research Institute at Nationwide Children' s Hospital, Center for Perinatal Research, Columbus, OH (United States)

    2010-10-15

    Lung inflation and respiratory motion during chest CT affect diagnostic accuracy and reproducibility. To describe a simple volume-monitored (VM) method for performing reproducible, motion-free full inspiratory and end expiratory chest CT examinations in children. Fifty-two children with cystic fibrosis (mean age 8.8 {+-} 2.2 years) underwent pulmonary function tests and inspiratory and expiratory VM-CT scans (1.25-mm slices, 80-120 kVp, 16-40 mAs) according to an IRB-approved protocol. The VM-CT technique utilizes instruction from a respiratory therapist, a portable spirometer and real-time documentation of lung volume on a computer. CT image quality was evaluated for achievement of targeted lung-volume levels and for respiratory motion. Children achieved 95% of vital capacity during full inspiratory imaging. For end expiratory scans, 92% were at or below the child's end expiratory level. Two expiratory exams were judged to be at suboptimal volumes. Two inspiratory (4%) and three expiratory (6%) exams showed respiratory motion. Overall, 94% of scans were performed at optimal volumes without respiratory motion. The VM-CT technique is a simple, feasible method in children as young as 4 years to achieve reproducible high-quality full inspiratory and end expiratory lung CT images. (orig.)

  7. Effect of nasal continuous and biphasic positive airway pressure on lung volume in preterm infants

    NARCIS (Netherlands)

    Miedema, Martijn; van der Burg, Pauline S.; Beuger, Sabine; de Jongh, Frans H.; Frerichs, Inez; van Kaam, Anton H.

    2013-01-01

    To monitor regional changes in end-expiratory lung volume (EELV), tidal volumes, and their ventilation distribution during different levels of nasal continuous positive airway pressure (nCPAP) and nasal biphasic positive airway pressure (BiPAP) in stable preterm infants. By using electrical

  8. Sudden versus gradual pressure wean from Nasal CPAP in preterm infants: a randomized controlled trial.

    Science.gov (United States)

    Amatya, S; Macomber, M; Bhutada, A; Rastogi, D; Rastogi, S

    2017-06-01

    In preterm infants, nasal continuous positive airway pressure (NCPAP) is widely used for treatment of respiratory distress syndrome. However, the strategies for successfully weaning infants off NCPAP are still not well defined and there remains considerable variation between the methods. The objective of this study is to determine whether gradual weaning of NCPAP pressure is more successful than sudden weaning off NCPAP to room air. A randomized controlled trial was conducted in a level 3 neonatal intensive care unit on 70 preterm neonates who were born between 26 and 32 weeks gestation and required NCPAP for at least 48 h. When infants were stable on NCPAP at 0.21 FiO 2 and 5 cm H 2 O positive end expiratory pressure, neonates were randomized to the gradual wean group (reduction in pressure by 1 cm every 8 h until 3 cm H 2 0 was reached) or to sudden wean group (one time NCPAP removal to room air). The primary outcome was a success at the first trial to wean to room air. Secondary outcomes were a number of trials, and weight and postmenstrual age (PMA) at the time of successful wean. Total number of days on NCPAP and length of stay (LOS) in the hospital were also compared between the groups. Of the 70 infants included in the study, 35 were randomized to sudden group and 33 infants to gradual group (2 excluded for protocol deviation). In sudden and gradual groups, 14 and 22 infants, respectively, were weaned successfully in the first attempt (P=0.03). The infants were successfully weaned at 32.7±1.7 weeks versus 33.1±2.4 weeks (P=0.39) PMA and at a weight of 1651±290 g versus 1589±398 g (P=0.46) in the sudden and gradual groups, respectively. The total number of days on NCPAP was 27±19 days versus 32±24 days (P=0.38) and LOS was 63±25 days versus 63±22 days (P=0.99) in the sudden and gradual groups, respectively. Gradual weaning method was more successful as compared to sudden weaning method in the initial trial off NCPAP. There was no

  9. The respiratory drive to thoracic motoneurones in the cat and its relation to the connections from expiratory bulbospinal neurones

    DEFF Research Database (Denmark)

    Saywell, S A; Anissimova, N P; Ford, T W

    2007-01-01

    of connection revealed were related to the presence and size of central respiratory drive potentials in the same motoneurones. Intracellular recordings were made from motoneurones in segments T5-T9 of the spinal cord of anaesthetized cats. Spike-triggered averaging from expiratory bulbospinal neurones...... in the caudal medulla revealed monosynaptic EPSPs in all groups of motoneurones, with the strongest connections to expiratory motoneurones with axons in the internal intercostal nerve. In the latter, connection strength was similar irrespective of the target muscle (e.g. external abdominal oblique or internal...... intercostal) and the EPSP amplitude was positively correlated with the amplitude of the central respiratory drive potential of the motoneurone. For this group, EPSPs were found in 45/83 bulbospinal neurone/motoneurone pairs, with a mean amplitude of 40.5 microV. The overall strength of the connection supports...

  10. The respiratory drive to thoracic motoneurones in the cat and its relation to the connections from expiratory bulbospinal neurones

    Science.gov (United States)

    Saywell, S A; Anissimova, N P; Ford, T W; Meehan, C F; Kirkwood, P A

    2007-01-01

    The descending control of respiratory-related motoneurones in the thoracic spinal cord remains the subject of some debate. In this study, direct connections from expiratory bulbospinal neurones to identified motoneurones were investigated using spike-triggered averaging and the strengths of connection revealed were related to the presence and size of central respiratory drive potentials in the same motoneurones. Intracellular recordings were made from motoneurones in segments T5–T9 of the spinal cord of anaesthetized cats. Spike-triggered averaging from expiratory bulbospinal neurones in the caudal medulla revealed monosynaptic EPSPs in all groups of motoneurones, with the strongest connections to expiratory motoneurones with axons in the internal intercostal nerve. In the latter, connection strength was similar irrespective of the target muscle (e.g. external abdominal oblique or internal intercostal) and the EPSP amplitude was positively correlated with the amplitude of the central respiratory drive potential of the motoneurone. For this group, EPSPs were found in 45/83 bulbospinal neurone/motoneurone pairs, with a mean amplitude of 40.5 μV. The overall strength of the connection supports previous measurements made by cross-correlation, but is about 10 times stronger than that reported in the only previous similar survey to use spike-triggered averaging. Calculations are presented to suggest that this input alone is sufficient to account for all the expiratory depolarization seen in the recorded motoneurones. However, extra sources of input, or amplification of this one, are likely to be necessary to produce a useful motoneurone output. PMID:17204500

  11. Predictors of response to a nasal expiratory resistor device and its potential mechanisms of action for treatment of obstructive sleep apnea.

    Science.gov (United States)

    Patel, Amit V; Hwang, Dennis; Masdeu, Maria J; Chen, Guo-Ming; Rapoport, David M; Ayappa, Indu

    2011-02-15

    A one-way nasal resistor has recently been shown to reduce sleep disordered breathing (SDB) in a subset of patients with Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS). The purpose of this study was to examine characteristics predictive of therapeutic response to the device and provide pilot data as to its potential mechanisms of action. PATIENTS, INTERVENTIONS, AND MEASUREMENTS: 20 subjects (15M/5F, age 54 ± 12 years, BMI 33.5 ± 5.6 kg/m²) with OSAHS underwent 3 nocturnal polysomnograms (NPSG) including diagnostic, therapeutic (with a Provent® nasal valve device), and CPAP. Additional measurements included intranasal pressures and PCO₂, closing pressures (Pcrit), and awake lung volumes in different body positions. In 19/20 patients who slept with the device, RDI was significantly reduced with the nasal valve device compared to the diagnostic NPSG (27 ± 29/h vs 49 ± 28/h), with 50% of patients having an acceptable therapeutic response. Among demographic, lung volume, or diagnostic NPSG measures or markers of collapsibility, no significant predictors of therapeutic response were found. There was a suggestion that patients with position-dependent SDB (supine RDI > lateral RDI) were more likely to have an acceptable therapeutic response to the device. Successful elimination of SDB was associated with generation and maintenance of an elevated end expiratory pressure. No single definitive mechanism of action was elucidated. The present study shows that the nasal valve device can alter SDB across the full spectrum of SDB severity. There was a suggestion that subjects with positional or milder SDB in the lateral position were those most likely to respond.

  12. Influence Of Number Of Pregnancies In Peak Expiratory Flow And Body Composition Of Pregnant Women

    Directory of Open Access Journals (Sweden)

    Andrea Carla Brandao da Costa Santos

    2017-06-01

    Full Text Available Objectives: to describe and compare the mean values of the body composition and the peak expiratory flow (PEF in primigravidae and multigravidae and, to determine its correlation with obstetric, anthropometric and body composition variables. Method: it was performed a cross-sectional study of 120 healthy pregnant women at low risk, including 77 primigravidae and 43 multigravidae. The PEF was measured by spirometry and the body composition by multisegmental electrical impedance. The unpaired t test was used to compare the groups and the Pearson correlation test was used to determine the association between PEF and independent variables. A multiple linear regression was used to estimate the relationship between the dependent variable, the PEF and the independent variables. Results: the body composition variables in multigravidae women showed higher values compared to the primigravidae, being statistically significant, except for fat mass. In primigravidae, the PEF was correlated significantly with maternal age and height. In multigravidae, the PEF was correlated with maternal age, height, pre-pregnancy and current weight, total body water, extracellular water, fat mass, lean mass and fat-free mass. A Multiple linear regression analysis showed that, in primigravidae, height and maternal age were associated with PEF, being responsible for explaining 14.5% of its variability. The current weight and the maternal age explained 42.3% of peak flow variability in multigravidae. Conclusion: The PEF seemed to be influenced by the number of pregnancies. Changes were observed in relation to the body composition, as it was evidenced in correlation with the PEF in multigravidae women. Keywords: Pregnancy. Spirometry. Weight gain.

  13. Difficulty in obtaining peak expiratory flow measurements in children with acute asthma.

    Science.gov (United States)

    Gorelick, Marc H; Stevens, Molly W; Schultz, Theresa; Scribano, Philip V

    2004-01-01

    To determine the frequency with which children >or=6 years with acute asthma can perform peak expiratory flow rate measurements (PEFR) in an emergency department (ED). Data were obtained from a prospective cohort study of children with acute asthma. All children (age 2-18 years old) treated in an urban pediatric ED for an acute exacerbation during randomly selected days over a 12-month period were prospectively evaluated. According to treatment protocols, PEFR was to be measured in all children age 6 years and older before therapy and after each treatment with inhaled bronchodilators. Registered respiratory therapists obtained PEFR and evaluated whether patients were able to perform the maneuver adequately. Four hundred and fifty-six children, 6 to 18 years old (median 10 years), were enrolled; 291 (64%) had PEFR measured at least once. Of those in whom PEFR was attempted at least once, only 190 (65%) were able to perform adequately. At the start of therapy, 54% (142/262) were able to perform PEFR. Of the 120 who were unable to perform initially, 76 had another attempt at the end of the ED treatment, and 55 (72%) were still unable to perform. A total of 149 patients had attempts at PEFR both at the start and end of treatment, of these, only 71 (48%) provided valid information on both attempts. Patients unable to perform PEFR were younger (mean +/- SD = 8.7 +/- 2.8 years) than those who were able to perform successfully (11.2 +/- 3.2 years) and those with no attempts (10.0 +/- 3.4 years). Children admitted to the hospital were more likely to be unable to perform PEFR (58/126 = 46%) than those discharged from the ED (43/330 = 13%, P < 0.0001). Adequate PEFR measurements are difficult to obtain in children with acute asthma. Treatment and research protocols cannot rely exclusively on PEFR for evaluation of severity.

  14. Evaluation of changes in central airway dimensions, lung area and mean lung density at paired inspiratory/expiratory high-resolution computed tomography

    International Nuclear Information System (INIS)

    Ederle, J.R.; Heussel, C.P.; Hast, J.; Ley, S.; Thelen, M.; Kauczor, H.U.; Fischer, B.; Beek, E.J.R. van

    2003-01-01

    The aim of this study was to improve the understanding of interdependencies of dynamic changes in central airway dimensions, lung area and lung density on HRCT. The HRCT scans of 156 patients obtained at full inspiratory and expiratory position were evaluated retrospectively. Patients were divided into four groups according to lung function tests: normal subjects (n=47); obstructive (n=74); restrictive (n=19); or mixed ventilatory impairment (n=16). Mean lung density (MLD) was correlated with cross-sectional area of the lung (CSA L ), cross-sectional area of the trachea (CSA T ) and diameter of main-stem bronchi (D B ). The CSA L was correlated with CSA T and D B . MLD correlated with CSA L in normal subjects (r=-0.66, p T in the control group (r=-0.50, p B was found (r=-0.52, p L and CSA T correlated in the control group (r=0.67, p L and D B correlated in the control group (r=0.42, p<0.0001) and in patients with obstructive lung disease (r=0.24, p<0.05). Correlations for patients with restrictive and mixed lung disease were constantly lower. Dependencies between central and peripheral airway dimensions and lung parenchyma are demonstrated by HRCT. Best correlations are observed in normal subjects and patients with obstructive lung disease. Based on these findings we postulate that the dependencies are the result of air-flow and pressure patterns. (orig.)

  15. Comparison of peak expiratory flow rate and lipid profile in asymptomatic smokers and non-smokers

    International Nuclear Information System (INIS)

    Fatima, F.; Abbasi, M.A.; Jadoon, J.; Sohail, M.; Shah, J.; Afridi, U.; Noor, M.M.

    2015-01-01

    Tobacco is the major risk factor for chronic obstructive airway disease (COAD), other pulmonary diseases, cancer, cardiovascular and cerebrovascular diseases. The objective of study was to determine the mean Peak Expiratory Flow Rate (PEFR) and serum lipid profile in apparently healthy male smokers and non-smokers. Methods: This cross-sectional study was conducted in Ayub Teaching Hospital, Abbottabad from 15th December, 2009 to 15th June, 2010. Apparently healthy smokers and non-smokers from population coming to Hospital as attendants of the patients or as employees of the hospital were inducted in the study. PEFR and lipid profile of all the subjects was accessed. Results: There were total of 300 male subjects, 150 smokers and 150 non-smokers. The mean age of study subjects was 26.60 ± 5.5 years. The mean PEFR of smokers was 450.62l/min and that of non-smokers was 494.81 L/min, the difference being statistically significant (p-value <0.05).The mean total cholesterol of smokers is 5.30 ± 0.86 mmol/l and it was 3.84 ± 0.54 mmol/l in non-smokers. Mean serum Triacyl Glycerols (TAGs) and Low Density Lipoproteins (LDL) cholesterol of smokers was 2.04 ± 0.38 and 3.5 ± 0.83 mmol/l whereas it was 1.44 ± 0.52 and 2.02 ± 0.66 mmol/l in non-smokers. Mean High Density Lipo-protein (HDL) of smokers was 0.86 ± 0.30 mmol/l and of non-smokers is 1.20 ± 0.41 mmo/l. There was statistically significant difference between serum lipid profile of smokers and non-smokers (p<0.05). the mean serum Total Cholesterol (TC), TAGs and LDL were significantly higher in smokers as compared to non-smokers. However HDL was significantly lower in smokers in comparison to non-smokers. Conclusion: There was statistically significant difference between PEFR of smokers and non-smokers. Higher and significant mean values of TC, TAG and LDL-C was observed in smokers as compared to non-smokers. (author)

  16. Effects of brief smoking cessation education with expiratory carbon monoxide measurement on level of motivation to quit smoking.

    Science.gov (United States)

    Choi, Won-Young; Kim, Cheol-Hwan; Lee, Ok-Gyu

    2013-05-01

    Smoking rates among Korean adult males is still high despite multifaceted efforts to reduce it. In Korea, there have been several studies on the effectiveness of smoking cessation education for inpatients, health check-ups, and smoking cessation clinics. However, there haven't been any studies on the effectiveness of smoking cessation education conducted outside the hospital. This study investigated effectiveness of brief education on smoking cessation with an expiratory carbon monoxide (CO) measurement outside the hospital among adult male office-workers in Korea. From April 1st to May 10th, 2012, we conducted a controlled trial among 95 adult male office workers over the age of 19 who smoke outside, in a public place in Seoul by cluster sampling. For the education group, we provided smoking cessation education for about 5 to 10 minutes, measured the expiratory CO level, and made the subjects complete questionnaires, while only self-help materials on quitting smoking were given to the control group. After 4 weeks, we evaluated the change in the level of motivation or success to quit smoking in both groups via e-mail or mobile phone. In the education group, the level of motivation to quit smoking was improved significantly. A multiple logistic regression analysis showed that the odds ratio of improved motivation to quit smoking in the education group was 28.10 times higher than that of the control group. Brief education on smoking cessation with expiratory CO measurement conducted outside the hospital could enhance the level of motivation to quit smoking.

  17. Numerical and experimental study of expiratory flow in the case of major upper airway obstructions with fluid structure interaction

    Science.gov (United States)

    Chouly, F.; van Hirtum, A.; Lagrée, P.-Y.; Pelorson, X.; Payan, Y.

    2008-02-01

    This study deals with the numerical prediction and experimental description of the flow-induced deformation in a rapidly convergent divergent geometry which stands for a simplified tongue, in interaction with an expiratory airflow. An original in vitro experimental model is proposed, which allows measurement of the deformation of the artificial tongue, in condition of major initial airway obstruction. The experimental model accounts for asymmetries in geometry and tissue properties which are two major physiological upper airway characteristics. The numerical method for prediction of the fluid structure interaction is described. The theory of linear elasticity in small deformations has been chosen to compute the mechanical behaviour of the tongue. The main features of the flow are taken into account using a boundary layer theory. The overall numerical method entails finite element solving of the solid problem and finite differences solving of the fluid problem. First, the numerical method predicts the deformation of the tongue with an overall error of the order of 20%, which can be seen as a preliminary successful validation of the theory and simulations. Moreover, expiratory flow limitation is predicted in this configuration. As a result, both the physical and numerical models could be useful to understand this phenomenon reported in heavy snorers and apneic patients during sleep.

  18. Effect of simultaneous application of postural techniques and expiratory muscle strength training on the enhancement of the swallowing function of patients with dysphagia caused by parkinson?s disease

    OpenAIRE

    Byeon, Haewon

    2016-01-01

    [Purpose] This study aimed to investigate the effect of simultaneous application of postural techniques and expiratory muscle strength training on the enhancement of the swallowing function of patients with dysphagia caused by Parkinson?s disease. [Subjects and Methods] The subjects of this study were 18 patients who received simultaneous application of postural techniques and expiratory muscle strength training and 15 patients who received expiratory muscle strength training only. Postural t...

  19. Simulation of late inspiratory rise in airway pressure during pressure support ventilation.

    Science.gov (United States)

    Yu, Chun-Hsiang; Su, Po-Lan; Lin, Wei-Chieh; Lin, Sheng-Hsiang; Chen, Chang-Wen

    2015-02-01

    Late inspiratory rise in airway pressure (LIRAP, Paw/ΔT) caused by inspiratory muscle relaxation or expiratory muscle contraction is frequently seen during pressure support ventilation (PSV), although the modulating factors are unknown. We investigated the effects of respiratory mechanics (normal, obstructive, restrictive, or mixed), inspiratory effort (-2, -8, or -15 cm H2O), flow cycle criteria (5-40% peak inspiratory flow), and duration of inspiratory muscle relaxation (0.18-0.3 s) on LIRAP during PSV using a lung simulator and 4 types of ventilators. LIRAP occurred with all lung models when inspiratory effort was medium to high and duration of inspiratory muscle relaxation was short. The normal lung model was associated with the fastest LIRAP, whereas the obstructive lung model was associated with the slowest. Unless lung mechanics were normal or mixed, LIRAP was unlikely to occur when inspiratory effort was low. Different ventilators were also associated with differences in LIRAP speed. Except for within the restrictive lung model, changes in flow cycle level did not abolish LIRAP if inspiratory effort was medium to high. Increased duration of inspiratory relaxation also led to the elimination of LIRAP. Simulation of expiratory muscle contraction revealed that LIRAP occurred only when expiratory muscle contraction occurred sometime after the beginning of inspiration. Our simulation study reveals that both respiratory resistance and compliance may affect LIRAP. Except for under restrictive lung conditions, LIRAP is unlikely to be abolished by simply lowering flow cycle criteria when inspiratory effort is strong and relaxation time is rapid. LIRAP may be caused by expiratory muscle contraction when it occurs during inspiration. Copyright © 2015 by Daedalus Enterprises.

  20. The impact of aerosolized mucolytic agents on the airflow resistance of bacterial filters used in mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Han-Chung Hu

    2015-08-01

    Conclusion: This study demonstrated the aerosolized mucolytic agents could increase the pressure drop of the bacterial filters during mechanical ventilation. The pressure drop of the bacterial filters was higher with 10% acetylcysteine. It is critical to continuously monitor the expiration resistance, auto-positive end-expiratory pressure, and ventilator output waveform when aerosolized 10% acetylcysteine was used in mechanical ventilation patients.

  1. Quantitative assessment of cross-sectional area of small pulmonary vessels in patients with COPD using inspiratory and expiratory MDCT

    International Nuclear Information System (INIS)

    Matsuura, Yukiko; Kawata, Naoko; Yanagawa, Noriyuki; Sugiura, Toshihiko; Sakurai, Yoriko; Sato, Misuzu; Iesato, Ken; Terada, Jiro; Sakao, Seiichiro; Tada, Yuji; Tanabe, Nobuhiro; Suzuki, Yoichi; Tatsumi, Koichiro

    2013-01-01

    Objectives: Structural and functional changes in pulmonary vessels are prevalent at the initial stages of chronic obstructive pulmonary disease (COPD). These vascular alterations can be assessed using cross-sectional area (CSA) of small pulmonary vessels. However, neither in non-COPD smokers nor in COPD patients it has been defined whether the structural changes of pulmonary vessels detected by paired inspiratory and expiratory CT scans are associated with emphysematous changes. We quantified the CSA and low attenuation area (LAA) and evaluated the changes in these parameters in the inspiratory and expiratory phases. Materials and methods: Fifty consecutive non-COPD smokers and COPD patients were subjected to multi detector-row CT and the percentage of vessels with a CSA less than 5 mm 2 as well as the percentage LAA for total lung area (%CSA < 5, %LAA, respectively) were calculated. Results: The %CSA < 5 correlated negatively with %LAA. The %CSA < 5 was lower in COPD patients with emphysema as compared with non-COPD smokers and COPD patients with or without mild emphysema. In addition, the %CSA < 5 was lower in the no/mild emphysema subgroup as compared with non-COPD smokers. The respiratory phase change of %CSA < 5 in COPD patients was greater than that in non-COPD smokers. Conclusion: The percentage of small pulmonary vessels decreased as emphysematous changes increase, and this decrease was observed even in patients with no/mild emphysema. Furthermore, respiratory phase changes in CSA were higher in COPD patients than in non-COPD smokers

  2. ERGONOMIC CONSIDERATION OF THE EFFECT OF FLOUR DUST ON PEAK EXPIRATORY FLOW RATE OF BAKERS IN ABEOKUTA, OGUN STATE

    Directory of Open Access Journals (Sweden)

    Adekunle Ibrahim MUSA

    2017-06-01

    Full Text Available Flour dusts are one of the most harmful chemicals in the bakery industries which could lead to serious heart and lung diseases. This study investigated the effect of flour dust on Peak Expiratory Flow Rate of male bakers in Abeokuta, Ogun State, Nigeria with the relationship to the anthropometrical parameters. A total of One hundred Eighty (180 male participants were investigated, where ninety (90 participants were bakers and ninety (90 individuals as control group. The Peak expiratory flow rate (PEFR and anthropometrical parameters of the participant were measured using mini-Wright peak flow meter (PFM 20, OMRON and Detecto PD300MDHR (Cardinal Scale manufacturing company, USA column scale with digital height rod was used to measure body mass [kg] and height (cm respectively. The PEFR and anthropometrical parameters of the bakers and control groups were analysed using descriptive statistics and T-test with SPSS. The results showed that lower PEFR, 182.67 ± 16.34 L/min existed in bakers compared to 287.67 ± 17.02 L/min in the control study. The result also showed that a significant correlation exist between body mass, height and age (P < 0.01, PEFR, height (P < 0.05 and years of exposure (P < 0.01 of the bakers respectively. Furthermore, the results also showed that workers in the dusting and mixing of flour are at a risk of developing related pulmonary function impairment such as asthma. The study concluded that there is need to develop an effective intervention strategy, treatment seeking behaviour through awareness programs to prevent lung impairment diseases among the bakery workers.

  3. Quantitative assessment of cross-sectional area of small pulmonary vessels in patients with COPD using inspiratory and expiratory MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, Yukiko, E-mail: matsuyuki_future@yahoo.co.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Kawata, Naoko, E-mail: chumito_03@yahoo.co.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Yanagawa, Noriyuki, E-mail: yanagawa@ho.chiba-u.ac.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Sugiura, Toshihiko, E-mail: sugiura@js3.so-net.ne.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Sakurai, Yoriko, E-mail: yoliri@nifty.com [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Sato, Misuzu, E-mail: mis_misuzu@yahoo.co.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Iesato, Ken, E-mail: iesato_k@yahoo.co.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Terada, Jiro, E-mail: jirotera@chiba-u.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Sakao, Seiichiro, E-mail: sakao@faculty.chiba-u.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Tada, Yuji, E-mail: ytada@faculty.chiba-u.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Tanabe, Nobuhiro, E-mail: ntanabe@faculty.chiba-u.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Suzuki, Yoichi, E-mail: ysuzuki@faculty.chiba-u.jp [Department of public Health, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan); Tatsumi, Koichiro, E-mail: tatsumi@faculty.chiba-u.jp [Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670 Japan (Japan)

    2013-10-01

    Objectives: Structural and functional changes in pulmonary vessels are prevalent at the initial stages of chronic obstructive pulmonary disease (COPD). These vascular alterations can be assessed using cross-sectional area (CSA) of small pulmonary vessels. However, neither in non-COPD smokers nor in COPD patients it has been defined whether the structural changes of pulmonary vessels detected by paired inspiratory and expiratory CT scans are associated with emphysematous changes. We quantified the CSA and low attenuation area (LAA) and evaluated the changes in these parameters in the inspiratory and expiratory phases. Materials and methods: Fifty consecutive non-COPD smokers and COPD patients were subjected to multi detector-row CT and the percentage of vessels with a CSA less than 5 mm{sup 2} as well as the percentage LAA for total lung area (%CSA < 5, %LAA, respectively) were calculated. Results: The %CSA < 5 correlated negatively with %LAA. The %CSA < 5 was lower in COPD patients with emphysema as compared with non-COPD smokers and COPD patients with or without mild emphysema. In addition, the %CSA < 5 was lower in the no/mild emphysema subgroup as compared with non-COPD smokers. The respiratory phase change of %CSA < 5 in COPD patients was greater than that in non-COPD smokers. Conclusion: The percentage of small pulmonary vessels decreased as emphysematous changes increase, and this decrease was observed even in patients with no/mild emphysema. Furthermore, respiratory phase changes in CSA were higher in COPD patients than in non-COPD smokers.

  4. [Modification of expiratory peak flow (EPF) in 14 asthmatic subjects from Benin by short duration exercise training].

    Science.gov (United States)

    Lawani, M M; Hounkpatin, S; Akplogan, B

    2006-01-01

    Asthma is a world wide public health problem. It is the most commom chronic disease of school age children. Its severity is in constant increase. The frequency of the hospitalizations for asthma increased in practically all countries. Physical exercises and sport are used more and more as therapeutic means, in northern deveopped countries of where it was very early understood that it is necessary to integrate the asthmatic subjects into a program of specific physical training. This study undertaken in south saharian african country considers also assiduity in a physical training program as the factor of increase in the expiratory peak flow, of reinforcement of some principal muscles necessary to the improvement, and of the respiratory function of the asthmatic subject. Physical exercise is used as a non pharmacological therapy of asthma. This transversal study was carried out on fourteen asthmatic subjects of colleges in Porto-Novo's town, aged 15 years old to 25 years, of the two sexes. The results showed that: the Expiratory Peak Flow of Point (EPF) of the subjects at the beginning of the program is lower than the minimal average value of the group whatever the sex; the subjects average EPF increased from approximately 35% compared to the average at the beginning of the program; the subjects from family with asthmatic line, are much more inclined with respiratory embarrassments post-exercises than those who did not come from it; the respiratory embarrassments post-exercises noticed in the first weeks, grew blurred before the end of the program. This study suggests physical exercise adapted to the asthmatic subjects for the improvement of their health.

  5. Inspiratory and expiratory HRCT findings in Behcet's disease and correlation with pulmonary function tests

    Energy Technology Data Exchange (ETDEWEB)

    Oezer, Caner [Department of Radiology, Mersin University, Faculty of Medicine, Mersin (Turkey)]. E-mail: cozer@mersin.edu.tr; Duce, Meltem Nass [Department of Radiology, Mersin University, Faculty of Medicine, Mersin (Turkey); Ulubas, Bahar [Department of Respiratory Disease, Mersin University, Faculty of Medicine, Mersin (Turkey); Bicer, Ali [Department of Physical Medicine and Rehabilitation, Mersin University, Faculty of Medicine, Mersin (Turkey); Tuersen, Uemit [Department of Dermatology, Mersin University, Faculty of Medicine, Mersin (Turkey); Apaydin, F. Demir [Department of Radiology, Mersin University, Faculty of Medicine, Mersin (Turkey); Yildiz, Altan [Department of Radiology, Mersin University, Faculty of Medicine, Mersin (Turkey); Camdeviren, Handan [Department of Biostatistics, Mersin University, Faculty of Medicine, Mersin (Turkey)

    2005-10-01

    Purpose: The purpose of our study was to describe the pulmonary parenchymal changes of Behcet's disease using high-resolution computed tomography and to correlate them with pulmonary function tests. Materials and methods: Thirty-four patients with Behcet's disease (18 men, 16 women), 3 of whom were symptomatic, were included as the study group. Four of 34 patients were smokers. Twenty asymptomatic volunteers (12 men, 8 women), 4 of whom were smokers, constituted the control group. The pulmonary function tests and high-resolution computed tomography were performed for both groups. Results: Inspiratory high-resolution computed tomography findings were abnormal in nine patients (26.5%) of the study group. In eight patients, there were multiple abnormalities, whereas one patient had only one abnormality. Pleural thickening and irregularities, major fissure thickening, emphysematous changes, bronchiectasis, parenchymal bands, and irregular densities, and parenchymal nodules were the encountered abnormalities. Inspiratory high-resolution computed tomography scans were normal in the control group. On expiratory scans, there was statistically significant difference between study group and control group when air trapping, especially grades 3 and 4, was compared (P < 0.01). Pulmonary function tests of both the study and the control groups were in normal ranges, and there was no statistically significant difference between the two groups according to pulmonary function tests (P > 0.05). Discussion and conclusion: High-resolution computed tomography is sensitive in the demonstration of pulmonary changes in patients with Behcet's disease. End-expiratory high-resolution computed tomography examination is very useful and necessary to show the presence of air trapping, thus the presence of small airway disease, even if the patient is asymptomatic or has normal pulmonary function tests.

  6. Incidence of tracheobronchomalacia associated with pulmonary emphysema. Detection with paired inspiratory-expiratory multidetector computed tomography using a low-dose technique

    International Nuclear Information System (INIS)

    Inoue, Masanori; Hasegawa, Ichiro; Nakano, Keiko; Yamaguchi, Kazuhiro; Kuribayashi, Sachio

    2009-01-01

    The purpose of this study was to evaluate the frequency of tracheobronchomalacia (TBM) associated with pulmonary emphysema with paired inspiratory-expiratory multidetector computed tomography (MDCT) using a low-dose technique. This study included 56 consecutive patients (55 men, 1 woman; mean age 68.9 years) with pulmonary emphysema who had undergone paired inspiratory-expiratory CT scanning with a low-dose technique (40 mA). All images were retrospectively examined by two thoracic radiologists in a blinded fashion. The diagnosis of TBM was based on the standard criterion of >50% reduction in the cross-sectional area of the tracheobronchial lumen at the end-expiratory phase. A mild TBM criterion of >30% reduction was also reviewed. All patients underwent pulmonary function tests. The relation between the forced expiratory volume in 1 s (FEV 1.0% ) and TBM was statistically analyzed. Four (7.1%) and eight (14.3%) patients were diagnosed as TBM based on the standard and mild criteria, respectively. In four patients, the percentages of luminal narrowing were 63.4% and 51.2%, respectively for tracheomalacia and 59.2% and 62.0%, respectively, for bronchomalacia. The FEV 1.0% values between patients with and without TBM showed no statistical difference. The incidence of TBM associated with pulmonary emphysema was 7.1% with the standard criterion. It is possible that TBM has been underdiagnosed in a number of patients with pulmonary emphysema. (author)

  7. Distribution of peak expiratory flow variability by age, gender and smoking habits in a random population sample aged 20-70 yrs

    NARCIS (Netherlands)

    Boezen, H M; Schouten, J. P.; Postma, D S; Rijcken, B

    1994-01-01

    Peak expiratory flow (PEF) variability can be considered as an index of bronchial lability. Population studies on PEF variability are few. The purpose of the current paper is to describe the distribution of PEF variability in a random population sample of adults with a wide age range (20-70 yrs),

  8. Effect of a mixture of pyridostigmine and atropine on forced expiratory volume (FEV1), and serum cholinesterase activity in normal subjects

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, B F; Gefke, Kaj; Mosbech, H

    1985-01-01

    injection with a decrease to 27 +/- 5% (mean +/- SEM) of the original activity. Forced expiratory volume in the first 1s (FEV1) was measured at fixed time intervals for 90 min. No decrease in FEV1 was observed; on the contrary, there was a small increase. We conclude that atropine effectively antagonizes...

  9. Paired maximum inspiratory and expiratory plain chest radiographs for assessment of airflow limitation in chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Takashi, E-mail: tkino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Kawayama, Tomotaka, E-mail: kawayama_tomotaka@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Imamura, Youhei, E-mail: mamura_youhei@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Sakazaki, Yuki, E-mail: sakazaki@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Hirai, Ryo, E-mail: hirai_ryou@kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Ishii, Hidenobu, E-mail: shii_hidenobu@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Suetomo, Masashi, E-mail: jin_t_f_c@yahoo.co.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Matsunaga, Kazuko, E-mail: kmatsunaga@kouhoukai.or.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Azuma, Koichi, E-mail: azuma@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan); Fujimoto, Kiminori, E-mail: kimichan@med.kurume-u.ac.jp [Department of Radiology, Kurume University School of Medicine, Kurume (Japan); Hoshino, Tomoaki, E-mail: hoshino@med.kurume-u.ac.jp [Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume (Japan)

    2015-04-15

    Highlights: •It is often to use computed tomography (CT) scan for diagnosis of chronic obstructive pulmonary disease. •CT scan is more expensive and higher. •A plane chest radiography more simple and cheap. Moreover, it is useful as detection of pulmonary emphysema, but not airflow limitation. •Our study demonstrated that the maximum inspiratory and expiratory plane chest radiography technique could detect severe airflow limitations. •We believe that the technique is helpful to diagnose the patients with chronic obstructive pulmonary disease. -- Abstract: Background: The usefulness of paired maximum inspiratory and expiratory (I/E) plain chest radiography (pCR) for diagnosis of chronic obstructive pulmonary disease (COPD) is still unclear. Objectives: We examined whether measurement of the I/E ratio using paired I/E pCR could be used for detection of airflow limitation in patients with COPD. Methods: Eighty patients with COPD (GOLD stage I = 23, stage II = 32, stage III = 15, stage IV = 10) and 34 control subjects were enrolled. The I/E ratios of frontal and lateral lung areas, and lung distance between the apex and base on pCR views were analyzed quantitatively. Pulmonary function parameters were measured at the same time. Results: The I/E ratios for the frontal lung area (1.25 ± 0.01), the lateral lung area (1.29 ± 0.01), and the lung distance (1.18 ± 0.01) were significantly (p < 0.05) reduced in COPD patients compared with controls (1.31 ± 0.02 and 1.38 ± 0.02, and 1.22 ± 0.01, respectively). The I/E ratios in frontal and lateral areas, and lung distance were significantly (p < 0.05) reduced in severe (GOLD stage III) and very severe (GOLD stage IV) COPD as compared to control subjects, although the I/E ratios did not differ significantly between severe and very severe COPD. Moreover, the I/E ratios were significantly correlated with pulmonary function parameters. Conclusions: Measurement of I/E ratios on paired I/E pCR is simple and

  10. Paired maximum inspiratory and expiratory plain chest radiographs for assessment of airflow limitation in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Kinoshita, Takashi; Kawayama, Tomotaka; Imamura, Youhei; Sakazaki, Yuki; Hirai, Ryo; Ishii, Hidenobu; Suetomo, Masashi; Matsunaga, Kazuko; Azuma, Koichi; Fujimoto, Kiminori; Hoshino, Tomoaki

    2015-01-01

    Highlights: •It is often to use computed tomography (CT) scan for diagnosis of chronic obstructive pulmonary disease. •CT scan is more expensive and higher. •A plane chest radiography more simple and cheap. Moreover, it is useful as detection of pulmonary emphysema, but not airflow limitation. •Our study demonstrated that the maximum inspiratory and expiratory plane chest radiography technique could detect severe airflow limitations. •We believe that the technique is helpful to diagnose the patients with chronic obstructive pulmonary disease. -- Abstract: Background: The usefulness of paired maximum inspiratory and expiratory (I/E) plain chest radiography (pCR) for diagnosis of chronic obstructive pulmonary disease (COPD) is still unclear. Objectives: We examined whether measurement of the I/E ratio using paired I/E pCR could be used for detection of airflow limitation in patients with COPD. Methods: Eighty patients with COPD (GOLD stage I = 23, stage II = 32, stage III = 15, stage IV = 10) and 34 control subjects were enrolled. The I/E ratios of frontal and lateral lung areas, and lung distance between the apex and base on pCR views were analyzed quantitatively. Pulmonary function parameters were measured at the same time. Results: The I/E ratios for the frontal lung area (1.25 ± 0.01), the lateral lung area (1.29 ± 0.01), and the lung distance (1.18 ± 0.01) were significantly (p < 0.05) reduced in COPD patients compared with controls (1.31 ± 0.02 and 1.38 ± 0.02, and 1.22 ± 0.01, respectively). The I/E ratios in frontal and lateral areas, and lung distance were significantly (p < 0.05) reduced in severe (GOLD stage III) and very severe (GOLD stage IV) COPD as compared to control subjects, although the I/E ratios did not differ significantly between severe and very severe COPD. Moreover, the I/E ratios were significantly correlated with pulmonary function parameters. Conclusions: Measurement of I/E ratios on paired I/E pCR is simple and

  11. Expiratory CT in cigarette smokers: correlation between areas of decreased lung attenuation, pulmonary function tests and smoking history

    Energy Technology Data Exchange (ETDEWEB)

    Verschakelen, J.A.; Scheinbaum, K.; Bogaert, J.; Baert, A.L. [Department of Radiology, University Hospitals, Leuven (Belgium); Demedts, M.; Lacquet, L.L. [Department of Pneumology, University Hospitals, Leuven (Belgium)

    1998-10-01

    The aim of this study was to determine the correlation between cigarette-smoke-related bronchial disease and air trapping as assessed by expiratory high-resolution CT (HRCT) scans. Thirty healthy subjects (11 non-smokers, 7 ex-smokers for > 2 years, 12 current smokers; age range 35-55 years) with a smoking history between 0 and 28.5 pack-years underwent pulmonary function tests (PFT) and HRCT in inspiration and expiration in supine and prone position. The extent of air trapping was scored in ventral and dorsal aspects of the upper, middle and lower lung portions. In 24 subjects (7 non-smokers, 7 ex-smokers, 10 current smokers) areas of focal air trapping were found, and were present significantly more often in dependent lung portions (p < 0.05) compared with non-dependent portions. No significant differences were found between apical and basal lung zones. Scores of focal air trapping were not significantly different between smokers and ex-smokers, but were significantly lower (p < 0.05) in non-smokers and showed a significant (p < 0.0005) correlation with pack-years. The degree of air trapping was also associated with several lung function tests, especially RV, DLCO, FRC, FEV1 and FEV1/VC. Air trapping is seen in smokers with normal PFT and correlates with the severity of the smoking history, independently of current smoking status. (orig.) (orig.) With 4 figs., 4 tabs., 59 refs.

  12. COMBINED REDUCED FORCED EXPIRATORY VOLUME IN 1-SECOND (FEV1) AND PERIPHERAL ARTERY DISEASE IN SEDENTARY ELDERS WITH FUNCTIONAL LIMITATIONS

    Science.gov (United States)

    Vaz Fragoso, Carlos A.; Hsu, Fang-Chi; Brinkley, Tina; Church, Timothy; Liu, Christine K.; Manini, Todd; Newman, Anne B.; Stafford, Randall S.; McDermott, Mary M.; Gill, Thomas M.

    2014-01-01

    Objectives Because they are potentially modifiable and may coexist, we evaluated the combined occurrence of a reduced forced expiratory volume in 1-second (FEV1) and peripheral artery disease (PAD), including its association with exertional symptoms, physical inactivity, and impaired mobility, in sedentary elders with functional limitations. Design Cross-sectional. Setting Lifestyle Interventions and Independence in Elder (LIFE) Study. Participants 1307 sedentary community-dwelling persons, mean age 78.9, with functional limitations (Short Physical Performance Battery [SPPB] the San Diego Claudication Questionnaire. Physical inactivity was evaluated by percent of accelerometry wear-time with activity the 400MWT (gait-speed The two combined conditions were associated with exertional dyspnea (adjusted odds ratio [adjOR] 2.59 [1.20, 5.60]) and slow gait-speed (adjOR 3.15 [1.72, 5.75]) but not with exertional leg symptoms, high sedentary-time, and moderate-to-severe mobility impairment. Conclusions In sedentary community-dwelling elders with functional limitations, a reduced FEV1 and PAD frequently coexisted and, in combination, were strongly associated with exertional dyspnea and slow gait-speed (a frailty indicator that increases the risk of deleterious outcomes). PMID:24973990

  13. Partial liquid ventilation improves lung function in ventilation-induced lung injury

    NARCIS (Netherlands)

    G.F. Vazquez de Anda; R.A. Lachmann; S.J.C. Verbrugge (Serge); D.A.M.P.J. Gommers (Diederik); J.J. Haitsma (Jack); B.F. Lachmann (Burkhard)

    2001-01-01

    textabstractDisturbances in lung function and lung mechanics are present after ventilation with high peak inspiratory pressures (PIP) and low levels of positive end-expiratory pressure (PEEP). Therefore, the authors investigated whether partial liquid ventilation can re-establish

  14. Whole-lung volume and density in spirometrically-gated inspiratory and expiratory CT in systemic sclerosis: correlation with static volumes at pulmonary function tests.

    Science.gov (United States)

    Camiciottoli, G; Diciotti, S; Bartolucci, M; Orlandi, I; Bigazzi, F; Matucci-Cerinic, M; Pistolesi, M; Mascalchi, M

    2013-03-01

    Spiral low-dose computed tomography (LDCT) permits to measure whole-lung volume and density in a single breath-hold. To evaluate the agreement between static lung volumes measured with LDCT and pulmonary function test (PFT) and the correlation between the LDCT volumes and lung density in restrictive lung disease. Patients with Systemic Sclerosis (SSc) with (n = 24) and without (n = 16) pulmonary involvement on sequential thin-section CT and patients with chronic obstructive pulmonary disease (COPD)(n = 29) underwent spirometrically-gated LDCT at 90% and 10% of vital capacity to measure inspiratory and expiratory lung volumes and mean lung attenuation (MLA). Total lung capacity and residual volume were measured the same day of CT. Inspiratory [95% limits of agreement (95% LoA)--43.8% and 39.2%] and expiratory (95% LoA -45.8% and 37.1%) lung volumes measured on LDCT and PFT showed poor agreement in SSc patients with pulmonary involvement, whereas they were in substantial agreement (inspiratory 95% LoA -14.1% and 16.1%; expiratory 95% LoA -13.5% and 23%) in SSc patients without pulmonary involvement and in inspiratory scans only (95% LoA -23.1% and 20.9%) of COPD patients. Inspiratory and expiratory LDCT volumes, MLA and their deltas differentiated both SSc patients with or without pulmonary involvement from COPD patients. LDCT lung volumes and density were not correlated in SSc patients with pulmonary involvement, whereas they did correlate in SSc without pulmonary involvement and in COPD patients. In restrictive lung disease due to SSc there is poor agreement between static lung volumes measured using LDCT and PFT and the relationship between volume and density values on CT is altered.

  15. A Simple Measure to Assess Hyperinflation and Air Trapping: 1-Forced Expiratory Volume in Three Second / Forced Vital Capacity

    Directory of Open Access Journals (Sweden)

    Sermin Börekçi

    2017-04-01

    Full Text Available Background: Several recent studies have suggested that 1 minus-forced expiratory volume expired in 3 seconds / forced vital capacity (1-FEV3/FVC may be an indicator of distal airway obstruction and a promising measure to evaluate small airways dysfunction. Aims: To investigate the associations of 1-FEV3/FVC with the spirometric measures and lung volumes that assess small airways dysfunction and reflects hyperinflation and air trapping. Study Design: Retrospective cross-sectional study. Methods: Retrospective assessment of a total of 1110 cases who underwent body plethysmographic lung volume estimations between a time span from 2005 to 2012. Patients were assigned into two groups: firstly by FEV1/FVC (FEV1/FVC <70% vs. FEV1/FVC ≥70%; secondly by FEV3/FVC < lower limits of normal (LLN (FEV3/FVC < LLN vs. FEV3/FVC ≥ LLN. Spirometric indices and lung volumes measured by whole-body plethysmography were compared in groups. Also the correlation of spirometric indices with measured lung volumes were assessed in the whole-study population and in subgroups stratified according to FEV1/FVC and FEV3/FVC. Results: Six hundred seven (54.7% were male and 503 (45.3% were female, with a mean age of 52.5±15.6 years. Mean FEV3/FVC and 1-FEV3/FVC were 87.05%, 12.95%, respectively. The mean 1-FEV3/FVC was 4.9% in the FEV1/FVC ≥70% group (n=644 vs. 24.1% in the FEV1/FVC <70% group (n=466. A positive correlation was found between 1-FEV3/FVC and residual volume (r=0.70; p<0.0001, functional residual capacity-pleth (r=0.61; p<0.0001, and total lung capacity (r=0.47; p<0.0001. 1-FEV3/FVC was negatively correlated with forced expiratory flow25-75 (r=−0.84; p<0.0001. The upper limit of 95% confidence interval for 1-FEV3/FVC was 13.7%. 1-FEV3/FVC showed significant correlations with parameters of air trapping and hyperinflation measured by whole-body plethysmography. Importantly, these correlations were higher in study participants with FEV1/FVC <70% or FEV3/FVC

  16. [Value of forced expiratory volume in 6 seconds (FEV(6)) in the evaluation of pulmonary function in Chinese elderly males].

    Science.gov (United States)

    Pan, M M; Zhang, H S; Sun, T Y

    2017-05-30

    Objective: To evaluate the value of forced expiratory volume in 6 seconds (FEV(6)) in the evaluation of pulmonary function in Chinese elderly males. Methods: Pulmonary function tests of elderly who had received regular physical examination in Beijing Hospital from July 2003 to April 2015 were analyzed on subjects with the following characteristics: aged 60 years or older, completion of bronchial dilation test and able to exhale for at least six seconds. The included subjects were divided into 2 groups: 60-function in the study population was evaluated. Results: A total of 475 elderly men aged 60 years or older were enrolled, with a mean age of (77.13±9.53) years. Totally there were 269 subjects in 60-accounted for 56.6%; 206 subjects were in ≥80 years group, which accounted for 43.4%. There were 292 subjects with irreversible airflow obstruction, accounting for 61.5%. In all the included subjects, FEV(6) was significantly correlated with FVC and post-bronchodilator FEV(1)/FEV(6) was significantly correlated with post-bronchodilator FEV(1)/FVC( r =0.971, 0.978; both P function middle group, a total of 73 cases, which included 20 cases ≥80 years old. The proportion of middle group among ≥80 years group was significantly less than that of the 60-function middle group, FEV(1)/FEV(6) or FEV(1)/FVC had no correlation with inspiratory capacity or residual volume/total lung capacity (all P >0.05). Conclusions: FEV(6) and FEV(1)/FEV(6) are strongly correlated with FVC and FEV(1)/FVC, and there is excellent agreement between FEV(1)/FEV(6) and FEV(1)/FVC. FEV(6) is simple, easy to operate and with less influencing factors, which can be used as a valid alternative for FVC in diagnosing airflow obstruction in elderly males.

  17. Peripheral chemoreceptors tune inspiratory drive via tonic expiratory neuron hubs in the medullary ventral respiratory column network.

    Science.gov (United States)

    Segers, L S; Nuding, S C; Ott, M M; Dean, J B; Bolser, D C; O'Connor, R; Morris, K F; Lindsey, B G

    2015-01-01

    Models of brain stem ventral respiratory column (VRC) circuits typically emphasize populations of neurons, each active during a particular phase of the respiratory cycle. We have proposed that "tonic" pericolumnar expiratory (t-E) neurons tune breathing during baroreceptor-evoked reductions and central chemoreceptor-evoked enhancements of inspiratory (I) drive. The aims of this study were to further characterize the coordinated activity of t-E neurons and test the hypothesis that peripheral chemoreceptors also modulate drive via inhibition of t-E neurons and disinhibition of their inspiratory neuron targets. Spike trains of 828 VRC neurons were acquired by multielectrode arrays along with phrenic nerve signals from 22 decerebrate, vagotomized, neuromuscularly blocked, artificially ventilated adult cats. Forty-eight of 191 t-E neurons fired synchronously with another t-E neuron as indicated by cross-correlogram central peaks; 32 of the 39 synchronous pairs were elements of groups with mutual pairwise correlations. Gravitational clustering identified fluctuations in t-E neuron synchrony. A network model supported the prediction that inhibitory populations with spike synchrony reduce target neuron firing probabilities, resulting in offset or central correlogram troughs. In five animals, stimulation of carotid chemoreceptors evoked changes in the firing rates of 179 of 240 neurons. Thirty-two neuron pairs had correlogram troughs consistent with convergent and divergent t-E inhibition of I cells and disinhibitory enhancement of drive. Four of 10 t-E neurons that responded to sequential stimulation of peripheral and central chemoreceptors triggered 25 cross-correlograms with offset features. The results support the hypothesis that multiple afferent systems dynamically tune inspiratory drive in part via coordinated t-E neurons. Copyright © 2015 the American Physiological Society.

  18. Relationship between spontaneous expiratory flow-volume curve pattern and air-flow obstruction in elderly COPD patients.

    Science.gov (United States)

    Nozoe, Masafumi; Mase, Kyoshi; Murakami, Shigefumi; Okada, Makoto; Ogino, Tomoyuki; Matsushita, Kazuhiro; Takashima, Sachie; Yamamoto, Noriyasu; Fukuda, Yoshihiro; Domen, Kazuhisa

    2013-10-01

    Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV(1) 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV(1)% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.

  19. Diaphragmatic thickness ratio (inspiratory/expiratory) as a diagnostic method of diaphragmatic palsy associated with interescalene block.

    Science.gov (United States)

    López Escárraga, V M; Dubos España, K; Castillo Bustos, R H; Peidró, L; Sastre, S; Sala-Blanch, X

    2018-02-01

    Diaphragmatic paralysis is a side-effect associated with interscalene block. Thickness index of the diaphragm muscle (inspiratory thickness/expiratory thickness) obtained by ultrasound has recently been introduced in clinical practice for diagnosis of diaphragm muscle atrophy. Our objective was to evaluate this index for the diagnosis of acute phrenic paresis associated with interscalene block. We designed an observational study in 22 patients scheduled for shoulder arthroscopy. Spirometry was performed (criteria of phrenic paresis was a decrease in FVC and FEV1 ≥20%). Ultrasound apposition zone was assessed in anterior axillary line and diaphragmatic displacement was evaluated on inspiration and expiration (number of intercostal spaces; phrenic paresis considered a reduction ≥25%) and thickness of the diaphragm muscle (a phrenic paresis was considered an index block at C5-C6 with 20ml of 0.5% ropivacaine. Twenty-one patients (95%) presented phrenic nerve block according to one or more of the methods used. One patient did not show any symptoms or signs suggestive of phrenic paralysis and was excluded. All the patients presented phrenic paresis based on the diaphragmatic thickness index, with the pre-block index being 1.8±0.5 and post-block of 1.05±0.06 (Pblock (from 1.9±0.5 intercostal spaces to 0.5±0.3; Pblock. This index does not require a baseline pre-assessment. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Effect of bedding control on amount of house dust mite allergens, asthma symptoms, and peak expiratory flow rate.

    Science.gov (United States)

    Lee, Inn-Sook

    2003-04-30

    This quasi-experimental study was designed to investigate the effect of bedding control on the amount of house dust mite (HDM) allergens, asthma symptoms, and peak expiratory flow rate (PEFR) in asthmatics sensitive to HDMs. The subjects in the study were drawn from patients receiving treatment at the allergy clinics of three university-affiliated hospitals in Seoul. Forty-two patients without prior practice of the bedding control used in this study were selected. They commonly showed bronchial asthma caused by HDMs, and exhibited strong positive points (more than 3 points) in skin prick test (D. farinae, D. pteronyssinus), and positive response in both fluoro-allergosorbent test (FAST), and PC20 methacholine test. Of the subjects, alternatively, 22 were assigned to the experimental group and 20 to control group. Bedding control consisted of the use of outer cotton covers, boiling them for 10 minutes fortnightly, and disinfecting bedding by sunlight fortnightly. The experimental group was under bedding control for 4 weeks. The data were collected from October 2000 to January 2001. The results were as follows: 1. After bedding control, the total amount of HDM allergens decreased significantly in the experimental group. However there was no significant difference in the decrease of the amount of HDM allergens between the two groups. 2. Of the asthma symptoms, there was significant difference only in the decrease of the frequency of dyspnea, and in the increase of sleeping disturbance between the two groups after bedding control. 3. After bedding control, PEFR increased in the experimental group whereas it decreased in the control group. However, neither change was significant. The above findings indicate that bedding control improved several asthma symptoms in asthmatics sensitive to HDMs. Accordingly, we suggest that bedding control is adopted as a useful nursing intervention in the field.

  1. Acute effects of combined exercise and oscillatory positive expiratory pressure therapy on sputum properties and lung diffusing capacity in cystic fibrosis: a randomized, controlled, crossover trial.

    Science.gov (United States)

    Radtke, Thomas; Böni, Lukas; Bohnacker, Peter; Maggi-Beba, Marion; Fischer, Peter; Kriemler, Susi; Benden, Christian; Dressel, Holger

    2018-06-14

    Regular airway clearance by chest physiotherapy and/or exercise is critical to lung health in cystic fibrosis (CF). Combination of cycling exercise and chest physiotherapy using the Flutter® device on sputum properties has not yet been investigated. This prospective, randomized crossover study compared a single bout of continuous cycling exercise at moderate intensity (experiment A, control condition) vs a combination of interval cycling exercise plus Flutter® (experiment B). Sputum properties (viscoelasticity, yield stress, solids content, spinnability, and ease of sputum expectoration), pulmonary diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) were assessed at rest, directly and 45 min post-exercise (recovery) at 2 consecutive visits. Primary outcome was change in sputum viscoelasticity (G', storage modulus; G", loss modulus) over a broad frequency range (0.1-100 rad.s - 1 ). 15 adults with CF (FEV 1 range 24-94% predicted) completed all experiments. No consistent differences between experiments were observed for G' and G" and other sputum properties, except for ease of sputum expectoration during recovery favoring experiment A. DLNO, DLCO, alveolar volume (V A ) and pulmonary capillary blood volume (V cap ) increased during experiment A, while DLCO and V cap increased during experiment B (all P < 0.05). We found no differences in absolute changes in pulmonary diffusing capacity and its components between experiments, except a higher V A immediately post-exercise favoring experiment A (P = 0.032). The additional use of the Flutter® to moderate intensity interval cycling exercise has no measurable effect on the viscoelastic properties of sputum compared to moderate intensity continuous cycling alone. Elevations in diffusing capacity represent an acute exercise-induced effect not sustained post-exercise. ClinicalTrials.gov; No.: NCT02750722 ; URL: clinical.trials.gov; Registration date: April 25th, 2016.

  2. Comparative evaluation of ventilatory function through pre and postoperative peak expiratory flow in patients submitted to elective upper abdominal surgery.

    Science.gov (United States)

    Scheeren, Caio Fernando Cavanus; Gonçalves, José Júlio Saraiva

    2016-01-01

    to evaluate the ventilatory function by Peak Expiratory Flow (PEF) in the immediate pre and postoperative periods of patients undergoing elective surgical procedures in the upper abdomen. we conducted a prospective cohort study including 47 patients admitted to the Hospital Regional de Mato Grosso do Sul from July to December 2014, who underwent elective surgeries of the upper abdomen, and submiited to spirometric evaluation and measurement of PEF immediately before and after surgery. of the 47 patients, 22 (46.8%) were male and 25 (53.20%) female. The mean preoperative PEF was 412.1±91.7, and postoperative, 331.0±87.8, indicating significant differences between the two variables. Men had higher PEF values than women, both in the pre and postoperative periods. There was a reasonable inverse correlation between age and decreased PEF. Both situations showed statistical significance (pvalores de PFE do que o feminino, tanto no pré-cirúrgico quanto no pós-cirúrgico. Observou-se razoável correlação inversamente proporcional entre as variáveis idade e diminuição do PFE. Ambas as situações mostraram significância estatística (pvalores de PFE tanto no pré como no pós-operatório. O grupo composto por portadores de co-morbidades (HAS e/ou DM) apresentou menores valores de PFE tanto no pré como no pós-operatório (p=0,005). Em ambos os grupos, o pós-operatório determinou uma diminuição significativa do PFE (p<0,001). O tipo de cirurgia realizada e o tipo de anestesia não mostraram diferenças significantes em relação ao PFE. as variáveis mais implicadas na diminuição da função ventilatória, avaliadas através da PFE, foram: idade avançada, tabagismo e presença de comorbidades.

  3. Lung volumes and maximal respiratory pressures in collegiate swimmers and runners.

    Science.gov (United States)

    Cordain, L; Tucker, A; Moon, D; Stager, J M

    1990-03-01

    To determine whether respiratory muscle strength is related to pulmonary volume differences in athletes and nonathletes, 11 intercollegiate female swimmers, 11 female cross-country runners, and two nonathletic control groups, matched to the athletes in height and age, were evaluated for pulmonary parameters including maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax). Swimmers exhibited larger (p less than .05) vital capacities (VC), residual lung volumes (RV), inspiratory capacities (IC), and functional residual capacities (FRC) than both the runners or the controls but no difference (p greater than .05) in either PImax or inspiratory flow (FIV 25%-75%). Timed expiratory volumes (FEV 0.5 and FEV 1.0) were significantly (p less than .05) lower in the swimmers than in the controls. These data suggest that an adaptational growth may be responsible, in part, for the augmented static lung volumes demonstrated in swimmers.

  4. Ambulatory blood pressure profiles in familial dysautonomia.

    Science.gov (United States)

    Goldberg, Lior; Bar-Aluma, Bat-El; Krauthammer, Alex; Efrati, Ori; Sharabi, Yehonatan

    2018-02-12

    Familial dysautonomia (FD) is a rare genetic disease that involves extreme blood pressure fluctuations secondary to afferent baroreflex failure. The diurnal blood pressure profile, including the average, variability, and day-night difference, may have implications for long-term end organ damage. The purpose of this study was to describe the circadian pattern of blood pressure in the FD population and relationships with renal and pulmonary function, use of medications, and overall disability. We analyzed 24-h ambulatory blood pressure monitoring recordings in 22 patients with FD. Information about medications, disease severity, renal function (estimated glomerular filtration, eGFR), pulmonary function (forced expiratory volume in 1 s, FEV1) and an index of blood pressure variability (standard deviation of systolic pressure) were analyzed. The mean (± SEM) 24-h blood pressure was 115 ± 5.6/72 ± 2.0 mmHg. The diurnal blood pressure variability was high (daytime systolic pressure standard deviation 22.4 ± 1.5 mmHg, nighttime 17.2 ± 1.6), with a high frequency of a non-dipping pattern (16 patients, 73%). eGFR, use of medications, FEV1, and disability scores were unrelated to the degree of blood pressure variability or to dipping status. This FD cohort had normal average 24-h blood pressure, fluctuating blood pressure, and a high frequency of non-dippers. Although there was evidence of renal dysfunction based on eGFR and proteinuria, the ABPM profile was unrelated to the measures of end organ dysfunction or to reported disability.

  5. Evaluation of image quality and patient safety: paired inspiratory and expiratory MDCT assessment of tracheobronchomalacia in paediatric patients under general anaesthesia with breath-hold technique

    International Nuclear Information System (INIS)

    Lee, Edward Y.; Bastos, Maria d' Almeida; Stark, Cynthia; Carrier, Maureen; Zurakowski, David; Mason, Keira P.

    2012-01-01

    The purpose of our investigation was to evaluate image quality and patient safety in infants and young children who required general anaesthesia with breath-hold technique for paired inspiratory and expiratory multidetector CT (MDCT) assessment of tracheobronchomalacia (TBM). Our hospital's institutional review board approved the review of radiological and clinical data of a consecutive series of 20 paediatric patients who underwent MDCT under general anaesthesia with breath-hold technique for evaluation of TBM from May 2006 to December 2008. For each MDCT study, two fellowship-trained paediatric radiologists reviewed the inspiratory and expiratory MDCT images in an independent, randomised and blinded fashion for the presence of motion artefact at three anatomic levels (upper, middle and lower central airways). The clinical history and anaesthesia outcome, including the occurrence of any adverse events during or following the MDCT examinations until discharge, were also reviewed and recorded. The study population consisted of 20 infants and young children (13 boys/seven girls, mean age 1.7 ± 1.4 years, age range 11 days to 4 years). The imaging quality of all 20 MDCT studies was diagnostic with no motion artefact in 16 studies (80%) and minimal motion artefact in the remaining four studies (20%). Minor adverse events occurred in three patients (15%) that included one patient (5%) with a brief (<60 s) oxygen desaturation during MDCT study, which resolved with oxygen, and two patients (5%) with either a brief (<60 s) oxygen desaturation (n = 1, 5%) or cough (n = 1, 5%) during recovery period, which were completely resolved with oxygen and dexamethasone, respectively. Diagnostic quality paired inspiratory and expiratory MDCT imaging with breath-hold technique can be safely performed in infants and young children under general anaesthesia for evaluation of TBM.

  6. Blood pressure

    Science.gov (United States)

    Normal blood pressure is important for proper blood flow to the body's organs and tissues. The force of the blood on the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart ...

  7. An asthma patient with steroid-resistant decrease in peak expiratory flow after the Great East Japan earthquake showing spontaneous recovery after 1 month.

    Science.gov (United States)

    Yanagimoto, Shintaro; Haida, Michiko; Suko, Matsunobu

    2012-01-01

    People living in Japan were affected in various ways after the Great East Japan earthquake of March 11, 2011. A 52-year-old female asthma patient not directly affected by the disaster experienced a decrease in peak expiratory flow (PEF) immediately after the earthquake. Despite increasing the inhaled and oral corticosteroid doses, her PEF did not recover. One month later, her PEF level abruptly returned to normal with minimal medications, which were previously ineffective, and the asthma-related symptoms vanished. The stabilization of her state of mind and actual social state seemed to be a part of the reason for the patient's recovery.

  8. The Neopuff's PEEP valve is flow sensitive.

    LENUS (Irish Health Repository)

    Hawkes, Colin Patrick

    2011-03-01

    The current recommendation in setting up the Neopuff is to use a gas flow of 5-15 L\\/min. We investigated if the sensitivity of the positive end expiratory pressure (PEEP) valve varies at different flow rates within this range.

  9. Rationale and study design of PROVHILO - a worldwide multicenter randomized controlled trial on protective ventilation during general anesthesia for open abdominal surgery

    NARCIS (Netherlands)

    Hemmes, S.N.T.; Severgnini, P.; Jaber, S.; Canet, J.; Wrigge, H.; Hiesmayr, M.; Tschernko, E.M.; Hollmann, M.W.; Binnekade, J.M.; Hedenstierna, G.; Putensen, C.; Gama de Abreu, M.; Pelosi, P.; Schultz, M.J.

    2011-01-01

    ABSTRACT: BACKGROUND: Post-operative pulmonary complications add to the morbidity and mortality of surgical patients, in particular after general anesthesia > 2 hours for abdominal surgery. Whether a protective mechanical ventilation strategy with higher levels of positive end-expiratory pressure

  10. Lung-protective perioperative mechanical ventilation

    NARCIS (Netherlands)

    Hemmes, S.N.T.

    2015-01-01

    Intraoperative ventilation has the potential to cause lung injury and possibly increase risk of pulmonary complications after surgery. Use of large tidal volumes could cause overdistension of lung tissue, which can be aggravated by too high levels of positive end-expiratory pressure (PEEP). Too low

  11. Current concepts of protective ventilation during general anaesthesia

    NARCIS (Netherlands)

    Serpa Neto, Ary; Schultz, Marcus J.; Slutsky, Arthur S.

    2015-01-01

    Mechanical ventilation with high tidal volumes (VT) has been common practice in operating theatres because this strategy recruits collapsed lung tissue and improves ventilation-perfusion mismatch, thus decreasing the need for high inspired oxygen concentrations. Positive end-expiratory pressure

  12. High flow nasal cannula for respiratory support in preterm infants.

    LENUS (Irish Health Repository)

    Wilkinson, Dominic

    2011-01-01

    High flow nasal cannulae (HFNC) are small, thin, tapered cannulae used to deliver oxygen or blended oxygen and air at flow rates of > 1 L\\/min. HFNC can be used to provide high concentrations of oxygen and may deliver positive end-expiratory pressure.

  13. Neurally adjusted ventilatory assist decreases ventilator-induced lung injury and non-pulmonary organ dysfunction in rabbits with acute lung injury

    NARCIS (Netherlands)

    Brander, Lukas; Sinderby, Christer; Lecomte, François; Leong-Poi, Howard; Bell, David; Beck, Jennifer; Tsoporis, James N.; Vaschetto, Rosanna; Schultz, Marcus J.; Parker, Thomas G.; Villar, Jesús; Zhang, Haibo; Slutsky, Arthur S.

    2009-01-01

    OBJECTIVE: To determine if neurally adjusted ventilatory assist (NAVA) that delivers pressure in proportion to diaphragm electrical activity is as protective to acutely injured lungs (ALI) and non-pulmonary organs as volume controlled (VC), low tidal volume (Vt), high positive end-expiratory

  14. Maximal respiratory pressures and pulmonary function in male runners.

    OpenAIRE

    Cordain, L; Glisan, B J; Latin, R W; Tucker, A; Stager, J M

    1987-01-01

    To determine the effects of long term exercise on respiratory muscle strength, maximal inspiratory (Pl max) and expiratory (PE max) pressures, pulmonary volumes and capacities and anthropometric parameters were measured in a group of 101 male runners aged 16 to 58 years. The runners exhibited significantly (p less than 0.05) lower PE max (202 +/- 41 cm H2O and significantly greater residual lung volumes (RV) (2.08 +/- 0.49 L) than predicted values for normal subjects of similar height and age...

  15. Normal expiratory flow rate and lung volumes in patients with combined emphysema and interstitial lung disease: a case series and literature review.

    Science.gov (United States)

    Heathcote, Karen L; Cockcroft, Donald W; Fladeland, Derek A; Fenton, Mark E

    2011-01-01

    Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.

  16. Normal Expiratory Flow Rate and Lung Volumes in Patients with Combined Emphysema and Interstitial Lung Disease: A Case Series and Literature Review

    Directory of Open Access Journals (Sweden)

    Karen L Heathcote

    2011-01-01

    Full Text Available Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.

  17. Effects of Hemibridge with Ball and Balloon Exercise on Forced Expiratory Volume and Pain in Patients with Chronic Low Back Pain: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Jorida Fernandes

    2017-08-01

    Full Text Available Background and objectives: Suboptimal breathing patterns and impairments of posture and trunk stability are often associated with musculoskeletal complaints such as low back pain. Respiration is also affected by poor neuromuscular control of core muscles. Immediate effects of hemibridge with ball and balloon exercise has been studied on chronic pain in athlete population. Objective: To evaluate the effects of hemibridge with ball and balloon exercise on pain, forced expiratory volume and functional abilities in patients with chronic low back pain using Visual Analogue Scale (VAS, Forced Expiratory Volume (FEV and Modified Oswestry Disability Questionnaire (MODQ. Methods: The present experimental study was conducted among 30 participants between the age of 21 to 55 years with chronic non-specific LBP. The participants were given a hemibridge with ball and balloon exercise. Pre-interventional and 3rd day Post-interventional outcome measurements were taken using VAS, FEV1 and FEV6 and MODQ. Results: The difference between pre-and post of VAS was statistically highly significant (p=0.0001. The p value of FEV6 and MODQ by paired t test was statistically significant with p value of 0.02 and 0.0007 respectively. Conclusion: The study concludes that there is an immediate effect of hemibridge with ball and balloon exercise on pain, FEV6 and functional ability in patients with chronic LBP.

  18. Peak expiratory flow rate in healthy rural school going children (5-16 years) of bellur region for construction of nomogram.

    Science.gov (United States)

    Cb, Manjunath; Sc, Kotinatot; Babu, Manjunatha

    2013-12-01

    Peak Expiratory Flow Rate (PEFR) recording is an essential measure in the management and evaluation of asthmatic children.It is helpful in monitoring disease progression and response to treatment. The PEFR can be measured by a simple instrument-peak expiratory flow meter. To construct nomogram of PEFR in healthy rural school going children from Mandya district of Karnataka state, India and to use these nomograms for comparison with that of children with obstructive lung diseases for this region. The study was conducted on Healthy rural school going children, both boys and girls between the age group of 5-16 years. For the determination of PEFR we used Mini Wright Peak Flow Meter. At three time measurement, the highest value of PEFR was recorded. Formula for prediction of PEFR was estimated by linear regression analysis after the correlation of PEFR with age and height for both boys and girls. PEFR was measured in 1028 children aged 5 to 16 years by using Wright's mini peak flow meter. Prediction equations were derived for PEFR with height in boys and girls. Normograms were plotted based on the observed values of PEFR in the study population. Significant linear correlation was seen of PEFR with height in boys (paffected by regional, environmental and anthropometric factors. Hence, it is necessary to have regional reference values for children. Among different factors affecting PEFR, height correlates better with PEFR than weight and sex. Hence nomograms constructed can be used for this region.

  19. Pressure Sores

    Science.gov (United States)

    Pressure sores are areas of damaged skin caused by staying in one position for too long. They commonly ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which are ...

  20. The correlation between the paired inspiratory and expiratory three-dimensional quantitative CT and pulmonary function test in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Sui Xi; Song Wei; Xue Huadan; Song Lan; Yang Liang; Jin Zhengyu

    2013-01-01

    Objective: To investigate the correlation between the paired inspiratory and expiratory quantitative CT and pulmonary function tests (PFTs) in patients with chronic obstructive pulmonary disease (COPD). Methods: A total of 84 patients with COPD were enrolled. For each patient, CT scan was performed in deep inspiration and expiration. Using automatic post-processing software, a three-dimension quantitative measurement was employed to assess the CT parameters of emphysema and air trapping. The correlation between CT and PFT was evaluated by the Spearman rank correlation test and multivariate linear regression analysis. Results: The percent 1 [Perc_1, (-984.28 ± 17.93) HU] and percent 15 [Perc_1_5, (-948.35 ± 22.26) HU] from the CT parameters of emphysema were positively correlated with the forced expiratory volume in 1 second predicted (FEV_1%, 48.69 ± 23, 47), the ratio of forced expiratory volume in 1 second over forced vital capacity [FEV_1/FVC, (45.89 ± 15.36)%, r = 0.45-0.67, P < 0.01], was negatively correlated with the ratio of residual volume to total lung capacity [RV/TLC, (61.32 ± 14.48)%]. The other CT parameters of emphysema index (EI) and the parameters of air trapping, the change in relative lung volume with attenuation values from -860 to -950 HU [RVC_-_8_6_0_-_-_9_5_0, (17.66 ± 22.36)%], the expiration to inspiration ratio of mean lung density (MLD_e_x_/_i_n, 0.93 ± 0.06), the expiration to inspiration ratio of lung volume (LV_e_x_/_i_n, 0.71 ± 0.14) had negative correlations with logFEV_1%, FEV_1/FVC (r = -0.48--0.69, P < 0.01) and positive correlations with RV/TLC (r = 0.41-0.66, P < 0.01). The further univariate linear regressions showed that EI, Perc_1, Pere_1_5, RVC_-_8_6_0_-_-_9_5_0, MLD_e_x_/_i_n, LV_e_x_/_i_n were correlated with the parameters of PFTs (R square values of the regression equation, ranged from 0.27 to 0.66, P < 0.01). After the pairwise combinations of the parameters of emphysema and air trapping, multivariate stepwise

  1. Changes in Cross-Sectional Area and Transverse Diameter of the Heart on Inspiratory and Expiratory Chest CT: Correlation with Changes in Lung Size and Influence on Cardiothoracic Ratio Measurement.

    Directory of Open Access Journals (Sweden)

    Hayato Tomita

    Full Text Available The aim of this study was to investigate physiological changes in cardiac area and diameters between inspiratory and expiratory chest computed tomography (CT, and to assess their correlation with lung size change and influence on cardiothoracic ratio (CTR measurements.The institutional review board of our institution approved this study, and informed consent was waived. Forty-three subjects underwent inspiratory and expiratory chest CT as part of routine clinical care. On both inspiratory and expiratory scans, lung volumes and maximum lung diameters (transverse and vertical directions were measured. The maximum cardiac cross-sectional area (CSA and the maximum transverse cardiac diameter were measured on both scans, and the CT-based CTR was calculated. Changes in the lung and cardiac measurements were expressed as the expiratory/inspiratory (E/I ratios. Comparisons between inspiratory and expiratory measurements were made by the Wilcoxon signed-rank test. Correlations between the E/I ratios of lung and heart measurements were evaluated by Spearman's rank correlation analysis.Cardiac CSA and transverse cardiac diameter was significantly larger on expiratory than on inspiratory CT (p < 0.0001. Significant negative correlations were found between the E/I ratios of these cardiac measurements and the E/I ratios of lung volume and vertical lung diameter (p < 0.01. CT-based CTR was significantly larger on expiration than on inspiration (p < 0.0001.Heart size on chest CT depends on the phase of ventilation, and is correlated with changes in lung volume and craniocaudal lung diameter. The CTR is also significantly influenced by ventilation.

  2. High blood pressure, antihypertensive medication and lung function in a general adult population

    Science.gov (United States)

    2011-01-01

    Background Several studies showed that blood pressure and lung function are associated. Additionally, a potential effect of antihypertensive medication, especially beta-blockers, on lung function has been discussed. However, side effects of beta-blockers have been investigated mainly in patients with already reduced lung function. Thus, aim of this analysis is to determine whether hypertension and antihypertensive medication have an adverse effect on lung function in a general adult population. Methods Within the population-based KORA F4 study 1319 adults aged 40-65 years performed lung function tests and blood pressure measurements. Additionally, information on anthropometric measurements, medical history and use of antihypertensive medication was available. Multivariable regression models were applied to study the association between blood pressure, antihypertensive medication and lung function. Results High blood pressure as well as antihypertensive medication were associated with lower forced expiratory volume in one second (p = 0.02 respectively p = 0.05; R2: 0.65) and forced vital capacity values (p = 0.01 respectively p = 0.05, R2: 0.73). Furthermore, a detailed analysis of antihypertensive medication pointed out that only the use of beta-blockers was associated with reduced lung function, whereas other antihypertensive medication had no effect on lung function. The adverse effect of beta-blockers was significant for forced vital capacity (p = 0.04; R2: 0.65), while the association with forced expiratory volume in one second showed a trend toward significance (p = 0.07; R2: 0.73). In the same model high blood pressure was associated with reduced forced vital capacity (p = 0.01) and forced expiratory volume in one second (p = 0.03) values, too. Conclusion Our analysis indicates that both high blood pressure and the use of beta-blockers, but not the use of other antihypertensive medication, are associated with reduced lung function in a general adult

  3. Intracranial Pressure

    DEFF Research Database (Denmark)

    Hvedstrup, Jeppe; Radojicic, Aleksandra; Moudrous, Walid

    2018-01-01

    OBJECTIVE: To compare a new method of noninvasive intracranial pressure (nICP) measurement with conventional lumbar puncture (LP) opening pressure. METHODS: In a prospective multicenter study, patients undergoing LP for diagnostic purposes underwent intracranial pressure measurements with HeadSen...

  4. Pressure Ulcers

    OpenAIRE

    Monfre, Jill M.

    2016-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers, which affect up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease.

  5. Calculation of the capnographic index based on expiratory molar mass-volume-curves--a suitable tool to screen for cystic fibrosis lung disease.

    Science.gov (United States)

    Fuchs, Susanne I; Junge, Sibylle; Ellemunter, Helmut; Ballmann, Manfred; Gappa, Monika

    2013-05-01

    Volumetric capnography reflecting the course of CO2-exhalation is used to assess ventilation inhomogeneity. Calculation of the slope of expiratory phase 3 and the capnographic index (KPIv) from expirograms allows quantification of extent and severity of small airway impairment. However, technical limitations have hampered more widespread use of this technique. Using expiratory molar mass-volume-curves sampled with a handheld ultrasonic flow sensor during tidal breathing is a novel approach to extract similar information from expirograms in a simpler manner possibly qualifying as a screening tool for clinical routine. The aim of the present study was to evaluate calculation of the KPIv based on molar mass-volume-curves sampled with an ultrasonic flow sensor in patients with CF and controls by assessing feasibility, reproducibility and comparability with the Lung Clearance Index (LCI) derived from multiple breath washout (MBW) used as the reference method. Measurements were performed in patients with CF and healthy controls during a single test occasion using the EasyOne Pro, MBW Module (ndd Medical Technologies, Switzerland). Capnography and MBW were performed in 87/96 patients with CF and 38/42 controls, with a success rate of 90.6% for capnography. Mean age (range) was 12.1 (4-25) years. Mean (SD) KPIv was 6.94 (3.08) in CF and 5.10 (2.06) in controls (p=0.001). Mean LCI (SD) was 8.0 (1.4) in CF and 6.2 (0.4) in controls (p=molar mass-volume-curves is feasible. KPIv is significantly different between patients with CF and controls and correlates with the LCI. However, individual data revealed a relevant overlap between patients and controls requiring further evaluation, before this method can be recommended for clinical use. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  6. Impact of Different Ventilation Strategies on Driving Pressure, Mechanical Power, and Biological Markers During Open Abdominal Surgery in Rats.

    Science.gov (United States)

    Maia, Lígia de A; Samary, Cynthia S; Oliveira, Milena V; Santos, Cintia L; Huhle, Robert; Capelozzi, Vera L; Morales, Marcelo M; Schultz, Marcus J; Abreu, Marcelo G; Pelosi, Paolo; Silva, Pedro L; Rocco, Patricia Rieken Macedo

    2017-10-01

    Intraoperative mechanical ventilation may yield lung injury. To date, there is no consensus regarding the best ventilator strategy for abdominal surgery. We aimed to investigate the impact of the mechanical ventilation strategies used in 2 recent trials (Intraoperative Protective Ventilation [IMPROVE] trial and Protective Ventilation using High versus Low PEEP [PROVHILO] trial) on driving pressure (ΔPRS), mechanical power, and lung damage in a model of open abdominal surgery. Thirty-five Wistar rats were used, of which 28 were anesthetized, and a laparotomy was performed with standardized bowel manipulation. Postoperatively, animals (n = 7/group) were randomly assigned to 4 hours of ventilation with: (1) tidal volume (VT) = 7 mL/kg and positive end-expiratory pressure (PEEP) = 1 cm H2O without recruitment maneuvers (RMs) (low VT/low PEEP/RM-), mimicking the low-VT/low-PEEP strategy of PROVHILO; (2) VT = 7 mL/kg and PEEP = 3 cm H2O with RMs before laparotomy and hourly thereafter (low VT/moderate PEEP/4 RM+), mimicking the protective ventilation strategy of IMPROVE; (3) VT = 7 mL/kg and PEEP = 6 cm H2O with RMs only before laparotomy (low VT/high PEEP/1 RM+), mimicking the strategy used after intubation and before extubation in PROVHILO; or (4) VT = 14 mL/kg and PEEP = 1 cm H2O without RMs (high VT/low PEEP/RM-), mimicking conventional ventilation used in IMPROVE. Seven rats were not tracheotomized, operated, or mechanically ventilated, and constituted the healthy nonoperated and nonventilated controls. Low VT/moderate PEEP/4 RM+ and low VT/high PEEP/1 RM+, compared to low VT/low PEEP/RM- and high VT/low PEEP/RM-, resulted in lower ΔPRS (7.1 ± 0.8 and 10.2 ± 2.1 cm H2O vs 13.9 ± 0.9 and 16.9 ± 0.8 cm H2O, respectively; Pmechanical power (63 ± 7 and 79 ± 20 J/min vs 110 ± 10 and 120 ± 20 J/min, respectively; P = .007). Low VT/high PEEP/1 RM+ was associated with less alveolar collapse than low VT/low PEEP/RM- (P = .03). E-cadherin expression was higher in

  7. Application of the Novel Ventilation Mode FLow-Controlled EXpiration (FLEX): A Crossover Proof-of-Principle Study in Lung-Healthy Patients.

    Science.gov (United States)

    Wirth, Steffen; Springer, Sebastian; Spaeth, Johannes; Borgmann, Silke; Goebel, Ulrich; Schumann, Stefan

    2017-10-01

    Traditionally, mechanical ventilation is achieved via active lung inflation during inspiration and passive lung emptying during expiration. By contrast, the novel FLEX (FLow-controlled EXpiration) ventilator mode actively decreases the rate of lung emptying. We investigated whether FLEX can be used during intraoperative mechanical ventilation of lung-healthy patients. In 30 adult patients scheduled for neurosurgical procedures, we studied respiratory system mechanics, regional ventilation, oxygenation, and hemodynamics during ventilation with and without FLEX at positive end-expiratory pressure (PEEP) of 5 and 7 cm H2O. The FLEX system was integrated into the expiratory limb and modified the expiratory flow profile by continuously changing expiratory resistance according to a computer-controlled algorithm. Mean airway pressure increased with PEEP by 1.9 cm H2O and with FLEX by 1 cm H2O (all P ventilated during general anesthesia. FLEX improves the homogeneous distribution of ventilation in the lungs.

  8. Pressure transducers

    International Nuclear Information System (INIS)

    Gomes, A.V.

    1975-01-01

    Strain gauges pressure transducers types are presented. Models, characteristics and calibration procedures were also analysed. Initially, a theoretical study was accomplished to evaluate metallic alloys behavior on sensing elements manufacturing, and diaphragm was used as deflecting elements. Electrical models for potenciometric transducers were proposed at the beginning and subsequently comproved according our experiments. Concerning bridge transducers, existing models confirmed the conditions of linearity and sensitivity related to the electrical signal. All the work done was of help on the calibration field and pressure measurements employing unbounded strain gauge pressure transducers

  9. Effect of driving pressure on mortality in ARDS patients during lung protective mechanical ventilation in two randomized controlled trials.

    Science.gov (United States)

    Guérin, Claude; Papazian, Laurent; Reignier, Jean; Ayzac, Louis; Loundou, Anderson; Forel, Jean-Marie

    2016-11-29

    Driving pressure (ΔPrs) across the respiratory system is suggested as the strongest predictor of hospital mortality in patients with acute respiratory distress syndrome (ARDS). We wonder whether this result is related to the range of tidal volume (V T ). Therefore, we investigated ΔPrs in two trials in which strict lung-protective mechanical ventilation was applied in ARDS. Our working hypothesis was that ΔPrs is a risk factor for mortality just like compliance (Crs) or plateau pressure (Pplat,rs) of the respiratory system. We performed secondary analysis of data from 787 ARDS patients enrolled in two independent randomized controlled trials evaluating distinct adjunctive techniques while they were ventilated as in the low V T arm of the ARDSnet trial. For this study, we used V T , positive end-expiratory pressure (PEEP), Pplat,rs, Crs, ΔPrs, and respiratory rate recorded 24 hours after randomization, and compared them between survivors and nonsurvivors at day 90. Patients were followed for 90 days after inclusion. Cox proportional hazard modeling was used for mortality at day 90. If colinearity between ΔPrs, Crs, and Pplat,rs was verified, specific Cox models were used for each of them. Both trials enrolled 805 patients of whom 787 had day-1 data available, and 533 of these survived. In the univariate analysis, ΔPrs averaged 13.7 ± 3.7 and 12.8 ± 3.7 cmH 2 O (P = 0.002) in nonsurvivors and survivors, respectively. Colinearity between ΔPrs, Crs and Pplat,rs, which was expected as these variables are mathematically coupled, was statistically significant. Hazard ratios from the Cox models for day-90 mortality were 1.05 (1.02-1.08) (P = 0.005), 1.05 (1.01-1.08) (P = 0.008) and 0.985 (0.972-0.985) (P = 0.029) for ΔPrs, Pplat,rs and Crs, respectively. PEEP and V T were not associated with death in any model. When ventilating patients with low V T , ΔPrs is a risk factor for death in ARDS patients, as is Pplat,rs or Crs. As our data

  10. Peer Pressure

    Science.gov (United States)

    ... for: Teens Dealing With Bullying Emotional Intelligence Sexual Harassment and Sexual Bullying Coping With Stressful Situations Prom Pressure What Stresses You Out About School? Virginity: A Very Personal Decision Stress & Coping Center ...

  11. An advanced expiratory circuit for the recovery of perfluorocarbon liquid from non-saturated perfluorocarbon vapour during partial liquid ventilation: an experimental model

    Directory of Open Access Journals (Sweden)

    Davies Mark W

    2006-02-01

    Full Text Available Abstract Background The loss of perfluorocarbon (PFC vapour in the expired gases during partial liquid ventilation should be minimized both to prevent perfluorocarbon vapour entering the atmosphere and to re-use the recovered PFC liquid. Using a substantially modified design of our previously described condenser, we aimed to determine how much perfluorocarbon liquid could be recovered from gases containing PFC and water vapour, at concentrations found during partial liquid ventilation, and to determine if the amount recovered differed with background flow rate (at flow rates suitable for use in neonates. Methods The expiratory line of a standard ventilator circuit set-up was mimicked, with the addition of two condensers. Perfluorocarbon (30 mL of FC-77 and water vapour, at concentrations found during partial liquid ventilation, were passed through the circuit at a number of flow rates and the percentage recovery of the liquids measured. Results From 14.2 mL (47% to 27.3 mL (91% of the infused 30 mL of FC-77 was recovered at the flow rates studied. Significantly higher FC-77 recovery was obtained at lower flow rates (ANOVA with Bonferroni's multiple comparison test, p -1 (ANOVA with Bonferroni's multiple comparison test, p -1, respectively. Conclusion Using two condensers in series 47% to 91% of perfluorocarbon liquid can be recovered, from gases containing perfluorocarbon and water vapour, at concentrations found during partial liquid ventilation.

  12. Peak expiratory flow mediates the relationship between handgrip strength and timed up and go performance in elderly women, but not men.

    Science.gov (United States)

    Ritti-Dias, Raphael Mendes; Cucato, Gabriel Grizzo; de Mello Franco, Fábio Gazelato; Cendoroglo, Maysa Seabra; Nasri, Fábio; Monteiro-Costa, Maria Luiza; de Carvalho, José Antonio Maluf; de Matos, Luciana Diniz Nagem Janot

    2016-09-01

    The aim of the present study was to verify if there is sex difference in the associations among handgrip strength, peak expiratory flow (PEF) and timed up and go (TUG) test results. The sample included 288 consecutive elderly men (n=93) and women (n=195). Functional capacity was measured using the TUG test, and muscle strength was measured based on handgrip. Moreover, as a measure of current health status, PEF was evaluated. Linear regression procedures were performed to analyze the relationships between handgrip and both PEF and TUG test results, with adjustment for confounders, and to identify the possible mediating role of PEF in the association between handgrip strength and TUG test results. In men, handgrip strength was associated with both PEF and TUG performance (prelationship between handgrip strength and TUG performance remained significant. In women, handgrip strength was also associated with both PEF and TUG performance (prelationship between handgrip strength and TUG performance was no longer significant. Mobility in the elderly is sex dependent. In particular, PEF mediates the relationship between handgrip strength and TUG performance in women, but not in men.

  13. Airway pressure release ventilation and biphasic positive airway pressure: a systematic review of definitional criteria.

    Science.gov (United States)

    Rose, Louise; Hawkins, Martyn

    2008-10-01

    The objective of this study was to identify the definitional criteria for the pressure-limited and time-cycled modes: airway pressure release ventilation (APRV) and biphasic positive airway pressure (BIPAP) available in the published literature. Systematic review. Medline, PubMed, Cochrane, and CINAHL databases (1982-2006) were searched using the following terms: APRV, BIPAP, Bilevel and lung protective strategy, individually and in combination. Two independent reviewers determined the paper eligibility and abstracted data from 50 studies and 18 discussion articles. Of the 50 studies, 39 (78%) described APRV, and 11 (22%) described BIPAP. Various study designs, populations, or outcome measures were investigated. Compared to BIPAP, APRV was described more frequently as extreme inverse inspiratory:expiratory ratio [18/39 (46%) vs. 0/11 (0%), P = 0.004] and used rarely as a noninverse ratio [2/39 (5%) vs. 3/11 (27%), P = 0.06]. One (9%) BIPAP and eight (21%) APRV studies used mild inverse ratio (>1:1 to branding may further add to confusion. Generic naming of modes and consistent definitional parameters may improve consistency of patient response for a given mode and assist with clinical implementation.

  14. Evaluation of the monitor cursor-line method for measuring pulmonary artery and central venous pressures.

    Science.gov (United States)

    Pasion, Editha; Good, Levell; Tizon, Jisebelle; Krieger, Staci; O'Kier, Catherine; Taylor, Nicole; Johnson, Jennifer; Horton, Carrie M; Peterson, Mary

    2010-11-01

    To determine if the monitor cursor-line feature on bedside monitors is accurate for measuring central venous and pulmonary artery pressures in cardiac surgery patients. Central venous and pulmonary artery pressures were measured via 3 methods (end-expiratory graphic recording, monitor cursor-line display, and monitor digital display) in a convenience sample of postoperative cardiac surgery patients. Pressures were measured twice during both mechanical ventilation and spontaneous breathing. Analysis of variance was used to determine differences between measurement methods and the percentage of monitor pressures that differed by 4 mm Hg or more from the measurement obtained from the graphic recording. Significance level was set at P less than .05. Twenty-five patients were studied during mechanical ventilation (50 measurements) and 21 patients during spontaneous breathing (42 measurements). Measurements obtained via the 3 methods did not differ significantly for either type of pressure (P > .05). Graphically recorded pressures and measurements obtained via the monitor cursor-line or digital display methods differed by 4 mm Hg or more in 4% and 6% of measurements, respectively, during mechanical ventilation and 4% and 11%, respectively, during spontaneous breathing. The monitor cursor-line method for measuring central venous and pulmonary artery pressures may be a reasonable alternative to the end-expiratory graphic recording method in hemodynamically stable, postoperative cardiac surgery patients. Use of the digital display on the bedside monitor may result in larger discrepancies from the graphically recorded pressures than when the cursor-line method is used, particularly in spontaneously breathing patients.

  15. Study of Peak Expiratory Flow Rate as the Assessment of Lung Function in Occupationally Exposed Petrol Pump Workers of Western Maharashtra

    Directory of Open Access Journals (Sweden)

    Patil Smita V

    2016-04-01

    Full Text Available Background: Fast urbanization trends, rapid industrial growth, globalization, and poor environmental conditions at work places have created a lot of healthrelated issues. Aim and Objectives: The aim of this study is to investigate Peak Expiratory Flow Rate (PEFR as the assessment of lung function in occupationally exposed petrol pump workers and also check whether PEFR increases or decreases with duration of exposure. Material and Methods: The study was conducted on 60 male petrol pump workers between age group of 20-40 years who were working as petrol filling attendants for more than one year from western Maharashtra. 50 normal healthy males with same socioeconomic status were chosen as controls to find out the effect of occupational exposure to petroleum product on PEFR as the assessment of lung function tests. Petrol pump workers were divided into three groups based on their duration of exposure i.e. 1- 5 yrs, 6- 10 yrs and more than 11 years. PEFR of petrol pump workers and control was measured by using a Mini Wright peak flow meter which is a portable device for measuring ventilator functions. Comparisons was done using unpaired t-test for 2 groups comparisons and one way ANOVAfor multiple groups of exposures. Results: The PEFR was significantly lower decrease (p=0.001 around petrol pump workers (389.17 as compared to control (534.2. As year of exposure increased mean value of PEFR was significantly decreased from 452.17, 378.00 and 283.64 respectively in petrol pump workers. Conclusion: The results suggested that respiratory functions i.e. PEFR of occupationally exposed petrol pump workers are significantly reduced as compared to controls, also PEFR is significantly reduced with increase in the duration of exposure.

  16. Three-section expiratory CT

    DEFF Research Database (Denmark)

    Loeve, Martine; de Bruijne, Marleen; Hartmann, Ieneke C. J.

    2012-01-01

    . Longitudinal follow-up was performed with three sections. All images were deidentified and randomized, and TA was scored with the Brody II system and a new quantitative system. Statistical analysis included the Wilcoxon signed rank test, calculation of Spearman and intraclass correlation coefficients, and use......Purpose: To estimate the effect of the number of computed tomography (CT) sections on trapped air (TA) assessment in patients with cystic fibrosis (CF) by using an established scoring system and a new quantitative scoring system and to compare CT and pulmonary function test (PFT) estimates of TA...

  17. High-Frequency Chest Compression: A Summary of the Literature

    Directory of Open Access Journals (Sweden)

    Cara F Dosman

    2005-01-01

    Full Text Available The purpose of the present literature summary is to describe high-frequency chest compression (HFCC, summarize its history and outline study results on its effect on mucolysis, mucus transport, pulmonary function and quality of life. HFCC is a mechanical method of self-administered chest physiotherapy, which induces rapid air movement in and out of the lungs. This mean oscillated volume is an effective method of mucolysis and mucus clearance. HFCC can increase independence. Some studies have shown that HFCC leads to more mucus clearance and better lung function compared with conventional chest physiotherapy. However, HFCC also decreases end-expiratory lung volume, which can lead to increased airway resistance and a decreased oscillated volume. Adding positive end-expiratory pressure to HFCC has been shown to prevent this decrease in end-expiratory lung volume and to increase the oscillated volume. It is possible that the HFCC-induced decrease in end-expiratory lung volume may result in more mucus clearance in airways that remain open by reducing airway size. Adjunctive methods, such as positive end-expiratory pressure, may not always be needed to make HFCC more effective.

  18. Determination of respiratory system compliance during pressure support ventilation by small variations of pressure support.

    Science.gov (United States)

    Becher, Tobias; Schädler, Dirk; Rostalski, Philipp; Zick, Günther; Frerichs, Inéz; Weiler, Norbert

    2017-09-22

    In mechanically ventilated patients, measurement of respiratory system compliance (C rs ) is of high clinical interest. Spontaneous breathing activity during pressure support ventilation (PSV) can impede the correct assessment of C rs and also alter the true C rs by inducing lung recruitment. We describe a method for determination of C rs during PSV and assess its accuracy in a study on 20 mechanically ventilated patients. To assess C rs during pressure support ventilation (C rs,PSV ), we performed repeated changes in pressure support level by ± 2 cmH 2 O. C rs,PSV was calculated from the volume change induced by these changes in pressure support level, taking into account the inspiration time and the expiratory time constant. As reference methods, we used C rs , measured during volume controlled ventilation (C rs,VCV ). In a post-hoc analysis, we assessed C rs during the last 20% of the volume-controlled inflation (C rs,VCV20 ). Values were compared by linear regression and Bland-Altman methods comparison. Comparing C rs,PSV to the reference value C rs,VCV , we found a coefficient of determination (r 2 ) of 0.90, but a relatively high bias of - 7 ml/cm H 2 O (95% limits of agreement - 16.7 to + 2.7 ml/cmH 2 O). Comparison with C rs,VCV20 resulted in a negligible bias (- 1.3 ml/cmH 2 O, 95% limits of agreement - 13.9 to + 11.3) and r 2 of 0.81. We conclude that the novel method provides an estimate of end-inspiratory C rs during PSV. Despite its limited accuracy, it might be useful for non-invasive monitoring of C rs in patients undergoing pressure support ventilation.

  19. [The clinical effect of airway pressure release ventilation for acute lung injury/acute respiratory distress syndrome].

    Science.gov (United States)

    Song, Shaohua; Tian, Huiyu; Yang, Xiufen; Hu, Zhenjie

    2016-01-01

    To evaluate the effect of airway pressure release ventilation (APRV) in patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS), to evaluate the extent of ventilator-induced lung injury (VILI), and to explore its possible mechanism. A prospective study was conducted in the Department of Critical Care Medicine of the First Hospital of Hebei Medical University from December 2010 to February 2012. The patients with ALI/ARDS were enrolled. They were randomly divided into two groups. The patients in APRV group were given APRV pattern, while those in control group were given lung protection ventilation, synchronized intermittent mandatory ventilation with positive end-expiratory pressure (SIMV+PEEP). All patients were treated with AVEA ventilator. The parameters such as airway peak pressure (Ppeak), mean airway pressure (Pmean), pulse oxygen saturation (SpO2), mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), arterial blood gas, urine output (UO), the usage of sedation and muscle relaxation drugs were recorded. AVEA ventilator "turning point (Pflex) operation" was used to describe the quasi-static pressure volume curve (P-V curve). High and low inflection point (UIP, LIP) and triangular Pflex volume (Vdelta) were automatically measured and calculated. The ventilation parameters were set, and the 24-hour P-V curve was recorded again in order to be compared with subsequent results. Venous blood was collected before treatment, 24 hours and 48 hours after ventilation to measure lung surfactant protein D (SP-D) and large molecular mucus in saliva (KL-6) by enzyme linked immunosorbent assay (ELISA), and the correlation between the above two parameters and prognosis on 28 days was analyzed by multinomial logistic regression. Twenty-six patients with ALI/ARDS were enrolled, and 22 of them completed the test with 10 in APRV group and 12 in control group. The basic parameters and P-V curves between two groups were similar before

  20. Blood Pressure Test

    Science.gov (United States)

    ... pressure monitors may have some limitations. Tracking your blood pressure readings It can be helpful in diagnosing or ... more Stage 2 high blood pressure (hypertension) Elevated blood pressure and stages 1 and 2 high blood pressure ( ...

  1. Intrathoracic pressure regulation during cardiopulmonary resuscitation: a feasibility case-series.

    Science.gov (United States)

    Segal, Nicolas; Parquette, Brent; Ziehr, Jonathon; Yannopoulos, Demetris; Lindstrom, David

    2013-04-01

    Intrathoracic pressure regulation (IPR) is a novel, noninvasive therapy intended to increase cardiac output and blood pressure in hypotensive states by generating a negative end expiratory pressure of -12 cm H2O between positive pressure ventilations. In this first feasibility case-series, we tested the hypothesis that IPR improves End tidal (ET) CO2 during cardiopulmonary resuscitation (CPR). ETCO2 was used as a surrogate measure for circulation. All patients were treated initially with manual CPR and an impedance threshold device (ITD). When IPR-trained medics arrived on scene the ITD was removed and an IPR device (CirQLATOR™) was attached to the patient's advanced airway (intervention group). The IPR device lowered airway pressures to -9 mmHg after each positive pressure ventilation for the duration of the expiratory phase. ETCO2, was measured using a capnometer incorporated into the defibrillator system (LifePak™). Values are expressed as mean ± SEM. Results were compared using paired and unpaired Student's t test. p values of <0.05 were considered statistically significant. ETCO2 values in 11 patients in the case series were compared pre and during IPR therapy and also compared to 74 patients in the control group not treated with the new IPR device. ETCO2 values increased from an average of 21 ± 1 mmHg immediately before IPR application to an average value of 32 ± 5 mmHg and to a maximum value of 45 ± 5mmHg during IPR treatment (p<0.001). In the control group ETCO2 values did not change significantly. Return of spontaneous circulation (ROSC) rates were 46% (34/74) with standard CPR and ITD versus 73% (8/11) with standard CPR and the IPR device (p<0.001). ETCO2 levels and ROSC rates were significantly higher in the study intervention group. These findings demonstrate that during CPR circulation may be significantly augmented by generation of a negative end expiratory pressure between each breath. Copyright © 2012 Elsevier Ireland Ltd. All rights

  2. Computer quantification of “angle of collapse” on maximum expiratory flow volume curve for diagnosing asthma-COPD overlap syndrome

    Directory of Open Access Journals (Sweden)

    Wang W

    2016-12-01

    Full Text Available Wei Wang, Mengshuang Xie, Shuang Dou, Liwei Cui, Wei Xiao Department of Pulmonary Medicine, Qilu Hospital, Shandong University, Jinan, People’s Republic of China Background: In a previous study, we demonstrated that asthma patients with signs of emphysema on quantitative computed tomography (CT fulfill the diagnosis of asthma-COPD overlap syndrome (ACOS. However, quantitative CT measurements of emphysema are not routinely available for patients with chronic airway disease, which limits their application. Spirometry was a widely used examination tool in clinical settings and shows emphysema as a sharp angle in the maximum expiratory flow volume (MEFV curve, called the “angle of collapse (AC”. The aim of this study was to investigate the value of the AC in the diagnosis of emphysema and ACOS. Methods: This study included 716 participants: 151 asthma patients, 173 COPD patients, and 392 normal control subjects. All the participants underwent pulmonary function tests. COPD and asthma patients also underwent quantitative CT measurements of emphysema. The AC was measured using computer models based on Matlab software. The value of the AC in the diagnosis of emphysema and ACOS was evaluated using receiver-operating characteristic (ROC curve analysis. Results: The AC of COPD patients was significantly lower than that of asthma patients and control subjects. The AC was significantly negatively correlated with emphysema index (EI; r=-0.666, P<0.001, and patients with high EI had a lower AC than those with low EI. The ROC curve analysis showed that the AC had higher diagnostic efficiency for high EI (area under the curve =0.876 than did other spirometry parameters. In asthma patients, using the AC ≤137° as a surrogate criterion for the diagnosis of ACOS, the sensitivity and specificity were 62.5% and 89.1%, respectively. Conclusion: The AC on the MEFV curve quantified by computer models correlates with the extent of emphysema. The AC may become a

  3. Acute effects of particulate matter and black carbon from seasonal fires on peak expiratory flow of schoolchildren in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Ludmilla da Silva Viana Jacobson

    Full Text Available BACKGROUND: Panel studies have shown adverse effects of air pollution from biomass burning on children's health. This study estimated the effect of current levels of outdoor air pollution in the Amazonian dry season on peak expiratory flow (PEF. METHODS: A panel study with 234 schoolchildren from 6 to 15 years old living in the municipality of Tangará da Serra, Brazil was conducted. PEF was measured daily in the dry season in 2008. Mixed-effects models and unified modelling repeated for every child were applied. Time trends, temperature, humidity, and subject characteristics were regarded. Inhalable particulate matter (PM10, fine particulate matter (PM2.5, and black carbon (BC effects were evaluated based on 24-hour exposure lagged by 1 to 5 days and the averages of 2 or 3 days. Polynomial distributed lag models (PDLM were also applied. RESULTS: The analyses revealed reductions in PEF for PM10 and PM2.5 increases of 10 µg/m(3 and 1 µg/m(3 for BC. For PM10, the reductions varied from 0.15 (confidence interval (CI95%: -0.29; -0.01 to 0.25 l/min (CI95%: -0.40; -0.10. For PM2.5, they ranged from 0.46 (CI95%: -0.86 to -0.06 to 0.54 l/min (CI95%:-0.95; -0.14. As for BC, the reduction was approximately 1.40 l/min. In relation to PDLM, adverse effects were noticed in models based on the exposure on the current day through the previous 3 days (PDLM 0-3 and on the current day through the previous 5 days (PDLM 0-5, specially for PM10. For all children, for PDLM 0-5 the global effect was important for PM10, with PEF reduction of 0.31 l/min (CI95%: -0.56; -0.05. Also, reductions in lags 3 and 4 were observed. These associations were stronger for children between 6 and 8 years old. CONCLUSION: Reductions in PEF were associated with air pollution, mainly for lagged exposures of 3 to 5 days and for younger children.

  4. Predictive Value of Different Expressions of Forced Expiratory Volume in 1 Second (FEV1) for Adverse Outcomes in a Cohort of Adults Aged 80 and Older.

    Science.gov (United States)

    Hegendörfer, Eralda; Vaes, Bert; Andreeva, Elena; Matheï, Catharina; Van Pottelbergh, Gijs; Degryse, Jean-Marie

    2017-02-01

    Forced expiratory volume in 1 second (FEV 1 ) is proposed as a marker of healthy ageing and FEV 1 expressions that are independent of reference values have been reported to be better at predicting mortality in older adults. We assess and compare the predictive value of different FEV 1 expressions for mortality, hospitalization, and physical and mental decline in adults aged 80 and older. Population-based, prospective, cohort study. The BELFRAIL study, Belgium. A total of 501 community-dwelling adults aged 80 and older (mean age 84.7 years). Baseline FEV 1 expressed as percent predicted (FEV 1 PP) and z-score (FEV 1 Z) using the Global Lung Function Initiative 2012 reference values; over lowest sex-specific percentile (FEV 1 Q), and height squared (FEV 1 /Ht 2 ) and cubed (FEV 1 /Ht 3 ). Mortality data until 5.1 ± 0.2 years from baseline; hospitalization data until 3.0 ± 0.25 years. Activities of daily living, battery of physical performance tests, Mini-Mental State Examination, and 15-item Geriatric Depression Scale at baseline and after 1.7 ± 0.2 years. Individuals in the lowest quartile of FEV 1 expressions had higher adjusted risk than the rest of study population for all-cause mortality (highest hazard ratio 2.05 [95% Confidence Interval 1.50-2.80] for FEV 1 Q and 2.01 [1.47-2.76] for FEV 1 /Ht 3 ), first hospitalization (highest hazard ratio 1.63 [1.21-2.16] for FEV 1 /Ht 2 and 1.61[1.20-2.16] for FEV 1 /Ht 3 ), mental decline (highest odds ratio 2.80 [1.61-4.89] for FEV 1 Q) and physical decline (only FEV 1 /Ht 3 with odds ratio 1.93 [1.13-3.30]). Based on risk classification improvement measures, FEV 1 /Ht 3 and FEV 1 Q performed better than FEV 1 PP. In a cohort of adults aged 80 and older, FEV 1 expressions that are independent of reference values (FEV 1 /Ht 3 and FEV 1 Q) were better at predicting adverse health outcomes than traditional expressions that depend on reference values, and should be used in further research on FEV 1 and aging

  5. Hearing Impairment and High Blood Pressure among Bus Drivers in Puducherry.

    Science.gov (United States)

    Balaji, Rajeshwar; Rajasegaran, Rajalakshmi; John, Nitin Ashok; Venkatappa, Umadevi Sajja

    2016-02-01

    Noise Induced Hearing Loss (NIHL), a major heath concern due to constant exposure to loud noise is on the rising trend in today's world. The bus drivers are more vulnerable to the auditory and non-auditory ill effects of noise pollution. The aim of this study was to assess and compare the hearing level, blood pressure and peak expiratory flow rate of bus drivers and individuals employed in office jobs. Fifty male bus drivers aged 30-50 years and fifty males of the same group employed in office jobs were recruited as the test and control groups respectively. The hearing level of the individuals in both the groups was assessed using the Hearing Deterioration Index (HDI). The lung function and cardiovascular status of the study participants were assessed by measuring their Peak Expiratory Flow Rate (PEFR) and Blood Pressure (BP) respectively. The mean HDI, PEFR and BP values of both the groups were compared using the unpaired t-test and the extent of correlation between HDI, service years, exposure level, systolic blood pressure (SBP) and diastolic blood pressure (DBP) was determined using Pearson correlation coefficient test. HDI, SBP and DBP were significantly higher among the bus drivers when compared to the controls. However, there was no significant difference in the PEFR values between the test and the control groups. There was a highly significant positive correlation between HDI and service years and exposure level. Similarly, there was a significant positive correlation between exposure level and systolic and diastolic blood pressure. Prolonged exposure to high intensity of sound results in deterioration of hearing capacity and increase in blood pressure among the bus drivers.

  6. Some infant ventilators do not limit peak inspiratory pressure reliably during active expiration.

    Science.gov (United States)

    Kirpalani, H; Santos-Lyn, R; Roberts, R

    1988-09-01

    In order to minimize barotrauma in newborn infants with respiratory failure, peak inspiratory pressures should not exceed those required for adequate gas exchange. We examined whether four commonly used pressure-limited, constant flow ventilators limit pressure reliably during simulated active expiration against the inspiratory stroke of the ventilator. Three machines of each type were tested at 13 different expiratory flow rates (2 to 14 L/min). Flow-dependent pressure overshoot above a dialed pressure limit of 20 cm H2O was observed in all machines. However, the magnitude differed significantly between ventilators from different manufacturers (p = .0009). Pressure overshoot above 20 cm H2O was consistently lowest in the Healthdyne (0.8 cm H2O at 2 L/min, 3.6 cm H2O at 14 L/min) and highest in the Bourns BP200 (3.0 cm H2O at 2 L/min, 15.4 cm H2O at 14 L/min). We conclude that peak inspiratory pressure overshoots on pressure-limited ventilators occur during asynchronous expiration. This shortcoming may contribute to barotrauma in newborn infants who "fight" positive-pressure ventilation.

  7. Ventilator-driven xenon ventilation studies

    International Nuclear Information System (INIS)

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-01-01

    A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration

  8. Ultra-protective tidal volume: how low should we go?

    OpenAIRE

    Costa, Eduardo LV; Amato, Marcelo BP

    2013-01-01

    Applying tidal volumes of less than 6 mL/kg might improve lung protection in patients with acute respiratory distress syndrome. In a recent article, Retamal and colleagues showed that such a reduction is feasible with conventional mechanical ventilation and leads to less tidal recruitment and overdistension without causing carbon dioxide retention or auto-positive end-expiratory pressure. However, whether the compensatory increase in the respiratory rate blunts the lung protection remains une...

  9. Low Blood Pressure

    Science.gov (United States)

    ... a problem. Sometimes blood pressure that is too low can also cause problems. Blood pressure is the ... reading is 90/60 or lower, you have low blood pressure. Some people have low blood pressure ...

  10. Low Blood Pressure (Hypotension)

    Science.gov (United States)

    ... lowest at night and rises sharply on waking. Blood pressure: How low can you go? What's considered low ... low blood pressure. Medications that can cause low blood pressure Some medications can cause low blood pressure, including: ...

  11. Normal Pressure Hydrocephalus (NPH)

    Science.gov (United States)

    ... local chapter Join our online community Normal Pressure Hydrocephalus (NPH) Normal pressure hydrocephalus is a brain disorder ... Symptoms Diagnosis Causes & risks Treatments About Normal Pressure Hydrocephalus Normal pressure hydrocephalus occurs when excess cerebrospinal fluid ...

  12. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... of a pressure sore required? play_arrow How long is the typical healing time for a pressure ... arrow Why do some pressure sores take so long to heal? play_arrow Can a pressure sore ...

  13. Line pressure effects on differential pressure measurements

    International Nuclear Information System (INIS)

    Neff, G.G.; Evans, R.P.

    1982-01-01

    The performance of differential pressure transducers in experimental pressurized water reactor (PWR) systems was evaluated. Transient differential pressure measurements made using a simple calibration proportionality relating differential pressure to output voltage could have large measurement uncertainties. A more sophisticated calibration equation was derived to incorporate the effects of zero shifts and sensitivity shifts as pressure in the pressure sensing line changes with time. A comparison made between the original calibration proportionality equation and the derived compensation equation indicates that potential measurement uncertainties can be reduced

  14. Correlation between spirometry values and pulmonary artery pressure in young healthy subjects.

    Science.gov (United States)

    Grossman, Alon; Benderly, Michal; Prokupetz, Alex; Gordon, Barak; Kalter-Leibovici, Ofra

    2014-03-01

    Pulmonary hypertension is frequently associated with parenchymal lung disease. We evaluated the association between spirometry values and pulmonary artery systolic pressure (PASP) in young subjects without lung disease : We studied applicants to the Israeli Air Force, who undergo routine evaluation that includes resting spirometry and echocardiography. Applicants with overt lung disease were excluded. All echocardiographic studies performed in the years 1994 through 2010 (n = 6,598) were screened, and files that included PASP and spirometry values were analyzed for the association between PASP and FVC, FEV1, FEV1/FVC, peak expiratory flow, and forced expiratory flow during the middle half of the FVC maneuver. Of the 647 air force applicants who underwent echocardiography in which PASP was measurable and had spirometry data, 607 (94%) were male, and their average age was 18.16 ± 0.73 years. Mean PASP was 26.4 ± 5.2 mm Hg (range 10-41 mm Hg). None of the spirometry values significantly correlated with PASP. PASP in young healthy subjects is not significantly associated with spirometry values. Lung mechanics probably do not contribute significantly to PASP in this population.

  15. The Concave Shape of the Forced Expiratory Flow-Volume Curve in 3 Seconds Is a Practical Surrogate of FEV1/FVC for the Diagnosis of Airway Limitation in Inadequate Spirometry.

    Science.gov (United States)

    Li, Hao; Liu, Chunhong; Zhang, Yi; Xiao, Wei

    2017-03-01

    Spirometry is important for the differential diagnosis of dyspnea. However, some patients cannot exhale for ≥6 s to achieve the American Thoracic Society/European Respiratory Society criteria. The aim of this study was to demonstrate the reliability of a new parameter that quantifies the degree of concavity in the first 3 s to define airway limitation as a surrogate for the FEV 1 /FVC. Four hundred spirometry test results were selected through complete random sampling. The new parameter, termed the AUC 3 /AT 3 , was calculated as the area under the descending limb of the expiratory flow-volume curve before the end of the first 3 s (AUC 3 ) divided by the area of the triangle before the end of the first 3 s (AT 3 ). The AUC 3 /AT 3 was compared with the FEV 1 /FVC using Pearson's correlation analysis. The level of agreement between the AUC 3 /AT 3 and the FEV 1 /FVC in the detection of airway obstruction was analyzed using the kappa statistic. We also compared the diagnostic accuracy of the new index with that of the FEV 1 /forced expiratory volume in the first 3 s (FEV 3 ). There was a strong correlation (r = 0.88, P < .001) between the AUC 3 /AT 3 and the FEV 1 /FVC. There was also strong agreement between the AUC 3 /AT 3 and the FEV 1 /FVC in the detection of obstruction with kappa indices of 0.72 (Global Initiative for Chronic Obstructive Lung Disease [GOLD] criterion) and 0.67 (lower limit of normal criterion), and these values were greater than those obtained for the FEV 1 /FEV 3 . The AUC 3 /AT 3 also exhibited acceptable sensitivity, specificity, positive predictive value, and negative predictive value. The diagnostic accuracies of the AUC 3 /AT 3 were 86.3% (GOLD criterion) and 83.8% (lower limit of normal criterion), which were greater than the 76.0 and 74.0% obtained for the FEV 1 /FEV 3 , respectively. The AUC 3 /AT 3 can be utilized as a surrogate parameter for the FEV 1 /FVC when patients cannot complete a 6-s expiratory effort. Additionally, the

  16. Quantitative assessment of global and regional air trappings using non-rigid registration and regional specific volume change of inspiratory/expiratory CT scans: Studies on healthy volunteers and asthmatics

    International Nuclear Information System (INIS)

    Lee, Eun Sol; Seo, Joon Beom; Lee, Hyun Joo; Chae, Eun Jin; Lee, Sang Min; Oh, Sang Young; Kim, Nam Kug

    2015-01-01

    The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.

  17. Prediction of post-operative pulmonary function after lobectomy for primary lung cancer: A comparison among counting method, effective lobar volume, and lobar collapsibility using inspiratory/expiratory CT

    Energy Technology Data Exchange (ETDEWEB)

    Yabuuchi, Hidetake, E-mail: h-yabu@med.kyushu-u.ac.jp [Department of Health Sciences, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Kawanami, Satoshi, E-mail: kawanami_01@mac.com [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Kamitani, Takeshi, E-mail: kamitani@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Yonezawa, Masato, E-mail: ymasato@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Yamasaki, Yuzo, E-mail: yyama@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Yamanouchi, Torahiko, E-mail: tora0228jp@yahoo.co.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Nagao, Michinobu, E-mail: minagao@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Okamoto, Tatsuro, E-mail: tatsuro@surg2.med.kyushu-u.ac.jp [Department of Surgery and Science, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka (Japan)

    2016-11-15

    Highlights: • ΔFEV{sub 1.0} and ppoΔFEV{sub 1.0} using lobar collapsibility were strongly correlated. • ΔVC and ppoΔVC using effective lobar volume were strongly correlated. • Counting method was inferior to lobar collapsibility for prediction of ppoFEV{sub 1.0}. • Inspiratory/expiratory CT is useful to predict post-operative pulmonary function. - Abstract: Purpose: To compare the predictabilities of postoperative pulmonary function after lobectomy for primary lung cancer among counting method, effective lobar volume, and lobar collapsibility. Methods: Forty-nine patients who underwent lobectomy for primary lung cancer were enrolled. All patients underwent inspiratory/expiratory CT and pulmonary function tests 2 weeks before surgery and postoperative pulmonary function tests 6–7 months after surgery. Pulmonary function losses (ΔFEV{sub 1.0} and ΔVC) were calculated from the pulmonary function tests. Predictive postoperative pulmonary function losses (ppoΔFEV{sub 1.0} and ppoΔVC) were calculated using counting method, effective volume, and lobar collapsibility. Correlations and agreements between ΔFEV{sub 1.0} and ppoFEV{sub 1.0} and those between ΔVC and ppoΔVC were tested among three methods using Spearman’s correlation coefficient and Bland-Altman plots. Results: ΔFEV{sub 1.0} and ppoΔFEV{sub 1.0insp-exp} were strongly correlated (r = 0.72), whereas ΔFEV{sub 1.0} and ppoΔFEV{sub 1.0count} and ΔFEV{sub 1.0} and Pred. ΔFEV{sub 1.0eff.vol.} were moderately correlated (r = 0.50, 0.56). ΔVC and ppoΔVC{sub eff.vol.} (r = 0.71) were strongly correlated, whereas ΔVC and ppoΔVC{sub count}, and ΔVC and ppoΔVC {sub insp-exp} were moderately correlated (r = 0.55, 0.42). Conclusions: Volumetry from inspiratory/expiratory CT data could be useful to predict postoperative pulmonary function after lobectomy for primary lung cancer.

  18. Quantitative assessment of global and regional air trappings using non-rigid registration and regional specific volume change of inspiratory/expiratory CT scans: Studies on healthy volunteers and asthmatics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sol; Seo, Joon Beom; Lee, Hyun Joo; Chae, Eun Jin; Lee, Sang Min; Oh, Sang Young; Kim, Nam Kug [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2015-06-15

    The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.

  19. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... play_arrow What is "sepsis," and why is it dangerous? play_arrow How common are pressure sores ... likely to develop pressure sores? play_arrow Is it true that a pressure sore can develop in ...

  20. High Blood Pressure

    Science.gov (United States)

    ... normal blood pressure 140/90 or higher is high blood pressure Between 120 and 139 for the top number, ... prehypertension. Prehypertension means you may end up with high blood pressure, unless you take steps to prevent it. High ...

  1. High Blood Pressure Facts

    Science.gov (United States)

    ... Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN High Blood Pressure Facts Recommend on Facebook Tweet Share Compartir On ... Top of Page CDC Fact Sheets Related to High Blood Pressure High Blood Pressure Pulmonary Hypertension Heart Disease Signs ...

  2. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  3. Effect of an automatic triggering and cycling system on comfort and patient-ventilator synchrony during pressure support ventilation.

    Science.gov (United States)

    Vasconcelos, Renata dos S; Melo, Luíz Henrique de P; Sales, Raquel P; Marinho, Liégina S; Deulefeu, Flávio C; Reis, Ricardo C; Alves-de-Almeida, Mirizana; Holanda, Marcelo A

    2013-01-01

    The digital Auto-Trak™ system is a technology capable of automatically adjusting the triggering and cycling mechanisms during pressure support ventilation (PSV). To compare Auto-Trak with conventional settings in terms of patient-ventilator synchrony and discomfort. Twelve healthy volunteers underwent PSV via the mouth by breathing through an endotracheal tube. In the conventional setting, a pressure support of 8 cm H2O with flow cycling (25% peak inspiratory flow) and a sensitivity of 1 cm H2O was adjusted. In Auto-Trak the triggering and cycling were automatically set. Discomfort, effort of breathing, and the asynchrony index (AI) were assessed. In a complementary bench study, the inspiratory and expiratory time delays were quantified for both settings in three mechanical models: 'normal', obstructive (COPD), and restrictive (ARDS), using the ASL 5000 simulator. In the volunteer study the AI and the discomfort scores did not differ statistically between the two settings. In the bench investigation the use of Auto-Trak was associated with a greater triggering delay in the COPD model and earlier expiratory cycling in the ARDS model but with no asynchronic events. Use of the Auto-Trak system during PSV showed similar results in comparison to the conventional adjustments with respect to patient-ventilator synchrony and discomfort in simulated conditions of invasive mechanical ventilation. Copyright © 2013 S. Karger AG, Basel.

  4. Multiple shell pressure vessel

    International Nuclear Information System (INIS)

    Wedellsborg, B.W.

    1988-01-01

    A method is described of fabricating a pressure vessel comprising the steps of: attaching a first inner pressure vessel having means defining inlet and outlet openings to a top flange, placing a second inner pressure vessel, having means defining inlet and outlet opening, concentric with and spaced about the first inner pressure vessel and attaching the second inner pressure vessel to the top flange, placing an outer pressure vessel, having inlet and outlet openings, concentric with and spaced apart about the second inner pressure vessel and attaching the outer pressure vessel to the top flange, attaching a generally cylindrical inner inlet conduit and a generally cylindrical inner outlet conduit respectively to the inlet and outlet openings in the first inner pressure vessel, attaching a generally cylindrical outer inlet conduit and a generally cylindrical outer outlet conduit respectively to the inlet and outlet opening in the second inner pressure vessel, heating the assembled pressure vessel to a temperature above the melting point of a material selected from the group, lead, tin, antimony, bismuth, potassium, sodium, boron and mixtures thereof, filling the space between the first inner pressure vessel and the second inner pressure vessel with material selected from the group, filling the space between the second inner pressure vessel and the outer pressure vessel with material selected from the group, and pressurizing the material filling the spaces between the pressure vessels to a predetermined pressure, the step comprising: pressurizing the spaces to a pressure whereby the wall of the first inner pressure vessel is maintained in compression during steady state operation of the pressure vessel

  5. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Hypertension (High Blood Pressure) KidsHealth / For Teens / Hypertension (High Blood Pressure) What's ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  6. Comparison of three protocols for measuring the maximal respiratory pressures

    Directory of Open Access Journals (Sweden)

    Isabela Maria B. Sclauser Pessoa

    Full Text Available Introduction To avoid the selection of submaximal efforts during the assessment of maximal inspiratory and expiratory pressures (MIP and MEP, some reproducibility criteria have been suggested. Criteria that stand out are those proposed by the American Thoracic Society (ATS and European Respiratory Society (ERS and by the Brazilian Thoracic Association (BTA. However, no studies were found that compared these criteria or assessed the combination of both protocols. Objectives To assess the pressure values selected and the number of maneuvers required to achieve maximum performance using the reproducibility criteria proposed by the ATS/ERS, the BTA and the present study. Materials and method 113 healthy subjects (43.04 ± 16.94 years from both genders were assessed according to the criteria proposed by the ATS/ERS, BTA and the present study. Descriptive statistics were used for analysis, followed by ANOVA for repeated measures and post hoc LSD or by Friedman test and post hoc Wilcoxon, according to the data distribution. Results The criterion proposed by the present study resulted in a significantly higher number of maneuvers (MIP and MEP – median and 25%-75% interquartile range: 5[5-6], 4[3-5] and 3[3-4] for the present study criterion, BTA and ATS/ERS, respectively; p < 0.01 and higher pressure values (MIP – mean and 95% confidence interval: 103[91.43-103.72], 100[97.19-108.83] and 97.6[94.06-105.95]; MEP: median and 25%-75% interquartile range: 124.2[101.4-165.9], 123.3[95.4-153.8] and 118.4[95.5-152.7]; p < 0.05. Conclusion The proposed criterion resulted in the selection of pressure values closer to the individual’s maximal capacity. This new criterion should be considered in future studies concerning MIP and MEP measurements.

  7. High Flow Nasal Cannula Therapy for Improving Obstructive Sleep Apnea: A Case Report

    Directory of Open Access Journals (Sweden)

    Se Joong Kim

    2015-06-01

    Full Text Available Although continuous positive airway pressure is the treatment of choice for obstructive sleep apnea, its compliance is low. Therefore, alternative therapeutic strategies are often required. High flow nasal cannula therapy uses an air compressor to deliver a constant flow of oxygen via the nasal cannula at a maximum of 60 L/m. It can produce positive end expiratory pressure and increase end expiratory pharyngeal pressure, which can help to alleviate upper airway obstruction. This is a case report of high flow nasal cannula therapy for a 71 year-old man. He had an obstructive sleep apnea and severe desaturation but failed to use continuous positive airway pressure. He underwent titration with high flow nasal cannula under polysomnography. Using high flow nasal cannula at an airflow of 45 L/m, his apnea-hypopnea, respiratory arousal and oxygen desaturation were improved. Importantly, he is very compliant with high flow nasal cannula therapy.

  8. Pressure Dome for High-Pressure Electrolyzer

    Science.gov (United States)

    Norman, Timothy; Schmitt, Edwin

    2012-01-01

    A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom

  9. Diurnal blood pressure changes.

    Science.gov (United States)

    Asayama, Kei; Satoh, Michihiro; Kikuya, Masahiro

    2018-05-23

    The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

  10. Pressure drops in low pressure local boiling

    International Nuclear Information System (INIS)

    Courtaud, Michel; Schleisiek, Karl

    1969-01-01

    For prediction of flow reduction in nuclear research reactors, it was necessary to establish a correlation giving the pressure drop in subcooled boiling for rectangular channels. Measurements of pressure drop on rectangular channel 60 and 90 cm long and with a coolant gap of 1,8 and 3,6 mm were performed in the following range of parameters. -) 3 < pressure at the outlet < 11 bars abs; -) 25 < inlet temperature < 70 deg. C; -) 200 < heat flux < 700 W/cm 2 . It appeared that the usual parameter, relative length in subcooled boiling, was not sufficient to correlate experimental pressure losses on the subcooled boiling length and that there was a supplementary influence of pressure, heat flux and subcooling. With an a dimensional parameter including these terms a correlation was established with an error band of ±10%. With a computer code it was possible to derive the relation giving the overall pressure drop along the channel and to determine the local gradients of pressure drop. These local gradients were then correlated with the above parameter calculated in local conditions. 95 % of the experimental points were computed with an accuracy of ±10% with this correlation of gradients which can be used for non-uniform heated channels. (authors) [fr

  11. The effect of entrainment site and inspiratory pressure on the delivery of oxygen therapy during non-invasive mechanical ventilation (NIMV in acute COPD patients

    Directory of Open Access Journals (Sweden)

    Sundeep Kaul

    2006-12-01

    Full Text Available Supplemental O2 is frequently added to bi-level non-invasive ventilation circuits to maintain Sa,O2 >90%. Oxygen can be added at several points & in the presence of different inspiratory pressures. The effect of varying entrainment sites and inspiratory pressures (IPAP on PO2, PCO2, Fio2, inspiratory triggering and expiratory triggering in COPD patients is unknown. 18 patients with stable COPD (mean FEV1 47% participated in the study. Oxygen was added at 4 sites in the ventilatory circuit (site 1: between mask and exhalation port; site 2: just distal to exhalation port; site 3: at ventilator outlet; site 4: directly into the mask via an inlet. The effect of varying entrainment sites and inspiratory pressures on arterial PO2, PCO2, FIO2, was recorded at 3 mins. The same full face mask (Respironics, Image 3 & ventilator (Respironics, BIPAP ST 30 was used.

  12. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... L Sarah Harrison, OT Anne Bryden, OT The Role of the Social Worker after Spinal Cord Injury ... do to prevent pressure sores? play_arrow What role does diet and hydration play in preventing pressure ...

  13. Atmospheric Pressure Indicator.

    Science.gov (United States)

    Salzsieder, John C.

    1995-01-01

    Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

  14. Blood Pressure Medicines

    Science.gov (United States)

    High blood pressure, also called hypertension, usually has no symptoms. But it can cause serious problems such as stroke, heart ... kidney failure. If you cannot control your high blood pressure through lifestyle changes such as losing weight and ...

  15. High blood pressure - adults

    Science.gov (United States)

    ... pressure is found. This is called essential hypertension. High blood pressure that is caused by another medical condition or medicine you are taking is called secondary hypertension. Secondary hypertension may be due to: Chronic ...

  16. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Injury Medical Expert Videos Topics menu Topics Preventing Pressure Sores Adult Injuries Spinal Cord Injury 101 David Chen, MD Preventing Pressure Sores Mary Zeigler, MS Transition from Hospital to Home ...

  17. Preventing Pressure Sores

    Science.gov (United States)

    ... and how can it be increased? play_arrow What do family members and caregivers need to know about pressure sores? play_arrow What do family members and caregivers need to do to prevent pressure sores? play_ ...

  18. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  19. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... play_arrow What do family members and caregivers need to know about pressure sores? play_arrow What do family members and caregivers need to do to prevent pressure sores? play_arrow ...

  20. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... increased? play_arrow What do family members and caregivers need to know about pressure sores? play_arrow What do family members and caregivers need to do to prevent pressure sores? play_ ...

  1. High blood pressure - children

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007696.htm High blood pressure - children To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  2. Preventing High Blood Pressure

    Science.gov (United States)

    ... Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share ... meal and snack options can help you avoid high blood pressure and its complications. Be sure to eat plenty ...

  3. High blood pressure - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007329.htm High blood pressure - infants To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  4. High blood pressure medications

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  5. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... especially prone to pressure sores? play_arrow What parts of the body are most likely to develop ... play_arrow How long is the typical healing time for a pressure sore? play_arrow Why do ...

  6. High-pressure microbiology

    National Research Council Canada - National Science Library

    Michiels, Chris; Bartlett, Douglas Hoyt; Aertsen, Abram

    2008-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. High Hydrostatic Pressure Effects in the Biosphere: from Molecules to Microbiology * Filip Meersman and Karel Heremans . . . . . . . . . . . . 2. Effects...

  7. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... cord injuries? play_arrow Why are pressure sores so serious? play_arrow What is "sepsis," and why ... pressure sores? play_arrow Why is pressure relief so important when sitting in a wheelchair? play_arrow ...

  8. Pressure dependence of conductivity

    International Nuclear Information System (INIS)

    Bracewell, B.L.; Hochheimer, H.D.

    1993-01-01

    The overall objectives of this work were to attempt the following: (1) Measure the pressure dependence of the electrical conductivity of several quasi-one-dimensional, charge-density-wave solids, including measurements along various crystal directions. (2) Measure photocurrents in selected MX solids at ambient and elevated pressures. (3) Measure the resonance Raman spectra for selected MX solids as a function of pressure

  9. Exchange market pressure

    NARCIS (Netherlands)

    Jager, H.; Klaassen, F.; Durlauf, S.N.; Blume, L.E.

    2010-01-01

    Currencies can be under severe pressure in the foreign exchange market, but in a fixed (or managed) exchange rate regime that is not fully visible via the change in the exchange rate. Exchange market pressure (EMP) is a concept developed to nevertheless measure the pressure in such cases. This

  10. High-pressure apparatus

    NARCIS (Netherlands)

    Schepdael, van L.J.M.; Bartels, P.V.; Berg, van den R.W.

    1999-01-01

    The invention relates to a high-pressure device (1) having a cylindrical high-pressure vessel (3) and prestressing means in order to exert an axial pressure on the vessel. The vessel (3) can have been formed from a number of layers of composite material, such as glass, carbon or aramide fibers which

  11. An electrokinetic pressure sensor

    International Nuclear Information System (INIS)

    Kim, Dong-Kwon; Kim, Sung Jin; Kim, Duckjong

    2008-01-01

    A new concept for a micro pressure sensor is demonstrated. The pressure difference between the inlet and the outlet of glass nanochannels is obtained by measuring the electrokinetically generated electric potential. To demonstrate the proposed concept, experimental investigations are performed for 100 nm wide nanochannels with sodium chloride solutions having various concentrations. The proposed pressure sensor is able to measure the pressure difference within a 10% deviation from linearity. The sensitivity of the electrokinetic pressure sensor with 10 −5 M sodium chloride solution is 18.5 µV Pa −1 , which is one order of magnitude higher than that of typical diaphragm-based pressure sensors. A numerical model is presented for investigating the effects of the concentration and the channel width on the sensitivity of the electrokinetic pressure sensor. Numerical results show that the sensitivity increases as the concentration decreases and the channel width increases

  12. Pressure tube type reactors

    International Nuclear Information System (INIS)

    Komada, Masaoki.

    1981-01-01

    Purpose: To increase the safety of pressure tube type reactors by providing an additional ECCS system to an ordinary ECCS system and injecting heavy water in the reactor core tank into pressure tubes upon fractures of the tubes. Constitution: Upon fractures of pressure tubes, reduction of the pressure in the fractured tubes to the atmospheric pressure in confirmed and the electromagnetic valve is operated to completely isolate the pressure tubes from the fractured portion. Then, the heavy water in the reactor core tank flows into and spontaneously recycles through the pressure tubes to cool the fuels in the tube to prevent their meltdown. By additionally providing the separate ECCS system to the ordinary ECCS system, fuels can be cooled upon loss of coolant accidents to improve the safety of the reactors. (Moriyama, K.)

  13. Pressure (Or No Royal Road)

    Science.gov (United States)

    Bradley, J.

    1973-01-01

    Discusses how difficult the various problems of pressure, partial pressure, gas laws, and vapor pressure are for students. Outlines the evolution of the concept of pressure, the gas equation for a perfect gas, partial pressures, saturated vapor pressure, Avogadro's hypothesis, Raoult's law, and the vapor pressure of ideal solutions. (JR)

  14. Pressure locking test results

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1996-12-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  15. Pressure locking test results

    International Nuclear Information System (INIS)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D.

    1996-01-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, open-quotes Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.close quotes Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; we will publish the results of our thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions

  16. Protective ventilation reduces Pseudomonas aeruginosa growth in lung tissue in a porcine pneumonia model.

    Science.gov (United States)

    Sperber, Jesper; Nyberg, Axel; Lipcsey, Miklos; Melhus, Åsa; Larsson, Anders; Sjölin, Jan; Castegren, Markus

    2017-08-31

    Mechanical ventilation with positive end expiratory pressure and low tidal volume, i.e. protective ventilation, is recommended in patients with acute respiratory distress syndrome. However, the effect of protective ventilation on bacterial growth during early pneumonia in non-injured lungs is not extensively studied. The main objectives were to compare two different ventilator settings on Pseudomonas aeruginosa growth in lung tissue and the development of lung injury. A porcine model of severe pneumonia was used. The protective group (n = 10) had an end expiratory pressure of 10 cm H 2 O and a tidal volume of 6 ml x kg -1 . The control group (n = 10) had an end expiratory pressure of 5 cm H 2 O and a tidal volume of 10 ml x kg -1 . 10 11 colony forming units of Pseudomonas aeruginosa were inoculated intra-tracheally at baseline, after which the experiment continued for 6 h. Two animals from each group received only saline, and served as sham animals. Lung tissue samples from each animal were used for bacterial cultures and wet-to-dry weight ratio measurements. The protective group displayed lower numbers of Pseudomonas aeruginosa (p protective group was unchanged (p protective ventilation with lower tidal volume and higher end expiratory pressure has the potential to reduce the pulmonary bacterial burden and the development of lung injury.

  17. Pressure vessel failure at high internal pressure

    International Nuclear Information System (INIS)

    Laemmer, H.; Ritter, B.

    1995-01-01

    A RPV failure due to plastic instability was investigated using the ABAQUS finite element code together with a material model of thermal plasticity for large deformations. Not only rotational symmetric temperature distributions were studied, but also 'hot spots'. Calculations show that merely by the depletion of strength of the material - even at internal wall temperatures well below the melting point of the fuel elements of about 2000/2400 C - the critical internal pressure can decrease to values smaller than the operational pressure of 16 Mpa. (orig.)

  18. Chest compression with a higher level of pressure support ventilation: effects on secretion removal, hemodynamics, and respiratory mechanics in patients on mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Wagner da Silva Naue

    2014-01-01

    Full Text Available OBJECTIVE: To determine the efficacy of chest compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation, in comparison with that of aspiration alone, in removing secretions, normalizing hemodynamics, and improving respiratory mechanics in patients on mechanical ventilation. METHODS: This was a randomized crossover clinical trial involving patients on mechanical ventilation for more than 48 h in the ICU of the Porto Alegre Hospital de Clínicas, in the city of Porto Alegre, Brazil. Patients were randomized to receive aspiration alone (control group or compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation (intervention group. We measured hemodynamic parameters, respiratory mechanics parameters, and the amount of secretions collected. RESULTS: We included 34 patients. The mean age was 64.2 ± 14.6 years. In comparison with the control group, the intervention group showed a higher median amount of secretions collected (1.9 g vs. 2.3 g; p = 0.004, a greater increase in mean expiratory tidal volume (16 ± 69 mL vs. 56 ± 69 mL; p = 0.018, and a greater increase in mean dynamic compliance (0.1 ± 4.9 cmH2O vs. 2.8 ± 4.5 cmH2O; p = 0.005. CONCLUSIONS: In this sample, chest compression accompanied by an increase in pressure support significantly increased the amount of secretions removed, the expiratory tidal volume, and dynamic compliance. (ClinicalTrials.gov Identifier:NCT01155648 [http://www.clinicaltrials.gov/

  19. Mechanical ventilation management during extracorporeal membrane oxygenation for acute respiratory distress syndrome: a retrospective international multicenter study.

    Science.gov (United States)

    Schmidt, Matthieu; Stewart, Claire; Bailey, Michael; Nieszkowska, Ania; Kelly, Joshua; Murphy, Lorna; Pilcher, David; Cooper, D James; Scheinkestel, Carlos; Pellegrino, Vincent; Forrest, Paul; Combes, Alain; Hodgson, Carol

    2015-03-01

    To describe mechanical ventilation settings in adult patients treated for an acute respiratory distress syndrome with extracorporeal membrane oxygenation and assess the potential impact of mechanical ventilation settings on ICU mortality. Retrospective observational study. Three international high-volume extracorporeal membrane oxygenation centers. A total of 168 patients treated with extracorporeal membrane oxygenation for severe acute respiratory distress syndrome from January 2007 to January 2013. We analyzed the association between mechanical ventilation settings (i.e. plateau pressure, tidal volume, and positive end-expiratory pressure) on ICU mortality using multivariable logistic regression model and Cox-proportional hazards model. We obtained detailed demographic, clinical, daily mechanical ventilation settings and ICU outcome data. One hundred sixty-eight patients (41 ± 14 years old; PaO2/FIO2 67 ± 19 mm Hg) fulfilled our inclusion criteria. Median duration of extracorporeal membrane oxygenation and ICU stay were 10 days (6-18 d) and 28 days (16-42 d), respectively. Lower positive end-expiratory pressure levels and significantly lower plateau pressures during extracorporeal membrane oxygenation were used in the French center than in both Australian centers (23.9 ± 1.4 vs 27.6 ± 3.7 and 27.8 ± 3.6; p Protective mechanical ventilation strategies were routinely used in high-volume extracorporeal membrane oxygenation centers. However, higher positive end-expiratory pressure levels during the first 3 days on extracorporeal membrane oxygenation support were independently associated with improved survival. Further prospective trials on the optimal mechanical ventilation strategy during extracorporeal membrane oxygenation support are warranted.

  20. Measuring fluid pressure

    International Nuclear Information System (INIS)

    Lee, A.S.

    1978-01-01

    A method and apparatus are described for measuring the pressure of a fluid having characteristics that make it unsuitable for connection directly to a pressure gauge. The method is particularly suitable for the periodic measurement of the pressure of a supply of liquid Na to Na-lubricated bearings of pumps for pumping Na from a reservoir to the bearing via a filter, the reservoir being contained in a closed vessel containing an inert blanket gas, such as Ar, above the Na. (UK)

  1. Superconductivity at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, N B; Ginzburg, N I

    1969-07-01

    Work published during the last 3 or 4 yrs concerning the effect of pressure on superconductivity is reviewed. Superconducting modifications of Si, Ge, Sb, Te, Se, P and Ce. Change of Fermi surface under pressure for nontransition metals. First experiments on the influence of pressure on the tunneling effect in superconductors provide new information on the nature of the change in phonon and electron energy spectra of metals under hydrostatic compression. 78 references.

  2. Fuel vapor pressure (FVAPRS)

    International Nuclear Information System (INIS)

    Mason, R.E.

    1979-04-01

    A subcode (FVAPRS) is described which calculates fuel vapor pressure. This subcode was developed as part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The fuel vapor pressure subcode (FVAPRS), is presented and a discussion of literature data, steady state and transient fuel vapor pressure equations and estimates of the standard error of estimate to be expected with the FVAPRS subcode are included

  3. Pressure cryocooling protein crystals

    Science.gov (United States)

    Kim, Chae Un [Ithaca, NY; Gruner, Sol M [Ithaca, NY

    2011-10-04

    Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

  4. Pressurized water reactor with reactor pressure vessel

    International Nuclear Information System (INIS)

    Werres, L.

    1985-01-01

    The pressure vessel has a cylindrical jacket with a domed floor. A guide is arranged on the domed floor to even out the flow in the core. It consists of a cylindrical jacket, whose lower end has slots and fins. These fins are welded to the domed floor. (orig./PW)

  5. Pressurized water reactor with reactor pressure vessel

    International Nuclear Information System (INIS)

    Werres, L.

    1980-01-01

    The pressure vessel has a cylindrical jacket with a domed floor. A guide is arranged on the domed floor to even out the flow in the core. It consists of a cylindrical jacket, whose lower end has slots and fins. These fins are welded to the domed floor. (DG) [de

  6. Liberação de pressão de vias aéreas em pacientes pediátricos submetidos à cirurgia cardíaca Airway pressure release ventilation in post operative cardiac surgery in pediatric patients

    Directory of Open Access Journals (Sweden)

    W. B. de Carvalho

    2000-06-01

    positive end expiratory pressure (IMV+PEEP, APRV and continuous positive airway pressure (CPAP in children during cardiac surgery post operative with pulmonary hypertension and mild or moderate pulmonary lesion. METHODS: Ten patients were studied with respiratory monitoring (Bear Neonatal Volume Monitor-1Ò in MV with a continuos flow, time cycled and pressure limited ventilator. The cardiocirculatory variables analyzed were central venous pressure (CVP, oxygen extraction ratio, cardiac rate, systolic arterial pressure, and arterial- mixed venous CO2 difference. Friedman's test (non-parametric was used to compare the variables in three modalities of ventilation and the Wilcoxon test was used for the variables obtained in two of the modalities. RESULTS: The mean airway pressure (MAP showed a significant increasing during APRV compared to IMV+PEEP (p=0,012. The positive inspiratory pressure (PIP, the minute volume and the ratio of oxygen arterial pressure to oxygen inspired fraction (PaO2/FiO2 didn't show statistical difference. During APRV there was a significant decrease in respiratory rate (p= 0,004 and an increase in tidal volume (p=0,045 when compared to CPAP and IMV+PEEP. In the cardiocirculatory system only CVP showed a significant increased (p=0,019 during APRV. CONCLUSION: Due to the methodology utilized MAP was higher with APRV resulting in an increased tidal volume without respiratory or cardiocirculatory adverse effects when the three modes were compared. Our results suggest that APRV is a simple and safe method of ventilation.

  7. Relationship of serum levels of interleukin 6, interleukin 8, and C-reactive protein with forced expiratory volume in first second in patients with mustard lung and chronic obstructive pulmonary diseases: systematic review and meta-analysis.

    Science.gov (United States)

    Shahriary, Alireza; Panahi, Yunes; Shirali, Saeed; Rahmani, Hossein

    2017-06-01

    The chronic systemic inflammation is a result of releasing inflammatory cytokines from the cells relating to the body immunity system and chronic activation of the innate immunity system. To evaluate the relationship among serum levels of interleukin 6 (IL-6), interleukin 8 (IL-8), C-reactive protein (CRP) with forced expiratory volume in 1 st s (FEV 1 ) in patients with mustard lung (ML) and chronic obstructive pulmonary diseases (COPD). A published literature search was performed through SID, web of science, ISI, Science Direct, Scopus, Medline, and PubMed databases for articles published in English. The correlation coefficient ( r ) and 95% confidence intervals (95% CIs) were calculated using random or fixed effects models. Heterogeneity was assessed using χ 2 and I 2 statistics. In total, 4 published studies were included in the final analysis. Using the random-effect model, meta-analysis showed that the r was -0.052 (95% CI: -0.14-0.049, p = 0.28) at serum level of IL-8, serum levels of CRP and FEV 1 in these results were r = -0.13, p = 0.012, serum levels of tumor necrosis factor (TNF) and FEV 1 levels were r = -0.39, p = 0.03 in the conducted studies on mustard lung patients. The IL-6 serum level was explored in COPD patients. The results of the given studies in these patients are r = -0.006, 95% CI: -0.37-0.15, and p = 0.44. In this meta-analysis, there was evidence that serum levels of CRP and TNF have been significantly increased in chronic obstructive pulmonary diseases compared to the healthy control group, which signifies the presence of systemic inflammation in ML and COPD patients.

  8. Positive airway pressure adherence and subthreshold adherence in posttraumatic stress disorder patients with comorbid sleep apnea

    Directory of Open Access Journals (Sweden)

    Krakow BJ

    2017-11-01

    Full Text Available Barry J Krakow,1–3 Jessica J Obando,2 Victor A Ulibarri,1,2 Natalia D McIver1,2 1Sleep & Human Health Institute, 2Maimonides Sleep Arts & Sciences, Albuquerque, 3Los Alamos Medical Center, Los Alamos, NM, USA Study objectives: Patients with comorbid posttraumatic stress disorder (PTSD and obstructive sleep apnea (OSA manifest low adherence to continuous positive airway pressure (CPAP due to fixed, pressure-induced expiratory pressure intolerance (EPI, a subjective symptom and objective sign aggravated by anxiety sensitivity and somatosensory amplification. As advanced PAP therapy modes (ie, auto-bilevel PAP [ABPAP] or adaptive servo-ventilation [ASV] may address these side effects, we hypothesized such treatment would be associated with decreased expiratory intolerance and increased adherence in posttraumatic stress patients with co-occurring OSA.Methods: We reviewed charts of 147 consecutive adult patients with moderately severe posttraumatic stress symptoms and objectively diagnosed OSA. All patients failed or rejected CPAP and were manually titrated on auto-adjusting, dual-pressure ABPAP or ASV modes in the sleep laboratory, a technique to eliminate flow limitation breathing events while resolving EPI. Patients were then prescribed either mode of therapy. Follow-up encounters assessed patient use, and objective data downloads (ODDs measured adherence.Results: Of 147 charts reviewed, 130 patients were deemed current PAP users, and 102 provided ODDs: 64 used ASV and 38 used ABPAP. ODDs yielded three groups: 59 adherent per insurance conventions, 19 subthreshold compliant partial users, and 24 noncompliant. Compliance based on available downloads was 58%, notably higher than recently reported rates in PTSD patients with OSA. Among the 19 partial users, 17 patients were minutes of PAP use or small percentages of nights removed from meeting insurance compliance criteria for PAP devices.Conclusion: Research is warranted on advanced PAP modes in

  9. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... and how can it be increased? play_arrow What do family members and caregivers need to know about pressure sores? play_arrow What do family members and caregivers need to do to prevent pressure sores? play_ ...

  10. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... other risk factors, like diabetes, you may need treatment. How does high blood pressure affect pregnant women? A few women will get ... HIV, Birth Control Heart Health for Women Pregnancy Menopause More Women's Health ... High Blood Pressure--Medicines to Help You Women and Diabetes Heart ...

  11. High-pressure crystallography

    Science.gov (United States)

    Katrusiak, A.

    2008-01-01

    The history and development of high-pressure crystallography are briefly described and examples of structural transformations in compressed compounds are given. The review is focused on the diamond-anvil cell, celebrating its 50th anniversary this year, the principles of its operation and the impact it has had on high-pressure X-ray diffraction.

  12. Neonatal Pressure Ulcer Prevention.

    Science.gov (United States)

    Scheans, Patricia

    2015-01-01

    The incidence of pressure ulcers in acutely ill infants and children ranges up to 27 percent in intensive care units, with a range of 16-19 percent in NICUs. Anatomic, physiologic, and developmental factors place ill and preterm newborns at risk for skin breakdown. Two case studies illustrate these factors, and best practices for pressure ulcer prevention are described.

  13. Pressurized-water reactors

    International Nuclear Information System (INIS)

    Bush, S.H.

    1983-03-01

    An overview of the pressurized-water reactor (PWR) pressure boundary problems is presented. Specifically exempted will be discussions of problems with pumps, valves and steam generators on the basis that they will be covered in other papers. Pressure boundary reliability is examined in the context of real or perceived problems occurring over the past 5 to 6 years since the last IAEA Reliability Symposium. Issues explicitly covered will include the status of the pressurized thermal-shock problem, reliability of inservice inspections with emphasis on examination of the region immediately under the reactor pressure vessel (RPV) cladding, history of piping failures with emphasis on failure modes and mechanisms. Since nondestructive examination is the topic of one session, discussion will be limited to results rather than techniques

  14. Pressure suppression device

    International Nuclear Information System (INIS)

    Mizumachi, Wataru; Fukuda, Akira; Kitaguchi, Hidemi; Shimizu, Toshiaki.

    1976-01-01

    Object: To relieve and absorb impact wave vibrations caused by steam and non-condensed gases releasing into the pressure suppression chamber at the time of an accident. Structure: The reactor container is filled with inert gases. A safety valve attached main steam pipe is provided to permit the excessive steam to escape, the valve being communicated with the pressure suppression chamber through an exhaust pipe. In the pressure suppression chamber, a doughnut-like cylindrical outer wall is filled at its bottom with pool water to condense the high temperature vapor released through the exhaust pipe. A head portion of a vent tube which leads the exhaust pipe is positioned at the top, and a down comer and an exhaust vent tube are locked by means of steady rests. At the bottom is mounted a pressure adsorber device which adsorbs a pressure from the pool water. (Kamimura, M.)

  15. Comparative study of budesonide as a nebulized suspension vs pressurized metered-dose inhaler in adult asthmatics

    DEFF Research Database (Denmark)

    Bisgaard, H; Nikander, K; Munch, E

    1998-01-01

    The study objective was to compare the effect of budesonide administered as a nebulized suspension as compared to a spray with a spacer in adult asthmatics. In a double-blind, double-dummy crossover study, 26 adult patients with moderately severe unstable asthma were randomized to three 4-week...... treatment periods with budesonide 0.8 mg b.i.d. administered by a pressurized metered-dose inhaler (pMDI) with spacer (Nebuhaler) and budesonide 1 mg and 4 mg b.i.d. administered by a Pari Inhalier Boy jet nebulizer. The nebulizer was activated only during inspiration. The total mass output was similar from...... the two devices but their fraction of small particles differed by a factor of 2 in favour of pMDI. Effect was evaluated from daily home measurements of peak expiratory flow (PEF), need of beta 2-agonist and symptom scores. Plasma cortisol and budesonide levels were measured in a subgroup of 10 patients...

  16. Pulse pressure and diurnal blood pressure variation

    DEFF Research Database (Denmark)

    Knudsen, Søren Tang; Poulsen, Per Løgstrup; Hansen, Klavs Würgler

    2002-01-01

    retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence...... or absence of macrovascular disease was assessed by an independent physician. RESULTS: Forty-nine patients had no detectable retinal changes (grade 1), 13 had grade 2 retinopathy, and 18 had more advanced retinopathy (grades 3-6). Compared to patients without retinopathy (grade 1), patients with grades 2......BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between...

  17. Pressure Measurement Systems

    Science.gov (United States)

    1990-01-01

    System 8400 is an advanced system for measurement of gas and liquid pressure, along with a variety of other parameters, including voltage, frequency and digital inputs. System 8400 offers exceptionally high speed data acquisition through parallel processing, and its modular design allows expansion from a relatively inexpensive entry level system by the addition of modular Input Units that can be installed or removed in minutes. Douglas Juanarena was on the team of engineers that developed a new technology known as ESP (electronically scanned pressure). The Langley ESP measurement system was based on miniature integrated circuit pressure-sensing transducers that communicated pressure information to a minicomputer. In 1977, Juanarena formed PSI to exploit the NASA technology. In 1978 he left Langley, obtained a NASA license for the technology, introduced the first commercial product, the 780B pressure measurement system. PSI developed a pressure scanner for automation of industrial processes. Now in its second design generation, the DPT-6400 is capable of making 2,000 measurements a second and has 64 channels by addition of slave units. New system 8400 represents PSI's bid to further exploit the 600 million U.S. industrial pressure measurement market. It is geared to provide a turnkey solution to physical measurement.

  18. Pressure Ulcers Surveillance Report

    Directory of Open Access Journals (Sweden)

    Zehra Esin Gencer

    2015-04-01

    Full Text Available Objective: Pressure ulcer is a chronic wound. It reduces the quality of life of the elderly and individuals with restricted range of motion. It prolongs hospital stay and increases the risk of complications. The cost is quite high. Preventive actions for the prevention of pressure ulcers should be developed. Planning protocols and standards of care are among the main targets. Material and Method: Research was conducted in one-year period between 2012 May and 2013 May on patients who were followed up in Akdeniz University Hospital clinics and intensive care unit with pressure ulcers. The research population consisted of 569 patients. Patient data were recorded in SPSS 16 for Windows program. Statistical analyzes were performed with retrospective methods. The demographic characteristics of patients with pressure ulcers were analyzed as frequency and descriptive statistics. Prevalence and incidence of one year were calculated. Results: Of the patients, 58% were males, 42% were females. Of the patients, 36% were in the age range of 61-80 years, and their average length of stay was 42,9 days. Of the patients, 70% were at stage 2 and 3. In 15% of patients pressure ulcers occurred on the first day of hospitalization. Pressure ulcers were developed between days 2 and 10 in 59% of the patients. Prevalence rate was 2.5%, the incidence was 1.9%, the prevalence rate was 5.9% in the intensive care unit. Conclusion: It is easier to prevent pressure ulcers than treating.

  19. Pressure suppressing device

    International Nuclear Information System (INIS)

    Naito, Makoto.

    1980-01-01

    Purpose: To prevent the pressure in the reactor container from excessively increasing even when vapor leaks from the dry well to a space of the suppression chamber, without passing though the suppression pool at the time of loss of coolant accident. Constitution: When vapor of a high temperature and a high pressure at the time of loss of coolant accident flows from the dry well to the suppression chamber without passing through suppression pool water, vapor dose not condense with pool water, and therefore the pressure within the chamber abnormally increases. For this reason, this abnormal pressure is detected by a pressure detector thereby to start the operations of a blower and a pump. By starting the blower, the pressure in the dry well becomes lower than the pressure in the chamber, and vapor entirely passes through the pool water and entirely condenses with the pool water. By starting the pump, the pool water is sprayed over the space of the chamber, and vapor in the space is condensed. (Yoshino, Y.)

  20. Atmospheric Pressure During Landing

    Science.gov (United States)

    1997-01-01

    This figure shows the variation with time of pressure (dots) measured by the Pathfinder MET instrument during the landing period shown in image PIA00797. The two diamonds indicate the times of bridal cutting and 1st impact. The overall trend in the data is of pressure increasing with time. This is almost certainly due to the lander rolling downhill by roughly 10 m. The spacing of the horizontal dotted lines indicates the pressure change expected from 10 m changes in altitude. Bounces may also be visible in the data.

  1. Pressure Ulcer Prevention

    Science.gov (United States)

    2009-01-01

    Executive Summary In April 2008, the Medical Advisory Secretariat began an evidence-based review of the literature concerning pressure ulcers. Please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/tech/tech_mn.html to review these titles that are currently available within the Pressure Ulcers series. Pressure ulcer prevention: an evidence based analysis The cost-effectiveness of prevention strategies for pressure ulcers in long-term care homes in Ontario: projections of the Ontario Pressure Ulcer Model (field evaluation) Management of chronic pressure ulcers: an evidence-based analysis (anticipated pubicstion date - mid-2009) Purpose A pressure ulcer, also known as a pressure sore, decubitus ulcer, or bedsore, is defined as a localized injury to the skin/and or underlying tissue occurring most often over a bony prominence and caused by pressure, shear, or friction, alone or in combination. (1) Those at risk for developing pressure ulcers include the elderly and critically ill as well as persons with neurological impairments and those who suffer conditions associated with immobility. Pressure ulcers are graded or staged with a 4-point classification system denoting severity. Stage I represents the beginnings of a pressure ulcer and stage IV, the severest grade, consists of full thickness tissue loss with exposed bone, tendon, and or muscle. (1) In a 2004 survey of Canadian health care settings, Woodbury and Houghton (2) estimated that the prevalence of pressure ulcers at a stage 1 or greater in Ontario ranged between 13.1% and 53% with nonacute health care settings having the highest prevalence rate (Table 1). Executive Summary Table 1: Prevalence of Pressure Ulcers* Setting Canadian Prevalence,% (95% CI) Ontario Prevalence,Range % (n) Acute care 25 (23.8–26.3) 23.9–29.7 (3418) Nonacute care† 30 (29.3–31.4) 30.0–53.3 (1165) Community care 15 (13.4–16.8) 13.2 (91) Mixed health care‡ 22 (20.9

  2. Pressure Safety Orientation Live #769

    Energy Technology Data Exchange (ETDEWEB)

    Glass, George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-17

    Pressure Safety Orientation (course #769) introduces workers at Los Alamos National Laboratory (LANL) to the Laboratory Pressure Safety Program and to pressure-related hazards. This course also affords a hands-on exercise involving the assembly of a simple pressure system. This course is required for all LANL personnel who work on or near pressure systems and are exposed to pressure-related hazards. These personnel include pressure-system engineers, designers, fabricators, installers, operators, inspectors, maintainers, and others who work with pressurized fluids and may be exposed to pressure-related hazards.

  3. Normal Pressure Hydrocephalus

    Science.gov (United States)

    ... improves the chance of a good recovery. Without treatment, symptoms may worsen and cause death. What research is being done? The NINDS conducts and supports research on neurological disorders, including normal pressure hydrocephalus. Research on disorders such ...

  4. On Time Performance Pressure

    Science.gov (United States)

    Connell, Linda; Wichner, David; Jakey, Abegael

    2013-01-01

    Within many operations, the pressures for on-time performance are high. Each month, on-time statistics are reported to the Department of Transportation and made public. There is a natural tendency for employees under pressure to do their best to meet these objectives. As a result, pressure to get the job done within the allotted time may cause personnel to deviate from procedures and policies. Additionally, inadequate or unavailable resources may drive employees to work around standard processes that are seen as barriers. However, bypassing practices to enable on-time performance may affect more than the statistics. ASRS reports often highlight on-time performance pressures which may result in impact across all workgroups in an attempt to achieve on-time performance. Reporters often provide in-depth insights into their experiences which can be used by industry to identify and focus on the implementation of systemic fixes.

  5. Downhole pressure sensor

    Science.gov (United States)

    Berdahl, C. M.

    1980-01-01

    Sensor remains accurate in spite of varying temperatures. Very accurate, sensitive, and stable downhole pressure measurements are needed for vaiety of reservoir engineering applications, such as deep petroleum reservoirs, especially gas reservoirs, and in areas of high geothermal gradient.

  6. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  7. High Blood Pressure

    Science.gov (United States)

    ... kidney disease, diabetes, or metabolic syndrome Read less Unhealthy lifestyle habits Unhealthy lifestyle habits can increase the risk of high blood pressure. These habits include: Unhealthy eating patterns, such as eating too much sodium ...

  8. Understanding Blood Pressure Readings

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Understanding Blood Pressure Readings Updated:Jun 1,2018 What do your blood ... and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you learn about conditions, ...

  9. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... play_arrow What parts of the body are most likely to develop pressure sores? play_arrow Is ... daily skin inspections? play_arrow What are the most important things for someone with a spinal cord ...

  10. Increased intracranial pressure

    Science.gov (United States)

    ... the membranes covering the brain and spinal cord) Subdural hematoma (bleeding between the covering of the brain and ... intracranial pressure Patient Instructions Ventriculoperitoneal shunt - discharge Images Subdural hematoma Central nervous system and peripheral nervous system References ...

  11. Pressurized Vessel Slurry Pumping

    International Nuclear Information System (INIS)

    Pound, C.R.

    2001-01-01

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air

  12. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Preventing Pressure Sores ... sores? What is a Spinal Cord Injury? SCI Medical Experts People Living With SCI Personal Experiences By ...

  13. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... hours? play_arrow What's the best way to do daily skin inspections? play_arrow What are the ... for someone with a spinal cord injury to do to prevent pressure sores? play_arrow Why is ...

  14. Osteomyelitis beneath pressure sores

    International Nuclear Information System (INIS)

    Sugarman, B.; Hawes, S.; Musher, D.M.; Klima, M.; Young, E.J.; Pircher, F.

    1983-01-01

    Twenty-eight pressure sores were evaluated prospectively. Osteomyelitis was reported histologically in nine of 28 bones and pressure-related changes were reported in 14 bones. Roentgenograms suggested the presence of osteomyelitis in four instances of histologically proved osteomyelitis. Technetium Tc 99m medronate bone scans were highly sensitive, showing increased uptake in all cases of osteomyelitis; however, increased uptake also occurred commonly in uninfected bones due to pressure-related changes or other noninfectious causes. Cultures of bone biopsy samples usually disclosed anaerobic bacteria, gram-negative bacilli, or both. The diagnosis of osteomyelitis must be considered if a pressure sore does not respond to local therapy. If the technetium Tc 99m medronate uptake is increased in the involved area, or roentgenographic findings are abnormal, the diagnosis can only be made with certainty by histologic examination of bone. Antibacterial treatment should be selected based on the results of bone culture

  15. High Blood Pressure

    Science.gov (United States)

    ... factors Diabetes High blood pressure Family history Obesity Race/ethnicity Full list of causes and risk factors ... give Give monthly Memorials and tributes Donate a car Donate gently used items Stock donation Workplace giving ...

  16. Reactor pressure vessel support

    International Nuclear Information System (INIS)

    Butti, J.P.

    1977-01-01

    A link and pin support system provides the primary vertical and lateral support for a nuclear reactor pressure vessel without restricting thermally induced radial and vertical expansion and contraction. (Auth.)

  17. Normal pressure hydrocephalus

    Science.gov (United States)

    Hydrocephalus - occult; Hydrocephalus - idiopathic; Hydrocephalus - adult; Hydrocephalus - communicating; Dementia - hydrocephalus; NPH ... Ferri FF. Normal pressure hydrocephalus. In: Ferri FF, ed. ... Elsevier; 2016:chap 648. Rosenberg GA. Brain edema and disorders ...

  18. Pressurized water reactor systems

    International Nuclear Information System (INIS)

    Meyer, P.J.

    1975-01-01

    Design and mode of operation of the main PWR components are described: reactor core, pressure vessel and internals, cooling systems with pumps and steam generators, ancillary systems, and waste processing. (TK) [de

  19. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Medical Experts People Living with SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Preventing Pressure Sores Adult Injuries Spinal Cord Injury 101 David ...

  20. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Adult Injuries Spinal Cord Injury 101 David Chen, MD Preventing Pressure Sores Mary Zeigler, MS Transition from ... Rosenberg, PsyD Understanding SCI Rehabilitation Donald Peck Leslie, MD Adjusting to Social Life in a Wheelchair Lisa ...

  1. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... Living with SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Preventing Pressure Sores Adult Injuries Spinal Cord Injury 101 David ...

  2. High-pressure tritium

    International Nuclear Information System (INIS)

    Coffin, D.O.

    1976-01-01

    Some solutions to problems of compressing and containing tritium gas to 200 MPa at 700 0 K are discussed. The principal emphasis is on commercial compressors and high-pressure equipment that can be easily modified by the researcher for safe use with tritium. Experience with metal bellows and diaphragm compressors has been favorable. Selection of materials, fittings, and gauges for high-pressure tritium work is also reviewed briefly

  3. Reactor pressure vessel design

    International Nuclear Information System (INIS)

    Foehl, J.

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. In chapter 2, the general principles of reactor pressure vessel design are elaborated. Crack and fracture initiation and propagation are treated in some detail

  4. Krypton oxides under pressure

    OpenAIRE

    Zaleski-Ejgierd, Patryk; Łata, Paweł

    2015-01-01

    Under high pressure, krypton, one of the most inert elements is predicted to become sufficiently reactive to form a new class of krypton compounds; krypton oxides. Using modern ab-initio evolutionary algorithms in combination with Density Functional Theory, we predict the existence of several thermodynamically stable Kr/O species at elevated pressures. In particular, our calculations indicate that at approx. 300?GPa the monoxide, KrO, should form spontaneously and remain thermo- and dynamical...

  5. Destructive distillation under pressure

    Energy Technology Data Exchange (ETDEWEB)

    1932-09-08

    A process of destructive distillation of distillable carbonaceous material under pressure is described, consisting of regulating the temperature by introducing the carbonaceous materials to a point where the reaction of hydrogenation has begun but has not stopped, by placing it in indirect heat-exchange with a cooling agent at a critical temperature below the reaction temperature, the agent being under pressure and introduced in the liquid state. Water is used as the cooling agent.

  6. Deuterium high pressure target

    International Nuclear Information System (INIS)

    Perevozchikov, V.V.; Yukhimchuk, A.A.; Vinogradov, Yu.I.

    2001-01-01

    The design of the deuterium high-pressure target is presented. The target having volume of 76 cm 3 serves to provide the experimental research of muon catalyzed fusion reactions in ultra-pure deuterium in the temperature range 80-800 K under pressures of up to 150 MPa. The operation of the main systems of the target is described: generation and purification of deuterium gas, refrigeration, heating, evacuation, automated control system and data collection system

  7. Pressure tube reactor

    International Nuclear Information System (INIS)

    Seki, Osamu; Kumasaka, Katsuyuki.

    1988-01-01

    Purpose: To remove the heat of reactor core using a great amount of moderators at the periphery of the reactor core as coolants. Constitution: Heat of a reactor core is removed by disposing a spontaneous recycling cooling device for cooling moderators in a moderator tank, without using additional power driven equipments. That is, a spontaneous recycling cooling device for cooling the moderators in the moderator tank is disposed. Further, the gap between the inner wall of a pressure tube guide pipe disposed through the vertical direction of a moderator tank and the outer wall of a pressure tube inserted through the guide pipe is made smaller than the rupture distortion caused by the thermal expansion upon overheating of the pressure tube and greater than the minimum gap required for heat shiels between the pressure tube and the pressure tube guide pipe during usual operation. In this way, even if such an accident as can not using a coolant cooling device comprising power driven equipment should occur in the pressure tube type reactor, the rise in the temperature of the reactor core can be retarded to obtain a margin with time. (Kamimura, M.)

  8. Taking Care of Pressure Sores

    Science.gov (United States)

    ... Tract Infections: Indwelling (Foley) Catheter Taking Care of Pressure Sores [Download this pamphlet: "Taking Care of Pressure Sores" - ( ... may not show up right away. Stages of pressure sores and how to care for them: STAGE ONE ...

  9. Reotemp Pressure Indicator - Local Pressure Indication to Monitor the SCHe Supply Bottle Pressure

    International Nuclear Information System (INIS)

    VAN KATWIJK, C.

    1999-01-01

    These 0-3000 psig range pressure indicators are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. These accident monitoring local pressure indicators monitor the SCHe supply bottle pressure. There is one pressure indicator for each SCHe supply (4)

  10. Cryogenic, Absolute, High Pressure Sensor

    Science.gov (United States)

    Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

    2001-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  11. Cryogenic High Pressure Sensor Module

    Science.gov (United States)

    Chapman, John J. (Inventor); Shams, Qamar A. (Inventor); Powers, William T. (Inventor)

    1999-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  12. Pressure Effect on Entrance Flow

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Couch, Mark

    1997-01-01

    The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts.......The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts....

  13. Acute lung injury and acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Ragaller Maximillian

    2010-01-01

    Full Text Available Every year, more information accumulates about the possibility of treating patients with acute lung injury or acute respiratory distress syndrome with specially designed mechanical ventilation strategies. Ventilator modes, positive end-expiratory pressure settings, and recruitment maneuvers play a major role in these strategies. However, what can we take from these experimental and clinical data to the clinical practice? In this article, we discuss substantial options of mechanical ventilation together with some adjunctive therapeutic measures, such as prone positioning and inhalation of nitric oxide.

  14. High-Frequency Percussive Ventilation and Low Tidal Volume Ventilation in Burns: A Randomized Controlled Trial

    Science.gov (United States)

    2010-01-01

    incidence of ventilator-associated pneumonia ( VAP ) in patients with inha- lation injury when supported with HFPV compared with conventional modes of...mean ratio of PaO2 to FIO2 was 58 6 with a mean positive end- expiratory pressure of 22 2 cm H2O before rescue. Two of these patients were...a sample size of 110 patients in each arm would have been required to detect a difference in VAP with 80% power. A multicentered study would be

  15. Reactor pressure boundary materials

    International Nuclear Information System (INIS)

    Hong, Jun Hwa; Chi, S. H.; Lee, B. S.

    2002-04-01

    With a long-term operation of nuclear power plants, the component materials are degraded under severe reactor conditions such as neutron irradiation, high temperature, high pressure and corrosive environment. It is necessary to establish the reliable and practical technologies for improving and developing the component materials and for evaluating the mechanical properties. Especially, it is very important to investigate the technologies for reactor pressure boundary materials such as reactor vessel and pipings in accordance with their critical roles. Therefore, this study was focused on developing and advancing the microstructural/micro-mechanical evaluation technologies, and on evaluating the neutron irradiation characteristics and radiation effects analysis technology of the reactor pressure boundary materials, and also on establishing a basis of nuclear material property database

  16. 46 CFR 197.462 - Pressure vessels and pressure piping.

    Science.gov (United States)

    2010-10-01

    ... that each pressure vessel, including each volume tank, cylinder and PVHO, and each pressure piping... tests conducted in accordance with this section shall be either hydrostatic tests or pneumatic tests. (1... times the maximum allowable working pressure. (2) When a pneumatic test is conducted on a pressure...

  17. Acoustic Radiation Pressure

    Science.gov (United States)

    Cantrell, John H.

    2018-01-01

    The theoretical foundation of acoustic radiation pressure in plane wave beams is reexamined. It is shown from finite deformation theory and the Boltzmann-Ehrenfest Adiabatic Principle that the Brillouin stress tensor (BST) is the radiation stress in Lagrangian coordinates (not Eulerian coordinates) and that the terms in the BST are not the momentum flux density and mean excess Eulerian stress but are simply contributions to the variation in the wave oscillation period resulting from changes in path length and true wave velocity, respectively, from virtual variations in the strain. It is shown that the radiation stress in Eulerian coordinates is the mean Cauchy stress (not the momentum flux density, as commonly assumed) and that Langevin's second relation does not yield an assessment of the mean Eulerian pressure, since the enthalpy used in the traditional derivations is a function of the thermodynamic tensions - not the Eulerian pressure. It is shown that the transformation between Lagrangian and Eulerian quantities cannot be obtained from the commonly-used expansion of one of the quantities in terms of the particle displacement, since the expansion provides only the difference between the value of the quantity at two different points in Cartesian space separated by the displacement. The proper transformation is obtained only by employing the transformation coefficients of finite deformation theory, which are defined in terms of the displacement gradients. Finite deformation theory leads to the result that for laterally unconfined, plane waves the Lagrangian and Eulerian radiation pressures are equal with the value (1/4)(2K) along the direction of wave propagation, where (K) is the mean kinetic energy density, and zero in directions normal to the propagation direction. This is contrary to the Langevin result that the Lagrangian radiation pressure in the propagation direction is equal to (2K) and the BST result that the Eulerian radiation pressure in that direction

  18. The pressure suppression system

    International Nuclear Information System (INIS)

    Aust, E.

    1985-01-01

    Nuclear plants with boiling water reactors have a safety containment with a pressure suppression system (PSS). Proceeding on significant self-developments, today the three PSS-lines of General Electric Co. (GE), Kraftwerk Union AG (KWU) and ASEA-ATOM are predominant, which are currently represented by the MARK III type, the KWU type 72 and the BWR 75 containment. In addition, there are special developments for the nuclear ship propulsion and for the pressurized water reactors in the Soviet Union. Key design values of the PSS allow a first valuation of its loads during a hypothetical loss-of-coolant accident. (orig.) [de

  19. Reactor pressure tank

    International Nuclear Information System (INIS)

    Dorner, H.; Scholz, M.; Jungmann, A.

    1975-01-01

    In a reactor pressure tank for a nuclear reactor, self-locking hooks engage a steel ring disposed over the removable cover of the steel vessel. The hooks exert force upon the cover to maintain the cover in a closed position during operation of the reactor pressure tank. The force upon the removal cover is partly the result of the increasing temperature and thermal expansion of the steel vessel during operation. The steel vessel is surrounded by a reinforced-concrete tank. (U.S.)

  20. Krypton oxides under pressure.

    Science.gov (United States)

    Zaleski-Ejgierd, Patryk; Lata, Pawel M

    2016-02-02

    Under high pressure, krypton, one of the most inert elements is predicted to become sufficiently reactive to form a new class of krypton compounds; krypton oxides. Using modern ab-initio evolutionary algorithms in combination with Density Functional Theory, we predict the existence of several thermodynamically stable Kr/O species at elevated pressures. In particular, our calculations indicate that at approx. 300 GPa the monoxide, KrO, should form spontaneously and remain thermo- and dynamically stable with respect to constituent elements and higher oxides. The monoxide is predicted to form non-molecular crystals with short Kr-O contacts, typical for genuine chemical bonds.

  1. Low pressure lithium condensation

    International Nuclear Information System (INIS)

    Wadkins, R.P.; Oh, C.H.

    1985-01-01

    A low pressure experiment to evaluate the laminar film condensation coefficients of lithium was conducted. Some thirty-six different heat transfer tests were made at system pressures ranging from 1.3 to 26 Pa. Boiled lithium was condensed on the inside of a 7.6-cm (ID), 409 stainless-steel pipe. Condensed lithium was allowed to reflux back to the pool boiling region below the condensing section. Fourteen chromel/alumel thermocouples were attached in various regions of the condensing section. The thermocouples were initially calibrated with errors of less than one degree Celsius

  2. A sigmoidal fit for pressure-volume curves of idiopathic pulmonary fibrosis patients on mechanical ventilation: clinical implications

    Directory of Open Access Journals (Sweden)

    Juliana C. Ferreira

    2011-01-01

    Full Text Available OBJECTIVE: Respiratory pressure-volume curves fitted to exponential equations have been used to assess disease severity and prognosis in spontaneously breathing patients with idiopathic pulmonary fibrosis. Sigmoidal equations have been used to fit pressure-volume curves for mechanically ventilated patients but not for idiopathic pulmonary fibrosis patients. We compared a sigmoidal model and an exponential model to fit pressure-volume curves from mechanically ventilated patients with idiopathic pulmonary fibrosis. METHODS: Six idiopathic pulmonary fibrosis patients and five controls underwent inflation pressure-volume curves using the constant-flow technique during general anesthesia prior to open lung biopsy or thymectomy. We identified the lower and upper inflection points and fit the curves with an exponential equation, V = A-B.e-k.P, and a sigmoid equation, V = a+b/(1+e-(P-c/d. RESULTS: The mean lower inflection point for idiopathic pulmonary fibrosis patients was significantly higher (10.5 ± 5.7 cm H2O than that of controls (3.6 ± 2.4 cm H2O. The sigmoidal equation fit the pressure-volume curves of the fibrotic and control patients well, but the exponential equation fit the data well only when points below 50% of the inspiratory capacity were excluded. CONCLUSION: The elevated lower inflection point and the sigmoidal shape of the pressure-volume curves suggest that respiratory system compliance is decreased close to end-expiratory lung volume in idiopathic pulmonary fibrosis patients under general anesthesia and mechanical ventilation. The sigmoidal fit was superior to the exponential fit for inflation pressure-volume curves of anesthetized patients with idiopathic pulmonary fibrosis and could be useful for guiding mechanical ventilation during general anesthesia in this condition.

  3. A bench study of intensive-care-unit ventilators: new versus old and turbine-based versus compressed gas-based ventilators

    Science.gov (United States)

    Thille, Arnaud W.; Lyazidi, Aissam; Richard, Jean-Christophe M.; Galia, Fabrice; Brochard, Laurent

    2009-01-01

    Objective To compare 13 commercially available, new-generation, intensive-care-unit (ICU) ventilators regarding trigger function, pressurization capacity during pressure-support ventilation (PSV), accuracy of pressure measurements and expiratory resistance. Design and Setting Bench study at a research laboratory in a university hospital. Material Four turbine-based ventilators and nine conventional servo-valve compressed-gas ventilators were tested using a two-compartment lung model. Results Three levels of effort were simulated. Each ventilator was evaluated at four PSV levels (5, 10, 15, and 20 cm H2O), with and without positive end-expiratory pressure (5 cm H2O, Trigger function was assessed as the time from effort onset to detectable pressurization. Pressurization capacity was evaluated using the airway pressure-time product computed as the net area under the pressure-time curve over the first 0.3 s after inspiratory effort onset. Expiratory resistance was evaluated by measuring trapped volume in controlled ventilation. Significant differences were found across the ventilators, with a range of triggering-delay from 42 ms to 88 ms for all conditions averaged (Pventilators at PSV5 and three at PSV10, suggesting an inability to unload patient’s effort. On average, turbine-based ventilators performed better than conventional ventilators, which showed no improvement compared to a 2000 bench comparison. Conclusion Technical performances of trigger function, pressurization capacity and expiratory resistance vary considerably across new-generation ICU ventilators. ICU ventilators seem to have reached a technical ceiling in recent years, and some ventilators still perform inadequately. PMID:19352622

  4. A Dedicated Z-Stent for Acquired Saber-Sheath Tracheobronchomalacia

    International Nuclear Information System (INIS)

    Kishi, Kazushi; Fujimoto, Hisashi Kobayashi; Sonomura, Tetsuo; Uetani, Kosaku; Nishida, Norifumi; Ohata, Masahiro; Sato, Morio; Yamada, Ryusaku

    1997-01-01

    The tracheobronchial lumen has a continuous horseshoe arch morphology. We formed Z-stents accordingly to support the weakened cartilagenous portions. With this type of stent we treated a patient with acquired saber-sheath type tracheobronchomalacia (TBM), Rayl's type II, Johnson's grade III, whose condition was aggravated even under positive end expiratory pressure (PEEP) therapy. The patient improved gradually. No immediate complication was observed. Bronchofiberscopic examination revealed that the tracheobronchial arcade was closely strut-braced and showed no expiratory collapse. Six months later, when the patient was intubated due to asthmatic attacks, tissue ingrowth through the stent was found and removed. There was no recurrence of TBM. The patient died 2 years later of pneumoconiosis

  5. Pressure test method for reactor pressure vessel in construction field

    International Nuclear Information System (INIS)

    Takeda, Masakado; Ushiroda, Koichi; Miyahara, Ryohei; Takano, Hiroshi; Matsuura, Tadashi; Sato, Keiya.

    1998-01-01

    Plant constitutional parts as targets of both of a primary pressure test and a secondary pressure test are disposed in communication with a reactor pressure vessel, and a pressure of the primary pressure test is applied to the targets of both tests, so that the primary pressure test and the second pressure test are conducted together. Since the number of pressure tests can be reduced to promote construction, and the number of workers can also be reduced. A pressure exceeding the maximum pressure upon use is applied to the pressure vessel after disposing the incore structures, to continuously conduct the primary pressure test and the secondary pressure test joined together and an incore flowing test while closing the upper lid of the pressure vessel as it is in the construction field. The number of opening/closing of the upper lid upon conducting every test can be reduced, and since the pressure resistance test is conducted after arranging circumference conditions for the incore flowing test, the tests can be conducted collectively also in view of time. (N.H.)

  6. Pressure Effect on Extensional Viscosity

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Kjær, Erik Michael

    1999-01-01

    The primary object of these experiments was to investigate the influence of hydrostatic pressure on entrance flow. The effect of pressure on shear and extensional viscosity was evaluated using an axis symmetric capillary and a slit die where the hydrostatic pressure was raised with valves....... The experiments show a significant increase in extensional viscosity with increasing pressure....

  7. [Special artificial respiration procedures and intracranial pressure. Animal experiment studies, development and use of a new pressure measuring technic, clinical aspects].

    Science.gov (United States)

    Schedl, R

    1985-01-01

    -fluctuations were found to be markedly reduced at frequencies of 20/min and usually eliminated at 30/min. We found an exponential correlation between ICP-fluctuations and respiratory frequency and there was no correlation between tidal volume and ICP. Central venous pressure amplitudes were found to be in linear correlation with respiratory frequency and tidal volumes as well. The amplitude of respiratory ICP-fluctuations seems to be more dependent on duration of expiratory time. As our findings demonstrate, artificial ventilation without entilator-related fluctuations in ICP ("brain-protective" ventilation) may be performed by conventional volume-constant, time-cycled ventilators.(ABSTRACT TRUNCATED AT 400 WORDS)

  8. Plasma sheet pressure anisotropies

    International Nuclear Information System (INIS)

    Stiles, G.S.; Hones, E.W. Jr; Bame, S.J.; Asbridge, J.R.

    1978-01-01

    The ecliptic plane components of the pressure tensors for low-energy ( or =1.2 approximately 25% of the time. Due to the low energy density of the electrons, however, this anisotropy is not itself sufficient to balance the tension of the magnetic field

  9. Pressure vessel integrity 1991

    International Nuclear Information System (INIS)

    Bhandari, S.; Doney, R.O.; McDonald, M.S.; Jones, D.P.; Wilson, W.K.; Pennell, W.E.

    1991-01-01

    This volume contains papers relating to the structural integrity assessment of pressure vessels and piping, with special emphasis on nuclear industry applications. The papers were prepared for technical sessions developed under the sponsorship of the ASME Pressure Vessels and Piping Division Committees for Codes and Standards, Computer Technology, Design and Analysis, and Materials Fabrication. They were presented at the 1991 Pressure Vessels and Piping Division Conference in San Diego, California, June 23-27. The primary objective of the sponsoring organization is to provide a forum for the dissemination and discussion of information on development and application of technology for the structural integrity assessment of pressure vessels and piping. This publication includes contributions from authors from Australia, France, Japan, Sweden, Switzerland, the United Kingdom, and the United States. The papers here are organized in six sections, each with a particular emphasis as indicated in the following section titles: Fracture Technology Status and Application Experience; Crack Initiation, Propagation and Arrest; Ductile Tearing; Constraint, Stress State, and Local-Brittle-Zones Effects; Computational Techniques for Fracture and Corrosion Fatigue; and Codes and Standards for Fatigue, Fracture and Erosion/Corrosion

  10. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... arrow What's the best way to do daily skin inspections? play_arrow What are the most important ... to prevent pressure sores? play_arrow What is “skin tolerance” and how can it be increased? play_ ...

  11. Raised intracranial pressure

    African Journals Online (AJOL)

    is article presents an approach to raised intracranial pressure (ICP) constructed in a question-answer fashion. ..... Given that raised ICP is a serious and potentially life-threatening emergency, fast and reliable referral and transfer mechanisms should be established to ensure patients with this condition are effectively treated.

  12. Pressurized Thermal Shock, Pts

    International Nuclear Information System (INIS)

    Boyd, C.

    2008-01-01

    Pressurized Thermal Shock (Pts) refers to a condition that challenges the integrity of the reactor pressure vessel. The root cause of this problem is the radiation embrittlement of the reactor vessel. This embrittlement leads to an increase in the reference temperature for nil ductility transition (RTNDT). RTNDT can increase to the point where the reactor vessel material can loose fracture toughness during overcooling events. The analysis of the risk of having a Pts for a specific plant is a multi-disciplinary problem involving probabilistic risk analysis (PRA), thermal-hydraulic analysis, and ultimately a structural and fracture analysis of the vessel wall. The PRA effort involves the postulation of overcooling events and ultimately leads to an integrated risk analysis. The thermal-hydraulic effort involves the difficult task of predicting the system behavior during a postulated overcooling scenario with a special emphasis on predicting the thermal and mechanic loadings on the reactor pressure vessel wall. The structural and fracture analysis of the reactor vessel wall relies on the thermal-hydraulic conditions as boundary conditions. The US experience has indicated that medium and large diameter primary system breaks dominate the risk of Pts along with scenarios that involve a stuck open valve (and associated system cooldown) that recloses resulting in system re-pressurization while the vessel wall is cool.

  13. Intracranial Pressure Monitoring

    DEFF Research Database (Denmark)

    Raboel, P H; Bartek, J; Andresen, M

    2012-01-01

    Monitoring of intracranial pressure (ICP) has been used for decades in the fields of neurosurgery and neurology. There are multiple techniques: invasive as well as noninvasive. This paper aims to provide an overview of the advantages and disadvantages of the most common and well-known methods...

  14. Pressure tube reactor

    International Nuclear Information System (INIS)

    Susuki, Akira; Murata, Shigeto; Minato, Akihiko.

    1993-01-01

    In a pressure tube reactor, a reactor core is constituted by arranging more than two units of a minimum unit combination of a moderator sealing pipe containing a calandria tube having moderators there between and a calandria tube and moderators. The upper header and a lower header of the calandria tank containing moderators are communicated by way of the moderator sealing tube. Further, a gravitationally dropping mechanism is disposed for injecting neutron absorbing liquid to a calandria gas injection portion. A ratio between a moderator volume and a fuel volume is defined as a function of the inner diameter of the moderator sealing tube, the outer diameter of the calandria tube and the diameter of fuel pellets, and has no influence to intervals of a pressure tube lattice. The interval of the pressure tube lattice is enlarged without increasing the size of the pressure tube, to improve production efficiency of the reactor and set a coolant void coefficient more negative, thereby enabling to improve self controllability and safety. Further, the reactor scram can be conducted by injecting neutron absorbing liquid. (N.H.)

  15. Putting oysters under pressure

    Science.gov (United States)

    High pressure processing (HPP) is the most commercially important food processing technology in use now and is anticipated to remain of equal or greater importance during the next five to 10 years. This month’s column reviews the theory and current applications of HPP for oysters to improve their sa...

  16. Fascination at high pressures

    International Nuclear Information System (INIS)

    Chidambaram, R.

    1992-01-01

    Research at high pressures has developed into an interdisciplinary area which has important implications for and applications in the areas of physics, chemistry, materials sciences, planetary sciences, biology, engineering sciences and technology. The state of-the-art in this field is reviewed and future directions are indicated. (M.G.B.)

  17. ISCHIECTOMY FOR PRESSURE SORES

    Science.gov (United States)

    Stern, Mark; Cozen, Lewis; Aldes, John

    1960-01-01

    Ischiectomy with primary closure was carried out in five paraplegic patients with pressure sores. This operation, less extensive than the wide excision with full thickness graft that is now widely advocated, was successful in four of the five cases. In the fifth case none of the several attempts to heal the sores was in the least successful. PMID:18732351

  18. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... the most important thing to do to prevent pressure sores? What is a Spinal Cord Injury? SCI Medical Experts People Living With SCI Personal Experiences By Topic Resources Blog Peer Counseling About Media Donate Contact Us Terms of ...

  19. Sensing pressure for authentication

    NARCIS (Netherlands)

    Henderson, N.J.; White, N.M.; Veldhuis, Raymond N.J.; Hartel, Pieter H.; Slump, Cornelis H.

    The use of signals resulting from tapping a rhythm on a pressure sensor is explored for authentication. The features used for authentication can be divided into rhythm and waveform features. This paper studies the use of waveform features. A verification scheme based on prototype waveforms is

  20. Preventing pressure ulcers

    Science.gov (United States)

    ... for a prolonged time. This pressure reduces blood supply to that area. Lack of blood supply can cause the skin tissue in this area ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  1. [Prevention of pressure ulcers].

    Science.gov (United States)

    Negishi, Kenichi

    2009-12-01

    Even though they have not been diagnosed with a recognized disease, many people have or are at risk of contracting debilitating conditions. They can be referred to as being in the "ill-health zone." For example, many bedridden elderly develop pressure ulcers. The prevention and treatment of pressure ulcers should focus on two main factors: the role of pressure in the development of circulatory disorders; and increased dermal pH. In preventing the development of circulatory disorders resulting in pressure ulcers, using an air or polyurethane mattress is helpful. However, changing the mattress has little effect if the position of the bedridden person is not also changed regularly. To avoid an increase in dermal pH, caregivers should apply moisture-repellent cream and/or oil to the sacral region after careful cleansing. It is important that such preventive measures and treatment be performed daily, and caregivers should be educated on this need and subsequently monitored. Pharmacists have a role in caring for those in the ill-health zone.

  2. Positive airway pressure treatment

    Science.gov (United States)

    ... it. After using PAP regularly, you may notice: Better concentration and memory Feeling more alert and less sleepy during the day Improved sleep for your bed partner Being more productive at ... and a better mood Normal sleep patterns Lower blood pressure (in ...

  3. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... arrow Is it true that a pressure sore can develop in a few hours? play_arrow What's ... play_arrow What is “skin tolerance” and how can it be increased? play_arrow What do family ...

  4. Preventing Pressure Sores

    Medline Plus

    Full Text Available ... cushion? play_arrow What’s important to know about positioning in bed to prevent pressure sores? play_arrow ... Disabilities Photography by Rona Talcott Website by Mobile Marketing LLC Understanding Spinal Cord Injury About Us Expert ...

  5. Pressure suppression device

    International Nuclear Information System (INIS)

    Yoshida, Toyokazu.

    1976-01-01

    Purpose: To provide a pressure suppression device for a gas cooled reactor wherein the coolant is discharged in a reactor building by a loss-of-coolant accident or the like, the increase in the pressure and temperature is controlled and thermal energy of the discharged coolant of high temperature and high pressure can be absorbed. Constitution: A low heat source unit is provided at the upper part in an inner space of a reactor building provided around the reactor, and at the upper part of the low heat source unit a stirring fan for mixing gas within the building, and a low heat source circulating the low heat source through a pipe is connected to the low heat source unit. The low heat source unit is provided with the pipe arranged in a spiral shape at the upper part of the space of the unit, and a large number of fins are provided at the outer surface of the pipe for increasing the transmission area and improve the heat exchange. When the coolant of high temperature and high pressure has been lost in the building, the thermal energy of the coolant is absorbed by the low heat source unit. (Aizawa, K.)

  6. Magnetic measurements under pressure

    Czech Academy of Sciences Publication Activity Database

    Zentková, M.; Arnold, Zdeněk; Mihalik, M.; Mihalik, M.; Zentko, A.; Kamarád, Jiří; Mitróová, Z.; Mat`aš, S.

    2006-01-01

    Roč. 57, 8/S (2006), s. 29-32 ISSN 1335-3632 Institutional research plan: CEZ:AV0Z10100521 Keywords : hydrostatic pressure * Prussian blue analogues * AC susceptibility * intermetallic compound * ferromagnetism * errimagnetism Subject RIV: BM - Solid Matter Physics ; Magnetism

  7. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  8. Dealing with Peer Pressure

    Science.gov (United States)

    ... Peer Pressure Print en español Cómo lidiar con la presión de grupo "Come on! ALL of us are cutting ... and they learn from you. It's only human nature to listen to and learn from ... another student in your science class taught you an easy way to remember ...

  9. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  10. Smart blood pressure holter.

    Science.gov (United States)

    İlhan, İlhan

    2018-03-01

    In this study, a wireless blood pressure holter that can be used with smart mobile devices was developed. The developed blood pressure holter consists of two parts, which are a smart mobile device and a cuff. The smart mobile device is used as a recording, control and display device through a developed interface, while the cuff was designed to take measurements from the arm. Resistor-Capacitor (RC) and digital filters were used on the cuff that communicates with the smart mobile device via Bluetooth. The blood pressure was estimated using the Simple Hill Climbing Algorithm (HCA). It is possible to measure instantaneous or programmable blood pressure and heart rate values at certain intervals using this holter. The test was conducted with 30 individuals at different ages with the guidance of a specialist health personnel. The results showed that an accuracy at 93.89% and 91.95% rates could be obtained for systolic and diastolic pressure values, respectively, when compared with those obtained using a traditional sphygmomanometer. The accuracy level for the heart rate was measured as 97.66%. Furthermore, this device was tested day and night in the holter mode in terms of working time, the continuity of the Bluetooth connection and the reliability of the measurement results. The test results were evaluated separately in terms of measurement accuracy, working time, the continuity of the Bluetooth connection and the reliability of the measurement results. The measurement accuracy for systolic, diastolic blood pressure and heart rate values was obtained as 93.89%, 91.95% and 97.66%, respectively. The maximum number of measurements which can be conducted with four 1000 mA alkaline batteries at 20 min intervals was found approximately 79 (little more than 24 h). In addition, it was determined that the continuity of the Bluetooth connection and the reliability of the measurement results were automatically achieved through the features in the interface developed for the

  11. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  12. Pressure relieving support surfaces (PRESSURE) trial: cost effectiveness analysis.

    Science.gov (United States)

    Iglesias, Cynthia; Nixon, Jane; Cranny, Gillian; Nelson, E Andrea; Hawkins, Kim; Phillips, Angela; Torgerson, David; Mason, Su; Cullum, Nicky

    2006-06-17

    To assess the cost effectiveness of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers in patients admitted to hospital. Cost effectiveness analysis carried out alongside the pressure relieving support surfaces (PRESSURE) trial; a multicentre UK based pragmatic randomised controlled trial. 11 hospitals in six UK NHS trusts. Intention to treat population comprising 1971 participants. Kaplan Meier estimates of restricted mean time to development of pressure ulcers and total costs for treatment in hospital. Alternating pressure mattresses were associated with lower overall costs (283.6 pounds sterling per patient on average, 95% confidence interval--377.59 pounds sterling to 976.79 pounds sterling) mainly due to reduced length of stay in hospital, and greater benefits (a delay in time to ulceration of 10.64 days on average,--24.40 to 3.09). The differences in health benefits and total costs for hospital stay between alternating pressure mattresses and alternating pressure overlays were not statistically significant; however, a cost effectiveness acceptability curve indicated that on average alternating pressure mattresses compared with alternating pressure overlays were associated with an 80% probability of being cost saving. Alternating pressure mattresses for the prevention of pressure ulcers are more likely to be cost effective and are more acceptable to patients than alternating pressure overlays.

  13. Corpuls CPR Generates Higher Mean Arterial Pressure Than LUCAS II in a Pig Model of Cardiac Arrest

    Directory of Open Access Journals (Sweden)

    S. Eichhorn

    2017-01-01

    Full Text Available According to the European Resuscitation Council guidelines, the use of mechanical chest compression devices is a reasonable alternative in situations where manual chest compression is impractical or compromises provider safety. The aim of this study is to compare the performance of a recently developed chest compression device (Corpuls CPR with an established system (LUCAS II in a pig model. Methods. Pigs (n = 5/group in provoked ventricular fibrillation were left untreated for 5 minutes, after which 15 min of cardiopulmonary resuscitation was performed with chest compressions. After 15 min, defibrillation was performed every 2 min if necessary, and up to 3 doses of adrenaline were given. If there was no return of spontaneous circulation after 25 min, the experiment was terminated. Coronary perfusion pressure, carotid blood flow, end-expiratory CO2, regional oxygen saturation by near infrared spectroscopy, blood gas, and local organ perfusion with fluorescent labelled microspheres were measured at baseline and during resuscitation. Results. Animals treated with Corpuls CPR had significantly higher mean arterial pressures during resuscitation, along with a detectable trend of greater carotid blood flow and organ perfusion. Conclusion. Chest compressions with the Corpuls CPR device generated significantly higher mean arterial pressures than compressions performed with the LUCAS II device.

  14. Gravity predominates over ventilatory pattern in the prevention of ventilator-associated pneumonia.

    Science.gov (United States)

    Li Bassi, Gianluigi; Marti, Joan Daniel; Saucedo, Lina; Rigol, Montserrat; Roca, Ignasi; Cabanas, Maria; Muñoz, Laura; Ranzani, Otavio Tavares; Giunta, Valeria; Luque, Nestor; Esperatti, Mariano; Gabarrus, Albert; Fernandez, Laia; Rinaudo, Mariano; Ferrer, Miguel; Ramirez, Jose; Vila, Jordi; Torres, Antoni

    2014-09-01

    In the semirecumbent position, gravity-dependent dissemination of pathogens has been implicated in the pathogenesis of ventilator-associated pneumonia. We compared the preventive effects of a ventilatory strategy, aimed at decreasing pulmonary aspiration and enhancing mucus clearance versus the Trendelenburg position. Prospective randomized animal study. Animal research facility, University of Barcelona, Spain. Twenty-four Large White-Landrace pigs. Pigs were intubated and on mechanical ventilation for 72 hours. Following surgical preparation, pigs were randomized to be positioned: 1) in semirecumbent/prone position, ventilated with a duty cycle (TITTOT) of 0.33 and without positive end-expiratory pressure (control); 2) as in the control group, positive end-expiratory pressure of 5 cm H2O and TITTOT to achieve a mean expiratory-inspiratory flow bias of 10 L/min (treatment); 3) in Trendelenburg/prone position and ventilated as in the control group (Trendelenburg). Following randomization, Pseudomonas aeruginosa was instilled into the oropharynx. Mucus clearance rate was measured through fluoroscopic tracking of tracheal markers. Microspheres were instilled into the subglottic trachea to assess pulmonary aspiration. Ventilator-associated pneumonia was confirmed by histological/microbiological studies. The mean expiratory-inspiratory flow in the treatment, control, and Trendelenburg groups were 10.7 ± 1.7, 1.8 ± 3.7 and 4.3 ± 2.8 L/min, respectively (p gravity-dependent translocation of oropharyngeal pathogens and development of ventilator-associated pneumonia. These findings further substantiate the primary role of gravity in the pathogenesis of ventilator-associated pneumonia.

  15. Auto-trilevel versus bilevel positive airway pressure ventilation for hypercapnic overlap syndrome patients.

    Science.gov (United States)

    Su, Mei; Huai, De; Cao, Juan; Ning, Ding; Xue, Rong; Xu, Meijie; Huang, Mao; Zhang, Xilong

    2018-03-01

    Although bilevel positive airway pressure (Bilevel PAP) therapy is usually used for overlap syndrome (OS), there is still a portion of OS patients in whom Bilevel PAP therapy could not simultaneously eliminate residual apnea events and hypercapnia. The current study was expected to explore whether auto-trilevel positive airway pressure (auto-trilevel PAP) therapy with auto-adjusting end expiratory positive airway pressure (EEPAP) can serve as a better alternative for these patients. From January of 2014 to June of 2016, 32 hypercapnic OS patients with stable chronic obstructive pulmonary diseases (COPD) and moderate-to-severe obstructive sleep apnea syndrome (OSAS) were recruited. Three variable modes of positive airway pressure (PAP) from the ventilator (Prisma25ST, Weinmann Inc., Germany) were applicated for 8 h per night. We performed the design of each mode at each night with an interval of two nights with no PAP treatment as a washout period among different modes. In Bilevel-1 mode (Bilevel-1), the expiratory positive airway pressure (EPAP) delivered from Bilevel PAP was always set as the lowest PAP for abolishment of snoring. For each patient, the inspiratory positive airway pressure (IPAP) was constantly set the same as the minimal pressure for keeping end-tidal CO 2 (ETCO 2 ) ≤45 mmHg for all three modes. However, the EPAP issued by Bilevel PAP in Bilevel-2 mode (Bilevel-2) was kept 3 cmH 2 O higher than that in Bilevel-1. In auto-trilevel mode (auto-trilevel) with auto-trilevel PAP, the initial part of EPAP was fixed at the same PAP as that in Bilevel-1 while the EEPAP was automatically regulated to rise at a range of ≤4 cmH 2 O based on nasal airflow wave changes. Comparisons were made for parameters before and during or following treatment as well as among different PAP therapy modes. The following parameters were compared such as nocturnal apnea hypopnea index (AHI), minimal SpO 2 (minSpO 2 ), arousal index, sleep structure and efficiency

  16. Idiopathic Normal Pressure Hydrocephalus

    Directory of Open Access Journals (Sweden)

    Basant R. Nassar BS

    2016-04-01

    Full Text Available Idiopathic normal pressure hydrocephalus (iNPH is a potentially reversible neurodegenerative disease commonly characterized by a triad of dementia, gait, and urinary disturbance. Advancements in diagnosis and treatment have aided in properly identifying and improving symptoms in patients. However, a large proportion of iNPH patients remain either undiagnosed or misdiagnosed. Using PubMed search engine of keywords “normal pressure hydrocephalus,” “diagnosis,” “shunt treatment,” “biomarkers,” “gait disturbances,” “cognitive function,” “neuropsychology,” “imaging,” and “pathogenesis,” articles were obtained for this review. The majority of the articles were retrieved from the past 10 years. The purpose of this review article is to aid general practitioners in further understanding current findings on the pathogenesis, diagnosis, and treatment of iNPH.

  17. Radiography of pressure ulcers

    International Nuclear Information System (INIS)

    Borgstroem, P.S.; Ekberg, O.; Lasson, A.

    1988-01-01

    In patients with longstanding and/or deep pressure ulcers radiology is usually consulted. Survey radiography and sinography in 14 patients with pressure ulcers (6 over the tuber ischii and 8 over the femoral trochanter) were evaluated. Osteomyelitic involvement of adjacent bone was revealed in 9 patients on survey radiography. However, it was usually impossible to assess whether or not bony involvement represents healed or active osteomyelitis. Sinography did not contribute to the assessment of whether or not adjacent cortical bone was involved. However, when a fistulation to an adjacent joint was revealed this contributed substantially to the preoperative planning of resection. We therefore recommend that survey radiography and sinography should be included in the evaluation of these patients but that the results from such examinations are critically evaluated. Joint involvement should be taken seriously as progression of septic arthritis usually occurs rapidly. (orig.)

  18. High pressure shaft seal

    International Nuclear Information System (INIS)

    Martinson, A.R.; Rogers, V.D.

    1980-01-01

    In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

  19. A life under pressure

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik

    2012-01-01

    Microvessels live 'a life under pressure' in several ways. In a literal sense, vessels of the microcirculation are exposed to high levels of stress caused primarily by the intravascular pressure head. In a figurative sense, the individual vessel and the microvascular network as a whole must...... continuously strive to meet the changing demands of the surrounding tissue. The 'principle of optimal operation' as formulated by Y. C. Fung states that living tissues adapts structurally through remodelling and growth until a level of tensile and compressive stresses is reached at which tissue performance...... stress component has a huge impact on the state of the vascular wall. It is involved as a unifying factor on vastly different timescales in processes as diverse as acute regulation of vessel diameter, structural vessel remodelling and growth or atrophy of the vascular wall. The aim of this Mini...

  20. Reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Van De Velde, J.; Fabry, A.; Van Walle, E.; Chaouuadi, R.

    1998-01-01

    Research and development activities related to reactor pressure vessel steels during 1997 are reported. The objectives of activities of the Belgian Nuclear Research Centre SCK/CEN in this domain are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate a methodology on a broad database; (3) to achieve regulatory acceptance and industrial use

  1. Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Van de Velde, J.; Fabry, A.; Van Walle, E.; Chaoudi, R

    1998-07-01

    SCK-CEN's R and D programme on Reactor Pressure Vessel (RPV) Steels in performed in support of the RVP integrity assessment. Its main objectives are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate the applied methodology on a broad database; (3) to achieve regulatory acceptance and industrial use. Progress and achievements in 1999 are reported.

  2. The pressurized water reactor

    International Nuclear Information System (INIS)

    Gallagher, J.L.

    1987-01-01

    Pressurized water reactor technology has reached a maturity that has engendered a new surge of innovation, which in turn, has led to significant advances in the technology. These advances, characterized by bold thinking but conservative execution, are resulting in nuclear plant designs which offer significant performance and safety improvements. This paper describes the innovations which are being designed into mainstream PWR technology as well as the desings which are resulting from such innovations. (author)

  3. Low-pressure

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Richard [Membrane Technology And Research, Inc., Newark, CA (United States); Kniep, Jay [Membrane Technology And Research, Inc., Newark, CA (United States); Hao, Pingjiao [Membrane Technology And Research, Inc., Newark, CA (United States); Chan, Chi Cheng [Membrane Technology And Research, Inc., Newark, CA (United States); Nguyen, Vincent [Membrane Technology And Research, Inc., Newark, CA (United States); Huang, Ivy [Membrane Technology And Research, Inc., Newark, CA (United States); Amo, Karl [Membrane Technology And Research, Inc., Newark, CA (United States); Freeman, Brice [Membrane Technology And Research, Inc., Newark, CA (United States); Fulton, Don [Membrane Technology And Research, Inc., Newark, CA (United States); Ly, Jennifer [Membrane Technology And Research, Inc., Newark, CA (United States); Lipscomb, Glenn [Membrane Technology And Research, Inc., Newark, CA (United States); Lou, Yuecun [Membrane Technology And Research, Inc., Newark, CA (United States); Gogar, Ravikumar [Membrane Technology And Research, Inc., Newark, CA (United States)

    2015-01-29

    This final technical progress report describes work conducted by Membrane Technology and Research, Inc. (MTR) for the Department of Energy (DOE NETL) on development of low-pressure membrane contactors for carbon dioxide (CO2) capture from power plant flue gas (award number DE-FE0007553). The work was conducted from October 1, 2011 through September 30, 2014. The overall goal of this three-year project was to build and operate a prototype 500 m2 low-pressure sweep membrane module specifically designed to separate CO2 from coal-fired power plant flue gas. MTR was assisted in this project by a research group at the University of Toledo, which contributed to the computational fluid dynamics (CFD) analysis of module design and process simulation. This report details the work conducted to develop a new type of membrane contactor specifically designed for the high-gas-flow, low-pressure, countercurrent sweep operation required for affordable membrane-based CO2 capture at coal power plants. Work for this project included module development and testing, design and assembly of a large membrane module test unit at MTR, CFD comparative analysis of cross-flow, countercurrent, and novel partial-countercurrent sweep membrane module designs, CFD analysis of membrane spacers, design and fabrication of a 500 m2 membrane module skid for field tests, a detailed performance and cost analysis of the MTR CO2 capture process with low-pressure sweep modules, and a process design analysis of a membrane-hybrid separation process for CO2 removal from coal-fired flue gas. Key results for each major task are discussed in the report.

  4. Dynamic Pressure Microphones

    Science.gov (United States)

    Werner, E.

    In 1876, Alexander Graham Bell described his first telephone with a microphone using magnetic induction to convert the voice input into an electric output signal. The basic principle led to a variety of designs optimized for different needs, from hearing impaired users to singers or broadcast announcers. From the various sound pressure versions, only the moving coil design is still in mass production for speech and music application.

  5. Flurbiprofen and intraocular pressure.

    Science.gov (United States)

    Gieser, D K; Hodapp, E; Goldberg, I; Kass, M A; Becker, B

    1981-07-01

    Systemic or topical administration of corticosteroids may produce a rise in intraocular pressure (IOP). Nonsteroidal anti-inflammatory drugs (NSAI drugs) are alternate therapy for ocular inflammatory disease. Flurbiprofen, a new NSAI drug, was tested in double-masked fashion to delineate its effect on IOP. Flurbiprofen did not alter IOP in known high corticosteroid responders nor did it block corticosteroid-induced ocular hypertension.

  6. WHn under pressure

    International Nuclear Information System (INIS)

    Zaleski-Ejgierd, Patryk; Ashcroft, N W; Labet, Vanessa; Hoffmann, Roald; Strobel, Timothy A

    2012-01-01

    An initial observation of the formation of WH under pressure from W gaskets surrounding hydrogen in diamond anvil cells led to a theoretical study of tungsten hydride phases. At P = 1 atm no stoichiometry is found to be stable with respect to separation into the elements, but as the pressure is raised WH n (n = 1-6, 8) stoichiometries are metastable or stable. WH and WH 4 are calculated to be stable at P > 15 GPa, WH 2 becomes stable at P > 100 GPa and WH 6 at P > 150 GPa. In agreement with experiment, the structure computed for WH is anti-NiAs. WH 2 shares with WH a hexagonal arrangement of tungsten atoms, with hydrogen atoms occupying octahedral and tetrahedral holes. For WH 4 the W atoms are in a distorted fcc arrangement. As the number of hydrogens rises, the coordination of W by H increases correspondingly, leading to a twelve-coordinated W in WH 6 . In WH 8 H 2 units also develop. All of the hydrides considered should be metallic at high pressure, though the Fermi levels of WH 4 and WH 6 lie in a deep pseudogap. Prodded by these theoretical studies, experiments were then undertaken to seek phases other than WH, exploring a variety of experimental conditions that would favor further reaction. Though a better preparation and characterization of WH resulted, no higher hydrides have as yet been found. (paper)

  7. Pressure detection device

    International Nuclear Information System (INIS)

    Fuji, Akira.

    1997-01-01

    The present invention provides a pressure detection device having a function of preventing discharge of reactor water in pipelines to the outside of a system when a pipeline for detecting pressure to be connected to a reactor is failed. Namely, a fluid pressure detector is disposed at the downstream of the detection pipeline. A cylindrical member having a shrinkable inner diameter is disposed to the outer circumference at the upstream. A cylindrical member having an outer diameter substantially equal to the inner diameter of the detection pipeline is disposed while restricting the movement of the detection pipeline in the inner circumferential direction. Then, it fasten the detection pipeline from the outside upon failure of the pipeline thereby enabling to suppress the flow rate of the fluid in the detection pipeline. In addition, a shape memory alloy which shrinks upon elevation of temperature is used for the cylindrical member. Then, the discharge of the fluid can be prevented automatically upon rupture of the pipeline. (I.S.)

  8. Vapour pressure of trideuterioammonia

    Energy Technology Data Exchange (ETDEWEB)

    Calado, J.C.G.; Lopes, J.N.C.; Rebelo, L.P.N. (Instituto Superior Tecnico, Lisbon (Portugal). Centro de Quimica Estrutural)

    1992-09-01

    The H-to-D vapour-pressure isotope effect in liquid ammonia has been measured at 62 temperatures between 228 K and 260 K. The vapour pressures, corrected to 100 per cent nuclidic purity, have been fitted to the equation: T ln r = A+B/T+CT, where r is the vapour-pressure ratio p(NH[sub 3])/p(ND[sub 3]). The fit yielded the parameters: A = -8.22508 K, B = 12338.2 K[sup 2], and C = -0.05544. Comparisons with the results of other authors were made in order to clarify some discrepancies found in the literature. Our values are in accord with the previous results of King et al. and an extrapolation of the fitted equation down to the triple-point temperature gave good agreement with the published results. The fitted equation was used in conjunction with the Clapeyron equation to calculate the difference in the molar enthalpies of vaporization between NH[sub 3] and ND[sub 3]. At T = 230 K that difference is -846 J.mol[sup -1] decreasing to -747 J.mol[sup -1] at 260 K. (author).

  9. Pressure tube reactors

    International Nuclear Information System (INIS)

    Natori, Hisahide.

    1981-01-01

    Purpose: To improve the electrical power generation efficiency in a pressure tube reactor in which coolants and moderators are separated by feedwater heating with heat generated in heavy water and by decreasing the amount of steams to be extracted from the turbine. Constitution: A heat exchanger and a heavy water cooler are additionally provided to a conventional pressure tube reactor. The heat exchanger is disposed at the pre-stage of a low pressure feedwater heater series. High temperature heavy water heated in the core is passed through the primary side of the exchanger, while feedwater is passed through the secondary side. The cooler is disposed on the downstream of the heat exchanger in the flowing direction of the heavy water, in which heavy water from the heat exchanger is passed through the primary side and the auxiliary equipment cooling water is sent to the secondary side thereof. Accordingly, since extraction of heating steams is no more necessary, the steam can be used for the rotation of the turbine, and the electrical power generation efficiency can be improved. (Seki, T.)

  10. Pressure vessel design

    International Nuclear Information System (INIS)

    Annaratone, D.

    2007-01-01

    This book guides through general and fundamental problems of pressure vessel design. It moreover considers problems which seem to be of lower importance but which turn out to be crucial in the design phase. The basic approach is rigorously scientific with a complete theoretical development of the topics treated, but the analysis is always pushed so far as to offer concrete and precise calculation criteria that can be immediately applied to actual designs. This is accomplished through appropriate algorithms that lead to final equations or to characteristic parameters defined through mathematical equations. The first chapter describes how to achieve verification criteria, the second analyzes a few general problems, such as stresses of the membrane in revolution solids and edge effects. The third chapter deals with cylinders under pressure from the inside, while the fourth focuses on cylinders under pressure from the outside. The fifth chapter covers spheres, and the sixth is about all types of heads. Chapter seven discusses different components of particular shape as well as pipes, with special attention to flanges. The eighth chapter discusses the influence of holes, while the ninth is devoted to the influence of supports. Finally, chapter ten illustrates the fundamental criteria regarding fatigue analysis. Besides the unique approach to the entire work, original contributions can be found in most chapters, thanks to the author's numerous publications on the topic and to studies performed ad hoc for this book. (orig.)

  11. The 30-year evolution of airway pressure release ventilation (APRV).

    Science.gov (United States)

    Jain, Sumeet V; Kollisch-Singule, Michaela; Sadowitz, Benjamin; Dombert, Luke; Satalin, Josh; Andrews, Penny; Gatto, Louis A; Nieman, Gary F; Habashi, Nader M

    2016-12-01

    Airway pressure release ventilation (APRV) was first described in 1987 and defined as continuous positive airway pressure (CPAP) with a brief release while allowing the patient to spontaneously breathe throughout the respiratory cycle. The current understanding of the optimal strategy to minimize ventilator-induced lung injury is to "open the lung and keep it open". APRV should be ideal for this strategy with the prolonged CPAP duration recruiting the lung and the minimal release duration preventing lung collapse. However, APRV is inconsistently defined with significant variation in the settings used in experimental studies and in clinical practice. The goal of this review was to analyze the published literature and determine APRV efficacy as a lung-protective strategy. We reviewed all original articles in which the authors stated that APRV was used. The primary analysis was to correlate APRV settings with physiologic and clinical outcomes. Results showed that there was tremendous variation in settings that were all defined as APRV, particularly CPAP and release phase duration and the parameters used to guide these settings. Thus, it was impossible to assess efficacy of a single strategy since almost none of the APRV settings were identical. Therefore, we divided all APRV studies divided into two basic categories: (1) fixed-setting APRV (F-APRV) in which the release phase is set and left constant; and (2) personalized-APRV (P-APRV) in which the release phase is set based on changes in lung mechanics using the slope of the expiratory flow curve. Results showed that in no study was there a statistically significant worse outcome with APRV, regardless of the settings (F-ARPV or P-APRV). Multiple studies demonstrated that P-APRV stabilizes alveoli and reduces the incidence of acute respiratory distress syndrome (ARDS) in clinically relevant animal models and in trauma patients. In conclusion, over the 30 years since the mode's inception there have been no strict

  12. O volume expiratório forçado no primeiro segundo não é suficiente para avaliar resposta broncodilatadora em doença pulmonar obstrutiva crônica Measuring forced expiratory volume in one second alone is not an accurate method of assessing response to bronchodilators in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Felícia de Moraes Branco Tavares

    2005-10-01

    Full Text Available OBJETIVO: Avaliar a freqüência de variação no volume expiratório forçado no primeiro segundo após o uso de broncodilatador, em uma amostra de pacientes com doença pulmonar obstrutiva crônica. Correlacioná-la com dados clínicos e demográficos e avaliar a freqüência de resposta na capacidade vital forçada, capacidade vital lenta, capacidade inspiratória, volume residual, resistência das vias áreas e condutância das vias aéreas. MÉTODOS: Sessenta e quatro pacientes com doença pulmonar obstrutiva crônica foram submetidos a pletismografia de corpo inteiro e foi medida a reversibilidade da broncoconstrição após o uso de 400 µg de fenoterol. RESULTADOS: Tiveram resposta no volume expiratório forçado no primeiro segundo 31% dos pacientes. Excluindo-se os pacientes com resposta no volume expiratório forçado no primeiro segundo, 5% tiveram resposta em 5 dos demais parâmetros, 10% responderam em 4 parâmetros, 17,5% em 3, 27,5% em 2 e 25% em apenas 1 parâmetro. CONCLUSÃO: Os volumes pulmonares estáticos, a resistência e a condutância das vias aéreas, quando incluídos na avaliação da resposta ao broncodilatador juntamente com o volume expiratório forçado no primeiro segundo, permitem avaliar com maior amplitude o número de pacientes com resposta funcional à prova farmacodinâmica. Os resultados estão de acordo com a observação de que muitos pacientes com doença pulmonar obstrutiva crônica, mesmo sem melhora no volume expiratório forçado no primeiro segundo após o uso de broncodilatador, apresentam melhora clínica e alívio da dispnéia.OBJECTIVE: To assess the frequency of variation in forced expiratory volume in one second after bronchodilator use in a sample of patients with chronic obstructive pulmonary disease, correlating such variation with clinical and demographic variables and evaluating the frequency of response presented in forced vital capacity, slow vital capacity, inspiratory capacity

  13. Pressurized thermal shock (PTS)

    International Nuclear Information System (INIS)

    Rosso, Ricardo D.; Ventura, Mirta A.

    2006-01-01

    In the present work, a description of Thermal Shock in Pressurized conditions (PTS), and its influence in the treatment of the integrity of the pressure vessel (RPV) of a Pressurized Water Reactor (PWR) and/or of a Heavy water Pressurized water Reactor (PHWR) is made. Generally, the analysis of PTS involves a process of three stages: a-) Modeling with a System Code of relevant thermohydraulics transients in reference with the thermal shock; b-) The local distribution of temperatures in the downcomer and the heat transference coefficients from the RPV wall to the fluid, are determined; c-) The fracture mechanical analysis. These three stages are included in this work: Results with the thermohydraulics code Relap5/mod.3, are obtained, for a LOCA scenario in the hot leg of the cooling System of the Primary System of the CAN-I reactor. The method used in obtaining results is described. A study on the basis of lumped parameters of the local evolutions of the temperature of the flow is made, in the downcomer of the reactor pressure vessel. The purpose of this study is to determine how the intensification of the stress coefficient, varies in function of the emergency injected water during the thermohydraulic transients that take place under the imposed conditions in the postulated scene. Specially, it is considered a 50 cm 2 break, located in the neighborhoods of the pressurized with the corresponding hot leg connection. This size is considered like the most critical. The method used to obtain the results is described. The fracture mechanical analysis is made. From the obtained results we confirmed that we have a simple tool of easy application in order to analyze phenomena of the type PTS in the postulated scenes by break in the cold and hot legs of the primary system. This methodology of calculus is completely independent of the used ones by the Nucleoelectrica Argentina S.A. (NASA) in the analysis of the PTS phenomena in the CAN-I. The results obtained with the adopted

  14. Pressure-Application Device for Testing Pressure Sensors

    Science.gov (United States)

    2002-01-01

    A portable pressure-application device has been designed and built for use in testing and calibrating piezoelectric pressure transducers in the field. The device generates pressure pulses of known amplitude. A pressure pulse (in contradistinction to a steady pressure) is needed because in the presence of a steady pressure, the electrical output of a piezoelectric pressure transducer decays rapidly with time. The device includes a stainless- steel compressed-air-storage cylinder of 500 cu cm volume. A manual hand pump with check valves and a pressure gauge are located at one end of the cylinder. A three-way solenoid valve that controls the release of pressurized air is located at the other end of the cylinder. Power for the device is provided by a 3.7-V cordless-telephone battery. The valve is controlled by means of a pushbutton switch, which activates a 5 V to +/-15 V DC-to-DC converter that powers the solenoid. The outlet of the solenoid valve is connected to the pressure transducer to be tested. Before the solenoid is energized, the transducer to be tested is at atmospheric pressure. When the solenoid is actuated by the push button, pressurized air from inside the cylinder is applied to the transducer. Once the pushbutton is released, the cylinder pressure is removed from the transducer and the pressurized air applied to the transducer is vented, bringing the transducer back to atmospheric pressure. Before this device was used for actual calibration, its accuracy was checked with a NIST (National Institute of Standards and Technology) traceable calibrator and commercially calibrated pressure transducers. This work was done by Wanda Solano of Stennis Space Center and Greg Richardson of Lockheed Martin Corp.

  15. Revised National Pressure Ulcer Advisory Panel Pressure Injury Staging System

    OpenAIRE

    Edsberg, Laura E.; Black, Joyce M.; Goldberg, Margaret; McNichol, Laurie; Moore, Lynn; Sieggreen, Mary

    2016-01-01

    Our understanding of pressure injury etiology and development has grown in recent years through research, clinical expertise, and global interdisciplinary expert collaboration. Therefore, the National Pressure Ulcer Advisory Panel (NPUAP) has revised the definition and stages of pressure injury. The revision was undertaken to incorporate the current understanding of the etiology of pressure injuries, as well as to clarify the anatomical features present or absent in each stage of injury. An N...

  16. Aschroft Pressure Switch - Monitor for Low SCHe Supply Bottle Pressure

    International Nuclear Information System (INIS)

    VAN KATWIJK, C.

    2000-01-01

    These pressure switches are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. The switches monitor the SCHe supply bottle pressure and are set to alarm at 2200 psig. There is one switch for each SCHe supply (4). Electronic output signal is NON-SAFETY (GS)

  17. Social Stress Induced Pressure Breathing and Consequent Blood Pressure Oscillation

    NARCIS (Netherlands)

    Fokkema, Dirk S.; Koolhaas, Jaap M.; Meulen, Jan van der; Schoemaker, Regien

    1986-01-01

    A large amplitude blood pressure oscillation occurs during social defeat in a territorial fight between male rats, and during the application of a psychosocial stimulus associated with this defeat. Synchronous recording of blood pressure, intrathoracic pressure and diaphragm activity shows that the

  18. Estimation of vapour pressure and partial pressure of subliming ...

    Indian Academy of Sciences (India)

    Administrator

    conditions of (total) pressure by using thermogravimetry under those conditions. Further, from the partial pressure P, it is possible to determine the number of moles of material in the vapour phase using the ideal gas equation, PV = nRT, where P is the partial pressure, V the volume, n number of moles (of the vapour), R the ...

  19. Relationships between fluid pressure and capillary pressure in ...

    African Journals Online (AJOL)

    In this work, the Bower's and Gardner's technique of velocity-to fluid pressure gradient methods were applied on seismic reflection data in order to predict fluid pressure of an X- oil field in Niger Delta Basin. Results show significant deflection common with fluid pressure zones . With average connate water saturation Swc ...

  20. Delay Pressure Detection Method to Eliminate Pump Pressure Interference on the Downhole Mud Pressure Signals

    Directory of Open Access Journals (Sweden)

    Yue Shen

    2013-01-01

    Full Text Available The feasibility of applying delay pressure detection method to eliminate mud pump pressure interference on the downhole mud pressure signals is studied. Two pressure sensors mounted on the mud pipe in some distance apart are provided to detect the downhole mud continuous pressure wave signals on the surface according to the delayed time produced by mud pressure wave transmitting between the two sensors. A mathematical model of delay pressure detection is built by analysis of transmission path between mud pump pressure interference and downhole mud pressure signals. Considering pressure signal transmission characteristics of the mud pipe, a mathematical model of ideal low-pass filter for limited frequency band signal is introduced to study the pole frequency impact on the signal reconstruction and the constraints of pressure sensor distance are obtained by pole frequencies analysis. Theoretical calculation and numerical simulation show that the method can effectively eliminate mud pump pressure interference and the downhole mud continuous pressure wave signals can be reconstructed successfully with a significant improvement in signal-to-noise ratio (SNR in the condition of satisfying the constraints of pressure sensor distance.

  1. Blood pressure monitors for home

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007482.htm Blood pressure monitors for home To use the sharing features ... may ask you to keep track of your blood pressure at home. To do this, you will need ...

  2. Common High Blood Pressure Myths

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Common High Blood Pressure Myths Updated:May 4,2018 Knowing the facts ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  3. Blood Pressure vs. Heart Rate

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Blood Pressure vs. Heart Rate (Pulse) Updated:Nov 13,2017 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  4. Silicon pressure transducers: a review

    International Nuclear Information System (INIS)

    Aceves M, M.; Sandoval I, F.

    1994-01-01

    We present a review of the pressure sensors, which use the silicon piezo resistive effect and micro machining technique. Typical pressure sensors, applications, design and other different structures are presented. (Author)

  5. Human gallbladder pressure and volume

    DEFF Research Database (Denmark)

    Borly, L; Højgaard, L; Grønvall, S

    1996-01-01

    volume with only slight changes in intraluminal pressure (n = 4). Except for the zero drift, this piece of equipment seemed to fulfil the requirements of being able to measure pressure in the GB. In vivo measurements showed a good clinical reproducibility of the method, and also that respiration...... influenced by respiration (n = 8) and the pressure seems to be higher in the sitting position than in the supine position (n = 5). Cystic duct opening pressure was 10.4, 11.2 and 16.8 mmHg (n = 3). Pressure-volume responses showed that the GB up to a certain volume could accommodate increases in intraluminal...... and patient posture influenced the pressure measurements. Further, a GB pressure-volume relationship was demonstrated, and the possibility of a cystic duct opening pressure was described....

  6. High Blood Pressure in Pregnancy

    Science.gov (United States)

    ... of the baby. Controlling your blood pressure during pregnancy and getting regular prenatal care are important for ... your baby. Treatments for high blood pressure in pregnancy may include close monitoring of the baby, lifestyle ...

  7. Continuous Positive Airway Pressure (CPAP)

    Science.gov (United States)

    ... ENT Doctor Near You Continuous Positive Airway Pressure (CPAP) Continuous Positive Airway Pressure (CPAP) Patient Health Information ... relations staff at newsroom@entnet.org . What Is CPAP? The most common and effective nonsurgical treatment for ...

  8. Wrinkling of Pressurized Elastic Shells

    KAUST Repository

    Vella, Dominic; Ajdari, Amin; Vaziri, Ashkan; Boudaoud, Arezki

    2011-01-01

    We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells

  9. Medications for High Blood Pressure

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Medications for High Blood Pressure Share Tweet Linkedin Pin it More sharing options ... age and you cannot tell if you have high blood pressure by the way you feel, so have your ...

  10. High blood pressure and diet

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007483.htm High blood pressure and diet To use the sharing features on ... diet is a proven way to help control high blood pressure . These changes can also help you lose weight ...

  11. Saltstone Osmotic Pressure

    International Nuclear Information System (INIS)

    Nichols, Ralph L.; Dixon, Kenneth L.

    2013-01-01

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency 3 , KNO 3 , Na 3 PO 4 x12H 2 O, and K 3 PO 4 when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that

  12. A temperature and pressure controlled calibration system for pressure sensors

    Science.gov (United States)

    Chapman, John J.; Kahng, Seun K.

    1989-01-01

    A data acquisition and experiment control system capable of simulating temperatures from -184 to +220 C and pressures either absolute or differential from 0 to 344.74 kPa is developed to characterize silicon pressure sensor response to temperature and pressure. System software is described that includes sensor data acquisition, algorithms for numerically derived thermal offset and sensitivity correction, and operation of the environmental chamber and pressure standard. This system is shown to be capable of computer interfaced cryogenic testing to within 1 C and 34.47 Pa of single channel or multiplexed arrays of silicon pressure sensors.

  13. Urodynamic pressure sensor

    Science.gov (United States)

    Moore, Thomas

    1991-01-01

    A transducer system was developed for measuring the closing pressure profile along the female urethra, which provides up to five sensors within the functional length of the urethra. This new development is an improvement over an earlier measurement method that has a smaller sensor area and was unable to respond to transient events. Three sensors were constructed; one of them was subjected to approximately eight hours of use in a clinical setting during which 576 data points were obtained. The complete instrument system, including the signal conditioning electronics, data acquisition unit, and the computer with its display and printer is described and illustrated.

  14. Pressure vessel lid

    International Nuclear Information System (INIS)

    Schoening, J.; Elter, C.; Becker, G.; Pertiller, S.

    1986-01-01

    The invention concerns a lid for closing openings in reactor pressure vessels containing helium, which is made as a circular casting with hollow spaces and a flat floor and is set on the opening and kept down. It consists of helium-tight metal cast material with sufficient temperature resistance. There are at least two concentric heat resistant seals let into the bottom of the lid. The bottom is in immediate contact with the container atmosphere and has hollow spaces in its inside in the area opposite to the opening. (orig./HP) [de

  15. Saltstone Osmotic Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, Ralph L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, Kenneth L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRN

    2013-09-23

    Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR- 2013-0004.

  16. Fifty Years of Research in ARDS. Respiratory Mechanics in Acute Respiratory Distress Syndrome.

    Science.gov (United States)

    Henderson, William R; Chen, Lu; Amato, Marcelo B P; Brochard, Laurent J

    2017-10-01

    Acute respiratory distress syndrome is a multifactorial lung injury that continues to be associated with high levels of morbidity and mortality. Mechanical ventilation, although lifesaving, is associated with new iatrogenic injury. Current best practice involves the use of small Vt, low plateau and driving pressures, and high levels of positive end-expiratory pressure. Collectively, these interventions are termed "lung-protective ventilation." Recent investigations suggest that individualized measurements of pulmonary mechanical variables rather than population-based ventilation prescriptions may be used to set the ventilator with the potential to improve outcomes beyond those achieved with standard lung protective ventilation. This review outlines the measurement and application of clinically applicable pulmonary mechanical concepts, such as plateau pressures, driving pressure, transpulmonary pressures, stress index, and measurement of strain. In addition, the concept of the "baby lung" and the utility of dynamic in addition to static measures of pulmonary mechanical variables are discussed.

  17. The antigravity suit in neurosurgery. Cardiovascular responses in seated neurosurgical patients.

    Science.gov (United States)

    Brodrick, P M; Ingram, G S

    1988-09-01

    The haemodynamic responses associated with inflation of the antigravity suit (G suit, aviation type) to 8.0 kPa were studied in a series of 40 patients who underwent neurosurgical operations in the sitting position. The study showed statistically significant increases in systolic arterial pressure (p less than 0.005) and mean central venous pressure (p less than 0.001) with inflation of the suit. The systolic arterial and mean central venous pressures remained significantly elevated immediately before deflation of the suit at the end of the operation (p less than 0.001 and p less than 0.005 respectively). The addition of 0.8-1.0 kPa positive end expiratory pressure during suit inflation was also investigated. A further increase in central venous pressure occurred but this did not achieve statistical significance.

  18. Types of Blood Pressure Medications

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Types of Blood Pressure Medications Updated:Nov 6,2017 Prescription blood pressure ... This content was last reviewed October 2017. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  19. Micromachined pressure/flow-sensor

    NARCIS (Netherlands)

    Oosterbroek, R.E.; Lammerink, Theodorus S.J.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt; van den Berg, Albert

    1999-01-01

    The micromechanical equivalent of a differential pressure flow-sensor, well known in macro mechanics, is discussed. Two separate pressure sensors are used for the device, enabling to measure both, pressure as well as volume flow-rate. An integrated sensor with capacitive read-out as well as a

  20. Helping Teens Resist Sexual Pressure

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Helping Teens Resist Sexual Pressure Page Content Article Body Teens are more ... younger the first time they had intercourse. Helping Teens Resist Sexual Pressure “The pressure on teenagers to have sex ...

  1. Pressure Safety: Advanced Live 11459

    Energy Technology Data Exchange (ETDEWEB)

    Glass, George [Los Alamos National Laboratory

    2016-03-02

    Many Los Alamos National Laboratory (LANL) operations use pressure equipment and systems. Failure to follow proper procedures when designing or operating pressure systems can result in injuries to personnel and damage to equipment and/or the environment. This manual presents an overview of the requirements and recommendations that address the safe design and operation of pressure systems at LANL.

  2. The Myth of Peer Pressure.

    Science.gov (United States)

    Ungar, Michael T.

    2000-01-01

    The construct of peer pressure was examined as part of a qualitative study of the determinants of mental health for 41 high-risk adolescents. While the concept of peer pressure enables adults to explain youths' troubling behaviors, content analysis of the participants' accounts of their lives reveals peer pressure to be a myth. (Author/MKA)

  3. Controlling your high blood pressure

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000101.htm Controlling your high blood pressure To use the sharing features on this page, ... JavaScript. Hypertension is another term used to describe high blood pressure. High blood pressure can lead to: Stroke Heart ...

  4. Pressure transients in pipeline systems

    DEFF Research Database (Denmark)

    Voigt, Kristian

    1998-01-01

    This text is to give an overview of the necessary background to do investigation of pressure transients via simulations. It will describe briefly the Method of Characteristics which is the defacto standard for simulating pressure transients. Much of the text has been adopted from the book Pressur...

  5. Hydrostatic pressure mimics gravitational pressure in characean cells

    Science.gov (United States)

    Staves, M. P.; Wayne, R.; Leopold, A. C.

    1992-01-01

    Hydrostatic pressure applied to one end of a horizontal Chara cell induces a polarity of cytoplasmic streaming, thus mimicking the effect of gravity. A positive hydrostatic pressure induces a more rapid streaming away from the applied pressure and a slower streaming toward the applied pressure. In contrast, a negative pressure induces a more rapid streaming toward and a slower streaming away from the applied pressure. Both the hydrostatic pressure-induced and gravity-induced polarity of cytoplasmic streaming respond identically to cell ligation, UV microbeam irradiation, external Ca2+ concentrations, osmotic pressure, neutral red, TEA Cl-, and the Ca2+ channel blockers nifedipine and LaCl3. In addition, hydrostatic pressure applied to the bottom of a vertically-oriented cell can abolish and even reverse the gravity-induced polarity of cytoplasmic streaming. These data indicate that both gravity and hydrostatic pressure act at the same point of the signal transduction chain leading to the induction of a polarity of cytoplasmic streaming and support the hypothesis that characean cells respond to gravity by sensing a gravity-induced pressure differential between the cell ends.

  6. Serial blood pressure measurements

    Directory of Open Access Journals (Sweden)

    N.R. Koehler

    2002-05-01

    Full Text Available The objective of the present investigation was to study the effects of a 60-s interval of venous congestion between two noninvasive measurements of arterial blood pressure (ABP on the fluctuation of ABP, assessed by the standard deviation of the differences between two readings. ABP was measured in 345 successive patients, at rest, four times each. For 269 participants, one pair of readings was obtained with a 60-s interval and the other pair without an interval. For 76 patients, the first pair was read at the same interval, and the second pair had venous congestion interposed and there was no waiting interval. There was no increased ABP oscillation, either when there was no interval between ABP readings, or when venous congestion was interposed compared to pairs of ABP measurements performed with a 60-s interval. There was no increase in ABP oscillations when successive ABP readings were taken without an interval or even with venous congestion interposed. Contrary to the present belief, there seems to be no loss of reliability when blood pressure recordings are taken immediately one after another, in the clinical setting.

  7. Impact of continuous positive airway pressure on the pulmonary changes promoted by immersion in water

    Directory of Open Access Journals (Sweden)

    Danize Aparecida Rizzetti

    Full Text Available ABSTRACT Objective: To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. Methods: This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP; CPAP5 (CPAP at 5 cmH2O; and CPAP10 (CPAP at 10 cmH2O. We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR, and FEF25-75% at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. Results: We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. Conclusions: When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.

  8. Impact of continuous positive airway pressure on the pulmonary changes promoted by immersion in water.

    Science.gov (United States)

    Rizzetti, Danize Aparecida; Quadros, Janayna Rodembuch Borba; Ribeiro, Bruna Esmerio; Callegaro, Letícia; Veppo, Aline Arebalo; Wiggers, Giulia Alessandra; Peçanha, Franck Maciel

    2017-01-01

    To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP); CPAP5 (CPAP at 5 cmH2O); and CPAP10 (CPAP at 10 cmH2O). We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR), and FEF25-75%) at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.

  9. The effect of pressure-controlled inverse ratio ventilation on lung protection in obese patients undergoing gynecological laparoscopic surgery.

    Science.gov (United States)

    Xu, Lili; Shen, Jianjun; Yan, Min

    2017-10-01

    To examine the effects of pressure-controlled inverse ratio ventilation (PCIRV) and volume-control ventilation (VCV) on arterial oxygenation, pulmonary function, hemodynamics, levels of surfactant protein A (SP-A), and tumor necrosis factor-α (TNF-α) in obese patients undergoing gynecological laparoscopic surgery. Sixty patients, body mass index (BMI) ≥30 kg/m 2 , scheduled for elective gynecological laparoscopic surgery were enrolled in the study. Patients were randomly allocated to receive either PCIRV with an inspiratory-expiratory (I:E) ratio of 1.5:1 (PCIRV group n = 30) or VCV with an I:E ratio of 1:2 (VCV group n = 30). Ventilation variables, viz. tidal volume (V T ), dynamic respiratory-system compliance (C RS ), driving pressure (ΔP = V T /C RS ), arterial blood oxygen partial pressure/fraction of inspiration oxygen (PaO 2 /FiO 2 ) and arterial blood carbon dioxide partial pressure (PaCO 2 ), were measured. Hemodynamic variables, viz. mean arterial pressure (MAP), heart rate (HR), and serum levels of SP-A and TNF-α, were also measured. When compared to patients in the VCV group, patients in the PCIRV group had higher V T , dynamic C RS , and PaO 2 /FiO 2 , and lower ΔP and PaCO 2 at 20 and 60 min after the start of pneumoperitoneum (p ventilation, promote gas exchange and oxygenation, and is associated with decreased levels of SP-A and TNF-α. These effects demonstrate improved lung protection provided by PCIRV in this patient population.

  10. ORANGE JUICE AND BLOOD PRESSURE

    Directory of Open Access Journals (Sweden)

    M. F. VALIM

    2009-01-01

    Full Text Available

    Blood pressure is the force of blood against artery walls. It is measured in millimeters of mercury (mm Hg and recorded as two numbers: systolic pressure (as the heart contracts over diastolic pressure (as the heart relaxes between beats. High blood pressure (hypertension is defined as chronically elevated high blood pressure, with systolic blood pressure (SBP of 140 mm Hg or greater, and diastolic blood pressure (DBP of 90 mm Hg or greater. High blood pressure (HBP, smoking, abnormal blood lipid levels, obesity and diabetes are risk factors for coronary heart disease, the leading cause of death in the US. Lifestyle modifications such as engaging in regular physical activity, quitting smoking and eating a healthy diet (limiting intake of saturated fat and sodium and increasing consumption of fiber, fruits and vegetables are advocated for the prevention, treatment, and control of HBP. As multiple factors influence blood pressure, the effects of each factor are typically modest, particularly in normotensive subjects, yet the combined effects can be substantial. Nutrition plays an important role in influencing blood pressure. Orange juice should be included as part of any low sodium diet and/or any blood pressure reducing eating plan, as it is sodium free, fat-free and can help meet recommended levels of potassium intake that may contribute to lower BP.

  11. The vapor pressures of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  12. Pressure Measurement Sensor

    Science.gov (United States)

    1997-01-01

    FFPI Industries Inc. is the manufacturer of fiber-optic sensors that furnish accurate pressure measurements in internal combustion chambers. Such an assessment can help reduce pollution emitted by these engines. A chief component in the sensor owes its seven year- long development to Lewis Research Center funding to embed optical fibers and sensors in metal parts. NASA support to Texas A&M University played a critical role in developing this fiber optic technology and led to the formation of FFPI Industries and the production of fiber sensor products. The simple, rugged design of the sensor offers the potential for mass production at low cost. Widespread application of the new technology is forseen, from natural gas transmission, oil refining and electrical power generation to rail transport and the petrochemical paper product industry.

  13. EPR (European Pressurized Reactor)

    International Nuclear Information System (INIS)

    2015-01-01

    This document presents the EPR (European Pressurized Reactor), a modernised version of PWRs which uses nuclear fission. It indicates to which category it belongs (third generation). It briefly describes its operation: recalls on nuclear fission, electricity production in a nuclear reactor. It presents and comments its characteristics: power, thermal efficiency, redundant systems for safety control, double protective enclosure, expected lifetime, use of MOX fuel, modular design. It discusses economic stakes (expected higher nuclear electricity competitiveness, but high construction costs), and safety challenges (design characteristics, critics by nuclear safety authorities about the safety data processing system). It presents the main involved actors (Areva, EDF) and competitors in the field of advanced reactors (Rosatom with its VVER 1200, General Electric with its ABWR and its ESBWR, Mitsubishi with its APWR, Westinghouse with its AP100) while outlining the importance of certifications and delays to obtain them. After having evoked key data on EPR fuel consumption, it indicates reactors under construction, evokes potential markets and perspectives

  14. Reactor pressure vessel embrittlement

    International Nuclear Information System (INIS)

    1992-07-01

    Within the framework of the IAEA extrabudgetary programme on the Safety of WWER-440/230 NPPs, a list of safety issues requiring broad studies of generic interest have been agreed upon by an Advisory Group who met in Vienna in September 1990. The list was later revised in the light of the programme findings. The information on the status of the issues, and on the amount of work already completed and under way in the various countries, needs to be compiled. Moreover, an evaluation of what further work is required to resolve each one of the issues is also necessary. In view of this, the IAEA has started the preparation of a series of status reports on the various issues. This report on the generic safety issue ''Reactor Pressure Vessel Embrittlement'' presents a comprehensive survey of technical information available in the field and identifies those aspects which require further investigation. 39 refs, 21 figs, 4 tabs

  15. From Pressures to Impacts

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky

    2006-01-01

    materials over manufacture or construction through use to disposal or decommissioning and recycling. It is a holistic tool in the sense that it models all relevant environmental impacts from the global (like climate change and ozone depletion) to the local (like land use) and also the loss of resources......Life cycle assessment (LCA) has been developed as a tool for assessment of the environmental impacts which are caused by the pressures from products or systems, viewed in a life cycle perspective, i.e. covering all stages of the life cycle of the product or system from the extraction of raw...... is defined, Inventory analysis where data for the physical flows to and from all processes in the life cycle is collected and related to the functional unit, Impact assessment, where the physical flows are translated into impacts on the environment and resource base, and Interpretation where the outcomes...

  16. Pressure tube reactor

    International Nuclear Information System (INIS)

    Matsumoto, Tomoyuki; Fujino, Michihira.

    1980-01-01

    Purpose: To equalize heavy water flow distribution by providing a nozzle for externally injecting heavy water from a vibration preventive plate to the upper portion to feed the heavy water in a pressure tube reactor and swallowing up heavy water in a calandria tank to supply the heavy water to the reactor core above the vibration preventive plate. Constitution: A moderator injection nozzle is mounted on the inner wall of a calandria tank. Heavy water is externally injected above the vibration preventive plate, and heavy water in the calandria tank is swallowed up to supply the heavy water to the core reactor above the vibration preventive plate. Therefore, the heavy water flow distribution can be equalized over the entire reactor core, and the distribution of neutron absorber dissolved in the heavy water is equalized. (Yoshihara, H.)

  17. High pressure mechanical seal

    Science.gov (United States)

    Babel, Henry W. (Inventor); Anderson, Raymond H. (Inventor)

    1996-01-01

    A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test.

  18. Farmers under pressure

    DEFF Research Database (Denmark)

    Andrade, Stefan Bastholm; Anneberg, Inger

    2013-01-01

    In this paper we analyse how risk factors in highly industrialised agriculture are connected to animal neglect. With Danish agriculture as a case study, we use two types of data. First, we use register data from Statistics Denmark to map how risk factors such as farmers’ financial and social trou...... and a growing concern among the farmers towards the governmental control in farm animal production. We discuss how these factors can be used to identify and help farmers with a high risk of being convicted of livestock neglect....... of them face severe financial difficulties, divorce and psychiatric problems, which are connected to an increased risk of being convicted for the neglect of farm animals. The narratives bring forward themes of pressure related to financial trouble, technological break down, family problems, stress...

  19. Parent-Pressure

    DEFF Research Database (Denmark)

    Jensen, Helle Strandgaard

    2016-01-01

    of parents as co-consumers prevailed despite radical changes in views on children’s media consumption. In particular, I examine the shared inter-Scandinavian socio-cultural contexts that structured the changing professional and political groups’ pressure on parents to perform according to their norms......In this article, I examine change and continuity in conceptions of parental agency in public debates about children’s media consumption in Scandinavia, 1945-1975. During this period, public debates about the various kinds of media products children consumed were dominated by different groups....... However, a strong continuity in the debates was the negative influence parents were seen as having on children’s media consumption due to their lack of insight and interest in the topic. Drawing upon recent works on children’s media, consumption and enculturation, I analyse why the negative description...

  20. Thermal stratification in the pressurizer

    International Nuclear Information System (INIS)

    Baik, S.J.; Lee, K.W.; Ro, T.S.

    2001-01-01

    The thermal stratification in the pressurizer due to the insurge from the hot leg to the pressurizer has been studied. The insurge flow of the cold water into the pressurizer takes place during the heatup/cooldown and the normal or abnormal transients during power operation. The pressurizer vessel can undergo significant thermal fatigue usage caused by insurges and outsurges. Two-dimensional axisymmetric transient analysis for the thermal stratification in the pressurizer is performed using the computational fluid dynamics code, FLUENT, to get the velocity and temperature distribution. Parametric study has been carried out to investigate the effect of the inlet velocity and the temperature difference between the hot leg and the pressurizer on the thermal stratification. The results show that the insurge flow of cold water into the pressurizer does not mix well with hot water, and the cold water remains only in the lower portion of the pressurizer, which leads to the thermal stratification in the pressurizer. The thermal load on the pressurizer due to the thermal stratification or the cyclic thermal transient should be examined with respect to the mechanical integrity and this study can serve the design data for the stress analysis. (authors)