An Annotated Bibliography of Hypobaric Decompression Sickness Research Conducted at the Crew Technology Division, USAF School of Aerospace Medicine, Brooks AFB, Texas from 1983 to 1988

Science.gov (United States)

1990-06-01

AN ANNOTATED BIBLIOGRAPHY OF HYPOBARIC DECOMPRESSION SICKNESS RESEARCH CONDUCTED AT THE CREW TECHNOLOGY DIVISION, USAF SCHOOL OF AEROSPACE MEDICINE...190 man-flights to four selected altitudes (30000, 27500, 25000, and 22500 ft pressure equivalent) in a hypobaric chamber. The subjects’ ages ranged...conditions and two of these developed delayed sy~rtcms. Three of these five subjects underwent hyperbaric oxygen treatment. Conclusion. Female subjects

Severe capillary leak syndrome after inner ear decompression sickness in a recreational scuba diver.

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Gempp, Emmanuel; Lacroix, Guillaume; Cournac, Jean-Marie; Louge, Pierre

2013-07-01

Post-decompression shock with plasma volume deficit is a very rare event that has been observed under extreme conditions of hypobaric and hyperbaric exposure in aviators and professional divers. We report a case of severe hypovolemic shock due to extravasation of plasma in a recreational scuba diver presenting with inner ear decompression sickness. Impaired endothelial function can lead to capillary leak with hemoconcentration and hypotension in severe cases. This report suggests that decompression-induced circulating bubbles may have triggered the endothelial damage, activating the classic inflammatory pathway of increased vascular permeability. This observation highlights the need for an accurate diagnosis of this potentially life-threatening condition at the initial presentation in the Emergency Department after a diving-related injury. An elevated hematocrit in a diver should raise the suspicion for the potential development of capillary leak syndrome requiring specific treatment using albumin infusion as primary fluid replacement. Copyright © 2013 Elsevier Inc. All rights reserved.

Exploiting Aerobic Fitness to Reduce Risk of Hypobaric Decompression Sickness

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Conkin, J.; Gernhardt, M. L.; Wessel, J. H.

2007-01-01

Decompression sickness (DCS) is multivariable. But we hypothesize an aerobically fit person is less likely to experience hypobaric DCS than an unfit person given that fitness is exploited as part of the denitrogenation (prebreathe, PB) process prior to an altitude exposure. Aerobic fitness is peak oxygen uptake (VO2pk, ml/kg/min). Treadmill or cycle protocols were used over 15 years to determine VO2pks. We evaluated dichotomous DCS outcome and venous gas emboli (VGE) outcome detected in the pulmonary artery with Doppler ultrasound associated with VO2pk for two classes of experiments: 1) those with no PB or PB under resting conditions prior to ascent in an altitude chamber, and 2) PB that included exercise for some part of the PB. There were 165 exposures (mean VO2pk 40.5 plus or minus 7.6 SD) with 25 cases of DCS in the first protocol class and 172 exposures (mean VO2pk 41.4 plus or minus 7.2 SD) with 25 cases of DCS in the second. Similar incidence of the DCS (15.2% vs. 14.5%) and VGE (45.5% vs. 44.8%) between the two classes indicates that decompression stress was similar. The strength of association between outcome and VO2pk was evaluated using univariate logistic regression. An inverse relationship between the DCS outcome and VO2pk was evident, but the relationship was strongest when exercise was done as part of the PB (exercise PB, coef. = -0.058, p = 0.07; rest or no PB, coef. = -0.005, p = 0.86). There was no relationship between VGE outcome and VO2pk (exercise PB, coef. = -0.003, p = 0.89; rest or no PB, coef. = 0.014, p = 0.50). A significant change in probability of DCS was associated with fitness only when exercise was included in the denitrogenation process. We believe a fit person that exercises during PB efficiently eliminates dissolved nitrogen from tissues.

Effect of metabolic gases and water vapor, perfluorocarbon emulsions, and nitric oxide on tissue bubbles during decompression sickness.

Science.gov (United States)

Randsøe, Thomas

2016-05-01

In aviation and diving, fast decrease in ambient pressure, such as during accidental loss of cabin pressure or when a diver decompresses too fast to sea level, may cause nitrogen (N2) bubble formation in blood and tissue resulting in decompression sickness (DCS). Conventional treatment of DCS is oxygen (O2) breathing combined with recompression.  However, bubble kinetic models suggest, that metabolic gases, i.e. O2 and carbon dioxide (CO2), and water vapor contribute significantly to DCS bubble volume and growth at hypobaric altitude exposures. Further, perfluorocarbon emulsions (PFC) and nitric oxide (NO) donors have, on an experimental basis, demonstrated therapeutic properties both as treatment and prophylactic intervention against DCS. The effect was ascribed to solubility of respiratory gases in PFC, plausible NO elicited nuclei demise and/or N2 washout through enhanced blood flow rate. Accordingly, by means of monitoring injected bubbles in exposed adipose tissue or measurements of spinal evoked potentials (SEPs) in anaesthetized rats, the aim of this study was to: 1) evaluate the contribution of metabolic gases and water vapor to bubble volume at different barometrical altitude exposures, 2) clarify the O2 contribution and N2 solubility from bubbles during administration of PFC at normo- and hypobaric conditions and, 3) test the effect of different NO donors on SEPs during DCS upon a hyperbaric air dive and, to study the influence of  NO on tissue bubbles at high altitude exposures. The results support the bubble kinetic models and indicate that metabolic gases and water vapor contribute significantly to bubble volume at 25 kPa (~10,376 m above sea level) and constitute a threshold for bubble stabilization or decay at the interval of 47-36 kPa (~6,036 and ~7,920 m above sea level). The effect of the metabolic gases and water vapor seemed to compromise the therapeutic properties of both PFC and NO at altitude, while PFC significantly increased bubble

Optic neuropathy following an altitude exposure.

Science.gov (United States)

Steigleman, Allan; Butler, Frank; Chhoeu, Austin; O'Malley, Timothy; Bower, Eric; Giebner, Stephen

2003-09-01

This case report describes a 20-yr-old man who presented with retro-orbital pain and blurred vision in his left eye 3 wk after an altitude exposure in a hypobaric chamber. He was found to have significant deficits in color vision and visual fields consistent with an optic neuropathy in his left eye. The patient was diagnosed with decompression sickness and treated with hyperbaric oxygen with a U.S. Navy Treatment Table VI. All signs and symptoms resolved with a single hyperbaric oxygen treatment but recurred. A head MRI revealed a left frontoethmoid sinus opacity. A concomitant sinusitis was diagnosed. The patient had full resolution of symptoms after a total of four hyperbaric oxygen treatments and antibiotic therapy at 6-wk follow-up. Although a para-infectious etiology for this patient's optic neuropathy cannot be excluded, his history of altitude exposure and significant, rapid response to hyperbaric oxygen treatment strongly implies decompression sickness in this case.

Decompression sickness in caisson workers

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Ghawabi, Samir H. El; Mansour, Mohamed B.; Youssef, Fatma L.; Ghawabi, Mohamed H. El; Latif, Mohamed M. Abd El

1971-01-01

El Ghawabi, S. H., Mansour, M. B., Youssef, F. L., El Ghawabi, M. H., and Abd El Latif, M. M. (1971).Brit. J. industr. Med.,28, 323-329. Decompression sickness in caisson workers. An investigation of 55 bridge construction workers is reported. The overall bends rate was 0·97%. (The term `bends' as used in this study is defined in the paper.) Chokes were encountered in 67·27% of workers. A clinical, haematological, and radiological study was performed. Definite bony changes were found in 43·6% of all workers; 91·6% of these had lesions around the elbow. The presence of dense areas in the neck of the scapula is reported in two cases for the first time. The relatively high haematocrit value is thought to play a part in the pathogenesis of bone infarction through its relation with blood viscosity. Images PMID:5124832

Threshold altitude for bubble decay and stabilization in rat adipose tissue at hypobaric exposures

DEFF Research Database (Denmark)

Randsoe, Thomas; Larsen, Ole Hyldegaard

2013-01-01

Bubble formation during altitude exposures, causing altitude decompression sickness (aDCS), has been referred to in theoretical models as venous gas embolisms (VGE). This has also been demonstrated by intravascular gas formation. Previous reports indicate that the formation of VGE and aDCS incide...

[Research on the incidence of decompression sickness in compressed air works. The development of its recent five years' study].

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Mano, Y; Shibayama, M; Matsui, Y

1987-07-01

Compressed air works have been used as the safest construction work for the basic underground or underwater compressed shield or caisson works in Japan; however, the workers who were exposed to the compressed fields must have put themselves at risk of decompression sickness. Decompression sickness is generally considered to be due to the bubble effects and the bubbles originate from the supersaturated gas dissolved in the blood and other tissues. The standard decompression schedule by the Ministry of Labor has been practically applied at the end of compressed air works, and the laborers decompress slowly from the bottom pressure to the surface according to the schedule. It is difficult to completely prevent the sickness and the average percentage of contracting "bends," using the Japanese standard decompression schedule, is considered to be 0.54%. But previous papers reported higher incidences from 1.42 to 3.3% or more. We have continued an actual investigation on the incidence, and the number of the exposed trials amounted to nearly a hundred thousand. These data were compared between recent five years' group and before. Eventually, it was ascertained that the incidence has been significantly decreased in the recent five years; however, greater care in occupational safety control is still needed.

A review of the influence of physical condition parameters on a typical aerospace stress effect: Decompression sickness

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West, V. R.; Parker, J. F., Jr.

1973-01-01

The study examines data on episodes of decompression sickness, particularly from recent Navy work in which the event occurred under multiple stress conditions, to determine the extent to which decompression sickness might be predicted on the basis of personal characteristics such as age, weight, and physical condition. Such information should ultimately be useful for establishing medical selection criteria to screen individuals prior to participation inactivities involving extensive changes in ambient pressure, including those encountered in space operations. The main conclusions were as follows. There is a definite and positive relationship between increasing age and weight and the likelihood of decompression sickness. However, for predictive purposes, the relationship is low. To reduce the risk of bends, particularly for older individuals, strenuous exercise should be avoided immediately after ambient pressure changes. Temperatures should be kept at the low end of the comfort zone. For space activities, pressure changes of over 6-7 psi should be avoided. Prospective participants in future missions such as the Space Shuttle should not be excluded on the basis of age, certainly to age 60, if their general condition is reasonably good and they are not grossly obese. (Modified author abstract)

Propranolol Effects on Decompression Sickness in a Simulated DISSUB Rescue in Swine.

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Forbes, Angela S; Regis, David P; Hall, Aaron A; Mahon, Richard T; Cronin, William A

2017-04-01

Disabled submarine (DISSUB) survivors may face elevated CO2 levels and inert gas saturation, putting them at risk for CO2 toxicity and decompression sickness (DCS). Propranolol was shown to reduce CO2 production in an experimental DISSUB model in humans but its effects on DCS in a DISSUB rescue scenario are unknown. A 100% oxygen prebreathe (OPB) reduces DCS incidence and severity and is incorporated into some DISSUB rescue protocols. We used a swine model of DISSUB rescue to study the effect of propranolol on DCS incidence and mortality with and without an OPB. In Experiment 1, male Yorkshire Swine (70 kg) were pressurized to 2.8 ATA for 22 h. Propranolol 1.0 mg · kg-1 (IV) was administered at 21.25 h. At 22 h, the animal was rapidly decompressed and observed for DCS type, onset time, and mortality. Experimental animals (N = 21; 69 ± 4.1 kg), PROP1.0, were compared to PROP1.0-OPB45 (N = 8; 69 ± 2.8 kg) with the same dive profile, except for a 45 min OPB prior to decompression. In Experiment 2, the same methodology was used with the following changes: swine pressurized to 2.8 ATA for 28 h; experimental group (N = 25; 67 ± 3.3 kg), PROP0.5 bis, propranolol 0.5 mg · kg-1 bis (twice) (IV) was administered at 22 h and 26 h. Control animals (N = 25; 67 ± 3.9 kg) received normal saline. OPB reduced mortality in PROP1.0-OBP45 compared to PROP1.0 (0% vs. 71%). PROP0.5 bis had increased mortality compared to CONTROL (60-% vs. 4%). Administration of beta blockers prior to saturation decompression appears to increase DCS and worsen mortality in a swine model; however, their effects in bounce diving remain unknown.Forbes AS, Regis DP, HallAA, Mahon RT, Cronin WA. Propranolol effects on decompression sickness in a simulated DISSUB rescue in swine. Aerosp Med Hum Perform. 2017; 88(4):385-391.

Central nervous system decompression sickness and venous gas emboli in hypobaric conditions.

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Balldin, Ulf I; Pilmanis, Andrew A; Webb, James T

2004-11-01

Altitude decompression sickness (DCS) that involves the central nervous system (CNS) is a rare but potentially serious condition. Identification of early symptoms and signs of this condition might improve treatment. We studied data from 26 protocols carried out in our laboratory over the period 1983-2003; all were designed to provoke DCS in a substantial proportion of subjects. The data set included 2843 cases. We classified subject-exposures that resulted in DCS as: 1) neurological DCS of peripheral and/or central origin (NEURO); 2) a subset of those that involved only the CNS (CNS); and 3) all other cases, i.e., DCS cases that did not have a neurological component (OTHER). For each case, echo imaging data were used to document whether venous gas emboli (VGE) were present, and their level was classified as: 1) any level, i.e., Grade 1 or higher (VGE-1); and 2) high level, Grade 4 (VGE-4). There were 1108 cases of altitude DCS in the database; 218 were classified as NEURO and 49 of those as CNS. VGE-1 were recorded in 83.8% of OTHER compared with 58.7% of NEURO and 55.1% of CNS (both p Hyperbaric oxygen (HBO) was used to treat about half of the CNS cases, while all other cases were treated with 2 h breathing 100% oxygen at ground level. Since only about half of the rare cases of hypobaric CNS DCS cases were accompanied by any level of VGE, echo imaging for bubbles may have limited application for use as a predictor of such cases.

Effect of oxygen-breathing during a decompression-stop on bubble-induced platelet activation after an open-sea air dive: oxygen-stop decompression.

Science.gov (United States)

Pontier, J-M; Lambrechts, K

2014-06-01

We highlighted a relationship between decompression-induced bubble formation and platelet micro-particle (PMP) release after a scuba air-dive. It is known that decompression protocol using oxygen-stop accelerates the washout of nitrogen loaded in tissues. The aim was to study the effect of oxygen deco-stop on bubble formation and cell-derived MP release. Healthy experienced divers performed two scuba-air dives to 30 msw for 30 min, one with an air deco-stop and a second with 100% oxygen deco-stop at 3 msw for 9 min. Bubble grades were monitored with ultrasound and converted to the Kisman integrated severity score (KISS). Blood samples for cell-derived micro-particle analysis (AnnexinV for PMP and CD31 for endothelial MP) were taken 1 h before and after each dive. Mean KISS bubble score was significantly lower after the dive with oxygen-decompression stop, compared to the dive with air-decompression stop (4.3 ± 7.3 vs. 32.7 ± 19.9, p air-breathing decompression stop, we observed an increase of the post-dive mean values of PMP (753 ± 245 vs. 381 ± 191 ng/μl, p = 0.003) but no significant change in the oxygen-stop decompression dive (329 ± 215 vs. 381 +/191 ng/μl, p = 0.2). For the post-dive mean values of endothelial MP, there was no significant difference between both the dives. The Oxygen breathing during decompression has a beneficial effect on bubble formation accelerating the washout of nitrogen loaded in tissues. Secondary oxygen-decompression stop could reduce bubble-induced platelet activation and the pro-coagulant activity of PMP release preventing the thrombotic event in the pathogenesis of decompression sickness.

Decompression sickness in a vegetarian diver: are vegetarian divers at risk? A case report

NARCIS (Netherlands)

van Hulst, Robert A.; van der Kamp, Wim

2010-01-01

We present a case of a diver who suffered decompression sickness (DCS), but who also was a strict vegetarian for more than 10 years. He presented with symptoms of tingling of both feet and left hand, weakness in both legs and sensory deficits for vibration and propriocepsis after two deep dives with

Protective effects of fluoxetine on decompression sickness in mice.

Directory of Open Access Journals (Sweden)

Jean-Eric Blatteau

Full Text Available Massive bubble formation after diving can lead to decompression sickness (DCS that can result in central nervous system disorders or even death. Bubbles alter the vascular endothelium and activate blood cells and inflammatory pathways, leading to a systemic pathophysiological process that promotes ischemic damage. Fluoxetine, a well-known antidepressant, is recognized as having anti-inflammatory properties at the systemic level, as well as in the setting of cerebral ischemia. We report a beneficial clinical effect associated with fluoxetine in experimental DCS. 91 mice were subjected to a simulated dive at 90 msw for 45 min before rapid decompression. The experimental group received 50 mg/kg of fluoxetine 18 hours before hyperbaric exposure (n = 46 while controls were not treated (n = 45. Clinical assessment took place over a period of 30 min after surfacing. At the end, blood samples were collected for blood cells counts and cytokine IL-6 detection. There were significantly fewer manifestations of DCS in the fluoxetine group than in the controls (43.5% versus 75.5%, respectively; p = 0.004. Survivors showed a better and significant neurological recovery with fluoxetine. Platelets and red cells were significantly decreased after decompression in controls but not in the treated mice. Fluoxetine reduced circulating IL-6, a relevant marker of systemic inflammation in DCS. We concluded that fluoxetine decreased the incidence of DCS and improved motor recovery, by limiting inflammation processes.

[Developing and testing of decompression regimes for caisson operations while constructing Moscow metro].

Science.gov (United States)

Rodchenkov, S V; Syrovegin, A V; Shulagin, I A

1996-01-01

Decompression regimes for caisson operations at the pressures up to 5 ata exceeding duration of the regimes specified in the caisson regulations have been developed. The regimes were tested and validated in dry altitude chamber with participation of exercising human subjects. Seventeen test-subjects took part in 54 tests. No symptoms of decompression sickness were documented. Air embolism was observed in 28 +/- 6% of cases at rest and in 72 +/- 6% of cases following provocative leg movements. The air embolism expression tended to increase with exposure to pressure.

2014 Decompression Sickness/Extravehicular Activity Risks Standing Review Panel

Science.gov (United States)

Steinberg, Susan; Mahon, Richard; Klaus, David; Neuman, Tom; Pilmanis, Andrew; Regis, David

2014-01-01

The 2014 Decompression Sickness (DCS)/Extravehicular Activity (EVA) Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on November 4 - 5, 2014. The SRP reviewed the Research Plans for The Risk of Decompression Sickness and the Risk of Injury and Compromised Performance due to EVA Operations, as well as the Evidence Reports for both of these Risks. The SRP found that the NASA DCS/EVA team did an excellent job of presenting their research plans. The SRP considers it critical that NASA proceeds with the high priority tasks identified in this report (DCS1, DCS3, DCS5). The highest priority is to determine the acceptable DCS and hypoxia risk associated with the planned human exploration beyond low Earth orbit. The risk of DCS is highly dependent upon the pressure within the exploration vehicle. If slightly more hypoxia is permitted then (even with the same percentage of oxygen) the pressure within the exploration vehicle can be lowered thus further mitigating the risk of DCS. The second highest priority is to test and validate the recommended 8.2psi/34% O2 atmosphere. Development of procedures and equipment for human exploration missions are very limited until the results of this testing are completed. The SRP also suggests that DCS7 be separated into two Gaps. Gap DCS7 should deal with DCS treatment while a new Gap should be created to deal with the long-term effects of DCS. The SRP also encourages NASA to increase collaboration with other organizations and pool resources where possible. The current NASA DCS/EVA team has the extensive expertise and a wealth of knowledge in this area. The SRP suggests that increased manpower for this team would be highly productive.

General introduction to altitude adaptation and mountain sickness

DEFF Research Database (Denmark)

Bartsch, P.; Saltin, B.

2008-01-01

ascent (average ascent rate 300 m/day above 2000 m a.s.l.), primarily in order to sleep and feel well, and minimize the risk of mountain sickness. A new classification of altitude levels based on the effects on performance and well-being is proposed and an overview given over the various modalities using...

Computed chest tomography in an animal model for decompression sickness: radiologic, physiologic, and pathologic findings

International Nuclear Information System (INIS)

Reuter, M.; Struck, N.; Heller, M.; Tetzlaff, K.; Brasch, F.; Mueller, K.M.; Gerriets, T.; Weiher, M.; Hansen, J.; Hirt, S.

2000-01-01

This study was conducted to investigate the early pulmonary effects of acute decompression in an animal model for human decompression sickness by CT and light microscopy. Ten test pigs were exposed to severe decompression stress in a chamber dive. Three pigs were kept at ambient pressure to serve as controls. Decompression stress was monitored by measurement of pulmonary artery pressure and arterial and venous Doppler recording of bubbles of inert gas. Chest CT was performed pre- and postdive and in addition the inflated lungs were examined after resection. Each lung was investigated by light microscopy. Hemodynamic data and bubble recordings reflected severe decompression stress in the ten test pigs. Computed tomography revealed large quantities of ectopic gas, predominantly intravascular, in three of ten pigs. These findings corresponded to maximum bubble counts in the Doppler study. The remaining test pigs showed lower bubble grades and no ectopic gas by CT. Sporadic interstitial edema was demonstrated in all animals - both test and control pigs - by CT of resected lungs and on histologic examination. A severe compression-decompression schedule can liberate large volumes of inert gas which are detectable by CT. Despite this severe decompression stress, which led to venous microembolism, CT and light microscopy did not demonstrate changes in lung structure related to the experimental dive. Increased extravascular lung water found in all animals may be due to infusion therapy. (orig.)

Air Break During Preoxygenation and Risk of Altitude Decompression Sickness

Science.gov (United States)

2010-10-01

examination and were representative of the USAF rated aircrew popula- tion. They were not allowed to participate in scuba div- ing, hyperbaric exposures, or...subjects dur- ing the hypobaric exposures and the subjects were not questioned about how they felt during the altitude ex- posures. Each subject was...to consult with the physicians in Hyperbaric Medicine within the same building. Endpoints of the exposures were: 1) comple- tion of the scheduled

Perfluorocarbon in Delayed Recompression with a Mixed Gender Swine Model of Decompression Sickness.

Science.gov (United States)

Cronin, William A; Hall, Aaron A; Auker, Charles R; Mahon, Richard T

2018-01-01

Perfluorocarbons (PFC) are fluorinated hydrocarbons that dissolve gases to a much greater degree than plasma and hold promise in treating decompression sickness (DCS). The efficacy of PFC in a mixed gender model of DCS and safety in recompression therapy has not been previously explored. Swine (25 kg; N = 104; 51 male and 53 female) were randomized into normal saline solution (NSS) or PFC emulsion treatment groups and subjected to compression on air in a hyperbaric chamber at 200 fsw for 31 min. Then the animals were decompressed and observed for signs of DCS. Afterwards, they were treated with oxygen and either PFC (4 cc · kg-1) or NSS (4 cc · kg-1). Surviving animals were observed for 4 h, at which time they underwent recompression therapy using a standard Navy Treatment Table 6. After 24 h the animals were assessed and then euthanized. Survival rates were not significantly different between NSS (74.04%) and PFC (66.67%) treatment groups. All swine that received recompression treatment survived to the end of the study and no seizures were observed in either PFC or NSS animals. Within the saline treated swine group there were no significant differences in DCS survival between male (75.00%, N = 24) and female (73.08%, N = 26) swine. Within the PFC treated swine, survival of females (51.85%, N = 27) was significantly lower than males (81.48%, N = 27). In this large animal mixed gender efficacy study in DCS, PFC did not improve mortality or spinal cord injury, but appears safe during recompressive therapy. Gender differences in DCS treatment with PFC will need further study.Cronin WA, Hall AA, Auker CR, Mahon RT. Perfluorocarbon in delayed recompression with a mixed gender swine model of decompression sickness. Aerosp Med Hum Perform. 2018; 89(1):14-18.

Pathophysiology of acute mountain sickness and high altitude pulmonary oedema

DEFF Research Database (Denmark)

Sutton, J R; Lassen, N

1979-01-01

We review the evidence that acute mountain sickness (AMS) and high altitude pulmonary oedema (HAPO) occur together more often than is realized. We hypothesize that AMS and HAPO have a common pathophysiological basis: both are due to increased pressure and flow in the microcirculation, causing...

Probabilistic Assessment of Hypobaric Decompression Sickness Treatment Success

Science.gov (United States)

Conkin, Johnny; Abercromby, Andrew F. J.; Dervay, Joseph P.; Feiveson, Alan H.; Gernhardt, Michael L.; Norcross, Jason R.; Ploutz-Snyder, Robert; Wessel, James H., III

2014-01-01

The Hypobaric Decompression Sickness (DCS) Treatment Model links a decrease in computed bubble volume from increased pressure (DeltaP), increased oxygen (O2) partial pressure, and passage of time during treatment to the probability of symptom resolution [P(symptom resolution)]. The decrease in offending volume is realized in 2 stages: a) during compression via Boyle's Law and b) during subsequent dissolution of the gas phase via the O2 window. We established an empirical model for the P(symptom resolution) while accounting for multiple symptoms within subjects. The data consisted of 154 cases of hypobaric DCS symptoms along with ancillary information from tests on 56 men and 18 women. Our best estimated model is P(symptom resolution) = 1 / (1+exp(-(ln(Delta P) - 1.510 + 0.795×AMB - 0.00308×Ts) / 0.478)), where (DeltaP) is pressure difference (psid), AMB = 1 if ambulation took place during part of the altitude exposure, otherwise AMB = 0; and where Ts is the elapsed time in mins from start of the altitude exposure to recognition of a DCS symptom. To apply this model in future scenarios, values of DeltaP as inputs to the model would be calculated from the Tissue Bubble Dynamics Model based on the effective treatment pressure: (DeltaP) = P2 - P1 | = P1×V1/V2 - P1, where V1 is the computed volume of a spherical bubble in a unit volume of tissue at low pressure P1 and V2 is computed volume after a change to a higher pressure P2. If 100% ground level O2 (GLO) was breathed in place of air, then V2 continues to decrease through time at P2 at a faster rate. This calculated value of (DeltaP then represents the effective treatment pressure at any point in time. Simulation of a "pain-only" symptom at 203 min into an ambulatory extravehicular activity (EVA) at 4.3 psia on Mars resulted in a P(symptom resolution) of 0.49 (0.36 to 0.62 95% confidence intervals) on immediate return to 8.2 psia in the Multi-Mission Space Exploration Vehicle. The P(symptom resolution) increased

Different effect of l-NAME treatment on susceptibility to decompression sickness in male and female rats.

Science.gov (United States)

Mazur, Aleksandra; Buzzacott, Peter; Lambrechts, Kate; Wang, Qiong; Belhomme, Marc; Theron, Michael; Popov, Georgi; Distefano, Giovanni; Guerrero, Francois

2014-11-01

Vascular bubble formation results from supersaturation during inadequate decompression contributes to endothelial injuries, which form the basis for the development of decompression sickness (DCS). Risk factors for DCS include increased age, weight-fat mass, decreased maximal oxygen uptake, chronic diseases, dehydration, and nitric oxide (NO) bioavailability. Production of NO is often affected by diving and its expression-activity varies between the genders. Little is known about the influence of sex on the risk of DCS. To study this relationship we used an animal model of Nω-nitro-l-arginine methyl ester (l-NAME) to induce decreased NO production. Male and female rats with diverse ages and weights were divided into 2 groups: treated with l-NAME (in tap water; 0.05 mg·mL(-1) for 7 days) and a control group. To control the distribution of nitrogen among tissues, 2 different compression-decompression protocols were used. Results showed that l-NAME was significantly associated with increased DCS in female rats (p = 0.039) only. Weight was significant for both sexes (p = 0.01). The protocol with the highest estimated tissue pressures in the slower compartments was 2.6 times more likely to produce DCS than the protocol with the highest estimated tissue pressures in faster compartments. The outcome of this study had significantly different susceptibility to DCS after l-NAME treatment between the sexes, while l-NAME per se had no effect on the likelihood of DCS. The analysis also showed that for the appearance of DCS, the most significant factors were type of protocol and weight.

The probability and severity of decompression sickness

Science.gov (United States)

Hada, Ethan A.; Vann, Richard D.; Denoble, Petar J.

2017-01-01

Decompression sickness (DCS), which is caused by inert gas bubbles in tissues, is an injury of concern for scuba divers, compressed air workers, astronauts, and aviators. Case reports for 3322 air and N2-O2 dives, resulting in 190 DCS events, were retrospectively analyzed and the outcomes were scored as (1) serious neurological, (2) cardiopulmonary, (3) mild neurological, (4) pain, (5) lymphatic or skin, and (6) constitutional or nonspecific manifestations. Following standard U.S. Navy medical definitions, the data were grouped into mild—Type I (manifestations 4–6)–and serious–Type II (manifestations 1–3). Additionally, we considered an alternative grouping of mild–Type A (manifestations 3–6)–and serious–Type B (manifestations 1 and 2). The current U.S. Navy guidance allows for a 2% probability of mild DCS and a 0.1% probability of serious DCS. We developed a hierarchical trinomial (3-state) probabilistic DCS model that simultaneously predicts the probability of mild and serious DCS given a dive exposure. Both the Type I/II and Type A/B discriminations of mild and serious DCS resulted in a highly significant (p probability of ‘mild’ DCS resulted in a longer allowable bottom time for the same 2% limit. However, for the 0.1% serious DCS limit, we found a vastly decreased allowable bottom dive time for all dive depths. If the Type A/B scoring was assigned to outcome severity, the no decompression limits (NDL) for air dives were still controlled by the acceptable serious DCS risk limit rather than the acceptable mild DCS risk limit. However, in this case, longer NDL limits were allowed than with the Type I/II scoring. The trinomial model mild and serious probabilities agree reasonably well with the current air NDL only with the Type A/B scoring and when 0.2% risk of serious DCS is allowed. PMID:28296928

Decoupling of bilayer leaflets under gas supersaturation: nitrogen nanobubbles in a membrane and their implication in decompression sickness

Science.gov (United States)

Li, Jing; Zhang, Xianren; Cao, Dapeng

2018-05-01

Decompression sickness (also known as diver’s sickness) is a disease that arises from the formation of a bubble inside the body caused by rapid decompression from high atmospheric pressures. However, the nature of pre-existing micronuclei that are proposed for interpreting the formation and growth of the bubble, as well as their very existence, is still highly controversial. In this work, atomistic molecular dynamics simulations are employed to investigate the nucleation of gas bubbles under the condition of nitrogen supersaturation, in the presence of a lipid bilayer and lipid micelle representing other macromolecules with a smaller hydrophobic region. Our simulation results demonstrate that by crossing a small energy barrier, excess nitrogen molecules can enter the lipid bilayer nearly spontaneously, for which the hydrophobic core serves as a potential well for gas enrichment. At a rather low nitrogen supersaturation, gas molecules in the membrane are dispersed in the hydrophobic region of the bilayer, with a slight increase in membrane thickness. But as the level of gas supersaturation reaches a threshold, the accumulation of N2 molecules in the bilayer center causes the two leaflets to be decoupled and the formation of nanobubbles. Therefore, we propose a nucleation mechanism for bubble formation in a supersaturated solution of inert gas: a cell membrane acts as a potential well for gas enrichment, being an ideal location for forming nanobubbles that induce membrane damage at a high level of gas supersaturation. As opposed to previous models, the new mechanism involves forming gas nuclei in a very low-tension hydrophobic environment, and thus a rather low energy barrier is required and pre-existing bubble micronuclei are not needed.

Habitat Options to Protect Against Decompression Sickness on Mars

Science.gov (United States)

Conkin, J.

2000-07-01

Men and women are alive today, although perhaps still in diapers, who will explore the surface of Mars. Two achievable goals to enable this exploration are to use Martian resources, and to provide a safe means for unrestricted access to the surface. A cost-effective approach for Mars exploration is to use the available resources, such as water and atmospheric gases. Nitrogen (N2) and Argon (Ar) in a concentration ratio of 1.68/1.0 are available, and could form the inert gas component of a habitat atmosphere at 8.0, 9.0, or 10.0 pounds per square inch absolute (psia). The habitat and space suit must be designed as an integrated, complementary, system: a comfortable living environment about 85% of the time and a safe working environment about 15% of the time. A goal is to provide a system that permits unrestricted exploration of Mars. However the risk of decompression sickness (DCS) during the extravehicular activity (EVA) in a 3.75 psia suit after exposure to either of the three habitat conditions may limit unrestricted exploration.

Effect of oxygen breathing and perfluorocarbon emulsion treatment on air bubbles in adipose tissue during decompression sickness

DEFF Research Database (Denmark)

Randsoe, T; Hyldegaard, O

2009-01-01

Decompression sickness (DCS) after air diving has been treated with success by means of combined normobaric oxygen breathing and intravascular perfluorocarbon (PFC) emulsions causing increased survival rate and faster bubble clearance from the intravascular compartment. The beneficial PFC effect...... has been explained by the increased transport capacity of oxygen and inert gases in blood. However, previous reports have shown that extravascular bubbles in lipid tissue of rats suffering from DCS will initially grow during oxygen breathing at normobaric conditions. We hypothesize that the combined...... effect of normobaric oxygen breathing and intravascular PFC infusion could lead to either enhanced extravascular bubble growth on decompression due to the increased oxygen supply, or that PFC infusion could lead to faster bubble elimination due to the increased solubility and transport capacity in blood...

Impact of Sleeping Altitude on Symptoms of Acute Mountain Sickness on Mt. Fuji.

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Horiuchi, Masahiro; Uno, Tadashi; Endo, Junko; Handa, Yoko; Hasegawa, Tatsuya

2018-05-09

Horiuchi, Masahiro, Tadashi Uno, Junko Endo, Yoko Handa, and Tatsuya Hasegawa. Impact of sleeping altitude on symptoms of acute mountain sickness on Mt. Fuji. High Alt Med Biol. 00:000-000, 2018. We sought to investigate the factors influencing acute mountain sickness (AMS) on Mt. Fuji in Japan, in particular, to assess the effects of sleeping altitude, by means of a questionnaire survey. This study involved 1932 participants who climbed Mt. Fuji, and obtained information regarding sex, age, and whether participants stayed at the mountain lodges. The AMS survey excluded the perceived sleep difficulties assessed with the Lake Louise Scoring (LLS) system for all climbers. The overall prevalence of AMS was 31.6% for all participants (LLS score ≥3 with headache, excluding sleep difficulties). A univariate analysis revealed that overnight stay at Mt. Fuji was associated with an increased prevalence of AMS, but that sex and age were not. For overnight lodgers, the mean sleeping altitude in participants with AMS was slightly higher than that in participants without AMS (p lodge, especially one above 2870 m, may be associated with an increased prevalence of AMS on Mt. Fuji.

Decompression sickness in breath-hold diving, and its probable connection to the growth and dissolution of small arterial gas emboli.

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Goldman, Saul; Solano-Altamirano, J M

2015-04-01

We solved the Laplace equation for the radius of an arterial gas embolism (AGE), during and after breath-hold diving. We used a simple three-region diffusion model for the AGE, and applied our results to two types of breath-hold dives: single, very deep competitive-level dives and repetitive shallower breath-hold dives similar to those carried out by indigenous commercial pearl divers in the South Pacific. Because of the effect of surface tension, AGEs tend to dissolve in arterial blood when arteries remote from supersaturated tissue. However if, before fully dissolving, they reach the capillary beds that perfuse the brain and the inner ear, they may become inflated with inert gas that is transferred into them from these contiguous temporarily supersaturated tissues. By using simple kinetic models of cerebral and inner ear tissue, the nitrogen tissue partial pressures during and after the dive(s) were determined. These were used to theoretically calculate AGE growth and dissolution curves for AGEs lodged in capillaries of the brain and inner ear. From these curves it was found that both cerebral and inner ear decompression sickness are expected to occur occasionally in single competitive-level dives. It was also determined from these curves that for the commercial repetitive dives considered, the duration of the surface interval (the time interval separating individual repetitive dives from one another) was a key determinant, as to whether inner ear and/or cerebral decompression sickness arose. Our predictions both for single competitive-level and repetitive commercial breath-hold diving were consistent with what is known about the incidence of cerebral and inner ear decompression sickness in these forms of diving. Copyright © 2015 Elsevier Inc. All rights reserved.

Fluoxetine protection in decompression sickness in mice is enhanced by blocking TREK-1 potassium channel with the spadin antidepressant.

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Nicolas eVallée

2016-02-01

Full Text Available In mice, disseminated coagulation, inflammation and ischemia induce neurological damages that can lead to the death. These symptoms result from circulating bubbles generated by a pathogenic decompression. An acute fluoxetine treatment or the presence of the TREK-1 potassium channel increased the survival rate when mice are subjected to an experimental dive/decompression protocol. This is a paradox because fluoxetine is a blocker of TREK-1 channels. First, we studied the effects of an acute dose of fluoxetine (50mg/kg in wild-type (WT and TREK-1 deficient mice (Knockout homozygous KO and heterozygous HET. Then, we combined the same fluoxetine treatment with a five-day treatment by spadin, in order to specifically block TREK-1 activity (KO-like mice. KO and KO-like mice could be regarded as antidepressed models.167 mice (45 WTcont 46 WTflux 30 HETflux and 46 KOflux constituting the flux-pool and 113 supplementary mice (27 KO-like 24 WTflux2 24 KO-likeflux 21 WTcont2 17 WTno dive constituting the spad-pool were included in this study. Only 7% of KO-TREK-1 treated with fluoxetine (KOflux and 4% of mice treated with both spadin and fluoxetine (KO-likeflux died from decompression sickness (DCS symptoms. These values are much lower than those of WT control (62% or KO-like mice (41%. After the decompression protocol, mice showed a significant consumption of their circulating platelets and leukocytes.Spadin antidepressed mice were more likely to declare DCS. Nevertheless, which had both blocked TREK-1 channel and were treated with fluoxetine were better protected against DCS. We conclude that the protective effect of such an acute dose of fluoxetine is enhanced when TREK-1 is inhibited. We confirmed that antidepressed models may have worse DCS outcomes, but a concomitant fluoxetine treatment not only decreases DCS severity but increases the survival rate.

Case Descriptions and Observations About Cutis Marmorata From Hypobaric Decompressions

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Conkin, Johnny; Pilmanis, Andrew A.; Webb, James T.

2002-01-01

There is disagreement about the pathophysiology, classification, and treatment of cutis marmorata (CM), so there is disagreement about the disposition and medical status of a person that had CM. CM is rare, associated with stressful decompressions, and may be associated with serious signs and symptoms of decompression sickness (DCS). CM presents as purple or bluish-red skin mottling, often in the pectoral region, shoulders, chest, or upper abdomen. It is unethical to induce CM in humans so all information comes from retrospective analysis of case reports, or from animal models. A literature search, seven recent case reports from the Johnson Space Center and Brooks Air Force Base Hypobaric DCS Databases, interviews with DCS treatment experts, and responses to surveys provided the factual information used to arrive at our conclusions and recommendations. The "weight of evidence" indicates that CM is a local, not centrally mediated or systemic response to bubbles. It is unclear whether obstruction of arterial or venous blood flow is the primary insult since the lesion is reported under either condition. Any neurological or cardiovascular involvements are coincidental, developing along the same time course. The skin could be the source of the bubbles due to its mass, the associated layer of fat, and the variable nature of skin blood flow. CM should not be categorized as Type II DCS, should be included with other skin manifestations in a category called cutaneous DCS, and hyperbaric treatment is only needed if ground level oxygen is ineffective in the case of altitude-induced CM.

Magnetic Resonance Imaging in Breath-Hold Divers with Cerebral Decompression Sickness

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Ryu Matsuo

2014-01-01

Full Text Available The mechanism of cerebral decompression sickness (DCS is still unclear. We report 2 cases of breath-hold divers with cerebral DCS in whom magnetic resonance imaging (MRI demonstrated distinctive characteristics. One case presented right hemiparesthesia, diplopia, and gait disturbance after breath-hold diving into the sea at a depth of 20 m. Brain MRI with fluid-attenuated inversion recovery (FLAIR sequence revealed multiple hyperintense lesions in the right frontal lobe, bilateral thalamus, pons, and right cerebellar hemisphere. The second case presented visual and gait disturbance after repetitive breath-hold diving into the sea. FLAIR imaging showed hyperintense areas in the bilateral occipito-parietal lobes. In both cases, diffusion-weighted imaging and apparent diffusion coefficient mapping revealed hyperintense areas in the lesions identified by FLAIR. Moreover, follow-up MRI showed attenuation of the FLAIR signal abnormalities. These findings are suggestive of transient hyperpermeability in the microvasculature as a possible cause of cerebral DCS.

Inner ear decompression sickness in compressed-air diving.

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Klingmann, Christoph

2012-01-01

Inner ear decompression sickness (IEDCS) has become more frequently reported in recreational diving. We examined 34 divers after IEDCS and analyzed their dive profiles, pattern of symptoms, time of symptom onset and the association with a right-to left shunt (r/l shunt). Four divers used mixed gas and were excluded from the analysis. Of the remaining 30 divers, 25 presented with isolated IEDCS alone, while five divers had additional skin and neurological symptoms. All divers presented with vertigo (100%), and 12 divers reported additional hearing loss (40%). All symptoms occurred within 120 minutes (median 30 minutes) of ascent. Twenty-two of 30 divers (73.3%) showed a r/l shunt. A possible explanation for the frequent association of a r/l shunt and the dominance of vestibular rather than cochlear symptoms could be attributed to the different blood supply of the inner ear structures and the different size of the labyrinthine compartments. The cochlea has a blood supply up to four times higher than the vestibular part of the inner ear, whereas the vestibular fluid space is 30% larger. The higher prevalence of symptoms referrable to the less well-perfused vestibular organ provides further evidence that persistent local inert gas supersaturation may cause growth of incoming arterial bubbles and may therefore be an important pathophysiological factor in IEDCS.

Novel drugs in the management of acute mountain sickness and high altitude pulmonary edema

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Sikri G

2015-12-01

Full Text Available Gaurav Sikri, Anirban Bhattacharya Department of Physiology, Armed Forces Medical College, Wanowarie, Pune, IndiaWe read with great interest the review article titled “Wilderness medicine at high altitude: recent developments in the field” by Shah et al.1 The authors have comprehensively summarized the recent advances in the field of high altitude medicine relevant to sports and travel medicine. However, Shah et al have described potential drugs for management of high-altitude illnesses, such as acute mountain sickness (AMS, high altitude cerebral edema, and high altitude pulmonary edema (HAPE as one group under the section “Novel drug treatment for AMS”. The pathophysiologies of these two sets of diseases (AMS/high altitude cerebral edema as one and HAPE as another set are different2 and hence it would have been nice to have had the novel drugs described separately to elucidate the therapeutic approach for the two different classes of diseases.View original paper by Shah et al.

Thirty-five Day Fluoxetine Treatment Limits Sensory-Motor Deficit and Biochemical Disorders in a Rat Model of Decompression Sickness

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Caroline Cosnard

2017-09-01

Full Text Available According to the OECD statistical base for 2014, anti-depressants will, on average, be distributed at a rate of 62 daily doses per 1,000 inhabitants for the 25 countries surveyed (Health at a glance: Europe 2014; OECD Health Statistics; World Health Organization and OECD Health Statistics, 2014. Divers must be concerned. On another hand, divers are potentially exposed to decompression sickness including coagulation inflammation and ischemia, which can result in neurological lesions or even death. The purpose of this study is to assess whether chronic treatment with anti-depressants may represent a contraindication to the practice of an at-risk activity, such as, scuba diving, or even presents a benefit by attenuating the severity of the symptoms. We study for the first time the effect of a 35-day fluoxetine treatment (20 mg/kg on the occurrence of decompression sickness in laboratory rats (n = 79. Following exposure to the hazardous protocol, there is a significant correlation between the type of treatment and the clinical status of the rats in favor of a better clinical prognosis for the rats treated with fluoxetine with a significantly higher number of No DCS status and a lower number of Severe DCS status in the Flux, compared to Controls. The treatment modifies the rat performances both significantly and favorably during the physical and behavioral tests, just like their biological and biochemical constants. After decompression, rats under treatment display lower sensory-motor deficit and lowers biochemical disorders. From a biological point of view, we conclude fluoxetine should not be seen as a contraindication for diving on the basis of anticipated increased physiological risk.

Type II decompression sickness in a hyperbaric inside attendant.

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Johnson-Arbor, Kelly

2012-01-01

Decompression sickness (DCS) of an inside attendant (IA) is rarely encountered in hyperbarics. This report describes an IA who developed Type II DCS after a routine hyperbaric exposure. A 50-year-old male complained of lower extremity weakness and paresthesias after serving as an IA during a hyperbaric treatment to 40 fsw (122.52 kPa). Within 10 minutes after the conclusion of the treatment, the IA experienced irritability and confusion, and was unable to walk. Physical examination revealed decreased sensation below the T7 level, and decreased strength in the lower extremities. Type II DCS was diagnosed, and the IA was recompressed to 60 fsw (183.78 kPa) on a U.S. Navy Treatment Table 6, which resulted in improvement of his symptoms. Transthoracic echocardiography with bubble study performed 16 months after the event demonstrated a large patent foramen ovale (PFO). Increased age, decreased physical fitness and the undiagnosed PFO may have predisposed this attendant to developing DCS. Although rare, DCS may occur in IAs. Routine monitoring and reporting of the long-term health of hyperbaric IAs should be considered by hyperbaric facilities and medical directors in order to further understand the characteristics of DCS and other hyperbaric-related conditions in these workers.

Postural stability in patients with decompression sickness evaluated by means of Quantitative Romberg testing

DEFF Research Database (Denmark)

Hedetoft, Morten; Hyldegaard, Ole

2015-01-01

obtained with the Quantitative Romberg test were observed in the group of DCS with vertigo relative to DCS without vertigo and healthy controls. A stepwise improvement in postural instability for DCS patients with vertigo was found following HBO2 therapy. After three treatments of HBO2, postural stability...... was found to be within the normal range of healthy controls. CONCLUSIONS: The Quantitative Romberg test offers the the clinician a fast, reliable and objective set of parametrical data to document postural instability in patients with either confirmed or suspected DCS.......OBJECTIVE: The present study was designed to retrospectively evaluate the use of quantitative Romberg's testing on postural stability during the course of hyperbaric oxygen (HBO2) therapy in patients presenting with decompression sickness (DCS). METHODS: The Quantitative Romberg test was used...

Decompression Mechanisms and Decompression Schedule Calculations.

Science.gov (United States)

1984-01-20

phisiology - The effects of altitude. Handbook of Physiology, Section 3: Respiration, Vol. II. W.O. Fenn and H. Rahn eds. Wash, D.C.; Am. Physiol. Soc. 1 4...decompression studies from other laboratories. METHODS Ten experienced and physically qualified divers ( ages 22-42) were compressed at a rate of 60...STATISTICS* --- ---------------------------------------------------------- EXPERIMENT N AGE (yr) HEIGHT (cm) WEIGHT (Kg) BODY FAT

Decompression illness - critical review

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C S Mohanty

2015-01-01

Full Text Available Decompression illness is caused by intravascular or extravascular bubbles that are formed as a result of reduction in environmental pressure (decompression. The term covers both arterial gas embolism, in which alveolar gas or venous gas emboli (via cardiac shunts or via pulmonary vessels are introduced into the arterial circulation, and decompression sickness, which is caused by in-situ bubble formation from dissolved inert gas. Both syndromes can occur in divers, compressed air workers, aviators, and astronauts, but arterial gas embolism also arises from iatrogenic causes unrelated to decompression. Risk of decompression illness is affected by immersion, exercise, and heat or cold. Manifestations range from itching and minor pain to neurological symptoms, cardiac collapse, and death. First-aid treatment is 1 0 0 % oxygen and definitive treatment is recompression to increased pressure, breathing 1 0 0 % oxygen. Adjunctive treatment, including fluid administration and prophylaxis against venous thromboembolism in paralysed patients, is also recommended Treatment is, in most cases, effective although residual deficits can remain in serious cases, even after several recompressions.

The Mars Project: Avoiding Decompression Sickness on a Distant Planet

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Conkin, Johnny

2000-05-01

A cost-effective approach for Mars exploration is to use available resources, such as water and atmospheric gases. Nitrogen (N2) and argon (Ar) are available and could form the inert gas component of a habitat atmosphere at 8.0, 9.0, or 10.0 pounds per square inch (psia). The habitat and space suit are designed as an integrated system: a comfortable living environment about 85% of the time and a safe working environment about 15% of the time. A goal is to provide a system that permits unrestricted exploration of Mars, but the risk of decompression sickness (DCS) during the extravehicular activity in a 3.75-psia suit, after exposure to any of the three habitat conditions, may limit unrestricted exploration. I evaluate here the risk of DCS since a significant proportion of a trinary breathing gas in the habitat might contain Ar. I draw on past experience and published information to extrapolate into untested, multivariable conditions to evaluate risk. A rigorous assessment of risk as a probability of DCS for each habitat condition is not yet possible. Based on many assumptions about Ar in hypobaric decompressions, I conclude that the presence of Ar significantly increases the risk of DCS. The risk is significant even with the best habitat option: 2.56 psia oxygen, 3.41 psia N2, and 2.20 psia Ar. Several hours of prebreathing 100% 02, a higher suit pressure, or a combination of other important variables such as limited exposure time on the surface or exercise during prebreathe would be necessary to reduce the risk of DCS to an acceptable level. The acceptable level for DCS risk on Mars has not yet been determined. Mars is a great distance from Earth and therefore from primary medical care. The acceptable risk would necessarily be defined by the capability to treat DCS in the Rover vehicle, in the habitat, or both.

High altitude illness

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Hartman-Ksycińska, Anna; Kluz-Zawadzka, Jolanta; Lewandowski, Bogumił

High-altitude illness is a result of prolonged high-altitude exposure of unacclimatized individuals. The illness is seen in the form of acute mountain sickness (AMS) which if not treated leads to potentially life-threatening high altitude pulmonary oedema and high-altitude cerebral oedema. Medical problems are caused by hypobaric hypoxia stimulating hypoxia-inducible factor (HIF) release. As a result, the central nervous system, circulation and respiratory system function impairment occurs. The most important factor in AMS treatment is acclimatization, withdrawing further ascent and rest or beginning to descent; oxygen supplementation, and pharmacological intervention, and, if available, a portable hyperbaric chamber. Because of the popularity of high-mountain sports and tourism better education of the population at risk is essential.

Iso-risk air no decompression limits after scoring marginal decompression sickness cases as non-events.

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Murphy, F Gregory; Swingler, Ashleigh J; Gerth, Wayne A; Howle, Laurens E

2018-01-01

Decompression sickness (DCS) in humans is associated with reductions in ambient pressure that occur during diving, aviation, or certain manned spaceflight operations. Its signs and symptoms can include, but are not limited to, joint pain, radiating abdominal pain, paresthesia, dyspnea, general malaise, cognitive dysfunction, cardiopulmonary dysfunction, and death. Probabilistic models of DCS allow the probability of DCS incidence and time of occurrence during or after a given hyperbaric or hypobaric exposure to be predicted based on how the gas contents or gas bubble volumes vary in hypothetical tissue compartments during the exposure. These models are calibrated using data containing the pressure and respired gas histories of actual exposures, some of which resulted in DCS, some of which did not, and others in which the diagnosis of DCS was not clear. The latter are referred to as marginal DCS cases. In earlier works, a marginal DCS event was typically weighted as 0.1, with a full DCS event being weighted as 1.0, and a non-event being weighted as 0.0. Recent work has shown that marginal DCS events should be weighted as 0.0 when calibrating gas content models. We confirm this indication in the present work by showing that such models have improved performance when calibrated to data with marginal DCS events coded as non-events. Further, we investigate the ramifications of derating marginal events on model-prescribed air diving no-stop limits. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficacy of Residence at Moderate Versus Low Altitude on Reducing Acute Mountain Sickness in Men Following Rapid Ascent to 4300 m

Science.gov (United States)

2013-01-01

reduced AMS after rapid ascent to high altitude. Key Words: acute mountain sickness, hypobaric hypoxia, acclimatization, fluid balance, ventilatory...response to hypoxia Introduction Altitude acclimatization refers to a series of phys-iologic responses to prolonged exposure to hypobaric hypoxia in low...Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts. 2Center for Aerospace and Hyperbaric Medicine

HIGH-ALTITUDE ILLNESS

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Dwitya Elvira

2015-05-01

Full Text Available AbstrakHigh-altitude illness (HAI merupakan sekumpulan gejala paru dan otak yang terjadi pada orang yang baru pertama kali mendaki ke ketinggian. HAI terdiri dari acute mountain sickness (AMS, high-altitude cerebral edema (HACE dan high-altitude pulmonary edema (HAPE. Tujuan tinjauan pustaka ini adalah agar dokter dan wisatawan memahami risiko, tanda, gejala, dan pengobatan high-altitude illness. Perhatian banyak diberikan terhadap penyakit ini seiring dengan meningkatnya popularitas olahraga ekstrim (mendaki gunung tinggi, ski dan snowboarding dan adanya kemudahan serta ketersediaan perjalanan sehingga jutaan orang dapat terpapar bahaya HAI. Di Pherice, Nepal (ketinggian 4343 m, 43% pendaki mengalami gejala AMS. Pada studi yang dilakukan pada tempat wisata di resort ski Colorado, Honigman menggambarkan kejadian AMS 22% pada ketinggian 1850 m sampai 2750 m, sementara Dean menunjukkan 42% memiliki gejala pada ketinggian 3000 m. Aklimatisasi merupakan salah satu tindakan pencegahan yang dapat dilakukan sebelum pendakian, selain beberapa pengobatan seperti asetazolamid, dexamethasone, phosopodiestrase inhibitor, dan ginko biloba.Kata kunci: high-altitude illness, acute mountain sickness, edema cerebral, pulmonary edema AbstractHigh-altitude illness (HAI is symptoms of lung and brain that occurs in people who first climb to altitude. HAI includes acute mountain sickness (AMS, high-altitude cerebral edema (HACE and high altitude pulmonary edema (HAPE. The objective of this review was to understand the risks, signs, symptoms, and treatment of high-altitude illness. The attention was given to this disease due to the rising popularity of extreme sports (high mountain climbing, skiing and snowboarding and the ease and availability of the current travelling, almost each year, millions of people could be exposed to the danger of HAI. In Pherice, Nepal (altitude 4343 m, 43% of climbers have symptoms of AMS. Furthermore, in a study conducted at sites in

ACUTE MOUNTAIN SICKNESS

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Jakub Krzeszowiak

2012-03-01

Full Text Available This paper presents the most likely pathophysiological causes of the development of acute mountain sickness (AMS, also known as altitude sickness, its pulmonary form i.e. high altitude pulmonary edema (HAPE, and high altitude cerebral edema (HACE. These diseases constitute extraordinary environmental hazards because they are directly connected with low atmospheric pressure, and thus low partial oxygen pressure. The above adverse atmospheric conditions start to affect humans already at an altitude of 2,500 meters above the sea level and, coupled with extreme physical exertion, can quickly lead to respiratory alkalosis, which is not present under any other conditions in the lowlands. Mountaineering above 4,500 m a.s.l. leads to hypoxia of internal organs and, primarily, reduced renal perfusion with all its consequences. The above adverse changes, combined with inadequate acclimatization, can lead to a situation of imminent danger to life and health. This paper describes in detail the consequences of acute mountain sickness, which can ultimately lead to the development of AMS and one of severe forms of HACE and/or HAPE.

Robert Hooke, inventor of the vacuum pump and the first altitude chamber (1671).

Science.gov (United States)

Harsch, Viktor

2006-08-01

Robert Hooke (1635-1703), an assistant researcher to Robert Boyle (1627-1691), invented the first functional British air pump. Applying it to scientific research, Hooke operated the world's first hypobaric chamber in 1671, using it for self-experimentation. He recorded the first physiological observations in an artificial altitude-equivalent environment up to 2400 m. Though Hooke's experiment showed some methodological insufficiencies, his imaginative experimental techniques were remarkable for their time and were indicative of the lively intellectual atmosphere of the Royal Society and the significant contributions of Hooke, who was a member. Two centuries passed before the French physiologist Paul Bert (1830-1886) conducted his famous laboratory-supported investigations of high altitude physiology. Bert played a decisive role in the discovery of the causes of decompression sickness; a contribution Hooke could not make due to the technical deficiencies of the 17th century.

Evaluation of safety of hypobaric decompressions and EVA from positions of probabilistic theory

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Nikolaev, V. P.

Formation and subsequent evolution of gas bubbles in blood and tissues of subjects exposed to decompression are casual processes in their nature. Such character of bubbling processes in a body predetermines probabilistic character of decompression sickness (DCS) incidence in divers, aviators and astronauts. Our original probabilistic theory of decompression safety is based on stochastic models of these processes and on the concept of critical volume of a free gas phase in body tissues. From positions of this theory, the probability of DCS incidence during single-stage decompressions and during hypobaric decompressions under EVA in particular, is defined by the distribution of possible values of nucleation efficiency in "pain" tissues and by its critical significance depended on the parameters of a concrete decompression. In the present study the following is shown: 1) the dimensionless index of critical nucleation efficiency for "pain" body tissues is a more adequate index of decompression stress in comparison with Tissue Ratio, TR; 2) a priory the decompression under EVA performed according to the Russian protocol is more safe than decompression under EVA performed in accordance with the U.S. protocol; 3) the Russian space suit operated at a higher pressure and having a higher "rigidity" induces a stronger inhibition of mechanisms of cavitation and gas bubbles formation in tissues of a subject located in it, and by that provides a more considerable reduction of the DCS risk during real EVA performance.

Aseptic necrosis in caisson workers: a new set of decompression tables.

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Downs, G J; Kindwall, E P

1986-06-01

There is a high incidence of aseptic necrosis and decompression sickness among caisson workers due to inadequate decompression using the current OSHA decompression tables (1-7). Because of this, a new set of tables--Autodec III-O2--was developed which more effectively eliminates nitrogen from the body and, therefore, should decrease the incidence of both bends and aseptic necrosis. The Autodec III-O2 schedule's superiority was statistically significant at a level of 0.08 compared to the OSHA table. It is our conclusion that OSHA should adopt the Autodec III-O2 schedule as a replacement for the current decompression tables.

Association of microparticles and neutrophil activation with decompression sickness.

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Thom, Stephen R; Bennett, Michael; Banham, Neil D; Chin, Walter; Blake, Denise F; Rosen, Anders; Pollock, Neal W; Madden, Dennis; Barak, Otto; Marroni, Alessandro; Balestra, Costantino; Germonpre, Peter; Pieri, Massimo; Cialoni, Danilo; Le, Phi-Nga Jeannie; Logue, Christopher; Lambert, David; Hardy, Kevin R; Sward, Douglas; Yang, Ming; Bhopale, Veena B; Dujic, Zeljko

2015-09-01

Decompression sickness (DCS) is a systemic disorder, assumed due to gas bubbles, but additional factors are likely to play a role. Circulating microparticles (MPs)--vesicular structures with diameters of 0.1-1.0 μm--have been implicated, but data in human divers have been lacking. We hypothesized that the number of blood-borne, Annexin V-positive MPs and neutrophil activation, assessed as surface MPO staining, would differ between self-contained underwater breathing-apparatus divers suffering from DCS vs. asymptomatic divers. Blood was analyzed from 280 divers who had been exposed to maximum depths from 7 to 105 meters; 185 were control/asymptomatic divers, and 90 were diagnosed with DCS. Elevations of MPs and neutrophil activation occurred in all divers but normalized within 24 h in those who were asymptomatic. MPs, bearing the following proteins: CD66b, CD41, CD31, CD142, CD235, and von Willebrand factor, were between 2.4- and 11.7-fold higher in blood from divers with DCS vs. asymptomatic divers, matched for time of sample acquisition, maximum diving depth, and breathing gas. Multiple logistic regression analysis documented significant associations (P < 0.001) between DCS and MPs and for neutrophil MPO staining. Effect estimates were not altered by gender, body mass index, use of nonsteroidal anti-inflammatory agents, or emergency oxygen treatment and were modestly influenced by divers' age, choice of breathing gas during diving, maximum diving depth, and whether repetitive diving had been performed. There were no significant associations between DCS and number of MPs without surface proteins listed above. We conclude that MP production and neutrophil activation exhibit strong associations with DCS. Copyright © 2015 the American Physiological Society.

Relationship of altitude mountain sickness and smoking: a Catalan traveller's cohort study.

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Sánchez-Mascuñano, Alba; Masuet-Aumatell, Cristina; Morchón-Ramos, Sergio; Ramon, Josep M

2017-09-24

The aim of this study is to analyse the relationship between smoking and altitude mountain sickness in a cohort of travellers to 2500 metres above sea level (masl) or higher. Travel Health Clinic at the Hospital Universitari de Bellvitge, in Barcelona, Spain. A total of 302 adults seeking medical advice at the travel clinic, between July 2012 and August 2014, before travelling to 2500 masl or above, who agreed to participate in the study and to be contacted after the trip were included. Individuals who met the following criteria were excluded: younger than 18 years old, taking carbonic anhydrase inhibitors for chronic use, undergoing treatment with systemic corticosteroids and taking any medication that might prevent or treat altitude mountain sickness (AMS) prior to or during the trip. The majority of participants were women (n=156, 51.7%). The mean age was 37.7 years (SD 12.3). The studied cohort included 74 smokers (24.5%), 158 (52.3%) non-smokers and 70 (23.2%) ex-smokers. No statistical differences were observed between different sociodemographic characteristics, constitutional symptoms or drug use and smoking status. The main outcome was the development of AMS, which was defined according to the Lake Louise AMS criteria. AMS, according to the Lake Louise score, was significantly lower in smokers; the value was 14.9%, 95% CI (6.8 to 23.0%) in smokers and 29.4%, 95% CI (23.5 to 35.3%) in non-smokers with an adjusted OR of 0.54, 95% CI (0.31 to 0.97) independent of gender, age and maximum altitude reached. These results suggest that smoking could reduce the risk of AMS in non-acclimated individuals. Further studies should be performed in larger cohorts of travellers to confirm these results. Despite the results, smoking must be strongly discouraged because it greatly increases the risk of cardiorespiratory diseases, cancer and other diseases. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights

Benefits of hyperbaric oxygen pretreatment for decompression sickness in Bama pigs.

Science.gov (United States)

Qing, Long; Yi, Hong-Jie; Wang, Ye-Wei; Zhou, Quan; Ariyadewa, Dinesh K; Xu, Wei-Gang

2018-03-07

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly ( P <0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs. © 2018. Published by The Company of Biologists Ltd.

Effect of oxygen breathing on micro oxygen bubbles in nitrogen-depleted rat adipose tissue at sea level and 25 kPa altitude exposures

DEFF Research Database (Denmark)

Randsoe, Thomas; Hyldegaard, Ole

2012-01-01

The standard treatment of altitude decompression sickness (aDCS) caused by nitrogen bubble formation is oxygen breathing and recompression. However, micro air bubbles (containing 79% nitrogen), injected into adipose tissue, grow and stabilize at 25 kPa regardless of continued oxygen breathing...... at 101.3 kPa (sea level) or at 25 kPa altitude exposures during continued oxygen breathing. In keeping with previous observations and bubble kinetic models, we hypothesize that oxygen breathing may contribute to oxygen bubble growth at altitude. Anesthetized rats were exposed to 3 h of oxygen...... prebreathing at 101.3 kPa (sea level). Micro oxygen bubbles of 500-800 nl were then injected into the exposed abdominal adipose tissue. The oxygen bubbles were studied for up to 3.5 h during continued oxygen breathing at either 101.3 or 25 kPa ambient pressures. At 101.3 kPa, all bubbles shrank consistently...

Subatmospheric Decompression Sickness in Man,

Science.gov (United States)

1969-04-01

are described as ecchymotic or petechial but in the cases seen in the ac- tive phase, in none has the skin ever failed to blanch completely under local...are undoubtedly petechial . There has been no convincing evidence of extravasation in compressed air cases (Griffiths, personal communication) or in...recommended that exposure to altitude during the active stage of antibody production, when malaise and low grade fever are common, should be avoided

Heart rate variability changes at 2400 m altitude predicts acute mountain sickness on further ascent at 3000-4300 m altitudes

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Heikki Mikael Karinen

2012-08-01

Full Text Available ObjectiveIf the body fails to acclimatize at high altitude, acute mountain sickness (AMS may result. For the early detection of AMS, changes in cardiac autonomic function measured by heart rate variability (HRV may be more sensitive than clinical symptoms alone. The purpose of this study was to ascertain if the changes in HRV during ascent are related to AMS.MethodsWe followed Lake Louise Score (LLS, arterial oxygen saturation at rest (R-SpO2 and exercise (Ex-SpO2 and HRV parameters daily in 36 different healthy climbers ascending from 2400 m to 6300 m altitudes during five different expeditions.ResultsAfter an ascent to 2400 m, standard deviation (RMSSD2 min, high-frequency power (HF2 min of HRV were 17-51 % and Ex-SpO2 was 3% lower in those climbers who suffered from AMS at 3000- 4300 m than in those only developing AMS later (≥ 5000 m or not at all (all p < 0.01. At the altitude of 2400 m RMSSD2 min ≤ 30 ms and Ex-SpO2 ≤ 91% both had 92% sensitivity for AMS if ascent continued without extra acclimatization days.ConclusionsChanges in supine HRV parameters at 2400 m were related to AMS at 3000-4300 m Thus, diverse analyses of HRV could offer potential markers for identifying the climbers at risk for AMS.

Cutis marmorata in decompression illness may be cerebrally mediated: a novel hypothesis on the aetiology of cutis marmorata

NARCIS (Netherlands)

Kemper, Tom Cpm; Rienks, R.; van Ooij, P. Jam; van Hulst, R. A.

2015-01-01

Cutaneous decompression sickness (DCS) is often considered to be a mild entity that may be explained by either vascular occlusion of skin vessels by bubbles entering the arterial circulation through a right-to-left shunt or bubble formation due to saturated subcutaneous tissue during decompression.

Rapid decompression and desorption induced energetic failure in coal

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Shugang Wang

2015-06-01

Full Text Available In this study, laboratory experiments are conducted to investigate the rapid decompression and desorption induced energetic failure in coal using a shock tube apparatus. Coal specimens are recovered from Colorado at a depth of 610 m. The coal specimens are saturated with the strong sorbing gas CO2 for a certain period and then the rupture disc is suddenly broken on top of the shock tube to generate a shock wave propagating upwards and a rarefaction wave propagating downwards through the specimen. This rapid decompression and desorption has the potential to cause energetic fragmentation in coal. Three types of behaviors in coal after rapid decompression are found, i.e. degassing without fragmentation, horizontal fragmentation, and vertical fragmentation. We speculate that the characteristics of fracture network (e.g. aperture, spacing, orientation and stiffness and gas desorption play a role in this dynamic event as coal can be considered as a dual porosity, dual permeability, dual stiffness sorbing medium. This study has important implications in understanding energetic failure process in underground coal mines such as coal gas outbursts.

Blood Volume: Importance and Adaptations to Exercise Training, Environmental Stresses and Trauma/Sickness

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Sawka, Michael N.; Convertino, Victor A.; Eichner, E. Randy; Schnieder, Suzanne M.; Young, Andrew J.

2000-01-01

This paper reviews the influence of several perturbations (physical exercise, heat stress, terrestrial altitude, microgravity, and trauma/sickness) on adaptations of blood volume (BV), erythrocyte volume (EV), and plasma volume (PV). Exercise training can induced BV expansion; PV expansion usually occurs immediately, but EV expansion takes weeks. EV and PV expansion contribute to aerobic power improvements associated with exercise training. Repeated heat exposure induces PV expansion but does not alter EV. PV expansion does not improve thermoregulation, but EV expansion improves thermoregulation during exercise in the heat. Dehydration decreases PV (and increases plasma tonicity) which elevates heat strain and reduces exercise performance. High altitude exposure causes rapid (hours) plasma loss. During initial weeks at altitude, EV is unaffected, but a gradual expansion occurs with extended acclimatization. BV adjustments contribute, but are not key, to altitude acclimatization. Microgravity decreases PV and EV which contribute to orthostatic intolerance and decreased exercise capacity in astronauts. PV decreases may result from lower set points for total body water and central venous pressure, which EV decrease bay result form increased erythrocyte destruction. Trauma, renal disease, and chronic diseases cause anemia from hemorrhage and immune activation, which suppressions erythropoiesis. The re-establishment of EV is associated with healing, improved life quality, and exercise capabilities for these injured/sick persons.

A case-control study evaluating relative risk factors for decompression sickness: a research report.

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Suzuki, Naoko; Yagishita, Kazuyosi; Togawa, Seiichiro; Okazaki, Fumihiro; Shibayama, Masaharu; Yamamoto, Kazuo; Mano, Yoshihiro

2014-01-01

Factors contributing to the pathogenesis of decompression sickness (DCS) in divers have been described in many studies. However, relative importance of these factors has not been reported. In this case-control study, we compared the diving profiles of divers experiencing DCS with those of a control group. The DCS group comprised 35 recreational scuba divers who were diagnosed by physicians as having DCS. The control group consisted of 324 apparently healthy recreational divers. All divers conducted their dives from 2009 to 2011. The questionnaire consisted of 33 items about an individual's diving profile, physical condition and activities before, during and just after the dive. To simplify dive parameters, the dive site was limited to Izu Osezaki. Odds ratios and multiple logistic regression were used for the analysis. Odds ratios revealed several items as dive and health factors associated with DCS. The major items were as follows: shortness of breath after heavy exercise during the dive (OR = 12.12), dehydration (OR = 10.63), and maximum dive depth > 30 msw (OR = 7.18). Results of logistic regression were similar to those by odds ratio analysis. We assessed the relative weights of the surveyed dive and health factors associated with DCS. Because results of several factors conflict with previous studies, future studies are needed.

Treatment of micro air bubbles in rat adipose tissue at 25 kPa altitude exposures with perfluorocarbon emulsions and nitric oxide.

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Randsøe, Thomas; Hyldegaard, O

2014-01-01

Perfluorocarbon emulsions (PFC) and nitric oxide (NO) releasing agents have on experimental basis demonstrated therapeutic properties in treating and preventing the formation of venous gas embolism as well as increased survival rate during decompression sickness from diving. The effect is ascribed to an increased solubility and transport capacity of respiratory gases in the PFC emulsion and possibly enhanced nitrogen washout through NO-increased blood flow rate and/or the removal of endothelial micro bubble nuclei precursors. Previous reports have shown that metabolic gases (i.e., oxygen in particular) and water vapor contribute to bubble growth and stabilization during altitude exposures. Accordingly, we hypothesize that the administration of PFC and NO donors upon hypobaric pressure exposures either (1) enhance the bubble disappearance rate through faster desaturation of nitrogen, or in contrast (2) promote bubble growth and stabilization through an increased oxygen supply. In anesthetized rats, micro air bubbles (containing 79% nitrogen) of 4-500 nl were injected into exposed abdominal adipose tissue. Rats were decompressed in 36 min to 25 kPa (~10,376 m above sea level) and bubbles studied for 210 min during continued oxygen breathing (FIO2 = 1). Rats were administered PFC, NO, or combined PFC and NO. In all groups, most bubbles grew transiently, followed by a stabilization phase. There were no differences in the overall bubble growth or decay between groups or when compared with previous data during oxygen breathing alone at 25 kPa. During extreme altitude exposures, the contribution of metabolic gases to bubble growth compromises the therapeutic effects of PFC and NO, but PFC and NO do not induce additional bubble growth.

Change of occurance of type 1 and type 2 decompression sickness of divers treated at the Croatian Naval Medical Institute in the period from 1967 to 2000.

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Andrić, Dejan; Petri, Nadan M; Stipancević, Hrvoje; Petri, Lena Vranjković; Kovacević, Hasan

2003-01-01

A significant change of occurrence (p=0.0343) of type 1 and type 2 decompression sickness (DCS) of divers in Croatia was observed in the period from 1991 to 2002 (type 1: n=26, 37.68% and type 2: n=43, 62.32%) compared with the period from 1967 to 1990 (type 1: n=93, 52.84% and type 2: n=83, 47.16%). The change was attributed to the extensive usage of diving computers and artificial gas mixtures which enable extended bottom times and deeper dives, thus putting divers at an increased decompression risk. The importance of the results of this report is in the fact that permanent neurological deficit occurs only after type 2 DCS. Injured divers with permanent loss after type 2 DCS are not fit for diving and require a long term medical care, thus becoming a significant public health problem.

Vection and visually induced motion sickness: How are they related?

Directory of Open Access Journals (Sweden)

Behrang eKeshavarz

2015-04-01

Full Text Available The occurrence of visually induced motion sickness has been frequently linked to the sensation of illusory self-motion (so-called vection, however, the precise nature of this relationship is still not fully understood. To date, it is still a matter of debate whether or not vection is a necessary prerequisite for visually induced motion sickness (VIMS. That is, can there be visually induced motion sickness without any sensation of self-motion? In this paper, we will describe the possible nature of this relationship, review the literature that may speak to this relationship (including theoretical accounts of vection and VIMS, and offer suggestions with respect to operationally defining and reporting these phenomena in future.

High altitude headache and acute mountain sickness at moderate elevations in a military population during battalion-level training exercises.

Science.gov (United States)

Norris, Jacob N; Viirre, Erik; Aralis, Hilary; Sracic, Michael K; Thomas, Darren; Gertsch, Jeffery H

2012-08-01

Few studies have evaluated high altitude headache (HAH) and acute mountain sickness (AMS) in military populations training at moderate (1,500-2,500 m) to high altitudes (>2,500 m). In the current study, researchers interviewed active duty personnel training at Marine Corps Mountain Warfare Training Center. Participants were asked about HAH and AMS symptoms, potential risk factors, and medications used. In a sample of 192 U.S. Navy and Marine Corps personnel, 14.6% reported AMS (Lake Louise Criteria > or = 3) and 28.6% reported HAH. Dehydration and recent arrival at altitude (defined as data collected on days 2-3) were significantly associated with AMS; decreased sleep allowance was significantly associated with HAH. Although ibuprofen/Motrin users were more likely to screen positive for AMS, among AMS-positive participants, ibuprofen/Motrin users had decreased likelihood of reporting robust AMS relative to non-ibuprofen/Motrin users (p altitude. Further, ibuprofen/Motrin may be a reasonable treatment for the symptoms of AMS and HAH, although further study is warranted.

Dexmedetomidine reduces lipopolysaccharide induced neuroinflammation, sickness behavior, and anhedonia.

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Ching-Hua Yeh

Full Text Available Peripheral innate immune response may induce sickness behavior through activating microglia, excessive cytokines production, and neuroinflammation. Dexmedetomidine (Dex has anti-inflammatory effect. We investigated the effects of Dex on lipopolysaccharide (LPS-induced neuroinflammation and sickness behavior in mice.BALB/c mice were intraperitoneally (i.p. injected with Dex (50 ug/kg or vehicle. One hour later, the mice were injected (i.p. with Escherichia coli LPS (0.33 mg/kg or saline (n = 6 in each group. We analyzed the food and water intake, body weight loss, and sucrose preference of the mice for 24h. We also determined microglia activation and cytokines expression in the brains of the mice. In vitro, we determine cytokines expression in LPS-treated BV-2 microglial cells with or without Dex treatment.In the Dex-pretreated mice, LPS-induced sickness behavior (anorexia, weight loss, and social withdrawal were attenuated and microglial activation was lower than vehicle control. The mRNA expression of TNF-α, MCP-1, indoleamine 2, 3 dioxygenase (IDO, caspase-3, and iNOS were increased in the brain of LPS-challenged mice, which were reduced by Dex but not vehicle.Dexmedetomidine diminished LPS-induced neuroinflammation in the mouse brain and modulated the cytokine-associated changes in sickness behavior.

Altitude Stress During Participation of Medical Congress

Science.gov (United States)

Kim, Soon Bae; Kim, Jong Sung; Kim, Sang Jun; Cho, Su Hee

2016-01-01

Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI. Children are more susceptible to altitude stress than adults. Gradual ascent is the best method for the prevention of altitude stress. Adequate nutrition (mainly carbohydrates) and hydration are recommended. Consumption of alcohol can exacerbate the altitude-induced impairments in judgment and the visual senses and promote psychomotor dysfunction. For prevention or treatment of altitude stress, acetazolamide, phosphodiesterase inhibitors, dexamethasone and erythropoietin are helpful. Altitude stress can be experienced relatively often during participation of medical congress. It is necessary to remind the harmful effect of AMS because it can cause serious permanent organ damage even though the symptoms are negligible in most cases. PMID:27621942

Compressed air tunneling and caisson work decompression procedures: development, problems, and solutions.

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Kindwall, E P

1997-01-01

Multinational experience over many years indicates that all current air decompression schedules for caisson and compressed air tunnel workers are inadequate. All of them, including the Occupational Safety and Health Administration tables, produce dysbaric osteonecrosis. The problem is compounded because decompression sickness (DCS) tends to be underreported. Permanent damage in the form of central nervous system or brain damage may occur in compressed air tunnel workers, as seen on magnetic resonance imaging, in addition to dysbaric osteonecrosis. Oxygen decompression seems to be the only viable method for safely decompressing tunnel workers. Oxygen decompression of tunnel workers has been successfully used in Germany, France, and Brazil. In Germany, only oxygen decompression of compressed air workers is permitted. In our experience, U.S. Navy tables 5 and 6 usually prove adequate to treat DCS in caisson workers despite extremely long exposure times, allowing patients to return to work following treatment for DCS. Tables based on empirical data and not on mathematical formulas seem to be reasonably safe. U.S. Navy Exceptional Exposure Air Decompression tables are compared with caisson tables from the United States and Great Britain.

The effect of the perfluorocarbon emulsion Oxycyte on platelet count and function in the treatment of decompression sickness in a swine model.

Science.gov (United States)

Cronin, William A; Senese, Angela L; Arnaud, Francoise G; Regis, David P; Auker, Charles R; Mahon, Richard T

2016-09-01

Decompression from elevated ambient pressure is associated with platelet activation and decreased platelet counts. Standard treatment for decompression sickness (DCS) is hyperbaric oxygen therapy. Intravenous perfluorocarbon (PFC) emulsion is a nonrecompressive therapy being examined that improves mortality in animal models of DCS. However, PFC emulsions are associated with a decreased platelet count. We used a swine model of DCS to study the effect of PFC therapy on platelet count, function, and hemostasis. Castrated male swine (n = 50) were fitted with a vascular port, recovered, randomized, and compressed to 180 feet of sea water (fsw) for 31 min followed by decompression at 30 fsw/min. Animals were observed for DCS, administered 100% oxygen, and treated with either emulsified PFC Oxycyte (DCS-PFC) or isotonic saline (DCS-NS). Controls underwent the same procedures, but were not compressed (Sham-PFC and Sham-NS). Measurements of platelet count, thromboelastometry, and coagulation were obtained 1 h before compression and 1, 24, 48, 96, 168 and 192 h after treatment. No significant changes in normalized platelet counts were observed. Prothrombin time was elevated in DCS-PFC from 48 to 192 h compared with DCS-NS, and from 96 to 192 h compared with Sham-PFC. Normalized activated partial thromboplastin time was also elevated in DCS-PFC from 168 to 192 h compared with Sham-PFC. No bleeding events were noted. DCS treated with PFC (Oxycyte) does not impact platelet numbers, whole blood clotting by thromboelastometry, or clinical bleeding. Late changes in prothrombin time and activated partial thromboplastin time associated with PFC use in both DCS therapy and controls warrant further investigation.

Research progress on high altitude retinopathy and application of Traditional Chinese Medicine

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Hai-Xiang Huang

2014-11-01

Full Text Available High altitude retinopathy(HARrefers to the body which can't adapt to the hypobaric hypoxia environment at high altitude leading to retinal diseases, which typically manifested as retinal hemorrhages, optic disc edema and cotton wool spots. With the development of high altitude medicine, HAR become a hot topic of eye research in recent years. New researches show a significantly higher incidence of HAR, and HAR has a close contact with acute mountain sickness, high altitude cerebral edema and high altitude pulmonary edema. A further study in pathogenesis and prevention measures of HAR will promote the prevention of altitude sickness. Traditional Chinese Medicine has achieved good effects in the prevention of altitude sickness, but the effect and mechanism of herbs on HAR has not been reported. Through read and summarize the relevant literatures and reports, the author will give an overview of the research advances on HAR's pathogenesis and application of Traditional Chinese Medicine.

Redistribution of Decompression Stop Time from Shallow to Deep Stops Increases Incidence of Decompression Sickness in Air Decompression Dives

Science.gov (United States)

2011-07-22

year old active duty male diver surfaced from a 170/30 air dive at <corr>12:11<corr> on 24AUG06 using MK 20 FFM and following the A-2 “deep stops...effort, and this episode responded immediately to pressure. AGE is unlikely due to the experience of the diver, the MK 20 FFM characteristics, and...from a 170/30 air dive at <corr>12:11<corr> on 24AUG06 using MK 20 FFM and following the A-2 “deep stops” experimental decompression profile

Noninvasive Assessment of Excessive Erythrocytosis as a Screening Method for Chronic Mountain Sickness at High Altitude.

Science.gov (United States)

Vyas, Kaetan J; Danz, David; Gilman, Robert H; Wise, Robert A; León-Velarde, Fabiola; Miranda, J Jaime; Checkley, William

2015-06-01

Vyas, Kaetan J., David Danz, Robert H. Gilman, Robert A. Wise, Fabiola León-Velarde, J. Jaime Miranda, and William Checkley. Noninvasive assessment of excessive erythrocytosis as a screening method for chronic mountain sickness at high altitude. High Alt Med Biol 16:162-168, 2015.--Globally, over 140 million people are at risk of developing chronic mountain sickness, a common maladaptation to life at high altitude (>2500 meters above sea level). The diagnosis is contingent upon the identification of excessive erythrocytosis (EE). Current best practices to identify EE require a venous blood draw, which is cumbersome for large-scale surveillance. We evaluated two point-of-care biomarkers to screen for EE: noninvasive spot-check tests of total hemoglobin and oxyhemoglobin saturation (Pronto-7, Masimo Corporation). We conducted paired evaluations of total serum hemoglobin from a venous blood draw and noninvasive, spot-check testing of total hemoglobin and oxyhemoglobin saturation with the Pronto-7 in 382 adults aged ≥35 years living in Puno, Peru (3825 meters above sea level). We used the Bland-Altman method to measure agreement between the noninvasive hemoglobin assessment and the gold standard lab hemoglobin analyzer. Mean age was 58.8 years and 47% were male. The Pronto-7 test was unsuccessful in 21 (5%) participants. Limits of agreement between total hemoglobin measured via venous blood draw and the noninvasive, spot-check test ranged from -2.8 g/dL (95% CI -3.0 to -2.5) to 2.5 g/dL (95% CI 2.2 to 2.7), with a bias of -0.2 g/dL (95% CI -0.3 to -0.02) for the difference between total hemoglobin and noninvasive hemoglobin concentrations. Overall, the noninvasive spot-check test of total hemoglobin had a better area under the receiver operating characteristic curve compared to oxyhemoglobin saturation for the identification of EE as measured by a gold standard laboratory hemoglobin analyzer (0.96 vs. 0.82; p<0.001). Best cut-off values to screen for EE with

Delayed treatment of decompression sickness with short, no-air-break tables: review of 140 cases.

Science.gov (United States)

Cianci, Paul; Slade, John B

2006-10-01

Most cases of decompression sickness (DCS) in the U.S. are treated with hyperbaric oxygen using U.S. Navy Treatment Tables 5 and 6, although detailed analysis shows that those tables were based on limited data. We reviewed the development of these protocols and offer an alternative treatment table more suitable for monoplace chambers that has proven effective in the treatment of DCS in patients presenting to our facility. We reviewed the outcomes for 140 cases of DCS in civilian divers treated with the shorter tables at our facility from January 1983 through December 2002. Onset of symptoms averaged 9.3 h after surfacing. At presentation, 44% of the patients demonstrated mental aberration. The average delay from onset of symptoms to treatment was 93.5 h; median delay was 48 h. Complete recovery in the total group of 140 patients was 87%. When 30 patients with low probability of DCS were excluded, the recovery rate was 98%. All patients with cerebral symptoms recovered. Patients with the highest severity scores showed a high rate of complete recovery (97.5%). Short oxygen treatment tables as originally described by Hart are effective in the treatment of DCS, even with long delays to definitive recompression that often occur among civilian divers presenting to a major Divers Alert Network referral center.

[Decompression sickness accident management in remote areas. Use of immediate in-water recompression therapy. Review and elaboration of a new protocol targeted for a mission at Clipperton atoll].

Science.gov (United States)

Blatteau, J-E; Jean, F; Pontier, J-M; Blanche, E; Bompar, J-M; Meaudre, E; Etienne, J-L

2006-08-01

In-Water Recompression (IWR) is defined as a treatment of decompression sickness by immediate underwater recompression after the onset of symptoms in remote areas where hyperbaric chambers are not available. At least three methods of IWR have been published. They used pure oxygen breathing for prolonged periods of time at a depth of 9 m. IWR effectiveness in comparison with standard recompression techniques has not been assessed. IWR should be used in remote localities as an immediate measure to stop the evolution of decompression illness before evacuating the victim for subsequent treatment to the nearest hyperbaric facility. Resulting from environmental conditions, the risks of drowning and hypothermia are the most often quoted, pure oxygen breathing at 9 m can also expose to acute oxygen toxicity. The objectives of this work are: first, to examine existing published methods of IWR; second, to propose a new method of IWR. All published methods of IWR involve victim returning underwater for a long period of time. But dehydration due to a long period of immersion can worsen symptoms of decompression illness and acute oxygen toxicity is also related to the duration of the exposition. In response to these considerations we developed a shorter method of conducting IWR specifically targeted for a diving mission at Clipperton atoll in the Northern Pacific Ocean.

Bubble formation after a 20-m dive: deep-stop vs. shallow-stop decompression profiles

NARCIS (Netherlands)

Schellart, Nico A. M.; Corstius, Jan-Jaap Brandt; Germonpré, Peter; Sterk, Wouter

2008-01-01

OBJECTIVES: It is claimed that performing a "deep stop," a stop at about half of maximal diving depth (MDD), can reduce the amount of detectable precordial bubbles after the dive and may thus diminish the risk of decompression sickness. In order to ascertain whether this reduction is caused by the

Pleasant music as a countermeasure against visually induced motion sickness.

Science.gov (United States)

Keshavarz, Behrang; Hecht, Heiko

2014-05-01

Visually induced motion sickness (VIMS) is a well-known side-effect in virtual environments or simulators. However, effective behavioral countermeasures against VIMS are still sparse. In this study, we tested whether music can reduce the severity of VIMS. Ninety-three volunteers were immersed in an approximately 14-minute-long video taken during a bicycle ride. Participants were randomly assigned to one of four experimental groups, either including relaxing music, neutral music, stressful music, or no music. Sickness scores were collected using the Fast Motion Sickness Scale and the Simulator Sickness Questionnaire. Results showed an overall trend for relaxing music to reduce the severity of VIMS. When factoring in the subjective pleasantness of the music, a significant reduction of VIMS occurred only when the presented music was perceived as pleasant, regardless of the music type. In addition, we found a gender effect with women reporting more sickness than men. We assume that the presentation of pleasant music can be an effective, low-cost, and easy-to-administer method to reduce VIMS. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Phenylethanoid glycosides of Pedicularis muscicola Maxim ameliorate high altitude-induced memory impairment.

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Zhou, Baozhu; Li, Maoxing; Cao, Xinyuan; Zhang, Quanlong; Liu, Yantong; Ma, Qiang; Qiu, Yan; Luan, Fei; Wang, Xianmin

2016-04-01

Exposure to hypobaric hypoxia causes oxidative stress, neuronal degeneration and apoptosis that leads to memory impairment. Though oxidative stress contributes to neuronal degeneration and apoptosis in hypobaric hypoxia, the ability for phenylethanoid glycosides of Pedicularis muscicola Maxim (PhGs) to reverse high altitude memory impairment has not been studied. Rats were supplemented with PhGs orally for a week. After the fourth day of drug administration, rats were exposed to a 7500 m altitude simulation in a specially designed animal decompression chamber for 3 days. Spatial memory was assessed by the 8-arm radial maze test before and after exposure to hypobaric hypoxia. Histological assessment of neuronal degeneration was performed by hematoxylin-eosin (HE) staining. Changes in oxidative stress markers and changes in the expression of the apoptotic marker, caspase-3, were assessed in the hippocampus. Our results demonstrated that after exposure to hypobaric hypoxia, PhGs ameliorated high altitude memory impairment, as shown by the decreased values obtained for reference memory error (RME), working memory error (WME), and total error (TE). Meanwhile, administration of PhGs decreased hippocampal reactive oxygen species levels and consequent lipid peroxidation by elevating reduced glutathione levels and enhancing the free radical scavenging enzyme system. There was also a decrease in the number of pyknotic neurons and a reduction in caspase-3 expression in the hippocampus. These findings suggest that PhGs may be used therapeutically to ameliorate high altitude memory impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

High-Altitude-Induced alterations in Gut-Immune Axis: A review.

Science.gov (United States)

Khanna, Kunjan; Mishra, K P; Ganju, Lilly; Kumar, Bhuvnesh; Singh, Shashi Bala

2018-03-04

High-altitude sojourn above 8000 ft is increasing day by day either for pilgrimage, mountaineering, holidaying or for strategic reasons. In India, soldiers are deployed to these high mountains for their duty or pilgrims visit to the holy places, which are located at very high altitude. A large population also resides permanently in high altitude regions. Every year thousands of pilgrims visit Holy cave of Shri Amarnath ji, which is above 15 000 ft. The poor acclimatization to high altitude may cause alteration in immunity. The low oxygen partial pressure may cause alterations in gut microbiota, which may cause changes in gut immunity. Effect of high altitude on gut-associated mucosal system is new area of research. Many studies have been carried out to understand the physiology and immunology behind the high-altitude-induced gut problems. Few interventions have also been discovered to circumvent the problems caused due to high-altitude conditions. In this review, we have discussed the effects of high-altitude-induced changes in gut immunity particularly peyer's patches, NK cells and inflammatory cytokines, secretary immunoglobulins and gut microbiota. The published articles from PubMed and Google scholar from year 1975 to 2017 on high-altitude hypoxia and gut immunity are cited in this review.

High altitude pulmonary edema among "Amarnath Yatris"

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Parvaiz A Koul

2013-01-01

Full Text Available Background: Annual pilgrimage (Yatra to the cave shrine of Shri Amarnath Ji′ is a holy ritual among the Hindu devotees of Lord Shiva. Located in the Himalayan Mountain Range (altitude 13,000 ft in south Kashmir, the shrine is visited by thousands of devotees and altitude sickness is reportedly common. Materials and Methods: More than 600,000 pilgrims visited the cave shrine in 2011 and 2012 with 239 recorded deaths. Thirty one patients with suspected altitude sickness were referred from medical centers en-route the cave to Sher-i-Kashmir Institute of Medical Sciences, a tertiary-care center in capital Srinagar (5,000 ft. The clinical features and the response to treatment were recorded. Results: Thirty-one patients (all lowlanders, 19 male; age 18-60 years, median 41 had presented with acute onset breathlessness of 1-4 days (median 1.9 d starting within 12-24 h of a rapid ascent; accompanied by cough (68%, headache (8%, dizziness and nausea (65%. Sixteen patients had associated encephalopathy. Clinical features on admission included tachypnea ( n = 31, tachycardia ( n = 23, bilateral chest rales ( n = 29, cyanosis ( n = 22 and grade 2-4 encephalopathy. Hypoxemia was demonstrable in 24 cases and bilateral infiltrates on radiologic imaging in 29. Ten patients had evidence of high-altitude cerebral edema. All patients were managed with oxygen, steroids, nifedipine, sildenafil and other supportive measures including invasive ventilation ( n = 3. Three patients died due to multiorgan dysfunction. Conclusions: Altitude sickness is common among Amaranath Yatris from the plains and appropriate educational strategies should be invoked for prevention and prompt treatment.

Cardiovascular Pressures with Venous Gas Embolism and Decompression

Science.gov (United States)

Butler, B. D.; Robinson, R.; Sutton, T.; Kemper, G. B.

1995-01-01

Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range from 25-34% and yet aviators, astronauts, and deepsea divers who have decompression-induced venous bubbles do not demonstrate neurological symptoms at these high rates. This apparent disparity may be attributable to the normal pressure gradient across the atria of the heart that must be reversed for there to be flow potency. We evaluated the effects of: venous gas embolism (0.025, 0.05 and 0.15 ml/ kg min for 180 min.) hyperbaric decompression; and hypobaric decompression on the pressure gradient across the left and right atria in anesthetized dogs with intact atrial septa. Left ventricular end-diastolic pressure was used as a measure of left atrial pressure. In a total of 92 experimental evaluations in 22 dogs, there were no reported reversals in the mean pressure gradient across the atria; a total of 3 transient reversals occurred during the peak pressure gradient changes. The reasons that decompression-induced venous bubbles do not consistently cause serious symptoms of decompression illness may be that the amount of venous gas does not always cause sufficient pressure reversal across a patent foramen ovale to cause arterialization of the venous bubbles.

High-Altitude Illnesses: Physiology, Risk Factors, Prevention, and Treatment

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Andrew T. Taylor

2011-01-01

Full Text Available High-altitude illnesses encompass the pulmonary and cerebral syndromes that occur in non-acclimatized individuals after rapid ascent to high altitude. The most common syndrome is acute mountain sickness (AMS which usually begins within a few hours of ascent and typically consists of headache variably accompanied by loss of appetite, nausea, vomiting, disturbed sleep, fatigue, and dizziness. With millions of travelers journeying to high altitudes every year and sleeping above 2,500 m, acute mountain sickness is a wide-spread clinical condition. Risk factors include home elevation, maximum altitude, sleeping altitude, rate of ascent, latitude, age, gender, physical condition, intensity of exercise, pre-acclimatization, genetic make-up, and pre-existing diseases. At higher altitudes, sleep disturbances may become more profound, mental performance is impaired, and weight loss may occur. If ascent is rapid, acetazolamide can reduce the risk of developing AMS, although a number of high-altitude travelers taking acetazolamide will still develop symptoms. Ibuprofen can be effective for headache. Symptoms can be rapidly relieved by descent, and descent is mandatory, if at all possible, for the management of the potentially fatal syndromes of high-altitude pulmonary and cerebral edema. The purpose of this review is to combine a discussion of specific risk factors, prevention, and treatment options with a summary of the basic physiologic responses to the hypoxia of altitude to provide a context for managing high-altitude illnesses and advising the non-acclimatized high-altitude traveler.

Occupational health of miners at altitude: adverse health effects, toxic exposures, pre-placement screening, acclimatization, and worker surveillance.

Science.gov (United States)

Vearrier, David; Greenberg, Michael I

2011-08-01

Mining operations conducted at high altitudes provide health challenges for workers as well as for medical personnel. To review the literature regarding adverse health effects and toxic exposures that may be associated with mining operations conducted at altitude and to discuss pre-placement screening, acclimatization issues, and on-site surveillance strategies. We used the Ovid ( http://ovidsp.tx.ovid.com ) search engine to conduct a MEDLINE search for "coal mining" or "mining" and "altitude sickness" or "altitude" and a second MEDLINE search for "occupational diseases" and "altitude sickness" or "altitude." The search identified 97 articles of which 76 were relevant. In addition, the references of these 76 articles were manually reviewed for relevant articles. CARDIOVASCULAR EFFECTS: High altitude is associated with increased sympathetic tone that may result in elevated blood pressure, particularly in workers with pre-existing hypertension. Workers with a history of coronary artery disease experience ischemia at lower work rates at high altitude, while those with a history of congestive heart failure have decreased exercise tolerance at high altitude as compared to healthy controls and are at higher risk of suffering an exacerbation of their heart failure. PULMONARY EFFECTS: High altitude is associated with various adverse pulmonary effects, including high-altitude pulmonary edema, pulmonary hypertension, subacute mountain sickness, and chronic mountain sickness. Mining at altitude has been reported to accelerate silicosis and other pneumoconioses. Miners with pre-existing pneumoconioses may experience an exacerbation of their condition at altitude. Persons traveling to high altitude have a higher incidence of Cheyne-Stokes respiration while sleeping than do persons native to high altitude. Obesity increases the risk of pulmonary hypertension, acute mountain sickness, and sleep-disordered breathing. NEUROLOGICAL EFFECTS: The most common adverse neurological

Acute and Chronic Altitude-Induced Cognitive Dysfunction in Children and Adolescents.

Science.gov (United States)

Rimoldi, Stefano F; Rexhaj, Emrush; Duplain, Hervé; Urben, Sébastien; Billieux, Joël; Allemann, Yves; Romero, Catherine; Ayaviri, Alejandro; Salinas, Carlos; Villena, Mercedes; Scherrer, Urs; Sartori, Claudio

2016-02-01

To assess whether exposure to high altitude induces cognitive dysfunction in young healthy European children and adolescents during acute, short-term exposure to an altitude of 3450 m and in an age-matched European population permanently living at this altitude. We tested executive function (inhibition, shifting, and working memory), memory (verbal, short-term visuospatial, and verbal episodic memory), and speed processing ability in: (1) 48 healthy nonacclimatized European children and adolescents, 24 hours after arrival at high altitude and 3 months after return to low altitude; (2) 21 matched European subjects permanently living at high altitude; and (3) a matched control group tested twice at low altitude. Short-term hypoxia significantly impaired all but 2 (visuospatial memory and processing speed) of the neuropsychological abilities that were tested. These impairments were even more severe in the children permanently living at high altitude. Three months after return to low altitude, the neuropsychological performances significantly improved and were comparable with those observed in the control group tested only at low altitude. Acute short-term exposure to an altitude at which major tourist destinations are located induces marked executive and memory deficits in healthy children. These deficits are equally marked or more severe in children permanently living at high altitude and are expected to impair their learning abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Increased insulin requirements during exercise at very high altitude in type 1 diabetes

NARCIS (Netherlands)

de Mol, Pieter; de Vries, Suzanna T.; de Koning, Eelco J. P.; Gans, Rijk O. B.; Tack, Cees J.; Bilo, Henk J. G.

OBJECTIVE-Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in

Patent Foramen Ovale as a Risk Factor for Altitude Decompression Illness

Science.gov (United States)

2001-06-01

Medical Issues in Hypo-and Hyperbaric Conditions [les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares ] To order the...on "Operational Medical Issues in Hypo- and Hyperbaric Conditions ", held in Toronto, Canada, 16-19 October 2000, and published in RTO MP-062. 3-2...Space Environ Med 1996; 67: 1092-6. Powell MR, Norfleet WT, Kumar KV, Butler BD. Patent foramen ovale and hypobaric decompression. Aviat Space Environ

Zinc prevents sickness behavior induced by lipopolysaccharides after a stress challenge in rats.

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Thiago B Kirsten

Full Text Available Sickness behavior is considered part of the specific beneficial adaptive behavioral and neuroimmune changes that occur in individuals in response to infectious/inflammatory processes. However, in dangerous and stressful situations, sickness behavior should be momentarily abrogated to prioritize survival behaviors, such as fight or flight. Taking this assumption into account, we experimentally induced sickness behavior in rats using lipopolysaccharides (LPS, an endotoxin that mimics infection by gram-negative bacteria, and then exposed these rats to a restraint stress challenge. Zinc has been shown to play a regulatory role in the immune and nervous systems. Therefore, the objective of this study was to examine the effects of zinc treatment on the sickness response of stress-challenged rats. We evaluated 22-kHz ultrasonic vocalizations, open-field behavior, tumor necrosis factor α (TNF-α, corticosterone, and brain-derived neurotrophic factor (BDNF plasma levels. LPS administration induced sickness behavior in rats compared to controls, i.e., decreases in the distance traveled, average velocity, rearing frequency, self-grooming, and number of vocalizations, as well as an increase in the plasma levels of TNF-α, compared with controls after a stressor challenge. LPS also decreased BDNF expression but did not influence anxiety parameters. Zinc treatment was able to prevent sickness behavior in LPS-exposed rats after the stress challenge, restoring exploratory/motor behaviors, communication, and TNF-α levels similar to those of the control group. Thus, zinc treatment appears to be beneficial for sick animals when they are facing risky/stressful situations.

The effect of core decompression on local expression of BMP-2, PPAR-γ and bone regeneration in the steroid-induced femoral head osteonecrosis

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Wang Wei

2012-08-01

Full Text Available Abstract Background To investigate the efficacy of the sole core decompression surgery for the treatment of steroid-induced femoral head osteonecrosis. Methods The model was established by administration of steroids in combination with horse serum. The rabbits with bilateral femoral head osteonecrosis were randomly selected to do the one side of core decompression. The other side was used as the sham. Quantitative RT-PCR and western blot techniques were used to measure the local expression of BMP-2 and PPAR-γ. Bone tissues from control and operation groups were histologically analyzed by H&E staining. The comparisons of the local expression of BMP-2 and PPAR-γ and the bone regeneration were further analyzed between different groups at each time point. Results The expression of BMP-2 in the osteonecrosis femoral head with or without decompression was significantly lower than that in normal animals. BMP-2 expression both showed the decreasing trend with the increased post-operation time. No significant difference of BMP-2 expression occurred between femoral head osteonecrosis with and without decompression. The PPAR-γ expression in the femoral head osteonecrosis with and without core decompression both was significantly higher than that in control. Its expression pattern showed a significantly increased trend with increased the post-operation time. However, there was no significant difference of PPAR-γ expression between the femoral head osteonecrosis with and without decompression at each time point. Histopathological analysis revealed that new trabecular bone and a large number of osteoblasts were observed in the steroid-induced femoral head osteonecrosis with lateral decompression at 8 weeks after surgery, but there still existed trabecular bone fractures and bone necrosis. Conclusions Although decompression takes partial effect in promoting bone regeneration in the early treatment of femoral head osteonecrosis, such an effect does not

Athletes at High Altitude.

Science.gov (United States)

Khodaee, Morteza; Grothe, Heather L; Seyfert, Jonathan H; VanBaak, Karin

2016-01-01

Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes. A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar. Clinical review. Level 3. AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks. Individualized and appropriate acclimatization is an essential component of injury and illness prevention.

Decompression sickness among diving fishermen in Mexico: observational retrospective analysis of DCS in three sea cucumber fishing seasons.

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Huchim-Lara, Oswaldo; Chin, Walter; Salas, Silvia; Rivera-Canul, Normando; Cordero-Romero, Salvador; Tec, Juan; Joo, Ellie; Mendez-Dominguez, Nina

2017-01-01

The probabilities of decompression sickness (DCS) among diving fishermen are higher than in any other group of divers. Diving behavior of artisanal fishermen has been directed mainly to target high-value species. The aim of this study was to learn about the occurrence of DCS derived from sea cucumber harvesting in the Yucatán Peninsula, Mexico. We conducted a retrospective chart review of diving fishermen treated at a multiplace hyperbaric chamber in Tizimín, Mexico. In total, 233 recompression therapies were rendered to 166 diving fishermen from 2014 to 2016. The average age was 36.7 ± 9.2 years (range: 20-59 years); 84.3% had experienced at least one DCS event previously. There was a correlation between age and DCS incidents (F: 8.3; R2: 0.07) and differences in the fishing depth between seasons (H: 9.99; p⟨0.05). Musculoskeletal pain was the most frequently reported symptom. Three divers, respectively, suffered permanent hearing loss, spinal cord injury and fatal outcome. Diving fishermen experience DCS at an alarmingly high rate, probably due to the type of species targeted, given the requirements in each case. Understanding divers' behaviors and their incentives while in pursuit of high-value species such as sea cucumber could help to find ways to mitigate health risks and help enforce regulation. Copyright© Undersea and Hyperbaric Medical Society.

Preacclimatization in hypoxic chambers for high altitude sojourns.

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Küpper, Thomas E A H; Schöffl, Volker

2010-09-01

Since hypoxic chambers are more and more available, they are used for preacclimatization to prepare for sojourns at high altitude. Since there are different protocols and the data differ, there is no general consensus about the standard how to perform preacclimatization by simulated altitude. The paper reviews the different types of exposure and focuses on the target groups which may benefit from preacclimatization. Since data about intermittent hypoxia for some hours per day to reduce the incidence of acute mountain sickness differ, it is suggested to perform preacclimatization by sleeping some nights at a simulated altitude which follows the altitude profile of the "gold standard" for high altitude acclimatization.

Risk of Decompression Sickness in Shallow No-Stop Air Diving An Analysis of Naval Safety Center Data 1990-1994

National Research Council Canada - National Science Library

Flynn, E

1998-01-01

...) in shallow no-stop air diving using current U.S. Navy no-decompression limits (USN57). Navy and Marine Corp divers performed 163,400 no-decompression dives between 21 and 55 feet of sea water (fsw...

The Pathophysiology of Decompression Sickness and the Effects of Doppler Detectable Bubbles.

Science.gov (United States)

1980-12-18

workers (Harvey, 1951a and 1951b) and Blinks, Twitty and Whiteker (1951) show that muscular activity was a 23 ~I. predisposing factor to the formation of...Hills, 1966), the mechanism of action is somewhat specific (neural distension ); but for those theories utilizing circulation and/or intravascular...highly perfused non- muscular tissue, such as kidney, forms a gas phase following decompression, Doppler perivascular cuff probes were surgically placed on

Failure of the straight-line DCS boundary when extrapolated to the hypobaric realm.

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Conkin, J; Van Liew, H D

1992-11-01

The lowest pressure (P2) to which a diver can ascend without developing decompression sickness (DCS) after becoming equilibrated at some higher pressure (P1) is described by a straight line with a negative y-intercept. We tested whether extrapolation of such a line also predicts safe decompression to altitude. We substituted tissue nitrogen pressure (P1N2) calculated for a compartment with a 360-min half-time for P1 values; this allows data from hypobaric exposures to be plotted on a P2 vs. P1N2 graph, even if the subject breathes oxygen before ascent. In literature sources, we found 40 reports of human exposures in hypobaric chambers that fell in the region of a P2 vs. P1N2 plot where the extrapolation from hyperbaric data predicted that the decompression should be free of DCS. Of 4,576 exposures, 785 persons suffered decompression sickness (17%), indicating that extrapolation of the diver line to altitude is not valid. Over the pressure range spanned by human hypobaric exposures and hyperbaric air exposures, the best separation between no DCS and DCS on a P2 vs. P1N2 plot seems to be a curve which approximates a straight line in the hyperbaric region but bends toward the origin in the hypobaric region.

Cold induced peripheral vasodilation at high altitudes- a field study

NARCIS (Netherlands)

Daanen, H.A.M.; Ruiten, H.J.A. van

2000-01-01

A significant reduction in cold-induced vasodilation (CIVD) is observed at high altitudes. No agreement is found in the literature about acclimatization effects on CIVD. Two studies were performed to investigate the effect of altitude acclimatization on CIVD. In the first study 13 male subjects

Twenty Years of Research on Cytokine-Induced Sickness Behavior*

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Dantzer, Robert; Kelley, Keith W.

2007-01-01

Cytokine-induced sickness behavior was recognized within a few years of the cloning and expression of interferon-α, IL-1 and IL-2, which occurred around the time that the first issue of Brain, Behavior, and Immunity was published in 1987. Phase I clinical trials established that injection of recombinant cytokines into cancer patients led to a variety of psychological disturbances. It was subsequently shown that physiological concentrations of proinflammatory cytokines that occur after infection act in the brain to induce common symptoms of sickness, such as loss of appetite, sleepiness, withdrawal from normal social activities, fever, aching joints and fatigue. This syndrome was defined as sickness behavior and is now recognized to be part of a motivational system that reorganizes the organism's priorities to facilitate recovery from the infection. Cytokines convey to the brain that an infection has occurred in the periphery, and this action of cytokines can occur via the traditional endocrine route via the blood or by direct neural transmission via the afferent vagus nerve. The finding that sickness behavior occurs in all mammals and birds indicates that communication between the immune system and brain has been evolutionarily conserved and forms an important physiological adaptive response that favors survival of the organism during infections. The fact that cytokines act in the brain to induce physiological adaptations that promote survival has led to the hypothesis that inappropriate, prolonged activation of the innate immune system may be involved in a number of pathological disturbances in the brain, ranging from Alzheimers' disease to stroke. Conversely, the newly-defined role of cytokines in a wide variety of systemic co-morbid conditions, ranging from chronic heart failure to obesity, may begin to explain changes in the mental state of these subjects. Indeed, the newest findings of cytokine actions in the brain offer some of the first clues about the

Report on computation of repetitive hyperbaric-hypobaric decompression tables

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Edel, P. O.

1975-01-01

The tables were constructed specifically for NASA's simulated weightlessness training program; they provide for 8 depth ranges covering depths from 7 to 47 FSW, with exposure times of 15 to 360 minutes. These tables were based up on an 8 compartment model using tissue half-time values of 5 to 360 minutes and Workmanline M-values for control of the decompression obligation resulting from hyperbaric exposures. Supersaturation ratios of 1.55:1 to 2:1 were used for control of ascents to altitude following such repetitive dives. Adequacy of the method and the resultant tables were determined in light of past experience with decompression involving hyperbaric-hypobaric interfaces in human exposures. Using these criteria, the method showed conformity with empirically determined values. In areas where a discrepancy existed, the tables would err in the direction of safety.

Needle Decompression of Tension Pneumothorax with Colorimetric Capnography.

Science.gov (United States)

Naik, Nimesh D; Hernandez, Matthew C; Anderson, Jeff R; Ross, Erika K; Zielinski, Martin D; Aho, Johnathon M

2017-11-01

The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression. Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002). Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Operational Medical Issues in Hypo-and Hyperbaric Conditions (les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares)

Science.gov (United States)

2001-06-01

Research Centre; 1994:54-59. 15. Rudge FW. Relationship of menstrual history to altitude chamber decompression sickness. Aviation, Space, and...This is due to the pattern of the O2 dissociation curve. At low O2 saturation the same shunt gives a smaller effect on Pa,O2 versus PA,O2. 41-4 COPA

High Altitude and Heart

Directory of Open Access Journals (Sweden)

Murat Yalcin

2011-04-01

Full Text Available Nowadays, situations associated with high altitude such as mountaineering, aviation increasingly draw the attention of people. Gas pressure decreases and hypoxia is encountered when climbing higher. Physiological and pathological responses of human body to different heights are different. Therefore, physiological and pathological changes that may occur together with height and to know the clinical outcomes of these are important . Acute mountain sickness caused by high altitude and high altitude cerebral edema are preventable diseases with appropriate precautions. Atmospheric oxygen decreasing with height, initiates many adaptive mechanisms. These adaptation mechanisms and acclimatization vary widely among individuals because of reasons such as environmental factors, exercise and cold. High altitude causes different changes in the cardiovascular system with various mechanisms. Although normal individuals easily adapt to these changes, this situation can lead to undesirable results in people with heart disease. For this reason, it should be known the effective evaluation of the people with known heart disease before traveling to high altitude and the complications due to the changes with height and the recommendations can be made to these patients. [TAF Prev Med Bull 2011; 10(2.000: 211-222

White Matter Hyperintensities on MRI in High-Altitude U-2 Pilots

Science.gov (United States)

2013-08-19

SUBJECT TERMS MRI; white matter hyperintensities; hypobaric exposure; neurological decompression sickness 16. SECURITY CLASSIFICATION OF: 17...normal controls and did not increase with age in pilots, suggesting that hypobaric exposure produces white matter damage different from that occurring in...relapse we observed in 3 NDCS pilots after successful hyperbaric treatment (US Navy Treatment Table 6; 100% fraction of inspired oxygen; 2.8 atm absolute

Elevated plasma cholecystokinin at high altitude: metabolic implications for the anorexia of acute mountain sickness.

Science.gov (United States)

Bailey, D M; Davies, B; Milledge, J S; Richards, M; Williams, S R; Jordinson, M; Calam, J

2000-01-01

The aims of the present study were to measure the satiety neuropeptide cholecystokinin (CCK) in humans at terrestrial high altitude to investigate its possible role in the pathophysiology of anorexia, cachexia, and acute mountain sickness (AMS). Nineteen male mountaineers aged 38 +/- 12 years participated in a 20 +/- 5 day trek to Mt. Kanchenjunga basecamp (BC) located at 5,100 m, where they remained for 7 +/- 5 days. Subjects were examined at rest and during a maximal exercise test at sea-level before/after the expedition (SL1/SL2) and during the BC sojourn. There was a mild increase in Lake Louise AMS score from 1.1 +/- 1.2 points at SL1 to 2.3 +/- 2.3 points by the end of the first day at BC (P anorexia on Day 2 compared with those with a normal appetite. While there was no relationship between the increase in CCK and AMS score at BC, a more pronounced increase in resting CCK was observed in subjects with AMS (> or =3 points at the end of Day 1 at BC) compared with those without (+98.9 +/- 1.4 pmol/L(-1) vs. +67.6 +/- 37.2 pmol/L(-1), P < 0.05). Caloric intake remained remarkably low during the stay at BC (8.9 +/- 1.4 MJ.d(-1)) despite a progressive decrease in total body mass (-4.5 +/- 2.1 kg after 31 +/- 13 h at BC, P < 0.05 vs. SL1/SL2), which appeared to be due to a selective loss of torso adipose tissue. These findings suggest that the satiogenic effects of CCK may have contributed to the observed caloric deficit and subsequent cachexia at high altitude despite adequate availability of palatable foods. The metabolic implications of elevated CCK in AMS remain to be elucidated.

Iron supplementation at high altitudes induces inflammation and oxidative injury to lung tissues in rats

Energy Technology Data Exchange (ETDEWEB)

Salama, Samir A., E-mail: salama.3@buckeyemail.osu.edu [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11751 (Egypt); Department of Pharmacology and GTMR Unit, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); Omar, Hany A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Maghrabi, Ibrahim A. [Department of Clinical Pharmacy, College of Clinical Pharmacy, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); AlSaeed, Mohammed S. [Department of Surgery, College of Medicine, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia); EL-Tarras, Adel E. [High Altitude Research Center, Taif University, Al-Haweiah, Taif 21974 (Saudi Arabia)

2014-01-01

Exposure to high altitudes is associated with hypoxia and increased vulnerability to oxidative stress. Polycythemia (increased number of circulating erythrocytes) develops to compensate the high altitude associated hypoxia. Iron supplementation is, thus, recommended to meet the demand for the physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes-associated oxidative stress. The aim of this study was to explore the potential iron-induced oxidative lung tissue injury in rats at high altitudes (6000 ft above the sea level). Iron supplementation (2 mg elemental iron/kg, once daily for 15 days) induced histopathological changes to lung tissues that include severe congestion, dilatation of the blood vessels, emphysema in the air alveoli, and peribronchial inflammatory cell infiltration. The levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), lipid peroxidation product and protein carbonyl content in lung tissues were significantly elevated. Moreover, the levels of reduced glutathione and total antioxidant capacity were significantly reduced. Co-administration of trolox, a water soluble vitamin E analog (25 mg/kg, once daily for the last 7 days of iron supplementation), alleviated the lung histological impairments, significantly decreased the pro-inflammatory cytokines, and restored the oxidative stress markers. Together, our findings indicate that iron supplementation at high altitudes induces lung tissue injury in rats. This injury could be mediated through excessive production of reactive oxygen species and induction of inflammatory responses. The study highlights the tissue injury induced by iron supplementation at high altitudes and suggests the co-administration of antioxidants such as trolox as protective measures. - Highlights: • Iron supplementation at high altitudes induced lung histological changes in rats. • Iron induced oxidative stress in lung tissues of rats at high altitudes. • Iron

Iron supplementation at high altitudes induces inflammation and oxidative injury to lung tissues in rats

International Nuclear Information System (INIS)

Salama, Samir A.; Omar, Hany A.; Maghrabi, Ibrahim A.; AlSaeed, Mohammed S.; EL-Tarras, Adel E.

2014-01-01

Exposure to high altitudes is associated with hypoxia and increased vulnerability to oxidative stress. Polycythemia (increased number of circulating erythrocytes) develops to compensate the high altitude associated hypoxia. Iron supplementation is, thus, recommended to meet the demand for the physiological polycythemia. Iron is a major player in redox reactions and may exacerbate the high altitudes-associated oxidative stress. The aim of this study was to explore the potential iron-induced oxidative lung tissue injury in rats at high altitudes (6000 ft above the sea level). Iron supplementation (2 mg elemental iron/kg, once daily for 15 days) induced histopathological changes to lung tissues that include severe congestion, dilatation of the blood vessels, emphysema in the air alveoli, and peribronchial inflammatory cell infiltration. The levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), lipid peroxidation product and protein carbonyl content in lung tissues were significantly elevated. Moreover, the levels of reduced glutathione and total antioxidant capacity were significantly reduced. Co-administration of trolox, a water soluble vitamin E analog (25 mg/kg, once daily for the last 7 days of iron supplementation), alleviated the lung histological impairments, significantly decreased the pro-inflammatory cytokines, and restored the oxidative stress markers. Together, our findings indicate that iron supplementation at high altitudes induces lung tissue injury in rats. This injury could be mediated through excessive production of reactive oxygen species and induction of inflammatory responses. The study highlights the tissue injury induced by iron supplementation at high altitudes and suggests the co-administration of antioxidants such as trolox as protective measures. - Highlights: • Iron supplementation at high altitudes induced lung histological changes in rats. • Iron induced oxidative stress in lung tissues of rats at high altitudes. • Iron

Isosorbide-Induced Decompression Effect on the Scala Media: Participation of Plasma Osmolality and Plasma Arginine Vasopressin.

Science.gov (United States)

Takeda, Taizo; Takeda, Setsuko; Uehara, Natsumi; Yanagisawa, Shungaku; Furukawa, Tatsuya; Nibu, Ken-Ichi; Kakigi, Akinobu

2017-04-01

The correlation between the isosorbide-induced decompression effect on the endolymphatic space and plasma osmolality (p-OSM) or plasma arginine vasopressin (p-AVP) was investigated on comparing two different dosages of isosorbide (2.8 and 1.4 g/kg) to elucidate why the decompression effect is delayed with a large dose of isosorbide. Two experiments were performed using 80 guinea pigs. Experiment 1 was designed to morphologically investigate the sequential influence of the oral intake of 1.4- and 2.8-g/kg doses of isosorbide on the endolymphatic volume. The animals used were 50 guinea pigs (control: 10, experimental: 40). All animals underwent surgical obliteration of the endolymphatic sac of the left ear. One month after the surgery, control animals were sacrificed 3 hours after the intake of distilled water, and experimental animals were sacrificed 3 and 6 hours after the isosorbide intake. All of the left temporal bone served for the quantitative assessment of changes in the endolymphatic space, and the cross-sectional area of the scala media was measured from the mid-modiolar sections of the cochlea.Experiment 2 was designed to investigate changes in p-OSM and p-AVP levels 3 hours after the oral intake of isosorbide. Animals used were 15 guinea pigs (control: 5, experimental: 10). The control group received the oral administration of distilled water (4 ml/kg), and the experimental animals were subdivided into two groups consisting of 10 animals each by the dosage of isosorbide (1.4 or 2.8 g/kg). All animals were sacrificed for the measurement of p-OSM and p-AVP concentrations 3 hours after the intake of water or 70% isosorbide solution. Morphologically, an isosorbide-induced decompression effect was noted in animals with both 1.4- and 2.8-g/kg doses of isosorbide. According to the regression analysis, however, the volumetric decrease of the endolymphatic space was more evident in cases with the small dose (1.4 g/kg) 3 hours after the intake

Effect of carbon dioxide in acute mountain sickness

DEFF Research Database (Denmark)

Harvey, T C; Raichle, M E; Winterborn, M H

1988-01-01

of the respiratory alkalosis normally seen at high altitude. Symptoms of acute mountain sickness were rapidly relieved. In three subjects cerebral blood flow increased by 17-39%, so that oxygen delivery to the brain would have been considerably improved. This study confirms earlier suggestions of the beneficial...

Decompression Retinopathy after ExPRESS Shunt Implantation for Steroid-Induced Ocular Hypertension: A Case Report

Directory of Open Access Journals (Sweden)

Khawla Abu Samra

2011-01-01

Full Text Available Purpose. To present a unique case of decompression retinopathy after the implantation of ExPRESS drainage device. Method. A 25-year-old female patient underwent implantation of ExPRESS drainage device in the left eye for the management of steroid-induced ocular hypertension. Results. On the postoperative day one, best-corrected visual acuity in the left eye was 20/50. Fundus examination revealed diffuse intraretinal hemorrhages, some white-centered, throughout the retina. There was also marked tortuosity to the retinal vasculature and no evidence of choroidal effusion. Intravenous fluorescein angiography and indocyanine green did not contribute to the aetiopathogenesis. Conclusion. Decompression retinopathy can occur following the implantation of ExPRESS drainage device. It is very important to be aware of this complication in patients with relatively high intraocular pressure who is planned for filtration surgery, including the ExPRESS implant.

Evaluation of adaptation to visually induced motion sickness based on the maximum cross-correlation between pulse transmission time and heart rate

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Chiba Shigeru

2007-09-01

Full Text Available Abstract Background Computer graphics and virtual reality techniques are useful to develop automatic and effective rehabilitation systems. However, a kind of virtual environment including unstable visual images presented to wide field screen or a head mounted display tends to induce motion sickness. The motion sickness induced in using a rehabilitation system not only inhibits effective training but also may harm patients' health. There are few studies that have objectively evaluated the effects of the repetitive exposures to these stimuli on humans. The purpose of this study is to investigate the adaptation to visually induced motion sickness by physiological data. Methods An experiment was carried out in which the same video image was presented to human subjects three times. We evaluated changes of the intensity of motion sickness they suffered from by a subjective score and the physiological index ρmax, which is defined as the maximum cross-correlation coefficient between heart rate and pulse wave transmission time and is considered to reflect the autonomic nervous activity. Results The results showed adaptation to visually-induced motion sickness by the repetitive presentation of the same image both in the subjective and the objective indices. However, there were some subjects whose intensity of sickness increased. Thus, it was possible to know the part in the video image which related to motion sickness by analyzing changes in ρmax with time. Conclusion The physiological index, ρmax, will be a good index for assessing the adaptation process to visually induced motion sickness and may be useful in checking the safety of rehabilitation systems with new image technologies.

MR imaging of the central nervous system in diving-related decompression illness

International Nuclear Information System (INIS)

Reuter, M.; Hutzelmann, A.; Steffens, J.C.; Heller, M.; Fritsch, G.

1997-01-01

Purpose: This investigation was conducted to determine whether MR imaging showed cerebral or spinal damage in acute diving-related decompression illness, a term that includes decompressions sickness (DCS) and arterial gas embolism (AGE). Material and Methods: A total of 16 divers with dysbaric injuries were examined after the initiation of therapeutic recompression. Their injuries comprised: neurological DCS II n=8; AGE n=7; combined cerebral-AGE/spinal-DCS n=1. T1- and T2-weighted images of the brain were obtained in 2 planes. In addition, the spinal cord was imaged in 7 subjects. The imaging findings were correlated with the neurological symptoms. Results: MR images of the head showed ischemic cerebrovascular lesions in 6/8 patients with AGE but showed focal hyperintensities in only 2/8 divers with DCS. Spinal-cord involvement was detected in 1/7 examinations, which was the combined cerebral-AGE/spinal-DCS case. There was agreement between the locations of the documented lesions and the clinical manifestations. Conclusion: MR readily detects cerebral damage in AGE but yields low sensitivity in DCS. A negative MR investigation cannot rule out AGE or DCS. However, MR is useful in the examination of patients with decompression illness. (orig.)

The incidence of diplopia following coronal and translid orbital decompression in Graves' orbitopathy

NARCIS (Netherlands)

Paridaens, D.; Hans, K.; van Buitenen, S.; Mourits, M. P.

1998-01-01

PURPOSE: Firstly, to assess the incidence of induced diplopia following orbital decompression in patients with Graves' orbitopathy. Secondly, to assess patient satisfaction after orbital decompression. Thirdly, to determine the factors that contribute to the variable reported incidence of diplopia

Shilajit: A panacea for high-altitude problems.

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Meena, Harsahay; Pandey, H K; Arya, M C; Ahmed, Zakwan

2010-01-01

High altitude problems like hypoxia, acute mountain sickness, high altitude cerebral edema, pulmonary edema, insomnia, tiredness, lethargy, lack of appetite, body pain, dementia, and depression may occur when a person or a soldier residing in a lower altitude ascends to high-altitude areas. These problems arise due to low atmospheric pressure, severe cold, high intensity of solar radiation, high wind velocity, and very high fluctuation of day and night temperatures in these regions. These problems may escalate rapidly and may sometimes become life-threatening. Shilajit is a herbomineral drug which is pale-brown to blackish-brown, is composed of a gummy exudate that oozes from the rocks of the Himalayas in the summer months. It contains humus, organic plant materials, and fulvic acid as the main carrier molecules. It actively takes part in the transportation of nutrients into deep tissues and helps to overcome tiredness, lethargy, and chronic fatigue. Shilajit improves the ability to handle high altitudinal stresses and stimulates the immune system. Thus, Shilajit can be given as a supplement to people ascending to high-altitude areas so that it can act as a "health rejuvenator" and help to overcome high-altitude related problems.

Wilderness medicine at high altitude: recent developments in the field

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Shah NM

2015-09-01

Full Text Available Neeraj M Shah,1 Sidra Hussain,2 Mark Cooke,3 John P O’Hara,3 Adrian Mellor3,4 1Division of Asthma, Allergy and Lung Biology, King’s College London, UK; 2School of Medicine, University College London, London, UK; 3Research Institute for Sport, Physical Activity and Leisure, Leeds Beckett University, Leeds, UK; 4Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, UK Abstract: Travel to high altitude is increasingly popular. With this comes an increased incidence of high-altitude illness and therefore an increased need to improve our strategies to prevent and accurately diagnose these. In this review, we provide a summary of recent advances of relevance to practitioners who may be advising travelers to altitude. Although the Lake Louise Score is now widely used as a diagnostic tool for acute mountain sickness (AMS, increasing evidence questions the validity of doing so, and of considering AMS as a single condition. Biomarkers, such as brain natriuretic peptide, are likely correlating with pulmonary artery systolic pressure, thus potential markers of the development of altitude illness. Established drug treatments include acetazolamide, nifedipine, and dexamethasone. Drugs with a potential to reduce the risk of developing AMS include nitrate supplements, propagators of nitric oxide, and supplemental iron. The role of exercise in the development of altitude illness remains hotly debated, and it appears that the intensity of exercise is more important than the exercise itself. Finally, despite copious studies demonstrating the value of preacclimatization in reducing the risk of altitude illness and improving performance, an optimal protocol to preacclimatize an individual remains elusive. Keywords: hypoxia, acute mountain sickness, acclimatization, biomarkers, preacclimatization

The efficacy of airflow and seat vibration on reducing visually induced motion sickness

NARCIS (Netherlands)

D’Amour, Sarah; Bos, Jelte E.; Keshavarz, Behrang

2017-01-01

Visually induced motion sickness (VIMS) is a well-known sensation in virtual environments and simulators, typically characterized by a variety of symptoms such as pallor, sweating, dizziness, fatigue, and/or nausea. Numerous methods to reduce VIMS have been previously introduced; however, a reliable

Effets cardiovasculaires d'un bloqueur calcique en hypoxie d'altitude

DEFF Research Database (Denmark)

Dugas, L; Dubray, C; Herry, J P

1995-01-01

High altitude pulmonary oedema can be successfully treated and prevented by calcium channel blockers. Moreover, calcium entering in the cells could explain the congestive phenomena of acute mountain sickness (AMS). These findings led us to study the action of a calcium channel blocker, isradipine...

Acetazolamide improves cerebral oxygenation during exercise at high altitude

NARCIS (Netherlands)

Vuyk, J.; Bos, J. van den; Terhell, K.; Bos, R. de; Vletter, A.; Valk, P.; Beuzekom, M. van; Kleef, J. van; Dahan, A.

2006-01-01

Acute mountain sickness is thought to be triggered by cerebral hypoxemia and be prevented by acetazolamide (Actz). The effect of Actz on cerebral oxygenation at altitude remains unknown. In 16 members of the 2005 Dutch Cho Oyu (8201 m, Tibet) expedition, the influence of Actz and exercise (750 mg PO

Altitude training improves glycemic control.

Science.gov (United States)

Chen, Shu-Man; Lin, Hsueh-Yi; Kuo, Chia-Hua

2013-08-31

Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate the shortfall caused by reduced fatty acid oxidation. Short-term moderate altitude exposure plus endurance physical activity has been found to improve glucose tolerance (not fasting glucose) in humans, which is associated with the improvement in the whole-body insulin sensitivity. However, most of people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness and insulin resistance. There is a wide variation among individuals in response to the altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity was not apparent in those individuals with low baseline dehydroepiandrosterone sulfate (DHEA-S) concentration. In rats, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can also improve insulin sensitivity, secondary to an effective suppression of adiposity. After prolonged hypoxia training, obese abnormality in upregulated baseline levels of AMP-activated protein kinase (AMPK) and AS160 phosphorylation in skeletal muscle can be reversed. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on the favorable change in body composition. Altitude training can exert strong impact on our metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting metabolic syndromes.

Development of an Operational Altitude Decompression Sickness Computer Model: Feasibility Study Results

Science.gov (United States)

1995-08-01

1955;36pp. 44. Eger El. II. A mathematical model of uptake and distribution, ch. 7, pp.72-87 In E. M. Papper and R. J. Kitz (eds.). Uptake and...Space Environ. Med. 1992;63:386. 119. Papper EM and Kitz RJ. Uptake and distribution of anesthetic agents. New York: McGraw Hill, 1963. 67 120. Per W and

The role of oxygen-increased respirator in humans ascending to high altitude

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Shen Guanghao

2012-08-01

Full Text Available Abstract Background Acute mountain sickness (AMS is common for people who live in low altitude areas ascending to the high altitude. Many instruments have been developed to treat mild cases of AMS. However, long-lasting and portable anti-hypoxia equipment for individual is not yet available. Methods Oxygen-increased respirator (OIR has been designed to reduce the risk of acute mountain sickness in acute exposure to low air pressure. It can increase the density of oxygen by increasing total atmospheric pressure in a mask. Male subjects were screened, and eighty-eight were qualified to perform the experiments. The subjects were divided into 5 groups and were involved in some of the tests at 4 different altitudes (Group 1, 2: 3700 m; Group 3,4,5: 4000 m, 4700 m, 5380 m with and without OIR. These tests include heart rate, saturation of peripheral oxygen (SpO2, malondialdehyde (MDA, superoxide dismutase (SOD, blood lactate (BLA and PWC (physical work capacity -170. Results The results showed that higher SpO2, lower heart rate (except during exercise and better recovery of heart rate were observed from all the subjects ’with OIR’ compared with ’without OIR’ (P Conclusions We suggested that OIR may play a useful role in protecting people ascending to high altitude before acclimatization.

The effect of internal and external fields of view on visually induced motion sickness

NARCIS (Netherlands)

Bos, J.E.; Vries, S.C. de; Emmerik, M.L. van; Groen, E.L.

2010-01-01

Field of view (FOV) is said to affect visually induced motion sickness. FOV, however, is characterized by an internal setting used by the graphics generator (iFOV) and an external factor determined by screen size and viewing distance (eFOV). We hypothesized that especially the incongruence between

The use of EEG to measure cerebral changes during computer-based motion-sickness-inducing tasks

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Strychacz, Christopher; Viirre, Erik; Wing, Shawn

2005-05-01

Motion sickness (MS) is a stressor commonly attributed with causing serious navigational and performance errors. The distinct nature of MS suggests this state may have distinct neural markers distinguishable from other states known to affect performance (e.g., stress, fatigue, sleep deprivation, high workload). This pilot study used new high-resolution electro-encephalograph (EEG) technologies to identify distinct neuronal activation changes that occur during MS. Brain EEG activity was monitored while subjects performed a ball-tracking task and viewed stimuli on a projection screen intended to induce motion sickness/spatial disorientation. Results show the presence of EEG spectral changes in all subjects who developed motion sickness when compared to baseline levels. These changes included: 1) low frequency (1 to 10 Hz) changes that may reflect oculomotor movements rather than intra-cerebral sources; 2) increased spectral power across all frequencies (attributable to increased scalp conductivity related to sweating), 3) local increases of power spectra in the 20-50 Hz range (likely attributable to external muscles on the skull) and; 4) a central posterior (occipital) independent component that shows suppression of a 20 Hz peak in the MS condition when compared to baseline. Further research is necessary to refine neural markers, characterize their origin and physiology, to distinguish between motion sickness and other states and to enable markers to be used for operator state monitoring and the designing of interventions for motion sickness.

Sickness presence, sick leave and adjustment latitude

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Joachim Gerich

2014-10-01

Full Text Available Objectives: Previous research on the association between adjustment latitude (defined as the opportunity to adjust work efforts in case of illness and sickness absence and sickness presence has produced inconsistent results. In particular, low adjustment latitude has been identified as both a risk factor and a deterrent of sick leave. The present study uses an alternative analytical strategy with the aim of joining these results together. Material and Methods: Using a cross-sectional design, a random sample of employees covered by the Upper Austrian Sickness Fund (N = 930 was analyzed. Logistic and ordinary least square (OLS regression models were used to examine the association between adjustment latitude and days of sickness absence, sickness presence, and an estimator for the individual sickness absence and sickness presence propensity. Results: A high level of adjustment latitude was found to be associated with a reduced number of days of sickness absence and sickness presence, but an elevated propensity for sickness absence. Conclusions: Employees with high adjustment latitude experience fewer days of health complaints associated with lower rates of sick leave and sickness presence compared to those with low adjustment latitude. In case of illness, however, high adjustment latitude is associated with a higher pro­bability of taking sick leave rather than sickness presence.

Changes in the dark focus of accommodation associated with simulator sickness

Science.gov (United States)

Fowlkes, Jennifer E.; Kennedy, Robert S.; Hettinger, Lawrence J.; Harm, Deborah L.

1993-01-01

The relationship between the dark focus of accommodation and simulator sickness, a form of motion sickness, was examined in three experiments. In Experiment 1, dark focus was measured in 18 college students in a laboratory setting before and after they viewed a projected motion scene depicting low altitude helicopter flight. In Experiments 2 and 3, dark focus was measured in pilots (N = 16 and 23, respectively) before and after they 'flew' in moving-base helicopter flight simulators with optical infinity CRT visual systems. The results showed that individuals who experienced simulator sickness had either an inward (myopic) change in dark focus (Experiments 1 and 3) or attenuated outward shifts in dark focus (Experiment 2) relative to participants who did not get sick. These results are consonant with the hypothesis that parasympathetic activity, which may be associated with simulator sickness, should result in changes in dark focus that are in a myopic direction. Night vision goggles, virtual environments, extended periods in microgravity, and heads-up displays all produce related visual symptomatology. Changes in dark focus may occur in these conditions, as well, and should be measured.

Hyperventilation in a motion sickness desensitization program

NARCIS (Netherlands)

Mert, A.; Bles, W.; Nooij, S.A.E.

2007-01-01

Introduction: In motion sickness desensitization programs, the motion sickness provocative stimulus is often a forward bending of the trunk on a rotating chair, inducing Coriolis effects. Since respiratory relaxation techniques are applied successfully in these courses, we investigated whether these

The effect of internal and external fields of view on visually induced motion sickness.

Science.gov (United States)

Bos, Jelte E; de Vries, Sjoerd C; van Emmerik, Martijn L; Groen, Eric L

2010-07-01

Field of view (FOV) is said to affect visually induced motion sickness. FOV, however, is characterized by an internal setting used by the graphics generator (iFOV) and an external factor determined by screen size and viewing distance (eFOV). We hypothesized that especially the incongruence between iFOV and eFOV would lead to sickness. To that end we used a computer game environment with different iFOV and eFOV settings, and found the opposite effect. We speculate that the relative large differences between iFOV and eFOV used in this experiment caused the discrepancy, as may be explained by assuming an observer model controlling body motion. Copyright 2009 Elsevier Ltd. All rights reserved.

Autoradiographic observations of the induced vascular injuries by arachidonic acid in rabbit's brain and lung using 111In-oxine labeled platelets

International Nuclear Information System (INIS)

Fujimoto, Tsukasa; Fukushima, Yoshiharu; Suzuki, Hidenori; Kuroiwa, Kyoko; Tanoue, Kenjiro; Yamazaki, Hiroh.

1985-01-01

Autoradiography using 111 In-oxine labeled autologous platelets was performed to observe the behavior of platelets in induced vascular injury by activated platelets in rabbit's brain and lung. Cerebrovascular injuries were induced by injection of arachidonic acid (AA) (0.7 mg/kg) into right internal carotid artery. Fourteen animals were pretreated with antiplatelet drug, ticlopidine (200 mg/kg) and 10 were controls. Before the AA injection, 111 In-oxine (300 μCi) labeled platelets were injected intravenously. Evans blue was given as a marker of disturbances of blood brain barrier. Sixty min after the AA injection, brains were removed and autoradiographic and electron microscopic studies were done. In the nontreated animals and some of the treated animals whose platelet aggregability was not suppressed, blue staining were seen in the cerebral hemisphere of injection side and hot radioactivity in autoradiogram were revealed in corresponding area. In the treated animals whose platelet aggregability was remarkably suppressed, no or slight blue staining or radioactivity were recognized. Only in hot radioactive area, platelet thrombi and vascular injuries were seen. Vascular injuries of lung were produced by decompression after keeping animals under hyperbalic condition (6 atomosphere absolute for 40 min). Before this procedure, 111 In-oxine labeled platelets were injected. Lungs of both 4 control and 4 decompression sickness animals were removed and autoradiographic and lightmicroscopic observations were performed. In lungs of decompression sickness animals remarkable spotty high radioactivity and prominent platelet aggregates in the vessels were seen. These findings were not seen in control animals. Our results suggested important roles of platelets in induced vascular injuries. And this autoradiographic approach seemed to be quite useful for observation of platelet's behavior in injured vessels and evaluation of antiplatelet drugs. (author)

Thin Air Resulting in High Pressure: Mountain Sickness and Hypoxia-Induced Pulmonary Hypertension

Science.gov (United States)

Richter, Manuel; Tello, Khodr; Sommer, Natascha; Gall, Henning; Ghofrani, Hossein Ardeschir

2017-01-01

With rising altitude the partial pressure of oxygen falls. This phenomenon leads to hypobaric hypoxia at high altitude. Since more than 140 million people permanently live at heights above 2500 m and more than 35 million travel to these heights each year, understanding the mechanisms resulting in acute or chronic maladaptation of the human body to these circumstances is crucial. This review summarizes current knowledge of the body's acute response to these circumstances, possible complications and their treatment, and health care issues resulting from long-term exposure to high altitude. It furthermore describes the characteristic mechanisms of adaptation to life in hypobaric hypoxia expressed by the three major ethnic groups permanently dwelling at high altitude. We additionally summarize current knowledge regarding possible treatment options for hypoxia-induced pulmonary hypertension by reviewing in vitro, rodent, and human studies in this area of research. PMID:28522921

The efficacy of airflow and seat vibration on reducing visually induced motion sickness.

Science.gov (United States)

D'Amour, Sarah; Bos, Jelte E; Keshavarz, Behrang

2017-09-01

Visually induced motion sickness (VIMS) is a well-known sensation in virtual environments and simulators, typically characterized by a variety of symptoms such as pallor, sweating, dizziness, fatigue, and/or nausea. Numerous methods to reduce VIMS have been previously introduced; however, a reliable countermeasure is still missing. In the present study, the effect of airflow and seat vibration to alleviate VIMS was investigated. Eighty-two participants were randomly assigned to one of four groups (airflow, vibration, combined airflow and vibration, and control) and then exposed to a 15 min long video of a bicycle ride shot from first-person view. VIMS was measured using the Fast Motion Sickness Scale (FMS) and the Simulator Sickness Questionnaire (SSQ). Results showed that the exposure of airflow significantly reduced VIMS, whereas the presence of seat vibration, in contrast, did not have an impact on VIMS. Additionally, we found that females reported higher FMS scores than males, however, this sex difference was not found in the SSQ scores. Our findings demonstrate that airflow can be an effective and easy-to-apply technique to reduce VIMS in virtual environments and simulators, while vibration applied to the seat is not a successful method.

[Hemoglobin and testosterone: importance on high altitude acclimatization and adaptation].

Science.gov (United States)

Gonzales, Gustavo F

2011-03-01

The different types of response mechanisms that the organism uses when exposed to hypoxia include accommodation, acclimatization and adaptation. Accommodation is the initial response to acute exposure to high altitude hypoxia and is characterized by an increase in ventilation and heart rate. Acclimatization is observed in individuals temporarily exposed to high altitude, and to some extent, it enables them to tolerate the high altitudes. In this phase, erythropoiesis is increased, resulting in higher hemoglobin and hematocrit levels to improve oxygen delivery capacity. Adaptation is the process of natural acclimatization where genetical variations and acclimatization play a role in allowing subjects to live without any difficulties at high altitudes. Testosterone is a hormone that regulates erythropoiesis and ventilation and could be associated to the processes of acclimatization and adaptation to high altitude. Excessive erythrocytosis, which leads to chronic mountain sickness, is caused by low arterial oxygen saturation, ventilatory inefficiency and reduced ventilatory response to hypoxia. Testosterone increases during acute exposure to high altitude and also in natives at high altitude with excessive erythrocytosis. Results of current research allow us to conclude that increase in serum testosterone and hemoglobin is adequate for acclimatization, as they improve oxygen transport, but not for high altitude adaptation, since high serum testosterone levels are associated to excessive erythrocytosis.

Comparative incidences of decompression illness in repetitive, staged, mixed-gas decompression diving: is 'dive fitness' an influencing factor?

Science.gov (United States)

Sayer, Martin Dj; Akroyd, Jim; Williams, Guy D

2008-06-01

Wreck diving at Bikini Atoll consists of a relatively standard series of decompression dives with maximum depths in the region of 45-55 metres' sea water (msw). In a typical week of diving at Bikini, divers can perform up to 12 decompression dives to these depths over seven days; on five of those days, divers can perform two decompression dives per day. All the dives employ multi-level, staged decompression schedules using air and surface-supplied nitrox containing 80% oxygen. Bikini is serviced by a single diving operator and so a relatively precise record exists both of the actual number of dives undertaken and of the decompression illness incidents both for customer divers and the dive guides. The dive guides follow exactly the dive profiles and decompression schedules of the customers. Each dive guide will perform nearly 400 decompression dives a year, with maximum depths mostly around 50 msw, compared with an average of 10 (maximum of 12) undertaken typically by each customer diver in a week. The incidence of decompression illness for the customer population (presumed in the absence of medical records) is over ten times higher than that for the dive guides. The physiological reasons for such a marked difference are discussed in terms of customer demographics and dive-guide acclimatization to repetitive decompression stress. The rates of decompression illness for a range of diving populations are reviewed.

The potential role of perfluorocarbon emulsions in decompression illness.

Science.gov (United States)

Spiess, Bruce D

2010-03-01

Decompression illness (DCI) is an occasional occurrence in sport, professional, and military diving as well as a potential catastrophe in high-altitude flight, space exploration, mining, and caisson bridge construction. DCI theoretically could be a success-limiting problem in escape from a disabled submarine (DISSUB). Perfluorocarbon emulsions (PFCs) have previously been investigated as 'blood substitutes' with one approved by the United States Food and Drug Administration for the treatment of myocardial ischaemia. PFCs possess enhanced (as compared to plasma) respiratory gas solubility characteristics, including oxygen, nitrogen and carbon dioxide. This review examines approximately 30 years of research regarding the utilization of PFCs in gas embolism as well as experimental DCI. To date, no humans have been treated with PFCs for DCI.

Cardiopulmonary Changes with Moderate Decompression in Rats

Science.gov (United States)

Robinson, R.; Little, T.; Doursout, M.-F.; Butler, B. D.; Chelly, J. E.

1996-01-01

Sprague-Dawley rats were compressed to 616 kPa for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at base-line, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression, pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.

Update in the understanding of altitude-induced limitations to performance in team-sport athletes.

Science.gov (United States)

Billaut, François; Aughey, Robert J

2013-12-01

The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200-2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform consecutive accelerations (CAC) or sprint endurance and thereby change the outcome of a match. The higher the altitude, the more severe the hypoxaemia, and thus, the larger the expected decline in aerobic endurance, CAC and match running performance. Therefore, it is critical for athletes and coaches to understand how arterial hypoxaemia affects aerobic endurance and CAC and the magnitude of decline they may face at altitude for optimal preparation and increased chances of success. This mini review summarises the effects of acute altitude/hypoxia exposure on aerobic endurance, CAC and activity profiles of TS athletes performing in the laboratory and during matches at natural altitude, and analyses the latest findings about the consequences of arterial hypoxaemia on the relationship between peripheral perturbations, neural adjustments and performance during repeated sprints or CAC. Finally, we briefly discuss how altitude training can potentially help athletes prepare for competition at altitude.

[Decompression problems in diving in mountain lakes].

Science.gov (United States)

Bühlmann, A A

1989-08-01

The relationship between tolerated high-pressure tissue nitrogen and ambient pressure is practically linear. The tolerated nitrogen high pressure decreases at altitude, as the ambient pressure is lower. Additionally, tissues with short nitrogen half-times have a higher tolerance than tissues which retain nitrogen for longer duration. For the purpose of determining safe decompression routines, the human body can be regarded as consisting of 16 compartments with half-times from 4 to 635 minutes for nitrogen. The coefficients for calculation of the tolerated nitrogen-high pressure in the tissues can be deduced directly from the half-times for nitrogen. We show as application the results of 573 simulated air dives in the pressure-chamber and 544 real dives in mountain lakes in Switzerland (1400-2600 m above sea level) and in Lake Titicaca (3800 m above sea level). They are in accordance with the computed limits of tolerance.

Incidence and Symptoms of High Altitude Illness in South Pole Workers: Antarctic Study of Altitude Physiology (ASAP

Directory of Open Access Journals (Sweden)

Paul J. Anderson

2011-01-01

Full Text Available Introduction Each year, the US Antarctic Program rapidly transports scientists and support personnel from sea level (SL to the South Pole (SP, 2835 m providing a unique natural laboratory to quantify the incidence of acute mountain sickness (AMS, patterns of altitude related symptoms and the field effectiveness of acetazolamide in a highly controlled setting. We hypothesized that the combination of rapid ascent (3 hr, accentuated hypobarism (relative to altitude, cold, and immediate exertion would increase altitude illness risk. Methods Medically screened adults (N = 246, age = 37 ± 11 yr, 30% female, BMI = 26 ± 4 kg/m 2 were recruited. All underwent SL and SP physiological evaluation, completed Lake Louise symptom questionnaires (LLSQ, to define AMS, and answered additional symptom related questions (eg, exertional dyspnea, mental status, cough, edema and general health, during the 1st week at altitude. Acetazolamide, while not mandatory, was used by 40% of participants. Results At SP, the barometric pressure resulted in physiological altitudes that approached 3400 m, while T ° C averaged -42, humidity 0.03%. Arterial oxygen saturation averaged 89% ± 3%. Overall, 52% developed LLSQ defined AMS. The most common symptoms reported were exertional dyspnea-(87%, sleeping difficulty-(74%, headache-(66%, fatigue-(65%, and dizziness/lightheadedness-(46%. Symptom severity peaked on days 1-2, yet in >20% exertional dyspnea, fatigue and sleep problems persisted through day 7. AMS incidence was similar between those using acetazolamide and those abstaining (51 vs. 52%, P = 0.87. Those who used acetazolamide tended to be older, have less altitude experience, worse symptoms on previous exposures, and less SP experience. Conclusion The incidence of AMS at SP tended to be higher than previously reports in other geographic locations at similar altitudes. Thus, the SP constitutes a more intense altitude exposure than might be expected considering physical

Neutron-induced single event upsets in static RAMS observed at 10 km flight altitude

International Nuclear Information System (INIS)

Olsen, J.; Becher, P.E.; Fynbo, P.B.; Raaby, P. Schultz, J.

1993-01-01

Neutron induced single event upsets (SEUs) in static memory devices (SRAMs) have so far been seen only in laboratory environments. The authors report observations of 14 neutron induced SEUs at commercial aircraft flight altitudes as well. The observed SEU rate at 10 km flight altitude based on exposure of 160 standard 256 Kbit CMOS SRAMs is 4.8 · 10 -8 upsets/bit/day. In the laboratory 117 SRAMs of two different brands were irradiated with fast neutrons from a Pu-Be source. A total of 176 SEUs have been observed, among these are two SEU pairs. The upset rates from the laboratory tests are compared to those found in the airborne SRAMS

An anxiety, personality and altitude symptomatology study during a 31-day period of hypoxia in a hypobaric chamber (experiment 'Everest-Comex 1997').

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Nicolas, M; Thullier-Lestienne, F; Bouquet, C; Gardette, B; Gortan, C; Joulia, F; Bonnon, M; Richalet, J P; Therme, P; Abraini, J H

1999-12-01

Extreme environmental situations are useful tools for the investigation of the general processes of adaptation. Among such situations, high altitude of more than 3000 m produces a set of pathological disorders that includes both cerebral (cAS) and respiratory (RAS) altitude symptoms. High altitude exposure further induces anxiety responses and behavioural disturbances. The authors report an investigation on anxiety responses, personality traits, and altitude symptoms (AS) in climbers participating in a 31-day period of confinement and gradual decompression in a hypobaric chamber equivalent to a climb from sea-level to Mount Everest (8848 m altitude). Personality traits, state-trait anxiety, and AS were assessed, using the Cattell 16 Personality Factor questionnaire (16PF), the Spielberger's State-Trait Anxiety Inventory (STAI), and the Lake Louise concensus questionnaire. Results show significant group effect for state-anxiety and AS; state-anxiety and AS increased as altitude increased. They also show that state-type anxiety shows a similar time-course to cAS, but not RAS. Alternatively, our results demonstrate a significant negative correlation between Factor M of the 16PF questionnaire, which is a personality trait that ranges from praxernia to autia. In contrast, no significant correlation was found between personality traits and AS. This suggests that AS could not be predicted using personality traits and further support that personality traits, such as praxernia (happening sensitivity), could play a major role in the occurrence of state-type anxiety responses in extreme environments. In addition, the general processes of coping and adaptation in individuals participating in extreme environmental experiments are discussed.

Novel drugs in the management of acute mountain sickness and high altitude pulmonary edema

OpenAIRE

Gaurav Sikri, Gaurav; Bhattacharya,Anirban

2015-01-01

Gaurav Sikri, Anirban Bhattacharya Department of Physiology, Armed Forces Medical College, Wanowarie, Pune, IndiaWe read with great interest the review article titled “Wilderness medicine at high altitude: recent developments in the field” by Shah et al.1 The authors have comprehensively summarized the recent advances in the field of high altitude medicine relevant to sports and travel medicine. However, Shah et al have described potential drugs for management of high-alti...

The characters and developments of therapy and research of neutron-induced acute radiation sickness

International Nuclear Information System (INIS)

Wang Xinru; Luo Qingliang; Wang Baoqing; Dong Shukui

2003-01-01

Neutron radiation will exert seriously lesions on body and lead to acute radiation sickness (ARS). Neutron induced ARS is characterized by complicated symptoms of gastrointestinal, high earlier death rate and lacking of specially therapeutic approaches. The primarily curable method is to treat patients with comprehensive means such as anti-infection, anti-bleeding and blood infusion, et. Cytokines can improve the hematopoietic functions of bone marrow. With the rapid development of the molecular biology and the emergence of cytokines such as recombinant human interleukin-11 that could help the regeneration of the gastrointestinal mucosa, neutron-induced ARS will be treated with new methods

A metastable liquid melted from a crystalline solid under decompression

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Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Kono, Yoshio; Park, Changyong; Kenney-Benson, Curtis; Shen, Guoyin

2017-01-01

A metastable liquid may exist under supercooling, sustaining the liquid below the melting point such as supercooled water and silicon. It may also exist as a transient state in solid-solid transitions, as demonstrated in recent studies of colloidal particles and glass-forming metallic systems. One important question is whether a crystalline solid may directly melt into a sustainable metastable liquid. By thermal heating, a crystalline solid will always melt into a liquid above the melting point. Here we report that a high-pressure crystalline phase of bismuth can melt into a metastable liquid below the melting line through a decompression process. The decompression-induced metastable liquid can be maintained for hours in static conditions, and transform to crystalline phases when external perturbations, such as heating and cooling, are applied. It occurs in the pressure-temperature region similar to where the supercooled liquid Bi is observed. Akin to supercooled liquid, the pressure-induced metastable liquid may be more ubiquitous than we thought.

Cinerama sickness and postural instability.

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Bos, Jelte E; Ledegang, Wietse D; Lubeck, Astrid J A; Stins, John F

2013-01-01

Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation. Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.

Smartphone-Enabled Heart Rate Variability and Acute Mountain Sickness.

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Mellor, Adrian; Bakker-Dyos, Josh; OʼHara, John; Woods, David Richard; Holdsworth, David A; Boos, Christopher J

2018-01-01

The autonomic system and sympathetic activation appears integral in the pathogenesis of acute mountain sickness (AMS) at high altitude (HA), yet a link between heart rate variability (HRV) and AMS has not been convincingly shown. In this study we investigated the utility of the smartphone-derived HRV score to predict and diagnose AMS at HA. Twenty-one healthy adults were investigated at baseline at 1400 m and over 10 days during a trek to 5140 m. HRV was recorded using the ithlete HRV device. Acute mountain sickness occurred in 11 subjects (52.4%) at >2650 m. HRV inversely correlated with AMS Scores (r = -0.26; 95% CI, -0.38 to -0.13: P HRV significantly fell at 3700, 4100, and 5140 m versus low altitude. HRV scores were lower in those with both mild (69.7 ± 14.0) and severe AMS (67.1 ± 13.1) versus those without AMS (77.5 ± 13.1; effect size n = 0.043: P = 0.007). The HRV score was weakly predictive of severe AMS (AUC 0.74; 95% CI, 0.58-0.89: P = 0.006). The change (delta) in the HRV Score (compared with baseline at 1400 m) was a moderate diagnostic marker of severe AMS (AUC 0.80; 95% CI, 0.70-0.90; P = 0.0004). A fall in the HRV score of >5 had a sensitivity of 83% and specificity of 60% to identify severe AMS (likelihood ratio 1.9). Baseline HRV at 1400 m was not predictive of either AMS at higher altitudes. The ithlete HRV score can be used to help in the identification of severe AMS; however, a baseline score is not predictive of future AMS development at HA.

Orientation Preferences and Motion Sickness Induced in a Virtual Reality Environment.

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Chen, Wei; Chao, Jian-Gang; Zhang, Yan; Wang, Jin-Kun; Chen, Xue-Wen; Tan, Cheng

2017-10-01

Astronauts' orientation preferences tend to correlate with their susceptibility to space motion sickness (SMS). Orientation preferences appear universally, since variable sensory cue priorities are used between individuals. However, SMS susceptibility changes after proper training, while orientation preferences seem to be intrinsic proclivities. The present study was conducted to investigate whether orientation preferences change if susceptibility is reduced after repeated exposure to a virtual reality (VR) stimulus environment that induces SMS. A horizontal supine posture was chosen to create a sensory context similar to weightlessness, and two VR devices were used to produce a highly immersive virtual scene. Subjects were randomly allocated to an experimental group (trained through exposure to a provocative rotating virtual scene) and a control group (untrained). All subjects' orientation preferences were measured twice with the same interval, but the experimental group was trained three times during the interval, while the control group was not. Trained subjects were less susceptible to SMS, with symptom scores reduced by 40%. Compared with untrained subjects, trained subjects' orientation preferences were significantly different between pre- and posttraining assessments. Trained subjects depended less on visual cues, whereas few subjects demonstrated the opposite tendency. Results suggest that visual information may be inefficient and unreliable for body orientation and stabilization in a rotating visual scene, while reprioritizing preferences for different sensory cues was dynamic and asymmetric between individuals. The present findings should facilitate customization of efficient and proper training for astronauts with different sensory prioritization preferences and dynamic characteristics.Chen W, Chao J-G, Zhang Y, Wang J-K, Chen X-W, Tan C. Orientation preferences and motion sickness induced in a virtual reality environment. Aerosp Med Hum Perform. 2017

Classical altitude training.

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Friedmann-Bette, B

2008-08-01

For more than 40 years, the effects of classical altitude training on sea-level performance have been the subject of many scientific investigations in individual endurance sports. To our knowledge, no studies have been performed in team sports like football. Two well-controlled studies showed that living and training at an altitude of >or=1800-2700 m for 3-4 weeks is superior to equivalent training at sea level in well-trained athletes. Most of the controlled studies with elite athletes did not reveal such an effect. However, the results of some uncontrolled studies indicate that sea-level performance might be enhanced after altitude training also in elite athletes. Whether hypoxia provides an additional stimulus for muscular adaptation, when training is performed with equal intensity compared with sea-level training is not known. There is some evidence for an augmentation of total hemoglobin mass after classical altitude training with duration >or=3 weeks at an altitude >or=2000 m due to altitude acclimatization. Considerable individual variation is observed in the erythropoietic response to hypoxia and in the hypoxia-induced reduction of aerobic performance capacity during training at altitude, both of which are thought to contribute to inter-individual variation in the improvement of sea-level performance after altitude training.

Macroscopic time and altitude distribution of plasma turbulence induced in ionospheric modification experiments

International Nuclear Information System (INIS)

Rose, H.; Dubois, D.; Russell, D.; Hanssen, A.

1996-01-01

This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This research concentrated on the time dependence of the heater, induced-turbulence, and electron-density profiles excited in the ionosphere by a powerful radio-frequency heater wave. The macroscopic density is driven by the ponderomotive pressure and the density self-consistently determines the heater propagation. For typical parameters of the current Arecibo heater, a dramatic quasi-periodic behavior was found. For about 50 ms after turn-on of the heater wave, the turbulence is concentrated at the first standing-wave maximum of the heater near reflection altitude. From 50--100 ms the standing-wave pattern drops by about 1--2 km in altitude and the quasi-periodicity reappears at the higher altitudes with a period of roughly 50 ms. This behavior is due to the half-wavelength density depletion grating that is set up by the ponderomotive pressure at the maxima of the heater standing-wave pattern. Once the grating is established the heater can no longer propagate to higher altitudes. The grating is then unsupported by the heater at these altitudes and decays, allowing the heater to propagate again and initiate another cycle. For stronger heater powers, corresponding to the Arecibo upgrade and the HAARP heater now under construction, the effects are much more dramatic

A comparison of the incidence and understanding of altitude illness between porters and trekkers in the Solu Khumbu Region of Nepal.

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Newcomb, Lauren; Sherpa, Chhewang; Nickol, Annabel; Windsor, Jeremy

2011-09-01

Altitude illness can occur in anyone who ascends to high altitude. Better understanding of altitude illness is associated with a lower incidence of acute mountain sickness (AMS). The purpose of this study is to compare, for the first time, the incidence and understanding of altitude illness between foreign trekkers and indigenous porters in Nepal. Interviews and questionnaires were completed at the International Porter Protection Group Rescue Post at Machermo (4470 m). Participants completed the Lake Louise acute mountain sickness self-assessment questionnaire. They were also asked about their actions in response to high altitude illness scenarios as well as their perception of the vulnerability of porters vs trekkers to altitude illness. Ascent profile, age, gender, ethnic origin, and altitude of home residence were also obtained. Trekkers (n=131) had a significantly higher incidence of AMS (21% vs 8%) than porters (n=92; P porters (whose home villages were below 3050 m, n=61) had a numerically higher, though not significantly different, incidence of AMS (10% vs 3%) compared to highland porters (n=31). The majority of trekkers and porters recognized the symptoms of altitude illness and the most appropriate action to be taken. Despite the lower incidence of AMS in porters, around half felt that they were at greater risk than trekkers. Porters had a lower incidence of AMS, which may be attributable to repeated ascents through the trekking season, or differences in reporting symptoms. Both trekkers and porters demonstrated appropriate knowledge of actions to be taken in response to altitude illness. Copyright © 2011 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Nanobubbles Form at Active Hydrophobic Spots on the Luminal Aspect of Blood Vessels: Consequences for Decompression Illness in Diving and Possible Implications for Autoimmune Disease—An Overview

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Ran Arieli

2017-08-01

Full Text Available Decompression illness (DCI occurs following a reduction in ambient pressure. Decompression bubbles can expand and develop only from pre-existing gas micronuclei. The different hypotheses hitherto proposed regarding the nucleation and stabilization of gas micronuclei have never been validated. It is known that nanobubbles form spontaneously when a smooth hydrophobic surface is submerged in water containing dissolved gas. These nanobubbles may be the long sought-after gas micronuclei underlying decompression bubbles and DCI. We exposed hydrophobic and hydrophilic silicon wafers under water to hyperbaric pressure. After decompression, bubbles appeared on the hydrophobic but not the hydrophilic wafers. In a further series of experiments, we placed large ovine blood vessels in a cooled high pressure chamber at 1,000 kPa for about 20 h. Bubbles evolved at definite spots in all the types of blood vessels. These bubble-producing spots stained positive for lipids, and were henceforth termed “active hydrophobic spots” (AHS. The lung surfactant dipalmitoylphosphatidylcholine (DPPC, was found both in the plasma of the sheep and at the AHS. Bubbles detached from the blood vessel in pulsatile flow after reaching a mean diameter of ~1.0 mm. Bubble expansion was bi-phasic—a slow initiation phase which peaked 45 min after decompression, followed by fast diffusion-controlled growth. Many features of decompression from diving correlate with this finding of AHS on the blood vessels. (1 Variability between bubblers and non-bubblers. (2 An age-related effect and adaptation. (3 The increased risk of DCI on a second dive. (4 Symptoms of neurologic decompression sickness. (5 Preconditioning before a dive. (6 A bi-phasic mechanism of bubble expansion. (7 Increased bubble formation with depth. (8 Endothelial injury. (9 The presence of endothelial microparticles. Finally, constant contact between nanobubbles and plasma may result in distortion of proteins and their

Lung volumes, pulmonary ventilation, and hypoxia following rapid decompression to 60,000 ft (18,288 m).

Science.gov (United States)

Connolly, Desmond M; D'Oyly, Timothy J; McGown, Amanda S; Lee, Vivienne M

2013-06-01

Rapid decompressions (RD) to 60,000 ft (18,288 m) were undertaken by six subjects to provide evidence of satisfactory performance of a contemporary, partial pressure assembly life support system for the purposes of flight clearance. A total of 12 3-s RDs were conducted with subjects breathing 56% oxygen (balance nitrogen) at the base (simulated cabin) altitude of 22,500 ft (6858 m), switching to 100% oxygen under 72 mmHg (9.6 kPa) of positive pressure at the final (simulated aircraft) altitude. Respiratory pressures, flows, and gas compositions were monitored continuously throughout. All RDs were completed safely, but one subject experienced significant hypoxia during the minute at final altitude, associated with severe hemoglobin desaturation to a low of 53%. Accurate data on subjects' lung volumes were obtained and individual responses post-RD were reviewed in relation to patterns of pulmonary ventilation. The occurrence of severe hypoxia is explained by hypoventilation in conjunction with unusually large lung volumes (total lung capacity 10.18 L). Subjects' lung volumes and patterns of pulmonary ventilation are critical, but idiosyncratic, determinants of alveolar oxygenation and severity of hypoxia following RD to 60,000 ft (18,288 m). At such extreme altitudes even vaporization of water condensate in the oxygen mask may compromise oxygen delivery. An altitude ceiling of 60,000 ft (18,288 m) is the likely threshold for reliable protection using partial pressure assemblies and aircrew should be instructed to take two deep 'clearing' breaths immediately following RD at such extreme pressure breathing altitudes.

Pharmacological and neurophysiological aspects of space/motion sickness

Science.gov (United States)

Lucot, James B.; Crampton, George H.

1991-01-01

A motorized motion testing device modeled after a Ferris wheel was constructed to perform motion sickness tests on cats. Details of the testing are presented, and some of the topics covered include the following: xylazine-induced emesis; analysis of the constituents of the cerebrospinal fluid (CSF) during motion sickness; evaluation of serotonin-1A (5-HT sub 1A) agonists; other 5HT receptors; antimuscarinic mechanisms; and antihistaminergic mechanisms. The ability of the following drugs to reduce motion sickness in the cats was examined: amphetamines, adenosinergic drugs, opioid antagonists, peptides, cannabinoids, cognitive enhancers (nootropics), dextromethorphan/sigma ligands, scopolamine, and diphenhydramine.

Exercises may be as efficient as subacromial decompression in patients with subacromial stage II impingement: 4-8-years' follow-up in a prospective, randomized study

DEFF Research Database (Denmark)

Haahr, J. P.; Andersen, JH

2006-01-01

with graded physiotherapy and exercises or arthroscopic subacromial decompression. Outcomes were proportion of time per year with income transfers (indexed 0-1), including total transfers (marginalization), sick leave and disability pension obtained from the registry at the Ministry of Work. Self......-reported function, working capability, employment status and global improvement were obtained by questionnaire in September 2004. The main outcomes are given as differences in development from baseline. RESULTS: Seventy-nine (88%) responded to the questionnaire and registry data were obtained from 81. After 1 year...

Motion sickness, stress and the endocannabinoid system.

Directory of Open Access Journals (Sweden)

Alexander Choukèr

Full Text Available BACKGROUND: A substantial number of individuals are at risk for the development of motion sickness induced nausea and vomiting (N&V during road, air or sea travel. Motion sickness can be extremely stressful but the neurobiologic mechanisms leading to motion sickness are not clear. The endocannabinoid system (ECS represents an important neuromodulator of stress and N&V. Inhibitory effects of the ECS on N&V are mediated by endocannabinoid-receptor activation. METHODOLOGY/PRINCIPAL FINDINGS: We studied the activity of the ECS in human volunteers (n = 21 during parabolic flight maneuvers (PFs. During PFs, microgravity conditions (<10(-2 g are generated for approximately 22 s which results in a profound kinetic stimulus. Blood endocannabinoids (anandamide and 2-arachidonoylglycerol, 2-AG were measured from blood samples taken in-flight before start of the parabolic maneuvers, after 10, 20, and 30 parabolas, in-flight after termination of PFs and 24 h later. Volunteers who developed acute motion sickness (n = 7 showed significantly higher stress scores but lower endocannabinoid levels during PFs. After 20 parabolas, blood anandamide levels had dropped significantly in volunteers with motion sickness (from 0.39+/-0.40 to 0.22+/-0.25 ng/ml but increased in participants without the condition (from 0.43+/-0.23 to 0.60+/-0.38 ng/ml resulting in significantly higher anandamide levels in participants without motion sickness (p = 0.02. 2-AG levels in individuals with motion sickness were low and almost unchanged throughout the experiment but showed a robust increase in participants without motion sickness. Cannabinoid-receptor 1 (CB1 but not cannabinoid-receptor 2 (CB2 mRNA expression in leucocytes 4 h after the experiment was significantly lower in volunteers with motion sickness than in participants without N&V. CONCLUSIONS/SIGNIFICANCE: These findings demonstrate that stress and motion sickness in humans are associated with impaired endocannabinoid

Impact of a Newly Constructed Motor Vehicle Road on Altitude Illness in the Nepal Himalayas.

Science.gov (United States)

Reisman, Jonathan; Deonarain, Dinesh; Basnyat, Buddha

2017-12-01

This study investigated the impact that motor vehicle travel along a newly constructed road has on altitude illness (including acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema). The new road from Besisahar (760 m) to Manang (3540 m) in Nepal was completed in December 2014. We enrolled all patients diagnosed with altitude illness at the Himalayan Rescue Association Manang clinic in fall 2016. Phi coefficients were calculated to test for an association between Nepali ethnicity and rapid ascent by motor vehicle. A retrospective review looked at all patients with altitude illness from fall (September-November) 2010 to spring (February-May) 2016. In fall 2016, more than half (54%) of patients with altitude illness traveled to Manang by motor vehicle, and one-third (33%) reached Manang from low altitude (Besisahar) in less than 48 hours. Nepali nationality had a significant association with motor vehicle travel (phi +0.69, P road (P constructed road from Besisahar to Manang appears to be related to a significant increase in the number of patients with all forms of altitude illness, especially among Nepalis. The authors believe that educational interventions emphasizing prevention are urgently needed. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Text mining and network analysis to find functional associations of genes in high altitude diseases.

Science.gov (United States)

Bhasuran, Balu; Subramanian, Devika; Natarajan, Jeyakumar

2018-05-02

Travel to elevations above 2500 m is associated with the risk of developing one or more forms of acute altitude illness such as acute mountain sickness (AMS), high altitude cerebral edema (HACE) or high altitude pulmonary edema (HAPE). Our work aims to identify the functional association of genes involved in high altitude diseases. In this work we identified the gene networks responsible for high altitude diseases by using the principle of gene co-occurrence statistics from literature and network analysis. First, we mined the literature data from PubMed on high-altitude diseases, and extracted the co-occurring gene pairs. Next, based on their co-occurrence frequency, gene pairs were ranked. Finally, a gene association network was created using statistical measures to explore potential relationships. Network analysis results revealed that EPO, ACE, IL6 and TNF are the top five genes that were found to co-occur with 20 or more genes, while the association between EPAS1 and EGLN1 genes is strongly substantiated. The network constructed from this study proposes a large number of genes that work in-toto in high altitude conditions. Overall, the result provides a good reference for further study of the genetic relationships in high altitude diseases. Copyright © 2018 Elsevier Ltd. All rights reserved.

Decompression of keratocystic odontogenic tumors leading to increased fibrosis, but without any change in epithelial proliferation.

Science.gov (United States)

Awni, Sarah; Conn, Brendan

2017-06-01

The aim of this study was to investigate whether decompression treatment induces changes in the histology or biologic behavior of keratocystic odontogenic tumor (KCOT). Seventeen patients with KCOT underwent decompression treatment with or without enucleation. Histologic evaluation and immunohistochemical expression of p53, Ki-67, and Bcl-2 were analyzed by using conventional microscopy. KCOT showed significantly increased fibrosis (P = .01) and a subjective reduction in mitotic activity (P = .03) after decompression. There were no statistically significant changes in the expression of proliferation markers. An increase in daughter-cysts or epithelial rests was seen after decompression (P = .04). Recurrence was noted in four of 16 cases, and expression of p53 was strongly correlated with prolonged duration of treatment (P = .01) and intense inflammatory changes (P = .02). Structural changes in the KCOT epithelium or capsule following decompression facilitate surgical removal of the tumor. There was no statistical evidence that decompression influences expression of proliferation markers in the lining, indicating that the potential for recurrence may not be restricted to the cellular level. The statistically significant increase of p53 expression with increased duration of treatment and increase of inflammation may also indicate the possibility of higher rates of recurrence with prolonged treatment and significant inflammatory changes. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Artificial horizon effects on motion sickness and performance.

Science.gov (United States)

Tal, Dror; Gonen, Adi; Wiener, Guy; Bar, Ronen; Gil, Amnon; Nachum, Zohar; Shupak, Avi

2012-07-01

To investigate whether the projection of Earth-referenced scenes during provocative motion can alleviate motion sickness severity and prevent motion sickness-induced degradation of performance. Exposure to unfamiliar motion patterns commonly results in motion sickness and decreased performance. Thirty subjects with moderate-to-severe motion sickness susceptibility were exposed to the recorded motion profile of a missile boat under moderate sea conditions in a 3-degrees-of-freedom ship motion simulator. During a 120-minute simulated voyage, the study participants were repeatedly put through a performance test battery and completed a motion sickness susceptibility questionnaire, while self-referenced and Earth-referenced visual scenes were projected inside the closed simulator cabin. A significant decrease was found in the maximal motion sickness severity score, from 9.83 ± 9.77 (mean ± standard deviation) to 7.23 ± 7.14 (p pitch, and heave movements of the simulator. Although there was a significant decrease in sickness severity, substantial symptoms still persisted. Decision making, vision, concentration, memory, simple reasoning, and psychomotor skills all deteriorated under the motion conditions. However, no significant differences between the projection conditions could be found in the scores of any of the performance tests. Visual information regarding the vessel's movement provided by an artificial horizon device might decrease motion sickness symptoms. However, although this device might be suitable for passive transportation, the continued deterioration in performance measures indicates that it provides no significant advantage for personnel engaged in the active operation of modern vessels.

MEDEX 2015: Heart Rate Variability Predicts Development of Acute Mountain Sickness.

Science.gov (United States)

Sutherland, Angus; Freer, Joseph; Evans, Laura; Dolci, Alberto; Crotti, Matteo; Macdonald, Jamie Hugo

2017-09-01

Sutherland, Angus, Joseph Freer, Laura Evans, Alberto Dolci, Matteo Crotti, and Jamie Hugo Macdonald. MEDEX 2015: Heart rate variability predicts development of acute mountain sickness. High Alt Med Biol. 18: 199-208, 2017. Acute mountain sickness (AMS) develops when the body fails to acclimatize to atmospheric changes at altitude. Preascent prediction of susceptibility to AMS would be a useful tool to prevent subsequent harm. Changes to peripheral oxygen saturation (SpO 2 ) on hypoxic exposure have previously been shown to be of poor predictive value. Heart rate variability (HRV) has shown promise in the early prediction of AMS, but its use pre-expedition has not previously been investigated. We aimed to determine whether pre- and intraexpedition HRV assessment could predict susceptibility to AMS at high altitude with better diagnostic accuracy than SpO 2 . Forty-four healthy volunteers undertook an expedition in the Nepali Himalaya to >5000 m. SpO 2 and HRV parameters were recorded at rest in normoxia and in a normobaric hypoxic chamber before the expedition. On the expedition HRV parameters and SpO 2 were collected again at 3841 m. A daily Lake Louise Score was obtained to assess AMS symptomology. Low frequency/high frequency (LF/HF) ratio in normoxia (cutpoint ≤2.28 a.u.) and LF following 15 minutes of exposure to normobaric hypoxia had moderate (area under the curve ≥0.8) diagnostic accuracy. LF/HF ratio in normoxia had the highest sensitivity (85%) and specificity (88%) for predicting AMS on subsequent ascent to altitude. In contrast, pre-expedition SpO 2 measurements had poor (area under the curve <0.7) diagnostic accuracy and inferior sensitivity and specificity. Pre-ascent measurement of HRV in normoxia was found to be of better diagnostic accuracy for AMS prediction than all measures of HRV in hypoxia, and better than peripheral oxygen saturation monitoring.

Vascular Endothelial Growth Factor-A Is Associated with Chronic Mountain Sickness in the Andean Population

Science.gov (United States)

Espinoza, Jose R.; Alvarez, Giancarlo; León-Velarde, Fabiola; Ju Preciado, Hugo F.; Macarlupu, Jose-Luis; Rivera-Ch, Maria; Rodriguez, Jorge; Favier, Judith; Gimenez-Roqueplo, Anne-Paule

2014-01-01

Abstract Espinoza, Jose R., Giancarlo Alvarez, Fabiola León-Velarde, Hugo F. Ju Preciado, Jose-Luis Macarlupu, Maria Rivera-Ch, Jorge Rodriguez, Judith Favier, Anne-Paule Gimenez-Roqueplo, and Jean-Paul Richalet. Vascular endothelial growth factor-A is associated with chronic mountain sickness in Andean population. High Alt Med Biol. 15:146–154, 2014.—A study of chronic mountain sickness (CMS) with a candidate gene—vascular endothelial growth factor A (VEGFA)—was carried out in a Peruvian population living at high altitude in Cerro de Pasco (4380 m). The study was performed by genotyping of 11 tag SNPs encompassing 2.2 kb of region of VEGFA gene in patients with a diagnosis of CMS (n=131; 49.1±12.7 years old) and unrelated healthy controls (n=84; 47.2±13.4 years old). The VEGFA tag SNP rs3025033 was found associated with CMS (p0.36, p<0.01), suggesting selection is operating on the VEGF gene. Our results suggest that VEGFA is associated with CMS in long-term residents at high altitude in the Peruvian Andes. PMID:24971768

Validation of sick leave measures: self-reported sick leave and sickness benefit data from a Danish national register compared to multiple workplace-registered sick leave spells in a Danish municipality.

Science.gov (United States)

Stapelfeldt, Christina Malmose; Jensen, Chris; Andersen, Niels Trolle; Fleten, Nils; Nielsen, Claus Vinther

2012-08-15

Previous validation studies of sick leave measures have focused on self-reports. Register-based sick leave data are considered to be valid; however methodological problems may be associated with such data. A Danish national register on sickness benefit (DREAM) has been widely used in sick leave research. On the basis of sick leave records from 3,554 and 2,311 eldercare workers in 14 different workplaces, the aim of this study was to: 1) validate registered sickness benefit data from DREAM against workplace-registered sick leave spells of at least 15 days; 2) validate self-reported sick leave days during one year against workplace-registered sick leave. Agreement between workplace-registered sick leave and DREAM-registered sickness benefit was reported as sensitivities, specificities and positive predictive values. A receiver-operating characteristic curve and a Bland-Altman plot were used to study the concordance with sick leave duration of the first spell. By means of an analysis of agreement between self-reported and workplace-registered sick leave sensitivity and specificity was calculated. Ninety-five percent confidence intervals (95% CI) were used. The probability that registered DREAM data on sickness benefit agrees with workplace-registered sick leave of at least 15 days was 96.7% (95% CI: 95.6-97.6). Specificity was close to 100% (95% CI: 98.3-100). The registered DREAM data on sickness benefit overestimated the duration of sick leave spells by an average of 1.4 (SD: 3.9) weeks. Separate analysis on pregnancy-related sick leave revealed a maximum sensitivity of 20% (95% CI: 4.3-48.1).The sensitivity of self-reporting at least one or at least 56 sick leave day/s was 94.5 (95% CI: 93.4 - 95.5) % and 58.5 (95% CI: 51.1 - 65.6) % respectively. The corresponding specificities were 85.3 (95% CI: 81.4 - 88.6) % and 98.9 (95% CI: 98.3 - 99.3) %. The DREAM register offered valid measures of sick leave spells of at least 15 days among eldercare employees. Pregnancy

Validation of sick leave measures: self-reported sick leave and sickness benefit data from a Danish national register compared to multiple workplace-registered sick leave spells in a Danish municipality

Directory of Open Access Journals (Sweden)

Stapelfeldt Christina Malmose

2012-08-01

Full Text Available Abstract Background Previous validation studies of sick leave measures have focused on self-reports. Register-based sick leave data are considered to be valid; however methodological problems may be associated with such data. A Danish national register on sickness benefit (DREAM has been widely used in sick leave research. On the basis of sick leave records from 3,554 and 2,311 eldercare workers in 14 different workplaces, the aim of this study was to: 1 validate registered sickness benefit data from DREAM against workplace-registered sick leave spells of at least 15 days; 2 validate self-reported sick leave days during one year against workplace-registered sick leave. Methods Agreement between workplace-registered sick leave and DREAM-registered sickness benefit was reported as sensitivities, specificities and positive predictive values. A receiver-operating characteristic curve and a Bland-Altman plot were used to study the concordance with sick leave duration of the first spell. By means of an analysis of agreement between self-reported and workplace-registered sick leave sensitivity and specificity was calculated. Ninety-five percent confidence intervals (95% CI were used. Results The probability that registered DREAM data on sickness benefit agrees with workplace-registered sick leave of at least 15 days was 96.7% (95% CI: 95.6-97.6. Specificity was close to 100% (95% CI: 98.3-100. The registered DREAM data on sickness benefit overestimated the duration of sick leave spells by an average of 1.4 (SD: 3.9 weeks. Separate analysis on pregnancy-related sick leave revealed a maximum sensitivity of 20% (95% CI: 4.3-48.1. The sensitivity of self-reporting at least one or at least 56 sick leave day/s was 94.5 (95% CI: 93.4 – 95.5 % and 58.5 (95% CI: 51.1 – 65.6 % respectively. The corresponding specificities were 85.3 (95% CI: 81.4 – 88.6 % and 98.9 (95% CI: 98.3 – 99.3 %. Conclusions The DREAM register offered valid measures of sick

Stroboscopic Goggles for Reduction of Motion Sickness

Science.gov (United States)

Reschke, M. F.; Somers, Jeffrey T.

2005-01-01

A device built around a pair of electronic shutters has been demonstrated to be effective as a prototype of stroboscopic goggles or eyeglasses for preventing or reducing motion sickness. The momentary opening of the shutters helps to suppress a phenomenon that is known in the art as retinal slip and is described more fully below. While a number of different environmental factors can induce motion sickness, a common factor associated with every known motion environment is sensory confusion or sensory mismatch. Motion sickness is a product of misinformation arriving at a central point in the nervous system from the senses from which one determines one s spatial orientation. When information from the eyes, ears, joints, and pressure receptors are all in agreement as to one s orientation, there is no motion sickness. When one or more sensory input(s) to the brain is not expected, or conflicts with what is anticipated, the end product is motion sickness. Normally, an observer s eye moves, compensating for the anticipated effect of motion, in such a manner that the image of an object moving relatively to an observer is held stationary on the retina. In almost every known environment that induces motion sickness, a change in the gain (in the signal-processing sense of gain ) of the vestibular system causes the motion of the eye to fail to hold images stationary on the retina, and the resulting motion of the images is termed retinal slip. The present concept of stroboscopic goggles or eyeglasses (see figure) is based on the proposition that prevention of retinal slip, and hence, the prevention of sensory mismatch, can be expected to reduce the tendency toward motion sickness. A device according to this concept helps to prevent retinal slip by providing snapshots of the visual environment through electronic shutters that are brief enough that each snapshot freezes the image on each retina. The exposure time for each snapshot is less than 5 ms. In the event that a higher

Complications of cranioplasty after decompressive craniectomy

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Maša Glišović

2015-04-01

Full Text Available Cranioplasty is a surgical repair of a defect or deformity of a skull with the use of autologous bone or synthetic materials.[4] It usually follows decompressive craniectomy, which is a commonly practiced neurosurgical intervention in patients with raised intracranial pressure unresponsive to other forms of treatment.[1] There are many conditions that may lead to intracranial hypertension, and the goal is to avoid brain necrosis caused by compartment pressure syndrome.[2] Consequently, the extensive use of decompressive craniectomy directly results in more cranioplasties, which sometimes present with unwanted complications.[5] Generally, the occurence of cranioplasty complications is between 16% and 34%.[3] Because of the many indications for craniectomy based on clinical data that speak in its favour, if will probably remain a relatively common neurosurgical intervention also in the future. The frequency of decompressive craniectomy and consequently of cranioplasty requires awareness of the many potential postoperative complications and understanding of its evolution. This article is a review of pathophysiological mechanisms after decompressive craniectomy and cranioplasty, of its complications and factors that potentially contribute to their occurence.

Delayed facial nerve decompression for Bell's palsy.

Science.gov (United States)

Kim, Sang Hoon; Jung, Junyang; Lee, Jong Ha; Byun, Jae Yong; Park, Moon Suh; Yeo, Seung Geun

2016-07-01

Incomplete recovery of facial motor function continues to be long-term sequelae in some patients with Bell's palsy. The purpose of this study was to investigate the efficacy of transmastoid facial nerve decompression after steroid and antiviral treatment in patients with late stage Bell's palsy. Twelve patients underwent surgical decompression for Bell's palsy 21-70 days after onset, whereas 22 patients were followed up after steroid and antiviral therapy without decompression. Surgical criteria included greater than 90 % degeneration on electroneuronography and no voluntary electromyography potentials. This study was a retrospective study of electrodiagnostic data and medical chart review between 2006 and 2013. Recovery from facial palsy was assessed using the House-Brackmann grading system. Final recovery rate did not differ significantly in the two groups; however, all patients in the decompression group recovered to at least House-Brackmann grade III at final follow-up. Although postoperative hearing threshold was increased in both groups, there was no significant between group difference in hearing threshold. Transmastoid decompression of the facial nerve in patients with severe late stage Bell's palsy at risk for a poor facial nerve outcome reduced severe complications of facial palsy with minimal morbidity.

Hyperbaric oxygen treatment for air or gas embolism.

Science.gov (United States)

Moon, R E

2014-01-01

Gas can enter arteries (arterial gas embolism) due to alveolar-capillary disruption (caused by pulmonary overpressurization, e.g., breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is sub-atmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces strokelike manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries. However, VGE can cause pulmonary edema, cardiac "vapor lock" and AGE due to transpulmonary passage or right-to-left shunt through a patent foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence-based review of adjunctive therapies is presented.

Treatment of micro air bubbles in rat adipose tissue at 25 kPa altitude exposures with perfluorocarbon emulsions and nitric oxide

DEFF Research Database (Denmark)

Randsøe, Thomas; Hyldegaard, O

2014-01-01

. The effect is ascribed to an increased solubility and transport capacity of respiratory gases in the PFC emulsion and possibly enhanced nitrogen washout through NO-increased blood flow rate and/or the removal of endothelial micro bubble nuclei precursors. Previous reports have shown that metabolic gases (i......INTRODUCTION: Perfluorocarbon emulsions (PFC) and nitric oxide (NO) releasing agents have on experimental basis demonstrated therapeutic properties in treating and preventing the formation of venous gas embolism as well as increased survival rate during decompression sickness from diving...

Molecular hydrogen reduces LPS-induced neuroinflammation and promotes recovery from sickness behaviour in mice.

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Stefan Spulber

Full Text Available Molecular hydrogen has been shown to have neuroprotective effects in mouse models of acute neurodegeneration. The effect was suggested to be mediated by its free-radical scavenger properties. However, it has been shown recently that molecular hydrogen alters gene expression and protein phosphorylation. The aim of this study was to test whether chronic ad libitum consumption of molecular hydrogen-enriched electrochemically reduced water (H-ERW improves the outcome of lipopolysaccharide (LPS-induced neuroinflammation. Seven days after the initiation of H-ERW treatment, C57Bl/6 mice received a single injection of LPS (0.33 mg/kg i.p. or an equivalent volume of vehicle. The LPS-induced sickness behaviour was assessed 2 h after the injection, and recovery was assessed by monitoring the spontaneous locomotor activity in the homecage for 72 h after the administration of LPS. The mice were killed in the acute or recovery phase, and the expression of pro- and antiinflammatory cytokines in the hippocampus was assessed by real-time PCR. We found that molecular hydrogen reduces the LPS-induced sickness behaviour and promotes recovery. These effects are associated with a shift towards anti-inflammatory gene expression profile at baseline (downregulation of TNF- α and upregulation of IL-10. In addition, molecular hydrogen increases the amplitude, but shortens the duration and promotes the extinction of neuroinflammation. Consistently, molecular hydrogen modulates the activation and gene expression in a similar fashion in immortalized murine microglia (BV-2 cell line, suggesting that the effects observed in vivo may involve the modulation of microglial activation. Taken together, our data point to the regulation of cytokine expression being an additional critical mechanism underlying the beneficial effects of molecular hydrogen.

[Orbital decompression in Grave's ophtalmopathy].

Science.gov (United States)

Longueville, E

2010-01-01

Graves disease orbitopathy is a complex progressive inflammatory disease. Medical treatment remains in all cases the proposed treatment of choice. Surgical treatment by bone decompression can be considered as an emergency mainly in cases of optic neuropathy or ocular hypertension not being controlled medically or in post-traumatic exophthalmos stage. Emergency bone decompression eliminates compression or stretching of the optic nerve allowing visual recovery. The uncontrolled ocular hypertension will benefit from decompression. The normalization of intraocular pressure may be obtained by this surgery or if needed by the use of postoperative antiglaucoma drops or even filtration surgery. In all operated cases, the IOP was normalized with an average decrease of 7.71 mmHg and a cessation of eye drops in 3/7 cases. Regarding sequelae, our therapeutic strategy involves consecutively surgery of the orbit, extraocular muscles and eyelids. The orbital expansion gives excellent results on the cosmetic level and facilitates the implementation of subsequent actions.

Pictorial essay: Role of ultrasound in failed carpal tunnel decompression

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Rajesh Botchu

2012-01-01

Full Text Available USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression.

Pictorial essay: Role of ultrasound in failed carpal tunnel decompression.

Science.gov (United States)

Botchu, Rajesh; Khan, Aman; Jeyapalan, Kanagaratnam

2012-01-01

USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression.

Eruptive dynamics during magma decompression: a laboratory approach

Science.gov (United States)

Spina, L.; Cimarelli, C.; Scheu, B.; Wadsworth, F.; Dingwell, D. B.

2013-12-01

A variety of eruptive styles characterizes the activity of a given volcano. Indeed, eruptive styles can range from effusive phenomena to explosive eruptions, with related implications for hazard management. Rapid changes in eruptive style can occur during an ongoing eruption. These changes are, amongst other, related to variations in the magma ascent rate, a key parameter affecting the eruptive style. Ascent rate is in turn dependent on several factors such as the pressure in the magma chamber, the physical properties of the magma and the rate at which these properties change. According to the high number of involved parameters, laboratory decompression experiments are the best way to achieve quantitative information on the interplay of each of those factors and the related impact on the eruption style, i.e. by analyzing the flow and deformation behavior of the transparent volatile-bearing analogue fluid. We carried out decompression experiments following different decompression paths and using silicone oil as an analogue for the melt, with which we can simulate a range of melt viscosity values. For a set of experiments we added rigid particles to simulate the presence of crystals in the magma. The pure liquid or suspension was mounted into a transparent autoclave and pressurized to different final pressures. Then the sample was saturated with argon for a fixed amount of time. The decompression path consists of a slow decompression from the initial pressure to the atmospheric condition. Alternatively, samples were decompressed almost instantaneously, after established steps of slow decompression. The decompression path was monitored with pressure transducers and a high-speed video camera. Image analysis of the videos gives quantitative information on the bubble distribution with respect to depth in the liquid, pressure and time of nucleation and on their characteristics and behavior during the ongoing magma ascent. Furthermore, we also monitored the evolution of

Decompressive craniectomy in herpes simplex encephalitis

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Muhammed Jasim Abdul Jalal

2015-01-01

Full Text Available Intracranial hypertension is a common cause of morbidity in herpes simplex encephalitis (HSE. HSE is the most common form of acute viral encephalitis. Hereby we report a case of HSE in which decompressive craniectomy was performed to treat refractory intracranial hypertension. A 32-year-old male presented with headache, vomiting, fever, and focal seizures involving the right upper limb. Cerebrospinal fluid-meningoencephalitic profile was positive for herpes simplex. Magnetic resonance image of the brain showed swollen and edematous right temporal lobe with increased signal in gray matter and subcortical white matter with loss of gray, white differentiation in T2-weighted sequences. Decompressive craniectomy was performed in view of refractory intracranial hypertension. Decompressive surgery for HSE with refractory hypertension can positively affect patient survival, with good outcomes in terms of cognitive functions.

When healthcare workers get sick: exploring sickness absenteeism in British Columbia, Canada.

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Gorman, Erin; Yu, Shicheng; Alamgir, Hasanat

2010-01-01

To determine the demographic and work characteristics of healthcare workers who were more likely to take sickness absences from work in British Columbia, Canada. Payroll data were analyzed for three health regions. Sickness absence rates were determined per person-year and then compared across demographic and work characteristics using multivariate Poisson regression models. The direct costs to the employer due to sickness absences were also estimated. Female, older, full-time workers, long-term care workers and those with a lower hourly wage were more likely to take sickness absences and had similar trends with respect to the costs due to sickness absence. For occupations, licensed practical nurses, care aides and facility support workers had higher rates of sickness absence. Registered nurses, and those workers paid high hourly wages were associated with highest sickness related costs. It is important to understand the demographic and work characteristics of those workers who are more likely to take sickness absences in order to make sure that they are not experiencing additional hazards at work or facing detrimental workplace conditions. Policy makers need to establish healthy, safe and in turn more productive workplaces. Further research is needed on how interventions can reduce sickness absence.

Radiation sickness

International Nuclear Information System (INIS)

Endoh, Masaru; Ishida, Yusei; Saeki, Mitsuaki

1983-01-01

The frequency of radiation sickness in 1,060 patients treated at our Department was 12.8 percent. It was frequent in patients with brain cancer (12 percent), whole spine cancer (47 percent), uterus cancer (28 percent), lung cancer (22 percent) and esophagus cancer (12 percent). Radiation sickness following X-irradiation was studied in its relation to patient's age, size of radiation fields, dosis and white blood cell count. However, we could not find any definite clinical feature relevant to occurrence. There are many theories published concerning the mechanism of radiation sickness. Clinical experiences have shown that radiation sickness cannot be explained by one theory alone but by several theories such as those based on psychology, stress or histamine. (author)

Explanation of diagnosis criteria for radiation sickness from internal exposure

International Nuclear Information System (INIS)

Xing Zhiwei; Jiang Enhai; Du Jianying; Bai Guang

2012-01-01

A revised edition of the Diagnostic Criteria for Radiation Sickness from Internal Exposure has been approved and issued by the Ministry of Health. It is necessary to research the internal radiation sickness to adapt to the current serious anti-terrorism situation. This standard was enacted based on the extensive research of related literature, from which 12 cases with internal radiation sickness and screened out were involving 7 types of radionuclide. The Development of Emergency Response Standard Extension Framework: Midterm Evaluation Report is the main reference which approved by the International Atomic Energy Agency and World Health Organization. This amendment contains many new provisions such as internal radiation sickness effects models and threshold dose, and the appendix added threshold dose of serious deterministic effects induced by radionuclide intake and radiotoxicology parameters of some radionuclides. In order to understand and implement this standard, and to diagnose and treat the internal radiation sickness correctly, the contents of this standard were interpreted in this article. (authors)

Awareness and prevalence of acute mountain sickness and prevalence of obstructive airflow limitation among Nepalese porters: A cross-sectional study in Khumbu Valley, Nepal

OpenAIRE

Parajuli, Ranjan

2009-01-01

Background: Acute mountain sickness is a major public health problem in high altitudes. Similarly, anecdotal evidence suggests that there is high prevalence of tobacco smoking among this group though prevalence of obstructive airflow limitation is not known. Objectives: The main aims of the study were to measure the awareness of AMS and report the prevalence of AMS and obstructive lung diseases in high altitude Nepalese porters. Setting: This study was done with bases in Namche Bazaar (...

Various anti-motion sickness drugs and core body temperature changes.

Science.gov (United States)

Cheung, Bob; Nakashima, Ann M; Hofer, Kevin D

2011-04-01

Blood flow changes and inactivity associated with motion sickness appear to exacerbate the rate of core temperature decrease during subsequent body cooling. We investigated the effects of various classes of anti-motion sickness drugs on core temperature changes. There were 12 healthy male and female subjects (20-35 yr old) who were given selected classes of anti-motion sickness drugs prior to vestibular Coriolis cross coupling induced by graded yaw rotation and periodic pitch-forward head movements in the sagittal plane. All subjects were then immersed in water at 18 degrees C for a maximum of 90 min or until their core temperature reached 35 degrees C. Double-blind randomized trials were administered, including a placebo, a non-immersion control with no drug, and six anti-motion sickness drugs: meclizine, dimenhydrinate, chlorpheniramine, promethazine + dexamphetamine, promethazine + caffeine, and scopolamine + dexamphetamine. A 7-d washout period was observed between trials. Core temperature and the severity of sickness were monitored throughout each trial. A repeated measures design was performed on the severity of sickness and core temperature changes prior to motion provocation, immediately after the motion sickness end point, and throughout the period of cold-water immersion. The most effective anti-motion sickness drugs, promethazine + dexamphetamine (with a sickness score/duration of 0.65 +/- 0.17) and scopolamine + dexamphetamine (with a sickness score/duration of 0.79 +/- 0.17), significantly attenuated the decrease in core temperature. The effect of this attenuation was lower in less effective drugs. Our results suggest that the two most effective anti-motion sickness drugs are also the most effective in attenuating the rate of core temperature decrease.

Car Sickness

Science.gov (United States)

... Preventable Diseases Healthy Children > Health Issues > Conditions > Head Neck & Nervous System > Car Sickness Health Issues Listen Español Text Size Email Print Share Car Sickness Page Content ...

Sick but yet at work. An empirical study of sickness presenteeism.

Science.gov (United States)

Aronsson, G; Gustafsson, K; Dallner, M

2000-07-01

The study is an empirical investigation of sickness presenteeism in relation to occupation, irreplaceability, ill health, sickness absenteeism, personal income, and slimmed down organisation. Cross sectional design. Swedish workforce. The study group comprised a stratified subsample of 3801 employed persons working at the time of the survey, interviewed by telephone in conjunction with Statistics Sweden's labour market surveys of August and September 1997. The response rate was 87 per cent. A third of the persons in the total material reported that they had gone to work two or more times during the preceding year despite the feeling that, in the light of their perceived state of health, they should have taken sick leave. The highest presenteeism is largely to be found in the care and welfare and education sectors (nursing and midwifery professionals, registered nurses, nursing home aides, compulsory school teachers and preschool/primary educationalists. All these groups work in sectors that have faced personnel cutbacks during the 1990s). The risk ratio (odds ratio (OR)) for sickness presenteeism in the group that has to re-do work remaining after a period of absence through sickness is 2.29 (95% CI 1.79, 2.93). High proportions of persons with upper back/neck pain and fatigue/slightly depressed are among those with high presenteeism (pwork when sick. The link between difficulties in replacement or finding a stand in and sickness presenteeism is confirmed by study results. The categories with high sickness presenteeism experience symptoms more often than those without presenteeism. The most common combination is low monthly income, high sickness absenteeism and high sickness presenteeism.

Network analysis reveals distinct clinical syndromes underlying acute mountain sickness.

Directory of Open Access Journals (Sweden)

David P Hall

Full Text Available Acute mountain sickness (AMS is a common problem among visitors at high altitude, and may progress to life-threatening pulmonary and cerebral oedema in a minority of cases. International consensus defines AMS as a constellation of subjective, non-specific symptoms. Specifically, headache, sleep disturbance, fatigue and dizziness are given equal diagnostic weighting. Different pathophysiological mechanisms are now thought to underlie headache and sleep disturbance during acute exposure to high altitude. Hence, these symptoms may not belong together as a single syndrome. Using a novel visual analogue scale (VAS, we sought to undertake a systematic exploration of the symptomatology of AMS using an unbiased, data-driven approach originally designed for analysis of gene expression. Symptom scores were collected from 292 subjects during 1110 subject-days at altitudes between 3650 m and 5200 m on Apex expeditions to Bolivia and Kilimanjaro. Three distinct patterns of symptoms were consistently identified. Although fatigue is a ubiquitous finding, sleep disturbance and headache are each commonly reported without the other. The commonest pattern of symptoms was sleep disturbance and fatigue, with little or no headache. In subjects reporting severe headache, 40% did not report sleep disturbance. Sleep disturbance correlates poorly with other symptoms of AMS (Mean Spearman correlation 0.25. These results challenge the accepted paradigm that AMS is a single disease process and describe at least two distinct syndromes following acute ascent to high altitude. This approach to analysing symptom patterns has potential utility in other clinical syndromes.

EEG based time and frequency dynamics analysis of visually induced motion sickness (VIMS).

Science.gov (United States)

Arsalan Naqvi, Syed Ali; Badruddin, Nasreen; Jatoi, Munsif Ali; Malik, Aamir Saeed; Hazabbah, Wan; Abdullah, Baharudin

2015-12-01

3D movies are attracting the viewers as they can see the objects flying out of the screen. However, many viewers have reported various problems which are usually faced after watching 3D movies. These problems include visual fatigue, eye strain, headaches, dizziness, blurred vision or collectively may be termed as visually induced motion sickness (VIMS). This research focuses on the comparison between 3D passive technology with a conventional 2D technology to find that whether 3D is causing trouble in the viewers or not. For this purpose, an experiment was designed in which participants were randomly assigned to watch 2D or a 3D movie. The movie was specially designed to induce VIMS. The movie was shown for the duration of 10 min to every participant. The electroencephalogram (EEG) data was recorded throughout the session. At the end of the session, participants rated their feelings using simulator sickness questionnaire (SSQ). The SSQ data was analyzed and the ratings of 2D and 3D participants were compared statistically by using a two tailed t test. From the SSQ results, it was found that participants watching 3D movies reported significantly higher symptoms of VIMS (p value EEG data was analyzed by using MATLAB and topographic plots are created from the data. A significant difference has been observed in the frontal-theta power which increases with the passage of time in 2D condition while decreases with time in 3D condition. Also, a decrease in beta power has been found in the temporal lobe of 3D group. Therefore, it is concluded that there are negative effects of 3D movies causing significant changes in the brain activity in terms of band powers. This condition leads to produce symptoms of VIMS in the viewers.

Motion sickness in ancient China: Seasickness and cart-sickness.

Science.gov (United States)

Brandt, Thomas; Bauer, Matthias; Benson, Judy; Huppert, Doreen

2016-07-19

To find and analyze descriptions of motion sickness in Chinese historical sources. Databases and dictionaries were searched for various terms for seasickness and travel sickness, which were then entered into databases of full texts allowing selection of relevant passages from about the third to the 19th century ad. Already in 300 ad the Chinese differentiated cart-sickness, particularly experienced by persons from the arid north of China, from a ship-illness experienced by persons from the south, where rivers were important for transportation and travel. In the Middle Ages, a third form of motion sickness was called litter-influence experienced by persons transported in a bed suspended between 2 long poles. The ancient Chinese recognized the particular susceptibility of children to motion sickness. Therapeutic recommendations include drinking the urine of young boys, swallowing white sand-syrup, collecting water drops from a bamboo stick, or hiding some earth from the middle of the kitchen hearth under the hair. The Chinese medical classics distinguished several forms of travel sickness, all of which had their own written characters. The pathophysiologic mechanism was explained by the medicine of correspondences, which was based on malfunctions within the body, its invasion by external pathogens like wind, or the deficit or surfeit of certain bodily substances such as the life force Qi. The concept of motion as the trigger of sickness initially appeared in a chapter on warding off the influence of demons and corpses, e.g., ancient magic and beliefs. © 2016 American Academy of Neurology.

The sick-building syndrome; Das Sick-Building-Syndrom

Energy Technology Data Exchange (ETDEWEB)

Henne, A.; Neumann, H.F.; Winneke, G.

1992-12-31

The sick-building syndrome is characterized by the presence of general, non-specific symptoms (e.g., headache, tiredness, respiratory problems, eye trouble, vertigo, nausea, unspecific hypersensitivity) in association with a particular indoor ambience. It is clearly distinguishable from `building-related illness`, referring to a well-defined clinical syndrome due to staying in a building and for which a cause can, in general, be established. Disorders in the case of the sick-building syndrome are manifold and confirmed objectifiable results are hardly available so far. Yet there are some organ-related methods for the confirmation of findings concerning, for instance, the eyes, the skin and the area of the nose. The causes of the incidence of sick-building syndrome are more or less unclear. It is a multifactorial phenomenon involving physical, biological, chemical, individual-specific and psychological factors. Buildings where sick-building syndrome occurs typically exhibit certain properties. The European Community has already made proposals for the investigation of incriminated buildings. A systematic survey by questionnaire together with individual interviews plays an import part towards clarifying the syndrome. (orig./UWA) [Deutsch] Das Sick-Building-Syndrom beschreibt das Vorhandensein von allgemeinen, nicht spezifischen Symptomen (z.B. Kopfschmerzen, Muedigkeit, Atembeschwerden, Augenreizungen, Schwindelgefuehl, Uebelkeit, unspezifische Ueberempfindlichkeit), assoziiert mit einer besonderen Innenraumumgebung. Deutlich hiervon abzugrenzen ist die ``Building related illness``, bei der ein klinisch definiertes Krankheitsbild vorliegt, das durch den Aufenthalt im Gebaeude verursacht wird und fuer das im allgemeinen eine Ursache ermittelt werden kann. Das Beschwerdebild beim Sick-Building-Syndrom ist vielfaeltig, und gesicherte, objektivierbare Befunde liegen hierzu bisher kaum vor. Dennoch gibt es einige organbezogenen Methoden zur Befundabsicherung, z.B. fuer das

Motion Cues in Flight Simulation and Simulator Induced Sickness

Science.gov (United States)

1988-06-01

military F7 .. vehicles, surface excavation equipment, underground mining devices, railway locomotives, .A space vehicles, shiv bridges, and submarines. Of...Evaluatort Rleference to Fukuda is: Fukuda, T. Postural behavior and motion sickness. Acca Otolaryngol. (Stockholm), 1976, B1:37-241.) %kI RTD-5

Respiratory impact on motion sickness induced by linear motion

NARCIS (Netherlands)

Mert, A.; Klöpping-Ketelaars, I.; Bles, W.

2009-01-01

Motion sickness incidence (MSI) for vertical sinusoidal motion reaches a maximum at 0.167 Hz. Normal breathing frequency is close to this frequency. There is some evidence for synchronization of breathing with this stimulus frequency. If this enforced breathing takes place over a larger frequency

Natural Selection on Genes Related to Cardiovascular Health in High-Altitude Adapted Andeans.

Science.gov (United States)

Crawford, Jacob E; Amaru, Ricardo; Song, Jihyun; Julian, Colleen G; Racimo, Fernando; Cheng, Jade Yu; Guo, Xiuqing; Yao, Jie; Ambale-Venkatesh, Bharath; Lima, João A; Rotter, Jerome I; Stehlik, Josef; Moore, Lorna G; Prchal, Josef T; Nielsen, Rasmus

2017-11-02

The increase in red blood cell mass (polycythemia) due to the reduced oxygen availability (hypoxia) of residence at high altitude or other conditions is generally thought to be beneficial in terms of increasing tissue oxygen supply. However, the extreme polycythemia and accompanying increased mortality due to heart failure in chronic mountain sickness most likely reduces fitness. Tibetan highlanders have adapted to high altitude, possibly in part via the selection of genetic variants associated with reduced polycythemic response to hypoxia. In contrast, high-altitude-adapted Quechua- and Aymara-speaking inhabitants of the Andean Altiplano are not protected from high-altitude polycythemia in the same way, yet they exhibit other adaptive features for which the genetic underpinnings remain obscure. Here, we used whole-genome sequencing to scan high-altitude Andeans for signals of selection. The genes showing the strongest evidence of selection-including BRINP3, NOS2, and TBX5-are associated with cardiovascular development and function but are not in the response-to-hypoxia pathway. Using association mapping, we demonstrated that the haplotypes under selection are associated with phenotypic variations related to cardiovascular health. We hypothesize that selection in response to hypoxia in Andeans could have vascular effects and could serve to mitigate the deleterious effects of polycythemia rather than reduce polycythemia itself. Copyright © 2017. Published by Elsevier Inc.

Understanding of Altitude Illness and Use of Pharmacotherapy Among Trekkers and Porters in the Annapurna Region of Nepal.

Science.gov (United States)

Havryliuk, Tatiana; Acharya, Bhuwan; Caruso, Emily; Cushing, Tracy

2015-09-01

We surveyed Nepali porters and guides as well as English- and non-English-speaking trekkers on their knowledge of altitude illness and its treatment during trekking expeditions to the Annapurna region of Nepal. From March 15 to April 15, 2014, Nepali porters and visiting trekkers were surveyed regarding their ability to recognize and treat altitude illness in Manang, Nepal (3540 m). Their personal use of medications and home remedies and presence of acute mountain sickness (AMS) symptoms were also assessed. 504 subjects were surveyed, including 108 Nepalis. Overall incidence of AMS symptoms was 16%, 5% among Nepalis, and 21% among trekkers. Subjects recognized that headache (88%) was one of the symptoms of AMS, however many reported not knowing the symptoms of high altitude pulmonary edema (40%) or high altitude cerebral edema (42%). 58% of subjects reported carrying and 16% reported taking acetazolamide, while only 2 (0.4%) respondents took dexamethasone. The majority of subjects reported that they would be able to recognize (67%) and treat (62%) altitude illness. Trekkers reported a higher incidence of AMS symptoms than Nepalis. Although most respondents recognized symptoms of AMS, both Nepalis and trekkers lacked knowledge regarding more serious presentations of altitude illness, thus both groups were overconfident in their ability to recognize and treat altitude illness.

Surgical Decompression for Traumatic Spinal Cord Injury in a ...

African Journals Online (AJOL)

2018-01-24

Jan 24, 2018 ... spinal cord decompression with or without spinal stabilization in our region. Methodology: We ... decompression and fixation in this series were surgical site infections (11.4%) and ..... group and died of respiratory failure.

Altitude and endurance training.

Science.gov (United States)

Rusko, Heikki K; Tikkanen, Heikki O; Peltonen, Juha E

2004-10-01

The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (altitude training period (training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

Original endoscopic orbital decompression of lateral wall through hairline approach for Graves’ ophthalmopathy: an innovation of balanced orbital decompression

Directory of Open Access Journals (Sweden)

Gong Y

2018-03-01

Full Text Available Yi Gong,1,* Jiayang Yin,2,* Boding Tong,2 Jingkun Li,3 Jiexi Zeng,2 Zhongkun Zuo,1 Fei Ye,1 Yongheng Luo,4 Jing Xiao,1 Wei Xiong2 1Department of Minimal Invasive Surgery, The Second Xiangya Hospital, Central South University, Changsha, China; 2Department of Ophthalmology and Eye Research Center, The Second Xiangya Hospital, Central South University, Changsha, China; 3E.N.T Department, The Second Xiangya Hospital, Central South University, Changsha, China; 4Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China *These authors contributed equally to this work Background: Orbital decompression is an important surgical procedure for treatment of Graves’ ophthalmopathy (GO, especially in women. It is reasonable for balanced orbital decompression of the lateral and medial wall. Various surgical approaches, including endoscopic transnasal surgery for medial wall and eye-side skin incision surgery for lateral wall, are being used nowadays, but many of them lack the validity, safety, or cosmetic effect. Patients and methods: Endoscopic orbital decompression of lateral wall through hairline approach and decompression of medial wall via endoscopic transnasal surgery was done to achieve a balanced orbital decompression, aiming to improve the appearance of proptosis and create conditions for possible strabismus and eyelid surgery afterward. From January 29, 2016 to February 14, 2017, this surgery was performed on 41 orbits in 38 patients with GO, all of which were at inactive stage of disease. Just before surgery and at least 3 months after surgery, Hertel’s ophthalmostatometer and computed tomography (CT were used to check proptosis and questionnaires of GO quality of life (QOL were completed. Findings: The postoperative retroversion of eyeball was 4.18±1.11 mm (Hertel’s ophthalmostatometer and 4.17±1.14 mm (CT method. The patients’ QOL was significantly improved, especially the change in appearance without

Sick building syndrome

Directory of Open Access Journals (Sweden)

Tjandra Y. Aditama

2002-06-01

Full Text Available Sick building syndrome describes a number of mostly unspesific complaints of some occupants of the building. The exact pathophysiological mechanism remains elusive. It is a multi factorial event which may include physical, chemical, biological as well as psycological factors. In many cases it is due to insufficient maintenance of the HVAC (heating, ventilation, air conditioning system in the building. Sign and symptoms can be uncomfortable and even disabling, which may include mucus membrane irritation, neurotoxic symptoms, asthma like symptoms, skin complaints, gastrointestinal symptoms and other related symptoms. There are various investigation methods to diagnose sick building syndrome, and on site assessment of the building is extremely useful. Prevention through a proactive air quality monitoring program is far more desirable than dealing with an actual sick building. Indoor air and the sick building symdrome serves as a paradigm of modern occupational and environmental medicine. (Med J Indones 2002; 11:124-31Keywords: indoor air pollution, sick building syndrome, building related illness

Virtual reality sickness questionnaire (VRSQ): Motion sickness measurement index in a virtual reality environment.

Science.gov (United States)

Kim, Hyun K; Park, Jaehyun; Choi, Yeongcheol; Choe, Mungyeong

2018-05-01

This study aims to develop a motion sickness measurement index in a virtual reality (VR) environment. The VR market is in an early stage of market formation and technological development, and thus, research on the side effects of VR devices such as simulator motion sickness is lacking. In this study, we used the simulator sickness questionnaire (SSQ), which has been traditionally used for simulator motion sickness measurement. To measure the motion sickness in a VR environment, 24 users performed target selection tasks using a VR device. The SSQ was administered immediately after each task, and the order of work was determined using the Latin square design. The existing SSQ was revised to develop a VR sickness questionnaire, which is used as the measurement index in a VR environment. In addition, the target selection method and button size were found to be significant factors that affect motion sickness in a VR environment. The results of this study are expected to be used for measuring and designing simulator sickness using VR devices in future studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultrastructural changes of compressed lumbar ventral nerve roots following decompression

International Nuclear Information System (INIS)

El-Barrany, Wagih G.; Hamdy, Raid M.; Al-Hayani, Abdulmonem A.; Jalalah, Sawsan M.; Al-Sayyad, Mohammad J.

2006-01-01

To study whether there will be permanent lumbar nerve rot scanning or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain. The study was performed at the Department of Anatomy, Faulty of Medicine, king Abdulaziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study. One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyentilated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The enoneurium was filed of myelinated and unmyelinated nerve fibers and collagen fibrils. Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve and nerve recovery without endoneurial scarring. (author)

The energy spectrum of cosmic-ray induced neutrons measured on an airplane over a wide range of altitude and latitude

International Nuclear Information System (INIS)

Goldhagen, P.; Clem, J. M.; Wilson, J. W.

2004-01-01

Crews of high-altitude aircraft are exposed to radiation from galactic cosmic rays (GCRs). To help determine such exposures, the Atmospheric Ionizing Radiation Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on a NASA ER-2 high-altitude airplane. The primary instrument was a sensitive extended-energy multisphere neutron spectrometer. Its detector responses were calculated for energies up to 100 GeV using the radiation transport code MCNPX 2.5.d with improved nuclear models and including the effects of the airplane structure. New calculations of GCR-induced particle spectra in the atmosphere were used to correct for spectrometer counts produced by protons, pions and light nuclear ions. Neutron spectra were unfolded from the corrected measured count rates using the deconvolution code MAXED 3.1. The results for the measured cosmic-ray neutron spectrum (thermal to >10 GeV), total neutron fluence rate, and neutron dose equivalent and effective dose rates, and their dependence on altitude and geomagnetic cut-off agree well with results from recent calculations of GCR-induced neutron spectra. (authors)

Defining Nitrogen Kinetics for Air Break in Prebreath

Science.gov (United States)

Conkin, Johnny

2010-01-01

Actual tissue nitrogen (N2) kinetics are complex; the uptake and elimination is often approximated with a single half-time compartment in statistical descriptions of denitrogenation [prebreathe(PB)] protocols. Air breaks during PB complicate N2 kinetics. A comparison of symmetrical versus asymmetrical N2 kinetics was performed using the time to onset of hypobaric decompression sickness (DCS) as a surrogate for actual venous N2 tension. METHODS: Published results of 12 tests involving 179 hypobaric exposures in altitude chambers after PB, with and without airbreaks, provide the complex protocols from which to model N2 kinetics. DCS survival time for combined control and airbreaks were described with an accelerated log logistic model where N2 uptake and elimination before, during, and after the airbreak was computed with a simple exponential function or a function that changed half-time depending on ambient N2 partial pressure. P1N2-P2 = (Delta)P defined decompression dose for each altitude exposure, where P2 was the test altitude and P1N2 was computed N2 pressure at the beginning of the altitude exposure. RESULTS: The log likelihood (LL) without decompression dose (null model) was -155.6, and improved (best-fit) to -97.2 when dose was defined with a 240 min half-time for both N2 elimination and uptake during the PB. The description of DCS survival time was less precise with asymmetrical N2 kinetics, for example, LL was -98.9 with 240 min half-time elimination and 120 min half-time uptake. CONCLUSION: The statistical regression described survival time mechanistically linked to symmetrical N2 kinetics during PBs that also included airbreaks. The results are data-specific, and additional data may change the conclusion. The regression is useful to compute additional PB time to compensate for an airbreak in PB within the narrow range of tested conditions.

A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and sickness behavior.

Science.gov (United States)

Morris, Gerwyn; Anderson, George; Galecki, Piotr; Berk, Michael; Maes, Michael

2013-03-08

It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation. There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gastrointestinal symptoms, anorexia and weight loss) between sickness and ME/CFS. While sickness is an adaptive response induced by proinflammatory cytokines, ME/CFS is a chronic, disabling disorder, where the pathophysiology is related to activation of immunoinflammatory and oxidative pathways and autoimmune responses. While sickness behavior is a state of energy conservation, which plays a role in combating pathogens, ME/CFS is a chronic disease underpinned by a state of energy depletion. While sickness is an acute response to infection/injury, the trigger factors in ME/CFS are less well defined and encompass acute and chronic infections, as well as inflammatory or autoimmune diseases. It is concluded that sickness behavior and ME/CFS are two different conditions.

Nutrição para os praticantes de exercício em grandes altitudes Nutritional strategy for exercising in high altitudes

Directory of Open Access Journals (Sweden)

Caroline Buss

2006-02-01

symptoms of Acute Mountain Sickness which may occur in the first days of high altitude sojourn. An adequate nutritional strategy is essential to protect the body from any additional stress. The aim of this paper was to present the main effects of altitude on the human body and physical performance; to discuss and/or suggest nutritional recommendations for this situation; and, if possible, to present practical nutritional guidelines for athletes in high altitudes. Some of the main conclusions found were: energy intake must be increased; it is essential to monitor fluid intake and to choose palatable energy and nutrient-dense foods. It is recommended to work with a sports dietitian in advance, so that an individual nutrition plan can be made and put into practice even before being exposed to high altitudes.

Standing body sway in women with and without morning sickness in pregnancy.

Science.gov (United States)

Yu, Yawen; Chung, Hyun Chae; Hemingway, Lauren; Stoffregen, Thomas A

2013-01-01

Morning sickness typically is attributed to hormonal changes in pregnancy. We asked whether morning sickness is associated with changes in standing postural equilibrium, as occurs in research on visually induced motion sickness. Twenty-one pregnant women (mean age=30 years, mean height=163cm; mean weight=63kg) were tested during the first trimester. Laboratory-based balance measures were collected, along with perceived postural stability, the presence of morning sickness, and the severity of subjective symptoms. We varied the distance between the feet and the visual task performed during stance. Participants were classified as either experiencing (Sick, n=12) or not experiencing (Well, n=9) morning sickness. Perceived balance stability was lower for Sick than for Well women. The positional variability of sway was reduced for the Sick group, relative to the Well group. Positional variability decreased with wider stance width, and was reduced during performance of a more demanding visual task. Stance width and visual task also influenced the temporal dynamics of sway. Effects of stance width and visual task on postural sway were similar to effects in non-pregnant adults, suggesting that sensitive tuning of posture is maintained during the first trimester. The findings suggest that women with morning sickness may attempt to stabilize their bodies by reducing overall body sway. It may be useful to recommend that women adopt wider stance early in pregnancy. Copyright © 2012 Elsevier B.V. All rights reserved.

Alcohol use disorder-related sick leave and mortality: a cohort study.

Science.gov (United States)

Wedegaertner, Felix; Geyer, Siegfried; Arnhold-Kerri, Sonja; Sittaro, Nicola-Alexander; te Wildt, Bert

2013-01-30

Alcohol use disorders (AUDs) are associated with the highest all-cause mortality rates of all mental disorders. The majority of patients with AUDs never receive inpatient treatment for their AUD, and there is lack of data about their mortality risks despite their constituting the majority of those affected. Absenteeism from work (sick leave) due to an AUD likely signals worsening. In this study, we assessed whether AUD-related sick leave was associated with mortality in a cohort of workers in Germany. 128,001 workers with health insurance were followed for a mean of 6.4 years. We examined the associations between 1) AUD-related sick leave managed on an outpatient basis and 2) AUD-related psychiatric inpatient treatment, and mortality using survival analysis, and Cox proportional hazard regression models (separately by sex) adjusted for age, education, and job code classification. We also stratified analyses by sick leave related to three groups of alcohol-related conditions (all determined by International Classification of Diseases 9th ed. (ICD-9) codes): alcohol abuse and dependence; alcohol-induced mental disorder; and alcohol-induced medical conditions. Outpatient-managed AUD-related sick leave was significantly associated with higher mortality (hazard ratio (HR) 2.90 (95% Confidence interval (CI) 2.24-3.75) for men, HR 5.83 (CI 2.90-11.75) for women). The magnitude of the association was similar for receipt of AUD-related psychiatric inpatient treatment (HR 3.2 (CI 2.76-3.78) for men, HR 6.5 (CI 4.41-9.47) for women). Compared to those without the conditions, higher mortality was observed consistently for outpatients and inpatients across the three groups of alcohol-related conditions. Those with alcohol-related medical conditions who had AUD-related psychiatric inpatient treatment appeared to have the highest mortality. Alcohol use disorder-related sick leave as documented in health insurance records is associated with higher mortality. Such sick leave does

Worried sick? Sickness absence during organizational turmoil

OpenAIRE

Bratberg, Espen; Monstad, Karin

2011-01-01

Sickness absence has risen over the past years in Norway. An explanation put forward is that a tougher labour market represents a health hazard, while a competing hypothesis predicts that loss of job security works as a disciplinary device. In this analysis we aim to trace a causal impact of organizational turmoil or job insecurity on sickness absence, applying a difference-in-difference approach. Utilizing a negative financial shock that hit specific employers and workplaces, we find that...

Does smoking affect the outcomes of lumbar decompression surgery?

Directory of Open Access Journals (Sweden)

Mehta Radha

2017-01-01

Full Text Available Introduction: Lumbar decompressions and micro-discectomies are commonly performed non-complex spinal surgeries that do not involve the insertion of metalwork into the spine and are done for symptomatic disc prolapse and lumbar spinal stenosis, whereas complex-spinal surgery does require metalwork [1]. Studies of complex-spinal surgeries show that smoking has a significant negative impact on the outcome of the surgery [2] therefore, the cessation of smoking is advised prior to surgery [3]. There are evidences in the literature supportive as well as opposing this statement about continued smoking and poor outcome of decompressive spinal surgeries. Methods: We retrospectively reviewed 143 consecutive patients who have had either a micro-discectomy or a micro-decompression. Results: We found no statistical difference between smokers and non-smokers in the outcomes of lumbar decompression surgery. Both groups improved equally and significantly in terms of back pain, leg pain and functions. Out of 143 patients, only 2% more non-smokers had improved leg pain compared to smokers, 1% less non-smokers had improved back pain and 2% more non-smokers had an improved Oswestry Disability Index (ODI score. Discussion: We recommend that it is important to surgically treat both smokers and non-smokers in need of a lumbar spinal decompression.

Vection is the main contributor to motion sickness induced by visual yaw rotation: Implications for conflict and eye movement theories.

Directory of Open Access Journals (Sweden)

Suzanne A E Nooij

Full Text Available This study investigated the role of vection (i.e., a visually induced sense of self-motion, optokinetic nystagmus (OKN, and inadvertent head movements in visually induced motion sickness (VIMS, evoked by yaw rotation of the visual surround. These three elements have all been proposed as contributing factors in VIMS, as they can be linked to different motion sickness theories. However, a full understanding of the role of each factor is still lacking because independent manipulation has proven difficult in the past. We adopted an integrative approach to the problem by obtaining measures of potentially relevant parameters in four experimental conditions and subsequently combining them in a linear mixed regression model. To that end, participants were exposed to visual yaw rotation in four separate sessions. Using a full factorial design, the OKN was manipulated by a fixation target (present/absent, and vection strength by introducing a conflict in the motion direction of the central and peripheral field of view (present/absent. In all conditions, head movements were minimized as much as possible. Measured parameters included vection strength, vection variability, OKN slow phase velocity, OKN frequency, the number of inadvertent head movements, and inadvertent head tilt. Results show that VIMS increases with vection strength, but that this relation varies among participants (R2 = 0.48. Regression parameters for vection variability, head and eye movement parameters were not significant. These results may seem to be in line with the Sensory Conflict theory on motion sickness, but we argue that a more detailed definition of the exact nature of the conflict is required to fully appreciate the relationship between vection and VIMS.

Scuba diving accidents.

Science.gov (United States)

Dembert, M L

1977-08-01

The principal scuba diving medical problems of barotrauma, air embolism and decompression sickness have as their pathophysiologic basis the Ideal Gas Law and Boyle's Law. Hyperbaric chamber recompression therapy is the only definitive treatment of air embolism and decompression sickness. However, with a basic knowledge of diving medicine, the family physician can provide effective supportive care to the patient prior to initiation of hyperbaric therapy.

Persistent sciatica induced by quadratus femoris muscle tear and treated by surgical decompression: a case report

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Tzanakakis George

2010-08-01

Full Text Available Abstract Introduction Quadratus femoris tear is an uncommon injury, which is only rarely reported in the literature. In the majority of cases the correct diagnosis is delayed due to non-specific symptoms and signs. A magnetic resonance imaging scan is crucial in the differential diagnosis since injuries to contiguous soft tissues may present with similar symptoms. Presentation with sciatica is not reported in the few cases existing in the English literature and the reported treatment has always been conservative. Case presentation We report here on a case of quadratus femoris tear in a 22-year-old Greek woman who presented with persistent sciatica. She was unresponsive to conservative measures and so was treated with surgical decompression. Conclusion The correct diagnosis of quadratus muscle tear is a challenge for physicians. The treatment is usually conservative, but in cases of persistent sciatica surgical decompression is an alternative option.

Air pollution and sick-leaves. A case study using air pollution data from Oslo

International Nuclear Information System (INIS)

Hansen, A.C.; Selte, H.K.

2000-01-01

During the last decade an increasing amount of studies have investigated the relationship between air pollution and human health effects. In this study we investigate how these effects in turn induce reduced labour productivity in terms of sick-leaves, which is an important factor in assessment of air pollution costs in urban areas. For this purpose we employ a logit model along with data on sick-leaves from a large office in Oslo and different air pollutants. Our results indicate that sick-leaves are significantly associated with particulate matter (PM 1 0), while the associations with SO 2 and NO 2 are more ambiguous. We also try to estimate the induced social costs in terms of lost labour productivity and increased governmental expenditures, although these estimates are more uncertain. 17 refs

Decompression Sickness, Extravehicular Activities, and Nitrogen Induced Osmosis: Brian Hills Revisited

Science.gov (United States)

2001-06-01

hypobares ou hyperbares ] To order the complete compilation report, use: ADA395680 The component part is provided here to allow users access to individually...report: TITLE: Operational Medical Issues in Hypo-and Hyperbaric Conditions [les Questions medicales a caractere oprationel liees aux conditions...Hypo- and Hyperbaric Conditions ", held in Toronto, Canada, 16-19 October 2000, and published in RTO MP-062. 45-2 upon the local pressure differential

Controlled progressive innate immune stimulation regimen prevents the induction of sickness behavior in the open field test.

Science.gov (United States)

Chen, Qun; Tarr, Andrew J; Liu, Xiaoyu; Wang, Yufen; Reed, Nathaniel S; Demarsh, Cameron P; Sheridan, John F; Quan, Ning

2013-01-01

Peripheral immune activation by bacterial mimics or live replicating pathogens is well known to induce central nervous system activation. Sickness behavior alterations are often associated with inflammation-induced increases in peripheral proinflammatory cytokines (eg, interleukin [IL]-1β and IL-6). However, most researchers have used acute high dose endotoxin/bacterial challenges to observe these outcomes. Using this methodology may pose inherent risks in the translational interpretation of the experimental data in these studies. Studies using Escherichia coli have yet to establish the full kinetics of repeated E. coli peripheral injections. Therefore, we sought to examine the effects of repeated low dose E. coli on sickness behavior and local peripheral inflammation in the open field test. Results from the current experiments showed a behavioral dose response, where increased amounts of E. coli resulted in correspondingly increased sickness behavior. Furthermore, animals that received a subthreshold dose (ie, one that did not cause sickness behavior) of E. coli 24 hours prior were able to withstand a larger dose of E. coli on the second day (a dose that would normally cause sickness behavior in mice without prior exposure) without inducing sickness behavior. In addition, animals that received escalating subthreshold doses of E. coli on days 1 and 2 behaviorally tolerated a dose of E. coli 25 times higher than what would normally cause sickness behavior if given acutely. Lastly, increased levels of E. coli caused increased IL-6 and IL-1β protein expression in the peritoneal cavity, and this increase was blocked by administering a subthreshold dose of E. coli 24 hours prior. These data show that progressive challenges with subthreshold levels of E. coli may obviate the induction of sickness behavior and proinflammatory cytokine expression.

The prevalence of sick leave

DEFF Research Database (Denmark)

Backhausen, Mette; Damm, Peter; Bendix, Jane

2018-01-01

of long-term sick leave. Method Data from 508 employed pregnant women seeking antenatal care was collected by questionnaires from August 2015 to March 2016. The questionnaires, which were filled in at 20 and 32 weeks of gestation, provided information on maternal characteristics, the number of days spent...... on sick leave and the associated reasons. Descriptive statistics and logistic regression analysis were applied. Results The prevalence of sick leave was 56% of employed pregnant women in the first 32 weeks of gestation and more than one in four reported long-term sick leave (>20 days, continuous...... was a negative predictor. Conclusions The prevalence of sick leave was 56% in the first 32 weeks of gestation and more than one in four women reported long-term sick leave. The majority of reasons for sick leave were pregnancy-related and low back pain was the most frequently given reason....

Avaliação dos efeitos da altitude sobre a visão Analysis of vision effects at altitude

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Luiz Filipe de Albuquerque Alves

2008-10-01

Full Text Available Este trabalho de revisão bibliográfica é direcionado para a investigação dos efeitos da hipóxia da altitude sobre a visão. Pretende assim, ser uma contribuição na identificação dos sinais e sintomas presentes durante a exposição do aeronavegante às altas altitudes. O conhecimento sobre as características da atmosfera terrestre e o comportamento dos gases quando submetidos à variação de pressão atmosférica são muito importantes para o correto diagnóstico dos disbarismos, hipóxia e doença da descompressão para os profissionais de saúde voltados para a atividade aeroespacial. O ambiente atmosférico a que os aeronavegantes são expostos, é capaz de interferir de forma significativa na função visual, podendo gerar lesões de caráter reversíveis ou não, tais como: hemorragias retinianas, diminuição da visão noturna e da acuidade visual, restrição do campo visual, aparecimento de estrabismos latentes, diminuição da pressão intra-ocular e alterações refracionais em indivíduos previamente submetidos às cirurgias refrativas.This bibliographic review work is pointed to the effects of altitude hypoxia on sight. It intends to contribute for the identification of signs and symptoms of hypoxia during high altitude exposition. The understanding of the terrestrial atmosphere and the laws of physics related to gas behavior under atmospheric pressure variation are very important for the correct diagnosis of the dysbarisms, hypoxia, decompression disease and others, by the aerospace health professionals. The atmospheric environment that pilots are exposed is able to interfere in a significant way on visual function and can lead to reversible or irreversible lesions such as: retinal bleeding, decrease of the night vision and vision acuity, restriction of the visual field, emergence of latent strabismus, decrease of the intra-ocular pressure and refractive alterations in individuals that went through refractive surgery.

Demonstrating the potential for dynamic auditory stimulation to contribute to motion sickness.

Directory of Open Access Journals (Sweden)

Behrang Keshavarz

Full Text Available Auditory cues can create the illusion of self-motion (vection in the absence of visual or physical stimulation. The present study aimed to determine whether auditory cues alone can also elicit motion sickness and how auditory cues contribute to motion sickness when added to visual motion stimuli. Twenty participants were seated in front of a curved projection display and were exposed to a virtual scene that constantly rotated around the participant's vertical axis. The virtual scene contained either visual-only, auditory-only, or a combination of corresponding visual and auditory cues. All participants performed all three conditions in a counterbalanced order. Participants tilted their heads alternately towards the right or left shoulder in all conditions during stimulus exposure in order to create pseudo-Coriolis effects and to maximize the likelihood for motion sickness. Measurements of motion sickness (onset, severity, vection (latency, strength, duration, and postural steadiness (center of pressure were recorded. Results showed that adding auditory cues to the visual stimuli did not, on average, affect motion sickness and postural steadiness, but it did reduce vection onset times and increased vection strength compared to pure visual or pure auditory stimulation. Eighteen of the 20 participants reported at least slight motion sickness in the two conditions including visual stimuli. More interestingly, six participants also reported slight motion sickness during pure auditory stimulation and two of the six participants stopped the pure auditory test session due to motion sickness. The present study is the first to demonstrate that motion sickness may be caused by pure auditory stimulation, which we refer to as "auditorily induced motion sickness".

Systemic Immune Activation Leads to Neuroinflammation and Sickness Behavior in Mice

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Steven Biesmans

2013-01-01

Full Text Available Substantial evidence indicates an association between clinical depression and altered immune function. Systemic administration of bacterial lipopolysaccharide (LPS is commonly used to study inflammation-associated behavioral changes in rodents. In these experiments, we tested the hypothesis that peripheral immune activation leads to neuroinflammation and depressive-like behavior in mice. We report that systemic administration of LPS induced astrocyte activation in transgenic GFAP-luc mice and increased immunoreactivity against the microglial marker ionized calcium-binding adapter molecule 1 in the dentate gyrus of wild-type mice. Furthermore, LPS treatment caused a strong but transient increase in cytokine levels in the serum and brain. In addition to studying LPS-induced neuroinflammation, we tested whether sickness could be separated from depressive-like behavior by evaluating LPS-treated mice in a panel of behavioral paradigms. Our behavioral data indicate that systemic LPS administration caused sickness and mild depressive-like behavior. However, due to the overlapping time course and mild effects on depression-related behavior per se, it was not possible to separate sickness from depressive-like behavior in the present rodent model.

Individual Susceptibility to Hypobaric Environments: An Update

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Law, Jennifer; Watkins, Sharmi

2009-01-01

Astronauts are at risk for developing decompression sickness (DCS) while exposed to the hypobaric environment of the extravehicular suit in space, in terrestrial hypobaric chambers, and during ascent from neutral buoyancy training dives. There is increasing recognition that DCS risk is different between diving and altitude exposures, with many individual parameters and environmental factors implicated as risk factors for development of DCS in divers but are not recognized as risk factors in altitude exposures. Much of the literature to date has focused on patent foramen ovale (PFO), which has long been considered a major risk factor for DCS in diving exposures, but its link to serious DCS in altitude exposures remains unclear. Knowledge of those risk factors specific to hypobaric DCS may help identify susceptible individuals and aid in astronaut selection, crew assignment, and mission planning. This paper reviews the current literature pertaining to these risk factors, including PFO, anthropometric parameters, gender, menstrual cycle, lifetime diving experience, physical fitness, biochemical levels, complement activation, cigarette smoking, fluid balance, and ambient temperature. Further research to evaluate pertinent risk factors for DCS in altitude exposures is recommended.

20 CFR 218.28 - Sick pay.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Sick pay. 218.28 Section 218.28 Employees... Beginning Date § 218.28 Sick pay. (a) From railroad employer. If the employee is carried on the payroll while sick, the annuity can begin no earlier than the day after the last day of sick pay. However, sick...

Piezosurgery in Modified Pterional Orbital Decompression Surgery in Graves Disease.

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Grauvogel, Juergen; Scheiwe, Christian; Masalha, Waseem; Jarc, Nadja; Grauvogel, Tanja; Beringer, Andreas

2017-10-01

Piezosurgery uses microvibrations to selectively cut bone, preserving the adjacent soft tissue. The present study evaluated the use of piezosurgery for bone removal in orbital decompression surgery in Graves disease via a modified pterional approach. A piezosurgical device (Piezosurgery medical) was used in 14 patients (20 orbits) with Graves disease who underwent orbital decompression surgery in additional to drills and rongeurs for bone removal of the lateral orbital wall and orbital roof. The practicability, benefits, and drawbacks of this technique in orbital decompression surgery were recorded. Piezosurgery was evaluated with respect to safety, preciseness of bone cutting, and preservation of the adjacent dura and periorbita. Preoperative and postoperative clinical outcome data were assessed. The orbital decompression surgery was successful in all 20 orbits, with good clinical outcomes and no postoperative complications. Piezosurgery proved to be a safe tool, allowing selective bone cutting with no damage to the surrounding soft tissue structures. However, there were disadvantages concerning the intraoperative handling in the narrow space and the efficiency of bone removal was limited in the orbital decompression surgery compared with drills. Piezosurgery proved to be a useful tool in bone removal for orbital decompression in Graves disease. It is safe and easy to perform, without any danger of damage to adjacent tissue because of its selective bone-cutting properties. Nonetheless, further development of the device is necessary to overcome the disadvantages in intraoperative handling and the reduced bone removal rate. Copyright © 2017 Elsevier Inc. All rights reserved.

Sick of Taxes?

DEFF Research Database (Denmark)

Ljunge, Jan Martin

I estimate a price elasticity of sickness absence. Sick leave is an intensive margin of labor supply where individuals are free to adjust. I exploit variation in tax rates over two decades, which provide thousands of differential incentives across time and space, to estimate the price responsiven...... of sick leave, -0.7, with respect to the net of tax rate. Though large relative to traditional labor supply elasticities, Swedes are half as price elastic as bike messengers, and just as elastic as stadium vendors on the margin which they can adjust freely....

Attitudes towards sickness absence and sickness presenteeism in health and care sectors in Norway and Denmark: a qualitative study.

Science.gov (United States)

Krane, Line; Larsen, Eva Ladekjær; Nielsen, Claus Vinther; Stapelfeldt, Christina Malmose; Johnsen, Roar; Risør, Mette Bech

2014-08-27

In the health and care sector, sickness absence and sickness presenteeism are frequent phenomena and constitute a field in need of exploration. Attitudes towards sickness absence involve also attitudes towards sickness presenteeism, i.e. going to work while sick, confirmed by previous studies. Sickness behavior, reflecting attitudes on work absence, could differ between countries and influence absence rates. But little is known about attitudes towards sickness absence and sickness presenteeism in the health and care sectors in Norway and Denmark. The aim of the present paper is therefore to explore attitudes towards sickness absence and sickness presenteeism among nursing home employees in both countries. Eight focus group discussions (FGDs) were conducted using a semi-structured interview guide, the main attention of which was attitudes towards sickness absence and sickness presenteeism. FGDs were conducted in two nursing homes in Norway and two in Denmark, with different geographic locations: one in a rural area and one in an urban area in each country. FGDs were recorded, transcribed and analyzed using framework analysis to identify major themes and explanatory patterns. Four major significant themes were identified from the FGDs: a) sickness absence and sickness presenteeism, b) acceptable causes of sickness absence, c) job identity, and d) organization of work and physical aspects of the workplace. Our analyses showed that social commitment and loyalty to residents and colleagues was important for sickness absence and sickness presenteeism, as were perceived acceptable and non-acceptable reasons for sickness absence. Organization of work and physical aspects of the workplace were also found to have an influence on attitudes towards sickness absence. The general interpretation of the findings was that attitudes towards sickness absence and sickness presenteeism among nursing home employees were embedded in situational patterns of moral relationships and were

KINETIC CHARACTERISTICS OF EUFLAMMATION: THE INDUCTION OF CONTROLLED INFLAMMATION WITHOUT OVERT SICKNESS BEHAVIOR

OpenAIRE

Tarr, Andrew J.; Liu, Xiaoyu; Reed, Nathaniel S.; Quan, Ning

2014-01-01

We found recently that controlled progressive challenge with subthreshold levels of E.coli can confer progressively stronger resistance to future reinfection-induced sickness behavior to the host. We have termed this type of inflammation “euflammation”. In this study, we further characterized the kinetic changes in the behavior, immunological, and neuroendocrine aspects of euflammation. Results show euflammatory animals only display transient and subtle sickness behaviors of...

Can High Altitude Influence Cytokines and Sleep?

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Valdir de Aquino Lemos

2013-01-01

Full Text Available The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2 induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β, Interleukin-6 (IL-6, and tumor necrosis factor-alpha (TNF-α production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain.

Can High Altitude Influence Cytokines and Sleep?

Science.gov (United States)

de Aquino Lemos, Valdir; dos Santos, Ronaldo Vagner Thomatieli; Lira, Fabio Santos; Rodrigues, Bruno; Tufik, Sergio; de Mello, Marco Tulio

2013-01-01

The number of persons who relocate to regions of high altitude for work, pleasure, sport, or residence increases every year. It is known that the reduced supply of oxygen (O2) induced by acute or chronic increases in altitude stimulates the body to adapt to new metabolic challenges imposed by hypoxia. Sleep can suffer partial fragmentation because of the exposure to high altitudes, and these changes have been described as one of the responsible factors for the many consequences at high altitudes. We conducted a review of the literature during the period from 1987 to 2012. This work explored the relationships among inflammation, hypoxia and sleep in the period of adaptation and examined a novel mechanism that might explain the harmful effects of altitude on sleep, involving increased Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) production from several tissues and cells, such as leukocytes and cells from skeletal muscle and brain. PMID:23690660

Does 3D produce more symptoms of visually induced motion sickness?

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Naqvi, Syed Ali Arsalan; Badruddin, Nasreen; Malik, Aamir Saeed; Hazabbah, Wan; Abdullah, Baharudin

2013-01-01

3D stereoscopy technology with high quality images and depth perception provides entertainment to its viewers. However, the technology is not mature yet and sometimes may have adverse effects on viewers. Some viewers have reported discomfort in watching videos with 3D technology. In this research we performed an experiment showing a movie in 2D and 3D environments to participants. Subjective and objective data are recorded and compared in both conditions. Results from subjective reporting shows that Visually Induced Motion Sickness (VIMS) is significantly higher in 3D condition. For objective measurement, ECG data is recorded to find the Heart Rate Variability (HRV), where the LF/HF ratio, which is the index of sympathetic nerve activity, is analyzed to find the changes in the participants' feelings over time. The average scores of nausea, disorientation and total score of SSQ show that there is a significant difference in the 3D condition from 2D. However, LF/HF ratio is not showing significant difference throughout the experiment.

Short-term cardiorespiratory adaptation to high altitude in children compared with adults.

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Kriemler, S; Radtke, T; Bürgi, F; Lambrecht, J; Zehnder, M; Brunner-La Rocca, H P

2016-02-01

As short-term cardiorespiratory adaptation to high altitude (HA) exposure has not yet been studied in children, we assessed acute mountain sickness (AMS), hypoxic ventilatory response (HVR) at rest and maximal exercise capacity (CPET) at low altitude (LA) and HA in pre-pubertal children and their fathers. Twenty father-child pairs (11 ± 1 years and 44 ± 4 years) were tested at LA (450 m) and HA (3450 m) at days 1, 2, and 3 after fast ascent (HA1/2/3). HVR was measured at rest and CPET was performed on a cycle ergometer. AMS severity was mild to moderate with no differences between generations. HVR was higher in children than adults at LA and increased at HA similarly in both groups. Peak oxygen uptake (VO2 peak) relative to body weight was similar in children and adults at LA and decreased significantly by 20% in both groups at HA; maximal heart rate did not change at HA in children while it decreased by 16% in adults (P < 0.001). Changes in HVR and VO2 peak from LA to HA were correlated among the biological child-father pairs. In conclusion, cardiorespiratory adaptation to altitude seems to be at least partly hereditary. Even though children and their fathers lose similar fractions of aerobic capacity going to high altitude, the mechanisms might be different. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Collagen levels are normalized after decompression of experimentally obstructed colon

DEFF Research Database (Denmark)

Rehn, Martin; Ågren, Sven Per Magnus; Syk, I

2011-01-01

Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction.......Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction....

Reliability of sickness certificates in detecting potential sick leave reduction by modifying working conditions: a clinical epidemiology study

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Johnsen Roar

2004-03-01

Full Text Available Abstract Background Medical sickness certificates are generally the main source for information when scrutinizing the need for aimed intervention strategies to avoid or reduce the individual and community side effects of sick leave. This study explored the value of medical sickness certificates related to daily work in Norwegian National Insurance Offices to identify sick-listed persons, where modified working conditions might reduce the ongoing sick leave. Methods The potential for reducing the ongoing sick leave by modifying working conditions was individually assessed on routine sickness certificates in 999 consecutive sick leave episodes by four Norwegian National Insurance collaborators, two with and two without formal medical competence. The study took place in Northern Norway in 1997 and 1998. Agreement analysed with differences against mean, kappa, and proportional-agreement analysis within and between groups of assessors was used in the judgement. Agreements between the assessors and the self-assessment of sick-listed subjects were additionally analysed in 159 sick-leave episodes. Results Both sick-listed subjects and National Insurance collaborators anticipated a potential reduction in sick leave in 20–30% of cases, and in another 20% the potential was assessed as possible. The chance corrected agreements, however, were poor (k Conclusion Information in medical sickness certificates proved ineffective in detecting cases where modified working conditions may reduce sick leave, and focusing on medical certificates may prevent identification of needed interventions. Strategies on how to communicate directly with sick-listed subjects would enable social authorities to exploit more of the sick leave reduction potential by modifying the working conditions than strategies on improving medical information.

Respiratory Muscle Training and Cognitive Function Exercising at Altitude.

Science.gov (United States)

Quackenbush, Joseph; Duquin, Aubrey; Helfer, Samuel; Pendergast, David R

2016-01-01

Hiking and trekking often occur at altitudes up to 12,000 ft altitude. The hypoxia-induced hyperventilation at altitude paradoxically reduces arterial CO2 (Paco2). A reduction in Paco2 results in vasoconstriction of the blood vessels of the brain and thus in local hypoxia. The local hypoxia likely affects cognitive function, which may result in reduced performance and altitude accidents. Recent publications have demonstrated that voluntary isocapnic hyperventilatory training of the respiratory muscles (VIHT) can markedly enhance exercise endurance as it is associated with reduced ventilation and its energy cost. VIHT may be useful in blunting the altitude-induced hyperventilation leading to higher Paco2 and improved cognitive function. This study examined the effects of VIHT, compared to control (C) and placebo (PVIHT) groups, on selected measures of executive functioning, including working memory and processing speed (i.e., Stroop Test, Symbol Digit Modalities Test, and Digit Span Forward) at simulated altitude up to 12,000 ft. Associated physiological parameters were also measured. The Digit Span Forward Test did not show improvements after VIHT in any group. The VIHT group, but not C or PVIHT groups, improved significantly (17-30%) on the Stroop Test. Similarly the VIHT group, but not the C and PVIHT groups, improved correct responses (26%) and number of attempts (24%) on the Symbol Digit Modalities Test. In addition, reaction time was also improved (16%). VIHT improved processing speed and working memory during exercise at altitude.

Introduction to altitude/hypoxic training symposium.

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Wilber, Randall L

2007-09-01

Altitude/hypoxic training has traditionally been an intriguing and controversial area of research and sport performance. This controversial aspect was evident recently in the form of scholarly debates in highly regarded professional journals, as well as the World Anti-Doping Agency's (WADA) consideration of placing "artificially-induced hypoxic conditions" on the 2007 Prohibited List of Substances/Methods. In light of the ongoing controversy surrounding altitude/hypoxic training, this symposium was organized with the following objectives in mind: 1) to examine the primary physiological responses and underlying mechanisms associated with altitude/hypoxic training, including the influence of genetic predisposition; 2) to present evidence supporting the effect of altitude/hypoxic acclimatization on both hematological and nonhematological markers, including erythrocyte volume, skeletal muscle-buffering capacity, hypoxic ventilatory response, and physiological efficiency/economy; 3) to evaluate the efficacy of several contemporary simulated altitude modalities and training strategies, including hypoxic tents, nitrogen apartments, and intermittent hypoxic exposure (IHE) or training, and to address the legal and ethical issues associated with the use of simulated altitude; and 4) to describe different altitude/hypoxic training strategies used by elite-level athletes, including Olympians and military special forces. In addressing these objectives, papers will be presented on the topics of: 1) effect of hypoxic "dose" on physiological responses and sea-level performance (Drs. Benjamin Levine and James Stray-Gundersen), 2) nonhematological mechanisms of improved performance after hypoxic exposure (Dr. Christopher Gore), 3) application of altitude/hypoxic training by elite athletes (Dr. Randall Wilber), and 4) military applications of hypoxic training (Dr. Stephen Muza).

Temporary percutaneous T-fastener gastropexy and continuous decompressive gastrostomy in dogs with experimentally induced gastric dilatation.

Science.gov (United States)

Fox-Alvarez, W Alexander; Case, J Brad; Cooke, Kirsten L; Garcia-Pereira, Fernando L; Buckley, Gareth J; Monnet, Eric; Toskich, Beau B

2016-07-01

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

ALMA to Help Solving Acute Mountain Sickness Mystery

Science.gov (United States)

2007-04-01

, family and social isolation, commuting, intermittent high altitude exposure and other environmental challenges such as low temperatures. "An adequate acclimatisation to 2500m altitude requires around two weeks, and we can thus speculate that going to 5000m would require more than one month to achieve complete acclimatisation," said Professor Juan Silva Urra, from the University of Antofagasta. However, short and long term effects of regular commuting between sea level and high altitude have scarcely been studied in biomedical terms. Scientifically based guidelines for appropriate preventive handling and care under these conditions are lacking and the new study will help bridging this gap. Among the studies to be done, some involve continuous monitoring of the human body through portable devices, including measurements of hormone levels and application of psychometric tests. All measurements at 5000m will be carried out on a voluntary basis, under strict safety protocols, with the presence of a doctor from the investigation team, paramedic personnel form ALMA and an ambulance. The symptoms of Acute Mountain Sickness are headache, sicknesses, gastrointestinal inconveniences, fatigue and insomnia that, depending on their intensities, decrease the capacity to carry out the most routine activities. The valuable data collected will enhance our knowledge of human physiology in extreme environments, generating recommendations that will improve wellbeing and health not only in high-altitude observatories, but also in mining and Antarctic personnel. "We are pleased that ALMA is contributing to other disciplines, like medicine, even before the antennas begin to explore the universe," said Felix Mirabel, ESO's representative in Chile. "This outstanding long-term research that will provide crucial information of human physiology to experts worldwide, has been made possible thanks to the combined effort of Chilean and European universities, in collaboration with ALMA". The Atacama

Age as a risk factor for acute mountain sickness upon rapid ascent to 3,700 m among young adult Chinese men

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Tang XG

2014-08-01

Full Text Available Xu-gang Tang,1 Ji-hang Zhang,1 Jun Qin,1 Xu-bin Gao,1 Qian-ning Li,2 Jie Yu,1 Xiao-han Ding,1 Lan Huang1 1Institute of Cardiovascular Diseases, 2Department of Neurology, Xinqiao Hospital, Third Military Medical University, Chongqing, People’s Republic of China Background: The aim of this study was to explore the relationship between age and acute mountain sickness (AMS when subjects are exposed suddenly to high altitude.Methods: A total of 856 young adult men were recruited. Before and after acute altitude exposure, the Athens Insomnia Scale score (AISS was used to evaluate the subjective sleep quality of subjects. AMS was assessed using the Lake Louise scoring system. Heart rate (HR and arterial oxygen saturation (SaO2 were measured.Results: Results showed that, at 500 m, AISS and insomnia prevalence were higher in older individuals. After acute exposure to altitude, the HR, AISS, and insomnia prevalence increased sharply, and the increase in older individuals was more marked. The opposite trend was observed for SaO2. At 3,700 m, the prevalence of AMS increased with age, as did severe AMS, and AMS symptoms (except gastrointestinal symptoms. Multivariate logistic regression analysis showed that age was a risk factor for AMS (adjusted odds ratio [OR] 1.07, 95% confidence interval [CI] 1.01–1.13, P<0.05, as well as AISS (adjusted OR 1.39, 95% CI 1.28–1.51, P<0.001.Conclusion: The present study is the first to demonstrate that older age is an independent risk factor for AMS upon rapid ascent to high altitude among young adult Chinese men, and pre-existing poor subjective sleep quality may be a contributor to increased AMS prevalence in older subjects. Keywords: acute mountain sickness, age, Athens Insomnia Scale, rapid ascent, sleep

Doctor-certified sickness absence in first and second trimesters of pregnancy among native and immigrant women in Norway.

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Brekke, Idunn; Berg, John E; Sletner, Line; Jenum, Anne Karen

2013-03-01

The authors sought to estimate differences in doctor-certified sickness absence during pregnancy among immigrant and native women. Population-based cohort study of pregnant women attending three Child Health Clinics in Groruddalen, Oslo, and their offspring. Questionnaire data were collected at gestational weeks 10-20 and 28. The participation rate was 74%. A multivariate Poisson regression was used to analyse differences in sickness absence in pregnancy between immigrant and native women. A total of 573 women who were employed prior to their pregnancies were included, 51% were immigrants. After adjusting for age, years of education, marital status, number of children, occupation, part-time/full-time work, health status, severe pregnancy-induced emesis and language proficiency, the immigrant/native differences in number of weeks with sickness absence decreased from 2.0 to 1.2 weeks. Part-time/full-time work, health status, severe pregnancy-induced emesis and language proficiency were significant predictors of sickness absence. Immigrant women had higher sickness absence than native women during pregnancy. The difference in average number of weeks between native and immigrant women was partly explained by poorer health status prior to pregnancy, severe pregnancy-induced emesis and poorer proficiency in the Norwegian language among the immigrant women.

Sensory conflict in motion sickness: An observer theory approach

Science.gov (United States)

Oman, Charles M.

1989-01-01

Motion sickness is the general term describing a group of common nausea syndromes originally attributed to motion-induced cerebral ischemia, stimulation of abdominal organ afferent, or overstimulation of the vestibular organs of the inner ear. Sea-, car-, and airsicknesses are the most commonly experienced examples. However, the discovery of other variants such as Cinerama-, flight simulator-, spectacle-, and space sickness in which the physical motion of the head and body is normal or absent has led to a succession of sensory conflict theories which offer a more comprehensive etiologic perspective. Implicit in the conflict theory is the hypothesis that neutral and/or humoral signals originate in regions of the brain subversing spatial orientation, and that these signals somehow traverse to other centers mediating sickness symptoms. Unfortunately, the present understanding of the neurophysiological basis of motion sickness is far from complete. No sensory conflict neuron or process has yet been physiologically identified. To what extent can the existing theory be reconciled with current knowledge of the physiology and pharmacology of nausea and vomiting. The stimuli which causes sickness, synthesizes a contemporary Observer Theory view of the Sensory Conflict hypothesis are reviewed, and a revised model for the dynamic coupling between the putative conflict signals and nausea magnitude estimates is presented. The use of quantitative models for sensory conflict offers a possible new approach to improving the design of visual and motion systems for flight simulators and other virtual environment display systems.

Intraoperative computed tomography for cervicomedullary decompression of foramen magnum stenosis in achondroplasia: two case reports.

Science.gov (United States)

Arishima, Hidetaka; Tsunetoshi, Kenzo; Kodera, Toshiaki; Kitai, Ryuhei; Takeuchi, Hiroaki; Kikuta, Ken-Ichiro

2013-01-01

The authors report two cases of cervicomedullary decompression of foramen magnum (FM) stenosis in children with achondroplasia using intraoperative computed tomography (iCT). A 14-month-old girl with myelopathy and retarded motor development, and a 10-year-old girl who had already undergone incomplete FM decompression was presented with myelopathy. Both patients underwent decompressive sub-occipitalcraniectomy and C1 laminectomy without duraplasty using iCT. It clearly showed the extent of FM decompression during surgery, which finally enabled sufficient decompression. After the operation, their myelopathy improved. We think that iCT can provide useful information and guidance for sufficient decompression for FM stenosis in children with achondroplasia.

High altitude dermatology

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G K Singh

2017-01-01

Full Text Available Approximately, 140 million people worldwide live permanently at high altitudes (HAs and approximately another 40 million people travel to HA area (HAA every year for reasons of occupation, sports or recreation. In India, whole of Ladakh region, part of Northwest Kashmir, Northern part of Sikkim and Tenga valley of Arunachal are considered inhabited areas of HAA. The low quantity of oxygen, high exposure of ultraviolet (UV light, very low humidity, extreme subzero temperature in winter, high wind velocity, make this region difficult for lowlanders as well as for tourists. Acute mountain sickness, HA pulmonary edema, HA cerebral edema, and thromboembolic conditions are known to occur in HA. However, enough knowledge has not been shared on dermatoses peculiar to this region. Xerosis, UV-related skin disorders (tanning, photomelanosis, acute and chronic sunburn, polymorphic light eruption, chronic actinic dermatitis, actinic cheilitis, etc., cold injuries (frostbite, chilblains, acrocyanosis, erythrocyanosis, etc. nail changes (koilonychias, airborne contact dermatitis, insect bite reaction, and skin carcinoma (basal cell carcinomas, squamous cell carcinomas, and also rarely malignant melanoma are the dermatoses seen in HAAs. Early diagnosis and knowledge of HA dermatoses may prevent serious consequences of disease and improve the quality of life for the visitors as well as for native of the place.

Decompressive craniectomy and hydrocephalus: proposal of a therapeutic flow chart.

Science.gov (United States)

Peraio, Simone; Calcagni, Maria Lucia; Mattoli, Maria Vittoria; Marziali, Giammaria; DE Bonis, Pasquale; Pompucci, Angelo; Anile, Carmelo; Mangiola, Annunziato

2017-12-01

Decompressive craniectomy (DC) may be necessary to save the lives of patients suffering from intracranial hypertension. However, this procedure is not complication-free. Its two main complications are hydrocephalus and the sinking skin-flap syndrome (SSFS). The radiological findings and the clinical evaluation may be not enough to decide when and/or how to treat hydrocephalus in a decompressed patient. SSFS and hydrocephalus may be not unrelated. In fact, a patient affected by hydrocephalus, after the ventriculo-peritoneal shunt, can develop SSFS; on the other hand, SSFS per se can cause hydrocephalus. Treating hydrocephalus in decompressed patients can be challenging. Radiological findings and clinical evaluation may not be enough to define the most appropriate therapeutic strategy. Cerebrospinal fluid (CSF) dynamics and metabolic evaluations can represent important diagnostic tools for assessing the need of a CSF shunt in patients with a poor baseline neurologic status. Based on our experience, we propose a flow chart for treating decompressed patients affected by ventriculomegaly.

Oxygen transport and cardiovascular function at extreme altitude: lessons from Operation Everest II

Science.gov (United States)

Sutton, J. R.; Reeves, J. T.; Groves, B. M.; Wagner, P. D.; Alexander, J. K.; Hultgren, H. N.; Cymerman, A.; Houston, C. S.

1992-01-01

Operation Everest II was designed to examine the physiological responses to gradual decompression simulating an ascent of Mt Everest (8,848 m) to an inspired PO2 of 43 mmHg. The principal studies conducted were cardiovascular, respiratory, muscular-skeletal and metabolic responses to exercise. Eight healthy males aged 21-31 years began the "ascent" and six successfully reached the "summit", where their resting arterial blood gases were PO2 = 30 mmHg and PCO2 = 11 mmHg, pH = 7.56. Their maximal oxygen uptake decreased from 3.98 +/- 0.2 L/min at sea level to 1.17 +/- 0.08 L/min at PIO2 43 mmHg. The principal factors responsible for oxygen transport from the atmosphere to tissues were (1) Alveolar ventilation--a four fold increase. (2) Diffusion from the alveolus to end capillary blood--unchanged. (3) Cardiac function (assessed by hemodynamics, echocardiography and electrocardiography)--normal--although maximum cardiac output and heart rate were reduced. (4) Oxygen extraction--maximal with PvO2 14.8 +/- 1 mmHg. With increasing altitude maximal blood and muscle lactate progressively declined although at any submaximal intensity blood and muscle lactate was higher at higher altitudes.

Autogenic-feedback training - A treatment for motion and space sickness

Science.gov (United States)

Cowings, Patricia S.

1990-01-01

A training method for preventing the occurrence of motion sickness in humans, called autogenic-feedback training (AFT), is described. AFT is based on a combination of biofeedback and autogenic therapy which involves training physiological self-regulation as an alternative to pharmacological management. AFT was used to reliably increase tolerance to motion-sickness-inducing tests in both men and women ranging in age from 18 to 54 years. The effectiveness of AFT is found to be significantly higher than that of protective adaptation training. Data obtained show that there is no apparent effect from AFT on measures of vestibular perception and no side effects.

Association between smoking and the risk of acute mountain sickness: a meta-analysis of observational studies.

Science.gov (United States)

Xu, Chen; Lu, Hong-Xiang; Wang, Yu-Xiao; Chen, Yu; Yang, Sheng-Hong; Luo, Yong-Jun

2016-01-01

People rapidly ascending to high altitudes (>2500 m) may suffer from acute mountain sickness (AMS). The association between smoking and AMS risk remains unclear. Therefore, we performed a meta-analysis to evaluate the association between smoking and AMS risk. The association between smoking and AMS risk was determined according to predefined criteria established by our team. Meta-analysis was conducted according to the PRISMA guidelines. We included all relevant studies listed in the PubMed and Embase databases as of September 2015 in this meta-analysis and performed systemic searches using the terms "smoking", "acute mountain sickness" and "risk factor". The included studies were required to provide clear explanations regarding their definitions of smoking, the final altitudes reached by their participants and the diagnostic criteria used to diagnose AMS. Odds ratios ( ORs ) were used to evaluate the association between smoking and AMS risk across the studies, and the Q statistic was used to test OR heterogeneity, which was considered significant when P  smoking patients and 1986 non-smoking controls to analyze the association between smoking and AMS risk. We observed a significant association between AMS and smoking ( OR  = 0.71, 95% CI 0.52-0.96, P  = 0.03). We determined that smoking may protect against AMS development. However, we do not advise smoking to prevent AMS. More studies are necessary to confirm the role of smoking in AMS risk.

Kinetic characteristics of euflammation: the induction of controlled inflammation without overt sickness behavior.

Science.gov (United States)

Tarr, Andrew J; Liu, Xiaoyu; Reed, Nathaniel S; Quan, Ning

2014-11-01

We found recently that controlled progressive challenge with subthreshold levels of E. coli can confer progressively stronger resistance to future reinfection-induced sickness behavior to the host. We have termed this type of inflammation "euflammation". In this study, we further characterized the kinetic changes in the behavior, immunological, and neuroendocrine aspects of euflammation. Results show euflammatory animals only display transient and subtle sickness behaviors of anorexia, adipsia, and anhedonia upon a later infectious challenge which would have caused much more severe and longer lasting sickness behavior if given without prior euflammatory challenges. Similarly, infectious challenge-induced corticosterone secretion was greatly ameliorated in euflammatory animals. At the site of E.coli priming injections, which we termed euflammation induction locus (EIL), innate immune cells displayed a partial endotoxin tolerant phenotype with reduced expression of innate activation markers and muted inflammatory cytokine expression upon ex vivo LPS stimulation, whereas innate immune cells outside EIL displayed largely opposite characteristics. Bacterial clearance function, however, was enhanced both inside and outside EIL. Finally, sickness induction by an infectious challenge placed outside the EIL was also abrogated. These results suggest euflammation could be used as an efficient method to "train" the innate immune system to resist the consequences of future infectious/inflammatory challenges. Copyright © 2014 Elsevier Inc. All rights reserved.

Frequency of decompression illness among recent and extinct mammals and "reptiles": a review

Science.gov (United States)

Carlsen, Agnete Weinreich

2017-08-01

The frequency of decompression illness was high among the extinct marine "reptiles" and very low among the marine mammals. Signs of decompression illness are still found among turtles but whales and seals are unaffected. In humans, the risk of decompression illness is five times increased in individuals with Patent Foramen Ovale; this condition allows blood shunting from the venous circuit to the systemic circuit. This right-left shunt is characteristic of the "reptile" heart, and it is suggested that this could contribute to the high frequency of decompression illness in the extinct reptiles.

Sick-listing adherence: a register study of 1.4 million episodes of sickness benefit 2010-2013 in Sweden.

Science.gov (United States)

Leijon, Ola; Josephson, Malin; Österlund, Niklas

2015-04-14

This register study aims to increase the knowledge on how common it is that sickness benefit recipients are sick-listed for as long as their physician prescribes in their medical sickness certificate, i.e. sick-listing adherence, or wholly/partly bring return-to-work (RTW) forward, i.e. early RTW. The unit for analysis was an episode of 100% sickness benefit, commenced between 1 January 2010 and 31 December 2013. Completed episodes of sickness benefit and full or partial early RTW was analysed by comparing the prescribed length of sick leave in medical sickness certificates and benefit days disbursed by the sickness insurance system. Probability for a full and partial early RTW was estimated with hazard ratio (HR) using the Cox proportional hazard model. In total, about 1.4 million episodes of sickness benefit (60% women) were included in the study. The overall sick-listing adherence was 84% for women and 82% for men during the first year of sick leave. Adherence varied between 82 and 87% among women and between 79 and 86% among men with regard to ICD-10 diagnosis chapter. The probability of an early RTW varied between diagnosis chapters, where mental disorders was associated with a lower probability of a full early RTW among women and men (HR 0.52 and HR 0.47) as well as a partial early RTW (HR 0.51 and HR 0.46). Younger age (16-29 years), high educational level and high income was associated with a higher probability of an early RTW, while older age (≥ 50 years), not native-born, low educational level, unemployment and parental leave were associated with a lower probability. The study demonstrates that sick-listing adherence is relatively high. Probability of an early RTW differs with regard to diagnosis chapter, demographic, socioeconomic and labour market characteristics of the sickness benefit recipients. Interventions intended to improve the sick-listing process, and to affect the length and degree of sick leave in certain target groups, should include

Decompression Theory.

Science.gov (United States)

1980-06-25

vessel- rich group, a vessel-poor group, a fatty group, and so on ( Papper and Kitz 1963). Behnke’s original suggestion, put forth in the first...An examination of the critical released volume concept in decom- pression sickness. Proc. Roy. Soc. Lond. B. 197:299-313, 1977. Papper , E.M., and R.J

Fit for high altitude: are hypoxic challenge tests useful?

Directory of Open Access Journals (Sweden)

Matthys Heinrich

2011-02-01

Full Text Available Abstract Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax, sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient. Instead of the hypoxia altitude simulation test (HAST, which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists including mechanical aids to

Fit for high altitude: are hypoxic challenge tests useful?

Science.gov (United States)

Matthys, Heinrich

2011-02-28

Altitude travel results in acute variations of barometric pressure, which induce different degrees of hypoxia, changing the gas contents in body tissues and cavities. Non ventilated air containing cavities may induce barotraumas of the lung (pneumothorax), sinuses and middle ear, with pain, vertigo and hearing loss. Commercial air planes keep their cabin pressure at an equivalent altitude of about 2,500 m. This leads to an increased respiratory drive which may also result in symptoms of emotional hyperventilation. In patients with preexisting respiratory pathology due to lung, cardiovascular, pleural, thoracic neuromuscular or obesity-related diseases (i.e. obstructive sleep apnea) an additional hypoxic stress may induce respiratory pump and/or heart failure. Clinical pre-altitude assessment must be disease-specific and it includes spirometry, pulsoximetry, ECG, pulmonary and systemic hypertension assessment. In patients with abnormal values we need, in addition, measurements of hemoglobin, pH, base excess, PaO2, and PaCO2 to evaluate whether O2- and CO2-transport is sufficient.Instead of the hypoxia altitude simulation test (HAST), which is not without danger for patients with respiratory insufficiency, we prefer primarily a hyperoxic challenge. The supplementation of normobaric O2 gives us information on the acute reversibility of the arterial hypoxemia and the reduction of ventilation and pulmonary hypertension, as well as about the efficiency of the additional O2-flow needed during altitude exposure. For difficult judgements the performance of the test in a hypobaric chamber with and without supplemental O2-breathing remains the gold standard. The increasing numbers of drugs to treat acute pulmonary hypertension due to altitude exposure (acetazolamide, dexamethasone, nifedipine, sildenafil) or to other etiologies (anticoagulants, prostanoids, phosphodiesterase-5-inhibitors, endothelin receptor antagonists) including mechanical aids to reduce periodical or

Decompression-induced melting of ice IV and the liquid-liquid transition in water

Science.gov (United States)

Mishima, Osamu; Stanley, H. Eugene

1998-03-01

Although liquid water has been the focus of intensive research for over 100 years, a coherent physical picture that unifies all of the known anomalies of this liquid, is still lacking. Some of these anomalies occur in the supercooled region, and have been rationalized on the grounds of a possible retracing of the liquid-gas spinodal (metastability limit) line into the supercooled liquid region, or alternatively the presence of a line of first-order liquid-liquid phase transitions in this region which ends in a critical point,. But these ideas remain untested experimentally, in part because supercooled water can be probed only above the homogeneous nucleation temperature TH at which water spontaneously crystallizes. Here we report an experimental approach that is not restricted by the barrier imposed by TH, involving measurement of the decompression-induced melting curves of several high-pressure phases of ice in small emulsified droplets. We find that the melting curve for ice IV seems to undergo a discontinuity at precisely the location proposed for the line of liquid-liquid phase transitions. This is consistent with, but does not prove, the coexistence of two different phases of (supercooled) liquid water. From the experimental data we calculate a possible Gibbs potential surface and a corresponding equation of state for water, from the forms of which we estimate the coordinates of the liquid-liquid critical point to be at pressure Pc ~ 0.1GPa and temperature Tc ~ 220K.

Evaluation of decompression tables by Doppler technique in caisson work in The Netherlands.

Science.gov (United States)

Breedijk, J H; Van der Putten, G J G M; Schrier, L M; Sterk, W

2009-01-01

Hyperbaric work was conducted for constructing an underground tramway in the Netherlands. A total of 11,647 exposures were conducted in 41,957 hours. For these working conditions specifically developed oxygen decompression tables were used. Fifteen workers were submitted to Doppler monitoring after caisson work at a depth at 12 msw. Measurements were done according to the Canadian DCIEM protocol. For bubble grading the Kisman-Masurel 12-points ordinal scale (0-IV) was used. Bubbles were detected in 17 of the 38 examinations. The highest grade (III-) was found in four measurements. At rest the grading was never higher than I+. Two hours after decompression the grading was remarkably higher than after one hour. Bubble scores were relatively low, although the maximum grading probably is not reached within two hours after decompression. It may be concluded that the oxygen decompression tables used, were reliable under these heavy working conditions. At group level, decompression stress can be evaluated by Doppler monitoring. In order to reduce health hazard of employees, use of oxygen during decompression in caisson work should be embodied in the occupational standard.

[Workplace bullying and sickness absenteeism].

Science.gov (United States)

Campanini, Paolo; Conway, Paul Maurice; Neri, Luca; Punzi, Silvia; Camerino, Donatella; Costa, Giovanni

2013-01-01

To assess the relationship between workplace bullying and sickness absenteeism in a large sample of Italian workers. A cross-sectional study conducted by means of questionnaires. In all, 8,992 subjects filled in a questionnaire to detect workplace bullying, the presence of work stress factors and days of sickness absence in the last year. Workplace bullying and psychosocial stressor were measured by the means of the CDL 2.0 questionnaire. Days of sickness absence reported by the subjects. On average, days of sickness absence were 7.4, and 7.2% of the respondents were defined as bullied. Results from logistic regression analyses showed that a workplace bullying was associated with more days of sickness absence after controlling for gender, age, professional qualification, company sector and juridical nature and other psychosocial factors (men: OR =1.62; women: OR =2.15). The present study confirms that workers exposed to a workplace bullying reported higher sickness absenteeism as compared with non-exposed subjects, also when a potentially highly stressful work environment is considered. The results of the present study support that workplace bullying may be viewed as an extreme stressful condition. Interventions to avoid workplace bullying not only favoure workers' health, but also avoid the company costs associated with workers' sickness absenteeism.

Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis: A Cross-Sectional Study.

Science.gov (United States)

van Os-Medendorp, Harmieke; Appelman-Noordermeer, Simone; Bruijnzeel-Koomen, Carla; de Bruin-Weller, Marjolein

2015-03-27

Little is known about the prevalence of sick leave due to atopic dermatitis (AD). The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify influencing factors. A cross-sectional study was carried out in adult patients with AD. sick leave during the two-week and one-year periods, socio-demographic characteristics, disease severity, quality of life and socio-occupational factors. Logistic regression analyses were used to determine influencing factors on sick leave over the two-week period. In total, 253 patients were included; 12% of the patients had to take sick leave in the last two weeks due to AD and 42% in the past year. A higher level of symptom interference (OR 1.26; 95% CI 1.13-1.40) or perfectionism/diligence (OR 0.90; 95% CI 0.83-0.96) may respectively increase or decrease the number of sick leave days. Sick leave in patients with AD is a common problem and symptom interference and perfectionism/diligence appeared to influence it. Novel approaches are needed to deal with symptoms at work or school to reduce the amount of sick leave due to AD.

Sickness absence and sickness attendance--what people with neck or back pain think.

Science.gov (United States)

Hansson, Margareta; Boström, Carina; Harms-Ringdahl, Karin

2006-05-01

This study explores the decision of 33 men and women to be sick-listed from work for neck pain or low-back pain. Qualitative interviews with the subjects, who lived in a city or a sparsely populated area of Sweden, were tape-recorded, transcribed and analysed in the interpretive tradition by the three authors. New, intense and threatening pain quickly made persons report sick. For other pain, sickness absence, its timing and duration, were negotiated on the basis of the subjects' self-image, work-duty norms, organisational and extra-organisational work factors. Thirty-one people aimed to return to work, but spine-related pain was a hindrance. Five strategies to avoid, delay or shorten sickness absence were identified. Concepts of the illness flexibility model well described how the workers balanced the factors driving them from work and those forcing them or attracting them to remain. The conclusion is that reporting sick is neither undertaken lightly nor for short-term reasons only. Instead, personal history and anticipated future, spine-related pain, workplace and labour market factors are also important considerations.

Changes in sickness absenteeism following the introduction of a qualifying day for sickness benefit--findings from Sweden Post

DEFF Research Database (Denmark)

Voss, M; Floderus, B; Diderichsen, F

2001-01-01

AIMS: In 1993, a qualifying day without sickness benefit was introduced to the Swedish sickness benefit system. The aim of the present study is to investigate sickness absenteeism before and after the introduction of the qualifying day, in the light of conditions inside and outside working life....... METHODS: The study was based on 1,952 female and 2,229 male employees of Sweden Post. Sickness absence was measured by sickness incidence one year before and one year after the introduction of the qualifying day (sick-leave events/person days at risk). Information about explanatory factors was collected...

Tension pneumothorax secondary to automatic mechanical compression decompression device.

Science.gov (United States)

Hutchings, A C; Darcy, K J; Cumberbatch, G L A

2009-02-01

The details are presented of the first published case of a tension pneumothorax induced by an automatic compression-decompression (ACD) device during cardiac arrest. An elderly patient collapsed with back pain and, on arrival of the crew, was in pulseless electrical activity (PEA) arrest. He was promptly intubated and correct placement of the endotracheal tube was confirmed by noting equal air entry bilaterally and the ACD device applied. On the way to the hospital he was noted to have absent breath sounds on the left without any change in the position of the endotracheal tube. Needle decompression of the left chest caused a hiss of air but the patient remained in PEA. Intercostal drain insertion in the emergency department released a large quantity of air from his left chest but without any change in his condition. Post-mortem examination revealed a ruptured abdominal aortic aneurysm as the cause of death. Multiple left rib fractures and a left lung laceration secondary to the use of the ACD device were also noted, although the pathologist felt that the tension pneumothorax had not contributed to the patient's death. It is recommended that a simple or tension pneumothorax should be considered when there is unilateral absence of breath sounds in addition to endobronchial intubation if an ACD device is being used.

Autogenic-Feedback Training (AFT) as a preventive method for space motion sickness: Background and experimental design

Science.gov (United States)

Cowings, Patricia S.; Toscano, William B.

1993-01-01

Finding an effective treatment for the motion sickness-like symptoms that occur in space has become a high priority for NASA. The background research is reviewed and the experimental design of a formal life sciences shuttle flight experiment designed to prevent space motion sickness in shuttle crew members is presented. This experiment utilizes a behavioral medicine approach to solving this problem. This method, Autogenic-Feedback Training (AFT), involves training subjects to voluntarily control several of their own physiological responses to environmental stressors. AFT has been used reliably to increase tolerance to motion sickness during ground-based tests in over 200 men and women under a variety of conditions that induce motion sickness, and preliminary evidence from space suggests that AFT may be an effective treatment for space motion sickness as well. Proposed changes to this experiment for future manifests are included.

Reasons for revision surgery after orbital decompression for Graves’ orbitopathy

Directory of Open Access Journals (Sweden)

Stefano Sellari-Franceschini

2008-06-01

Full Text Available Stefano Sellari-Franceschini1, Luca Muscatello1, Veronica Seccia1, Riccardo Lenzi1, Amelia Santoro1, Marco Nardi2, Barbara Mazzi3, Aldo Pinchera3, Claudio Marcocci31Department of Neuroscience, 1st ENT division, 2Ophthalmology Division, 3Department of Endocrinology and Metabolism, Orthopaedics and Traumatology, Occupational Medicine, University of Pisa, ItalyObjectives: An analysis of complications and causes of failure in orbital decompression necessitating a second operation.Methods: Between December 1992 and April 2007, 375 patients (719 orbits were operated on using various techniques. Fourteen patients were initially operated on in our unit: 8 (group A1 were re-operated on after a short time due to complications connected with the decompression operation, 7 (group A2 were operated on after some time due to recurrence of the illness or unsatisfactory decompression (one patient is in both group A1 and A2. Five patients (group B underwent a first operation elsewhere.Results: For group A1 the most serious complications were connected to the nasal approach. For group A2 the operations were performed either because of a neuropathy recurrence or for further proptosis reduction due to recurrence or patient dissatisfaction. Lack of preoperative data hinders conclusions about group B, apart from one patient where the operation had not resolved a serious optic neuropathy after decompression based on Olivari technique combined with three-wall operation according to Mourits and colleagues (1990.Conclusions: We can deduce from group A1 that extreme attention is necessary during endonasal access, from group A2 that balancing the eyes is advisable, sacrificing maximum proptosis reduction to gain greater patient satisfaction, and from group B that decompression of the orbital apex is fundamental in the case of neuropathy.Keywords: orbital decompression, Graves’ orbitopathy, revision surgery

General practitioners' use of sickness certificates.

Science.gov (United States)

Roope, Richard; Parker, Gordon; Turner, Susan

2009-12-01

At present, sickness certification is largely undertaken by general practitioners (GPs). Guidance from the Department of Work and Pensions (DWP) is available to help with this task; however, there has been little formal evaluation of the DWP's guidance in relation to day-to-day general practice. To assess GPs' training, knowledge and application of the DWP's sickness certification guidelines. A structured questionnaire was sent to GPs within a (former) primary care trust (PCT). It probed demographics, training and knowledge of sickness certification guidelines. Case histories and structured questions were used to assess current practice. In this group of 113 GPs, there was a low awareness and use of the DWP's guidelines and Website relating to sickness certification. The majority of the GPs (63%) had received no training in sickness certification, and the mean length of time for those who had received training was 4.1 h. Most GPs also felt that patients and GPs have equal influence on the duration of sickness certification. This evidence of variable practice indicates that GPs should have more guidance and education in sickness certification. Closer sickness certification monitoring through existing GP computer systems may facilitate an improvement in practice that benefits patients and employers. The DWP, medical educators and PCTs may all have an additional role in further improving sickness certification practice.

Technique of ICP monitored stepwise intracranial decompression effectively reduces postoperative complications of severe bifrontal contusion

Directory of Open Access Journals (Sweden)

Guan eSun

2016-04-01

Full Text Available Background Bifrontal contusion is a common clinical brain injury. In the early stage, it is often mild, but it progresses rapidly and frequently worsens suddenly. This condition can become life threatening and therefore requires surgery. Conventional decompression craniectomy is the commonly used treatment method. In this study, the effect of ICP monitored stepwise intracranial decompression surgery on the prognosis of patients with acute severe bifrontal contusion was investigated. Method A total of 136 patients with severe bifrontal contusion combined with deteriorated intracranial hypertension admitted from March 2001 to March 2014 in our hospital were selected and randomly divided into two groups, i.e., a conventional decompression group and an intracranial pressure (ICP monitored stepwise intracranial decompression group (68 patients each, to conduct a retrospective study. The incidence rates of acute intraoperative encephalocele, delayed hematomas, and postoperative cerebral infarctions and the Glasgow outcome scores (GOSs 6 months after the surgery were compared between the two groups.Results (1 The incidence rates of acute encephalocele and contralateral delayed epidural hematoma in the stepwise decompression surgery group were significantly lower than those in the conventional decompression group; the differences were statistically significant (P < 0.05; (2 6 months after the surgery, the incidence of vegetative state and mortality in the stepwise decompression group were significantly lower than those in the conventional decompression group (P < 0.05; the rate of favorable prognosis in the stepwise decompression group was also significantly higher than that in the conventional decompression group (P < 0.05.Conclusions The ICP monitored stepwise intracranial decompression technique reduced the perioperative complications of traumatic brain injury through the gradual release of intracranial pressure and was beneficial to the prognosis of

Outcome after decompressive craniectomy for the treatment of severe traumatic brain injury.

Science.gov (United States)

Howard, Jerry Lee; Cipolle, Mark D; Anderson, Meredith; Sabella, Victoria; Shollenberger, Daniele; Li, P Mark; Pasquale, Michael D

2008-08-01

Using decompressive craniectomy as part of the treatment regimen for severe traumatic brain injury (STBI) has become more common at our Level I trauma center. This study was designed to examine this practice with particular attention to long-term functional outcome. A retrospective review of prospectively collected data was performed for patients with STBI admitted from January 1, 2003 to December 31, 2005. Our institution manages patients using the Brain Trauma Foundation Guidelines. Data collected from patients undergoing decompressive craniectomy included: age, Injury Severity Score, admission and follow-up Glasgow Coma Score, timing of, and indication for decompressive craniectomy, and procedure-related complications. The Extended Glasgow Outcome Scale (GOSE) was performed by a experienced trauma clinical research coordinator using a structured phone interview to assess long-term outcome in the survivors. Student's t test and chi2 were used to examine differences between groups. Forty STBI patients were treated with decompressive craniectomy; 24 were performed primarily in conjunction with urgent evacuation of extra-axial hemorrhage and 16 were performed primarily in response to increased intracranial pressure with 4 of these after an initial craniotomy. Decompressive craniectomy was very effective at lowering intracranial pressure in these 16 patients (35.0 mm Hg +/- 13.5 mm Hg to 14.6 mm Hg +/- 8.7 mm Hg, p = 0.005). Twenty-two decompressive craniectomy patients did not survive to hospital discharge, whereas admission Glasgow Coma Score and admission pupil size and reactivity correlated with outcome, age, and Injury Severity Score did not. At a mean of 11 months (range, 3-26 months) after decompressive craniectomy, 6 survivors had a poor functional outcome (GOSE 1-4), whereas 12 survivors had a good outcome (GOSE 5-8). Therefore, 70% of these patients had an unfavorable outcome (death or severe disability), and 30% had a favorable long-term functional outcome

Deadly diving? Physiological and behavioural management of decompression stress in diving mammals

Science.gov (United States)

Hooker, S. K.; Fahlman, A.; Moore, M. J.; Aguilar de Soto, N.; Bernaldo de Quirós, Y.; Brubakk, A. O.; Costa, D. P.; Costidis, A. M.; Dennison, S.; Falke, K. J.; Fernandez, A.; Ferrigno, M.; Fitz-Clarke, J. R.; Garner, M. M.; Houser, D. S.; Jepson, P. D.; Ketten, D. R.; Kvadsheim, P. H.; Madsen, P. T.; Pollock, N. W.; Rotstein, D. S.; Rowles, T. K.; Simmons, S. E.; Van Bonn, W.; Weathersby, P. K.; Weise, M. J.; Williams, T. M.; Tyack, P. L.

2012-01-01

Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N2) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N2 loading to management of the N2 load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years. PMID:22189402

Brain Endothelial- and Epithelial-Specific Interferon Receptor Chain 1 Drives Virus-Induced Sickness Behavior and Cognitive Impairment

NARCIS (Netherlands)

Blank, Thomas; Detje, Claudia N.; Spiess, Alena; Hagemeyer, Nora; Brendecke, Stefanie M.; Wolfart, Jakob; Staszewski, Ori; Zoeller, Tanja; Papageorgiou, Ismini; Schneider, Justus; Paricio-Montesinos, Ricardo; Eisel, Ulrich L. M.; Manahan-Vaughan, Denise; Jansen, Stephan; Lienenklaus, Stefan; Lu, Bao; Imai, Yumiko; Mueller, Marcus; Goelz, Susan E.; Baker, Darren P.; Schwaninger, Markus; Kann, Oliver; Heikenwalder, Mathias; Kalinke, Ulrich; Prinz, Marco

2016-01-01

Sickness behavior and cognitive dysfunction occur frequently by unknown mechanisms in virus-infected individuals with malignancies treated with type I interferons (IFNs) and in patients with autoimmune disorders. We found that during sickness behavior, single-stranded RNA viruses, double-stranded

Healthy change processes - Relations with job insecurity, sickness absenteeism, sickness presenteeism and turnover intention

OpenAIRE

Bødal, Åshild

2017-01-01

The aim of this study was to investigate whether the presence of a healthy change process (HCPI) could predict negative outcomes that normally follow organisational change, such as qualitative job insecurity, total sickness (sickness absenteeism and -presenteesim) and turnover intention. It was hypothesised that negative relationships existed between a healthy change process and qualitative job insecurity, total sickness and turnover intention. In addition, it was believed that experienced st...

Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis: A Cross-Sectional Study

Directory of Open Access Journals (Sweden)

Harmieke van Os-Medendorp

2015-03-01

Full Text Available Background: Little is known about the prevalence of sick leave due to atopic dermatitis (AD. The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify influencing factors. Methods: A cross-sectional study was carried out in adult patients with AD. Outcome measures: sick leave during the two-week and one-year periods, socio-demographic characteristics, disease severity, quality of life and socio-occupational factors. Logistic regression analyses were used to determine influencing factors on sick leave over the two-week period. Results: In total, 253 patients were included; 12% of the patients had to take sick leave in the last two weeks due to AD and 42% in the past year. A higher level of symptom interference (OR 1.26; 95% CI 1.13–1.40 or perfectionism/diligence (OR 0.90; 95% CI 0.83–0.96 may respectively increase or decrease the number of sick leave days. Conclusion: Sick leave in patients with AD is a common problem and symptom interference and perfectionism/diligence appeared to influence it. Novel approaches are needed to deal with symptoms at work or school to reduce the amount of sick leave due to AD.

Oxygen breathing accelerates decompression from saturation at 40 msw in 70-kg swine.

Science.gov (United States)

Petersen, Kyle; Soutiere, Shawn E; Tucker, Kathryn E; Dainer, Hugh M; Mahon, Richard T

2010-07-01

Submarine disaster survivors can be transferred from a disabled submarine at a pressure of 40 meters of seawater (msw) to a new rescue vehicle; however, they face an inherently risky surface interval before recompression and an enormous decompression obligation due to a high likelihood of saturation. The goal was to design a safe decompression protocol using oxygen breathing and a trial-and-error methodology. We hypothesized that depth, timing, and duration of oxygen breathing during decompression from saturation play a role to mitigate decompression outcomes. Yorkshire swine (67-75 kg), compressed to 40 msw for 22 h, underwent one of three accelerated decompression profiles: (1) 13.3 h staged air decompression to 18 msw, followed by 1 h oxygen breathing, then dropout; (2) direct decompression to 18 msw followed by 1 h oxygen breathing then dropout; and (3) 1 h oxygen prebreathe at 40 msw followed by 1 h mixed gas breathing at 26 msw, 1 h oxygen breathing at 18 msw, and 1 h ascent breathing oxygen. Animals underwent 2-h observation for signs of DCS. Profile 1 (14.3 h total) resulted in no deaths, no Type II DCS, and 20% Type I DCS. Profile 2 (2.1 h total) resulted in 13% death, 50% Type II DCS, and 75% Type I DCS. Profile 3 (4.5 h total) resulted in 14% death, 21% Type II DCS, and 57% Type I DCS. No oxygen associated seizures occurred. Profile 1 performed best, shortening decompression with no death or severe DCS, yet it may still exceed emergency operational utility in an actual submarine rescue.

How to avoid simulation sickness in virtual environments during user displacement

Science.gov (United States)

Kemeny, A.; Colombet, F.; Denoual, T.

2015-03-01

Driving simulation (DS) and Virtual Reality (VR) share the same technologies for visualization and 3D vision and may use the same technics for head movement tracking. They experience also similar difficulties when rendering the displacements of the observer in virtual environments, especially when these displacements are carried out using driver commands, including steering wheels, joysticks and nomad devices. High values for transport delay, the time lag between the action and the corresponding rendering cues and/or visual-vestibular conflict, due to the discrepancies perceived by the human visual and vestibular systems when driving or displacing using a control device, induces the so-called simulation sickness. While the visual transport delay can be efficiently reduced using high frequency frame rate, the visual-vestibular conflict is inherent to VR, when not using motion platforms. In order to study the impact of displacements on simulation sickness, we have tested various driving scenarios in Renault's 5-sided ultra-high resolution CAVE. First results indicate that low speed displacements with longitudinal and lateral accelerations under a given perception thresholds are well accepted by a large number of users and relatively high values are only accepted by experienced users and induce VR induced symptoms and effects (VRISE) for novice users, with a worst case scenario corresponding to rotational displacements. These results will be used for optimization technics at Arts et Métiers ParisTech for motion sickness reduction in virtual environments for industrial, research, educational or gaming applications.

Modified “in-window” technique for decompressive craniotomy for severe brain injury

Directory of Open Access Journals (Sweden)

Jovanović Momir J.

2015-01-01

Full Text Available Increased intracranial pressure and decreased cerebral perfusion in patients with severe traumatic brain injury are associated with cerebral ischemia and poor outcome. Lowering intracranial pressure is one of the goals of treatment. We analyzed the effects of decompressive craniotomy on intracranial pressure levels and outcome. In addition, we compared the results of decompressive craniotomy performed with our original technique (modified “in-window” technique, with no need for cranioplasty with results of classic techniques. We formed two groups: 52 patients with TBI (GCS≤8, with monitored intracranial pressure, and the control: 45 patients without intracranial pressure monitoring. In the first group, malignant intracranial hypertension was treated by decompressive craniotomy, using a modified "in-window" technique. Results were analyzed using standard statistical methods. In the first group, with intracranial pressure monitoring, 17/52 had decompressive craniotomy, and significant reduction of intracranial pressure appeared in the early postoperative period (38.82 to 22.76 mmHg, mean, with significant decrease of intracranial pressure at the end of treatment, compared to the control group (mean=25.00, and 45.30 mmHg, respectively. Late complications were similar to results of other studies. Our results were 20% of epileptic seizures, 8% of hydrocephalus, 12% contusion/hematoma progression and 12% subdural hygroma. Outcome (measured with Glasgow Outcome Score-GOS in the first group, at the time of discharge, was better with decompressive craniotomy than without decompressive craniotomy (GOS=2.47, and GOS=1.00, respectively. Modified "in-window" technique for decompressive craniotomy in severe traumatic brain injury is safe, promising and according to our experience offers a lower rate of complications with no need for additional cranioplastic surgery.

Paid Sick Leave as a Means to Reduce Sickness Presenteeism Among Physicians

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Ingrid Steen Rostad

2017-06-01

Full Text Available Recurrent international data show that physicians often attend work while ill, termed sickness presenteeism. The current study investigated if sickness presenteeism scores among European physicians varied according to national paid sick leave legislation. We hypothesized that prevalence of presenteeism was higher in countries with lower levels of paid sick leave. We used repeated cross-sectional survey data, phase I (2004/2005, N = 1326 and phase II (2012/2013, N = 1403, among senior consultants at university hospitals in Sweden, Norway, and Italy. Analyses of variances assessed cross-country differences in presenteeism. To assess the impact of country on presenteeism, we used multiple regression analyses controlled for sex, age, family status, work hours, and work content. The results from phase I supported the initial hypothesis. At phase II, presenteeism scores had decreased among the Italian and Swedish sample. The results are discussed with regard to changes in legislation on workhours and medical liability in Italy and Sweden between phase I and II.

Hemorrhages and hemostasis in guinea-pigs exposed to irradiation at high altitude

International Nuclear Information System (INIS)

Tartakovskij, V.N.; Daniyarov, S.B.

1988-01-01

Hemorrhagic intensity, hemostasis and blood vessel wall resistance to mechanical effects were studied in guinea-pigs exposed to whole-body irradiation (3.0 Gy). The animals were irradiated at low altitude (760 m above sea level) and at high altitude (3200 m above sea level) after 1 and 31 days of adaptation. It was demonstrated that hemorrhagic intensity in both groups of guinea-pigs irradiated at high altitude was significantly reduced in comparison with that at low altitude. The decrease of radiation-induced hemorrhages at high altitude is associated with less severe changes in thrombopoiesis, blood vessel wall and blood coagulation

The effect of autogenic training and biofeedback on motion sickness tolerance.

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Jozsvai, E E; Pigeau, R A

1996-10-01

Motion sickness is characterized by symptoms of vomiting, drowsiness, fatigue and idiosyncratic changes in autonomic nervous system (ANS) responses such as heart rate (HR) and skin temperature (ST). Previous studies found that symptoms of motion sickness are controllable through self-regulation of ANS responses and the best method to teach such control is autogenic-feedback (biofeedback) training. Recent experiments indicated that biofeedback training is ineffective in reducing symptoms of motion sickness or in increasing tolerance to motion. If biofeedback facilitates learning of ANS self-regulation then autogenic training with true feedback (TFB) should lead to better control over ANS responses and better motion tolerance than autogenic training with false feedback (FFB). If there is a relationship between ANS self-regulation and coping with motion stress, a significant correlation should be found between amounts of control over ANS responses and measures of motion tolerance and/or symptoms of motion sickness. There were 3 groups of 6 subjects exposed for 6 weeks to weekly sessions of Coriolis stimulation to induce motion sickness. Between the first and second Coriolis sessions, subjects in the experimental groups received five episodes of autogenic training with either true (group TFB) or false (group FFB) feedback on their HR and ST. The control group (CTL) received no treatment. Subjects learned to control their HR and ST independent of whether they received true or false feedback. Learned control of ST and HR was not related to severity of motion sickness or subject's ability to withstand Coriolis stimulation following treatment. A lack of significant correlation between these variables suggested that subjects were not able to apply their skills of ANS self-regulation in the motion environment, and/ or such skills had little value in reducing symptoms of motion sickness or enhancing their ability to withstand rotations.

Recurrence of Neurological Deficits in an F/A-18D Pilot Following Loss of Cabin Pressure at Altitude.

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Robinson, Tom; Evangelista, Jose S; Latham, Emi; Mukherjee, Samir T; Pilmanis, Andrew

2016-08-01

Supersonic, high altitude aviation places its pilots and aircrew in complex environments, which may lead to injury that is not easily diagnosed or simply treated. Decompression illness (either venous or arterial) and environmental conditions (e.g., abnormal gases and pressure) are the most likely adverse effects aircrew often face. Though symptomatic aircrew personnel may occasionally require hyperbaric oxygen treatment, it is rare to require more than one treatment before returning to baseline function. This challenging aviation case details the clinical course and discusses the salient physiological factors of an F/A-18D pilot who presented with neurological symptoms following loss of cabin pressure at altitude. Most crucial to this discussion was the requirement for multiple hyperbaric oxygen treatments over several days due to recurrence of symptoms. The likelihood of recurrence during and after future flights cannot be estimated with accuracy. This case illustrates a degree of recurrences for neurological symptoms in aviation (hypobaric exposure to hyperbaric baseline environment) that has not previously been described. Robinson T, Evangelista JS III, Latham E, Mukherjee ST, Pilmanis A. Recurrence of neurological deficits in an F/A-18D pilot following loss of cabin pressure at altitude. Aerosp Med Hum Perform. 2016; 87(8):740-744.

Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

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Maes Michael

2012-06-01

Full Text Available Abstract It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia, physio-somatic (fatigue, hyperalgesia, malaise, anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuroinflammation and (neurodegenerative processes following less well defined triggers.

Emergency percutaneous needle decompression for tension pneumoperitoneum

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Körner Markus

2011-05-01

Full Text Available Abstract Background Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic. Methods This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension. Results Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs, between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs. Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion, bridging the time to the start of the operation. Conclusions Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no

Phenotypic plasticity and genetic adaptation to high-altitude hypoxia in vertebrates.

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Storz, Jay F; Scott, Graham R; Cheviron, Zachary A

2010-12-15

High-altitude environments provide ideal testing grounds for investigations of mechanism and process in physiological adaptation. In vertebrates, much of our understanding of the acclimatization response to high-altitude hypoxia derives from studies of animal species that are native to lowland environments. Such studies can indicate whether phenotypic plasticity will generally facilitate or impede adaptation to high altitude. Here, we review general mechanisms of physiological acclimatization and genetic adaptation to high-altitude hypoxia in birds and mammals. We evaluate whether the acclimatization response to environmental hypoxia can be regarded generally as a mechanism of adaptive phenotypic plasticity, or whether it might sometimes represent a misdirected response that acts as a hindrance to genetic adaptation. In cases in which the acclimatization response to hypoxia is maladaptive, selection will favor an attenuation of the induced phenotypic change. This can result in a form of cryptic adaptive evolution in which phenotypic similarity between high- and low-altitude populations is attributable to directional selection on genetically based trait variation that offsets environmentally induced changes. The blunted erythropoietic and pulmonary vasoconstriction responses to hypoxia in Tibetan humans and numerous high-altitude birds and mammals provide possible examples of this phenomenon. When lowland animals colonize high-altitude environments, adaptive phenotypic plasticity can mitigate the costs of selection, thereby enhancing prospects for population establishment and persistence. By contrast, maladaptive plasticity has the opposite effect. Thus, insights into the acclimatization response of lowland animals to high-altitude hypoxia can provide a basis for predicting how altitudinal range limits might shift in response to climate change.

The STAR Data Reporting Guidelines for Clinical High Altitude Research.

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Brodmann Maeder, Monika; Brugger, Hermann; Pun, Matiram; Strapazzon, Giacomo; Dal Cappello, Tomas; Maggiorini, Marco; Hackett, Peter; Bärtsch, Peter; Swenson, Erik R; Zafren, Ken

2018-03-01

Brodmann Maeder, Monika, Hermann Brugger, Matiram Pun, Giacomo Strapazzon, Tomas Dal Cappello, Marco Maggiorini, Peter Hackett, Peter Baärtsch, Erik R. Swenson, Ken Zafren (STAR Core Group), and the STAR Delphi Expert Group. The STARdata reporting guidelines for clinical high altitude research. High AltMedBiol. 19:7-14, 2018. The goal of the STAR (STrengthening Altitude Research) initiative was to produce a uniform set of key elements for research and reporting in clinical high-altitude (HA) medicine. The STAR initiative was inspired by research on treatment of cardiac arrest, in which the establishment of the Utstein Style, a uniform data reporting protocol, substantially contributed to improving data reporting and subsequently the quality of scientific evidence. The STAR core group used the Delphi method, in which a group of experts reaches a consensus over multiple rounds using a formal method. We selected experts in the field of clinical HA medicine based on their scientific credentials and identified an initial set of parameters for evaluation by the experts. Of 51 experts in HA research who were identified initially, 21 experts completed both rounds. The experts identified 42 key parameters in 5 categories (setting, individual factors, acute mountain sickness and HA cerebral edema, HA pulmonary edema, and treatment) that were considered essential for research and reporting in clinical HA research. An additional 47 supplemental parameters were identified that should be reported depending on the nature of the research. The STAR initiative, using the Delphi method, identified a set of key parameters essential for research and reporting in clinical HA medicine.

Forecasting Effusive Dynamics and Decompression Rates by Magmastatic Model at Open-vent Volcanoes.

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Ripepe, Maurizio; Pistolesi, Marco; Coppola, Diego; Delle Donne, Dario; Genco, Riccardo; Lacanna, Giorgio; Laiolo, Marco; Marchetti, Emanuele; Ulivieri, Giacomo; Valade, Sébastien

2017-06-20

Effusive eruptions at open-conduit volcanoes are interpreted as reactions to a disequilibrium induced by the increase in magma supply. By comparing four of the most recent effusive eruptions at Stromboli volcano (Italy), we show how the volumes of lava discharged during each eruption are linearly correlated to the topographic positions of the effusive vents. This correlation cannot be explained by an excess of pressure within a deep magma chamber and raises questions about the actual contributions of deep magma dynamics. We derive a general model based on the discharge of a shallow reservoir and the magmastatic crustal load above the vent, to explain the linear link. In addition, we show how the drastic transition from effusive to violent explosions can be related to different decompression rates. We suggest that a gravity-driven model can shed light on similar cases of lateral effusive eruptions in other volcanic systems and can provide evidence of the roles of slow decompression rates in triggering violent paroxysmal explosive eruptions, which occasionally punctuate the effusive phases at basaltic volcanoes.

Transnasal Endoscopic Optic Nerve Decompression in Post Traumatic Optic Neuropathy.

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Gupta, Devang; Gadodia, Monica

2018-03-01

To quantify the successful outcome in patients following optic nerve decompression in post traumatic unilateral optic neuropathy in form of improvement in visual acuity. A prospective study was carried out over a period of 5 years (January 2011 to June 2016) at civil hospital Ahmedabad. Total 20 patients were selected with optic neuropathy including patients with direct and indirect trauma to unilateral optic nerve, not responding to conservative management, leading to optic neuropathy and subsequent impairment in vision and blindness. Decompression was done via Transnasal-Ethmo-sphenoidal route and outcome was assessed in form of post-operative visual acuity improvement at 1 month, 6 months and 1 year follow up. After surgical decompression complete recovery of visual acuity was achieved in 16 (80%) patients and partial recovery in 4 (20%). Endoscopic transnasal approach is beneficial in traumatic optic neuropathy not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and oedematous optic nerve with proper exposure of orbital apex and optic canal without any major intracranial, intraorbital and transnasal complications.

Presenteeism among sick workers

NARCIS (Netherlands)

Houtman, I.L.D.

2003-01-01

Much attention has been focused on absenteeism. However, ‘presenteeism’ is also an issue, i.e. staying at work even when feeling sick. Analyses have shown that, the greater the work pressure, the higher the percentage of people who keep working when feeling sick.

MRI Evaluation of Post Core Decompression Changes in Avascular Necrosis of Hip.

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Nori, Madhavi; Marupaka, Sravan Kumar; Alluri, Swathi; Md, Naseeruddin; Irfan, Kazi Amir; Jampala, Venkateshwarlu; Apsingi, Sunil; Eachempati, Krishna Kiran

2015-12-01

Avascular necrosis of hip typically presents in young patients. Core decompression in precollapse stage provides pain relief and preservation of femoral head. The results of core decompression vary considerably despite early diagnosis. The role of MRI in monitoring patients post surgically has not been clearly defined. To study pre and post core decompression MRI changes in avascular necrosis of hip. This is a contiguous observational cohort of 40 hips treated by core decompression for precollapse avascular necrosis of femoral head, who had a baseline MRI performed before surgery. Core decompression of the femoral head was performed within 4 weeks. Follow up radiograph and MRI scans were done at six months. Harris hip score preoperatively, 1 month and 6 months after the surgery was noted. Success in this study was defined as postoperative increase in Harris hip score (HHS) by 20 points and no additional femoral collapse. End point of clinical adverse outcome as defined by fall in Harris hip score was conversion or intention to convert to total hip replacement (THR). MRI parameters in the follow up scan were compared to the preoperative MRI. Effect of core decompression on bone marrow oedema and femoral head collapse was noted. Results were analysed using SPSS software version. Harris hip score improved from 57 to 80 in all patients initially. Six hips had a fall in Harris hip score to mean value of 34.1 during follow up (9 to 12 months) and underwent total hip replacement. MRI predictors of positive outcome are lesions with grade A extent, Grade A & B location. Bone marrow oedema with lesions less than 50% involvement, medial and central location. Careful selection of patients by MR criteria for core decompression provides satisfactory outcome in precollapse stage of avascular necrosis of hip.

Decompression Induced Crystallization of Basaltic Andesite Magma: Constraints on the Eruption of Arenal Volcano, Costa Rica.

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Szramek, L. A.; Gardner, J. E.; Larsen, J. F.

2004-12-01

Arenal Volcano is a small stratovolcano located 90 km NW of San Jose, Costa Rica. In 1968 current activity began with a Plinian phase, and has continued to erupt lava flows and pyroclastic flows intermittently since. Samples from the Plinian, pyroclastic flow, strombolian, and effusive phases have been studied texturally. Little variation in crystallinity occurs amongst the different phases. Number density of crystals, both 2D and 3D are 50-70 mm-2 and 30,000-50,000 mm-3 in the Plinian sample, compared to the lesser values in other eruptive types. Characteristic crystal size also increases as explosivity decreases. Two samples, both lava flows collected while warm, overlap with the Plinian sample. This suggests that the variations seen may be a result of cooling history. Plagioclase differs between the Plinian sample, in which they are only tabular in shape, and the other eruptive types, which contain both tabular and equant crystals. To link decompression paths of the Arenal magma to possible pre-eruptive conditions, we have carried out hydrothermal experiments. The experiments were preformed in TZM pressure vessels buffered at a fugacity of Ni-NiO and water saturation. Phase equilibria results in conjunction with mineral compositions and temperature estimates by previous workers from active lava flows and two-pyroxene geothermometry, constrain the likely pre-eruptive conditions for the Arenal magma to 950-1040° C with a water pressure of 50-80 MPa. Samples that started from conditions that bracket our estimated pre-eruptive conditions were decompressed in steps of 5-30 MPa and held for various times at each step until 20 MPa was reached, approximating average decompression rates of 0.25, 0.025, 0.0013 MPa/s. Comparison of textures found in the natural samples to the experimentally produced textures suggest that the Plinian eruption likely was fed by magma ascending at 0.05-1 m/s, whereas the less explosive phases were fed by magma ascending at 0.05 m/s or less.

Failure rate of prehospital chest decompression after severe thoracic trauma.

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Kaserer, Alexander; Stein, Philipp; Simmen, Hans-Peter; Spahn, Donat R; Neuhaus, Valentin

2017-03-01

Chest decompression can be performed by different techniques, like needle thoracocentesis (NT), lateral thoracostomy (LT), or tube thoracostomy (TT). The aim of this study was to report the incidence of prehospital chest decompression and to analyse the effectiveness of these techniques. In this retrospective case series study, all medical records of adult trauma patients undergoing prehospital chest decompression and admitted to the resuscitation area of a level-1 trauma center between 2009 and 2015 were reviewed and analysed. Only descriptive statistics were applied. In a 6-year period 24 of 2261 (1.1%) trauma patients had prehospital chest decompression. Seventeen patients had NT, six patients TT, one patient NT as well as TT, and no patients had LT. Prehospital successful release of a tension pneumothorax was reported by the paramedics in 83% (5/6) with TT, whereas NT was effective in 18% only (3/17). In five CT scans all thoracocentesis needles were either removed or extrapleural, one patient had a tension pneumothorax, and two patients had no pneumothorax. No NT or TT related complications were reported during hospitalization. Prehospital NT or TT is infrequently attempted in trauma patients. Especially NT is associated with a high failure rate of more than 80%, potentially due to an inadequate ratio between chest wall thickness and catheter length as previously published as well as a possible different pathophysiological cause of respiratory distress. Therefore, TT may be considered already in the prehospital setting to retain sufficient pleural decompression upon admission. Copyright © 2016. Published by Elsevier Inc.

Preventing High Altitude Cerebral Edema in Rats with Repurposed Anti-Angiogenesis Pharmacotherapy.

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Tarshis, Samantha; Maltzahn, Joanne; Loomis, Zoe; Irwin, David C

2016-12-01

High altitude cerebral edema (HACE) is a fulminant, deadly, and yet still unpredictable brain disease. A new prophylactic treatment for HACE and its predecessor, acute mountain sickness (AMS), needs to be developed without the contraindications or adverse effect profiles of acetazolamide and dexamethasone. Since neovascularization signals are likely key contributors to HACE/AMS, our approach was to examine already existing anti-angiogenic drugs to inhibit potential initiating HACE pathway(s). This approach can also reveal crucial early steps in the frequently debated mechanism of HACE/AMS pathogenesis. We exposed four rat cohorts to hypobaric hypoxia and one to sea level (hyperbaric) conditions. The cohorts were treated with saline controls, an anti-angiogenesis drug (motesanib), a pro-angiogenesis drug (deferoxamine), or an intraperitoneal version of the established AMS prophylaxis drug, acetazolamide (benzolamide). Brain tissue was analyzed for cerebrovascular leak using the Evans Blue Dye (EVBD) protocol. We observed significantly increased EVBD in the altitude control and pro-angiogenesis (deferoxamine) cohorts, and significantly decreased EVBD in the anti-angiogenesis (motesanib), established treatment (benzolamide), and sea-level cohorts. Anti-angiogenesis-treated cohorts demonstrated less cerebrovascular extravasation than the altitude control and pro-angiogenesis treated rats, suggesting promise as an alternative prophylactic HACE/AMS treatment. The leak exacerbation with pro-angiogenesis treatment and improvement with anti-angiogenesis treatment support the hypothesis of early neovascularization signals provoking HACE. We demonstrate statistically significant evidence to guide further investigation for VEGF- and HIF-inhibitors as HACE/AMS prophylaxis, and as elucidators of still unknown HACE pathogenesis.Tarshis S, Maltzahn J, Loomis Z, Irwin DC. Preventing high altitude cerebral edema in rats with repurposed anti-angiogenesis pharmacotherapy. Aerosp Med

Office design's impact on sick leave rates.

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Bodin Danielsson, Christina; Chungkham, Holendro Singh; Wulff, Cornelia; Westerlund, Hugo

2014-01-01

The effect of office type on sickness absence among office employees was studied prospectively in 1852 employees working in (1) cell-offices; (2) shared-room offices; (3) small, (4) medium-sized and (5) large open-plan offices; (6) flex-offices and (7) combi-offices. Sick leaves were self-reported two years later as number of (a) short and (b) long (medically certified) sick leave spells as well as (c) total number of sick leave days. Multivariate logistic regression analysis was used, with adjustment for background factors. A significant excess risk for sickness absence was found only in terms of short sick leave spells in the three open-plan offices. In the gender separate analysis, this remained for women, whereas men had a significantly increased risk in flex-offices. For long sick leave spells, a significantly higher risk was found among women in large open-plan offices and for total number of sick days among men in flex-offices. A prospective study of the office environment's effect on employees is motivated by the high rates of sick leaves in the workforce. The results indicate differences between office types, depending on the number of people sharing workspace and the opportunity to exert personal control as influenced by the features that define the office types.

The Effect of Sex on Heart Rate Variability at High Altitude.

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Boos, Christopher John; Vincent, Emma; Mellor, Adrian; O'Hara, John; Newman, Caroline; Cruttenden, Richard; Scott, Phylip; Cooke, Mark; Matu, Jamie; Woods, David Richard

2017-12-01

There is evidence suggesting that high altitude (HA) exposure leads to a fall in heart rate variability (HRV) that is linked to the development of acute mountain sickness (AMS). The effects of sex on changes in HRV at HA and its relationship to AMS are unknown. HRV (5-min single-lead ECG) was measured in 63 healthy adults (41 men and 22 women) 18-56 yr of age at sea level (SL) and during a HA trek at 3619, 4600, and 5140 m, respectively. The main effects of altitude (SL, 3619 m, 4600 m, and 5140 m) and sex (men vs women) and their potential interaction were assessed using a factorial repeated-measures ANOVA. Logistic regression analyses were performed to assess the ability of HRV to predict AMS. Men and women were of similar age (31.2 ± 9.3 vs 31.7 ± 7.5 yr), ethnicity, and body and mass index. There was main effect for altitude on heart rate, SD of normal-to-normal (NN) intervals (SDNN), root mean square of successive differences (RMSSD), number of pairs of successive NN differing by >50 ms (NN50), NN50/total number of NN, very low-frequency power, low-frequency (LF) power, high-frequency (HF) power, and total power (TP). The most consistent effect on post hoc analysis was reduction in these HRV measures between 3619 and 5140 m at HA. Heart rate was significantly lower and SDNN, RMSSD, LF power, HF power, and TP were higher in men compared with women at HA. There was no interaction between sex and altitude for any of the HRV indices measured. HRV was not predictive of AMS development. Increasing HA leads to a reduction in HRV. Significant differences between men and women emerge at HA. HRV was not predictive of AMS.

Sick Leave and Factors Influencing Sick Leave in Adult Patients with Atopic Dermatitis : A Cross-Sectional Study

NARCIS (Netherlands)

van Os-Medendorp, Harmieke; Appelman-Noordermeer, Simone; Bruijnzeel-Koomen, Carla A.F.M.; de Bruin-Weller, MS

2015-01-01

BACKGROUND: Little is known about the prevalence of sick leave due to atopic dermatitis (AD). The current literature on factors influencing sick leave is mostly derived from other chronic inflammatory diseases. This study aimed to determine the prevalence of sick leave due to AD and to identify

Analyses of Sickness Absence

NARCIS (Netherlands)

Heijnen, S.M.M.

2014-01-01

Sickness absence is an empirical phenomenon of all time. Generally, it has a medical cause. However, other factors also appear to have an impact on the actual rate of sickness absence, such as the institutional setting, the business cycle and the economic structure. Many questions on the different

Decryption-decompression of AES protected ZIP files on GPUs

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Duong, Tan Nhat; Pham, Phong Hong; Nguyen, Duc Huu; Nguyen, Thuy Thanh; Le, Hung Duc

2011-10-01

AES is a strong encryption system, so decryption-decompression of AES encrypted ZIP files requires very large computing power and techniques of reducing the password space. This makes implementations of techniques on common computing system not practical. In [1], we reduced the original very large password search space to a much smaller one which surely containing the correct password. Based on reduced set of passwords, in this paper, we parallel decryption, decompression and plain text recognition for encrypted ZIP files by using CUDA computing technology on graphics cards GeForce GTX295 of NVIDIA, to find out the correct password. The experimental results have shown that the speed of decrypting, decompressing, recognizing plain text and finding out the original password increases about from 45 to 180 times (depends on the number of GPUs) compared to sequential execution on the Intel Core 2 Quad Q8400 2.66 GHz. These results have demonstrated the potential applicability of GPUs in this cryptanalysis field.

[Physiological aspects of altitude training and the use of altitude simulators].

Science.gov (United States)

Ranković, Goran; Radovanović, Dragan

2005-01-01

Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatisation, which improves oxygen transport and/or utilisation, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of travelling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarised.

Physiological aspects of altitude training and the use of altitude simulators

Directory of Open Access Journals (Sweden)

Ranković Goran

2005-01-01

Full Text Available Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training, live low and train high (training through hypoxia, and live high and train low (the new trend. In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters. Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized.

Isolated psychosis during exposure to very high and extreme altitude - characterisation of a new medical entity.

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Hüfner, Katharina; Brugger, Hermann; Kuster, Eva; Dünsser, Franziska; Stawinoga, Agnieszka E; Turner, Rachel; Tomazin, Iztok; Sperner-Unterweger, Barbara

2017-12-05

Psychotic episodes during exposure to very high or extreme altitude have been frequently reported in mountain literature, but not systematically analysed and acknowledged as a distinct clinical entity. Episodes reported above 3500 m altitude with possible psychosis were collected from the lay literature and provide the basis for this observational study. Dimensional criteria of the Diagnostic and Statistical Manual of Mental Disorders were used for psychosis, and the Lake Louise Scoring criteria for acute mountain sickness and high-altitude cerebral oedema (HACE). Eighty-three of the episodes collected underwent a cluster analysis to identify similar groups. Ratings were done by two independent, trained researchers (κ values 0.6-1). Findings Cluster 1 included 51% (42/83) episodes without psychosis; cluster 2 22% (18/83) cases with psychosis, plus symptoms of HACE or mental status change from other origins; and cluster 3 28% (23/83) episodes with isolated psychosis. Possible risk factors of psychosis and associated somatic symptoms were analysed between the three clusters and revealed differences regarding the factors 'starvation' (χ2 test, p = 0.002), 'frostbite' (p = 0.024) and 'supplemental oxygen' (p = 0.046). Episodes with psychosis were reversible but associated with near accidents and accidents (p = 0.007, odds ratio 4.44). Episodes of psychosis during exposure to high altitude are frequently reported, but have not been specifically examined or assigned to medical diagnoses. In addition to the risk of suffering from somatic mountain illnesses, climbers and workers at high altitude should be aware of the potential occurrence of psychotic episodes, the associated risks and respective coping strategies.

Positive and negative consequences of sick leave for the individual, with special focus on part-time sick leave.

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Sieurin, Leif; Josephson, Malin; Vingård, Eva

2009-01-01

To describe the consequences of long-term sick leave (>28 days) on working situation, health and lifestyle among employees from the public sector in Sweden. Employees in four county councils and two municipalities on long term sick leave on 1 November 2005 (n = 1,128) answered a questionnaire in February 2006. The response rate was 71.7%. Eighty seven per cent were still on sick leave when the questionnaire was answered: 54% part time and 33% full time. Reporting positive consequences was rare but reporting negative consequences, such as effects on the development of salary, the possibilities of pursuing a career or to change to another job were common. Sick leave seemed to lead to a considerable loss of zest for work, even if the respondents were back in work full time. Regardless of the negative consequences at work, 92% of those on part-time sick leave believed that the part-time sick leave was good for them even if many thought it had negative consequences for employer and colleagues. Long-term sick leave has negative consequences for the individual in work situations, even for those back at work full time. The development of salary and career seem to be most affected. The attitude towards part-time sick leave was positive and this result indicates that there is a potential for an increased degree of partial return to work in the group of people on long-term sick leave.

Trends in Orbital Decompression Techniques of Surveyed American Society of Ophthalmic Plastic and Reconstructive Surgery Members.

Science.gov (United States)

Reich, Shani S; Null, Robert C; Timoney, Peter J; Sokol, Jason A

To assess current members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) regarding preference in surgical techniques for orbital decompression in Graves' disease. A 10-question web-based, anonymous survey was distributed to oculoplastic surgeons utilizing the ASOPRS listserv. The questions addressed the number of years of experience performing orbital decompression surgery, preferred surgical techniques, and whether orbital decompression was performed in collaboration with an ENT surgeon. Ninety ASOPRS members participated in the study. Most that completed the survey have performed orbital decompression surgery for >15 years. The majority of responders preferred a combined approach of floor and medial wall decompression or balanced lateral and medial wall decompression; only a minority selected a technique limited to 1 wall. Those surgeons who perform fat decompression were more likely to operate in collaboration with ENT. Most surgeons rarely remove the orbital strut, citing risk of worsening diplopia or orbital dystopia except in cases of optic nerve compression or severe proptosis. The most common reason given for performing orbital decompression was exposure keratopathy. The majority of surgeons perform the surgery without ENT involvement, and number of years of experience did not correlate significantly with collaboration with ENT. The majority of surveyed ASOPRS surgeons prefer a combined wall approach over single wall approach to initial orbital decompression. Despite the technological advances made in the field of modern endoscopic surgery, no single approach has been adopted by the ASOPRS community as the gold standard.

Prognostic Factors for Satisfaction After Decompression Surgery for Lumbar Spinal Stenosis

DEFF Research Database (Denmark)

Paulsen, Rune Tendal; Bouknaitir, Jamal Bech; Fruensgaard, Søren

2018-01-01

: To present clinical outcome data and identify prognostic factors related to patient satisfaction 1 yr after posterior decompression surgery for lumbar spinal stenosis. METHOD: This multicenter register study included 2562 patients. Patients were treated with various types of posterior decompression. Patients...... with previous spine surgery or concomitant fusion were excluded. Patient satisfaction was analyzed for associations with age, sex, body mass index, smoking status, duration of pain, number of decompressed vertebral levels, comorbidities, and patient-reported outcome measures, which were used to quantify....... CONCLUSION: This study found smoking, long duration of leg pain, and cancerous and neurological disease to be associated with patient dissatisfaction, whereas good walking capacity at baseline was positively associated with satisfaction after 1 yr....

Sickness absence at a young age and later sickness absence, disability pension, death, unemployment and income in native Swedes and immigrants

Science.gov (United States)

Johansson, Bo; Nordqvist, Tobias; Lundberg, Ingvar; Vingård, Eva

2015-01-01

Background: Sickness absence with cash benefits from the sickness insurance gives an opportunity to be relieved from work without losing financial security. There are, however, downsides to taking sickness absence. Periods of sickness absence, even short ones, can increase the risk for future spells of sickness absence and unemployment. The sickness period may in itself have a detrimental effect on health. The aim of the study was to investigate if there is an association between exposure to sickness absence at a young age and later sickness absence, disability pension, death, unemployment and income from work. Methods: Our cohort consisted of all immigrants aged 21–25 years in Sweden in 1993 (N = 38 207) and a control group of native Swedes in the same age group (N = 225 977). We measured exposure to sickness absence in 1993 with a follow-up period of 15 years. We conducted separate analyses for men and women, and for immigrants and native Swedes. Results: Exposure to ≥60 days of sickness absence in 1993 increased the risk of sickness absence [hazard ratio (HR) 1.6–11.4], unemployment (HR 1.1–1.2), disability pension (HR 1.2–5.3) and death (HR 1.2–3.5). The income from work, during the follow-up period, among individuals with spells of sick leave for ≥60 days in 1993 was around two-thirds of that of the working population who did not take sick leave. Conclusions: Individuals on sickness absence had an increased risk for work absence, death and lower future income. PMID:25634955

High altitude-induced albuminuria in normal man is enhanced by infusion of low-dose dopamine

DEFF Research Database (Denmark)

Hansen, J M; Kanstrup, I L; Richalet, J P

1996-01-01

-85) (median with quartiles in parentheses) at high altitude. High altitude hypoxia increased Ualb from 3.2 micrograms min-1 (2.7-3.5) to 5.0 micrograms min-1 (3.3-6.6) (p ... flow (ERPF) from 465 ml min-1 (412-503) to 410 ml min-1 (385-451) (p high altitude. Dopamine...... increased ERPF, GFR, CLi, CNa, and decreased the filtration fraction in both environments. Infusion of dopamine further increased Ualb to 10.5 micrograms min-1 (5.5-64.8) (p high altitude, but had no effect on Ualb at sea level. In conclusion, high altitude hypoxia per se increases the urinary...

A traumatic central cord syndrome occurring after adequate decompression for cervical spondylosis: biomechanics of injury: case report.

Science.gov (United States)

Dickerman, Rob D; Lefkowitz, Michael; Epstein, Joseph A

2005-10-15

Case report with review of the literature. To present the first case of a central cord syndrome occurring after adequate decompression, and review the mechanics of the cervical spinal cord injury and postoperative biomechanical and anatomic changes occurring after cervical decompressive laminectomy. Cervical spondylosis is a common pathoanatomic occurrence in the elderly population and is thought to be one of the primary causes for a central cord syndrome. Decompressive laminectomy with or without fusion has been a primary treatment for spondylotic disease and is thought to be protective against further injury. To our knowledge, there are no cases of a central cord syndrome occurring after adequate decompression reported in the literature. Case study with extensive review of the literature. The patient underwent C3-C7 cervical laminectomy without complications. After surgery, the patient's spasticity and gait difficulties improved. She was discharged to inpatient rehabilitation for further treatment of upper extremity weakness. The patient fell in the rehabilitation center, with a central cord syndrome despite adequate decompression of her spinal canal. The patient was treated conservatively for the central cord and had minimal improvement. Decompressive laminectomy provides an immediate decompressive effect on the spinal cord as seen by the dorsal migration of the cord, however, the biomechanics of the cervical spine after decompressive laminectomy remain uncertain. This case supports the ongoing research and need for more intensive research on postoperative cervical spine biomechanics, including decompressive laminectomies, decompressive laminectomy and fusion, and laminoplasty.

Unusual Clinical Presentation and Role of Decompressive Craniectomy in Herpes Simplex Encephalitis.

Science.gov (United States)

Singhi, Pratibha; Saini, Arushi Gahlot; Sahu, Jitendra Kumar; Kumar, Nuthan; Vyas, Sameer; Vasishta, Rakesh Kumar; Aggarwal, Ashish

2015-08-01

Decompressive craniectomy in pediatric central nervous infections with refractory intracranial hypertension is less commonly practiced. We describe improved outcome of decompressive craniectomy in a 7-year-old boy with severe herpes simplex encephalitis and medically refractory intracranial hypertension, along with a brief review of the literature. Timely recognition of refractory intracranial hypertension and surgical decompression in children with herpes simplex encephalitis can be life-saving. Additionally, strokelike atypical presentations are being increasingly recognized in children with herpes simplex encephalitis and should not take one away from the underlying herpes simplex encephalitis. © The Author(s) 2014.

Optic neuropathy in thyroid eye disease: results of the balanced decompression technique.

Science.gov (United States)

Baril, Catherine; Pouliot, Denis; Molgat, Yvonne

2014-04-01

To determine the efficacy of combined endoscopic medial and external lateral orbital decompression for the treatment of compressive optic neuropathy (CON) in thyroid eye disease (TED). A retrospective review of all patients undergoing combined surgical orbital decompression for CON between 2000 and 2010 was conducted. Fifty-nine eyes of 34 patients undergoing combined surgical orbital decompression for CON. Clinical outcome measures included visual acuity, Hardy-Rand-Rittler (HRR) colour plate testing, relative afferent pupillary defect, intraocular pressure measurement, and Hertel exophthalmometry. A CON score was calculated preoperatively and postoperatively based on the visual acuity and the missed HRR plates. A higher CON score correlates with more severe visual dysfunction. All patients had improvement of their optic neuropathy after surgical decompression. CON score was calculated for 54 eyes and decreased significantly from a mean of 13.2 ± 10.35 preoperatively to a mean of 8.51 ± 10.24 postoperatively (p < 0.0001). Optic neuropathy was completely resolved in 93.22% (55/59 eyes). Eighteen of 34 patients (52.94%) experienced development of new-onset postoperative strabismus that required subsequent surgical intervention. Endoscopic medial combined with external lateral orbital decompression is an effective technique for the treatment of TED-associated CON. © 2013 Canadian Ophthalmological Society Published by Canadian Ophthalmological Society All rights reserved.

Serum immunoreactive erythropoietin in high altitude natives with and without excessive erythrocytosis.

Science.gov (United States)

León-Velarde, F; Monge, C C; Vidal, A; Carcagno, M; Criscuolo, M; Bozzini, C E

1991-05-01

We report the estimation of blood hemoglobin (Hb), arterial blood oxygen saturation (SaO2), and serum immunoreactive erythropoietin (siEPO) in a group of Peruvian workers residing in Cerro de Pasco at 4300 m showing "excessive erythrocytosis" (EE, Monge's disease, chronic mountain sickness). These estimates were compared with those of humans residing either in Cerro de Pasco and showing "normal erythrocytosis" (NE) or in Lima (sea level, SL) to determine whether Hb and SaO2 are related to siEPO in high altitude (HA) natives with NE or EE. The three parameters showed statistically significant differences between HA and SL groups--the values in SL being lower. Significant differences were also found between NE and EE groups in Hb and SaO2. There was no statistical difference in siEPo between the two groups. The results indicate, therefore, that HA residents who develop EE are not distinguishable from residents who develop NE on the basis of estimates of siEPO. As a result, siEPO and Hb do not show a dose-response relationship in HA residents, and variation in EPO does not explain the striking variation in Hb at high altitudes.

Morning Sickness: Nausea and Vomiting of Pregnancy

Science.gov (United States)

... About ACOG Morning Sickness: Nausea and Vomiting of Pregnancy Home For Patients Search FAQs Morning Sickness: Nausea ... PDF Format Morning Sickness: Nausea and Vomiting of Pregnancy Pregnancy How common is nausea and vomiting of ...

46 CFR 197.332 - PVHO-Decompression chambers.

Science.gov (United States)

2010-10-01

.... Each decompression chamber must— (a) Meet the requirements of § 197.328; (b) Have internal dimensions... pressure; (d) Have a means of operating all installed man-way locking devices, except disabled shipping...

Clinical characteristics of subacute radiation sickness

International Nuclear Information System (INIS)

Jiang Benrong; Ye Genyao; Huang Shimin

1991-01-01

The clinical characteristics, diagnosis and differential diagnosis of subacute radiation sickness are analysed and discussed in this paper on the basis of clinical data from cases in a 137 Cs source accident in Mudanjiang and of a review of the literature. We consider that the subacute radiation sickness is a whole body disease caused by comparatively large dose of continuous or intermittent external irradiation in several weeks or months. it must be differentiated from acute radiation sickness, chronic radiation sickness, idiopathic aplastic anemia and other hematological diseases, such as paroxysmal nocturnal hemoglobinuria, acute leukemia and myelodysplastic syndrome

Influenza in workplaces: transmission, workers' adherence to sick leave advice and European sick leave recommendations.

Science.gov (United States)

Edwards, Christina Hansen; Tomba, Gianpaolo Scalia; de Blasio, Birgitte Freiesleben

2016-06-01

Knowledge about influenza transmission in the workplace and whether staying home from work when experiencing influenza-like illness can reduce the spread of influenza is crucial for the design of efficient public health initiatives. This review synthesizes current literature on sickness presenteeism and influenza transmission in the workplace and provides an overview of sick leave recommendations in Europe for influenza. A search was performed on Medline, Embase, PsychINFO, Cinahl, Web of Science, Scopus and SweMed to identify studies related to workplace contacts, -transmission, -interventions and compliance with recommendations to take sick leave. A web-based survey on national recommendations and policies for sick leave during influenza was issued to 31 European countries. Twenty-two articles (9 surveys; 13 modelling articles) were eligible for this review. Results from social mixing studies suggest that 20-25% of weekly contacts are made in the workplace, while modelling studies suggest that on average 16% (range 9-33%) of influenza transmission occurs in the workplace. The effectiveness of interventions to reduce workplace presenteeism is largely unknown. Finally, estimates from studies reporting expected compliance with sick leave recommendations ranged from 71 to 95%. Overall, 18 countries participated in the survey of which nine (50%) had issued recommendations encouraging sick employees to stay at home during the 2009 A(H1N1) pandemic, while only one country had official recommendations for seasonal influenza. During the 2009 A(H1N1) pandemic, many European countries recommended ill employees to take sick leave. Further research is warranted to quantify the effect of reduced presenteeism during influenza illness. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association.

Influenza in workplaces: transmission, workers’ adherence to sick leave advice and European sick leave recommendations

Science.gov (United States)

Tomba, Gianpaolo Scalia; de Blasio, Birgitte Freiesleben

2016-01-01

Background: Knowledge about influenza transmission in the workplace and whether staying home from work when experiencing influenza-like illness can reduce the spread of influenza is crucial for the design of efficient public health initiatives. Aim: This review synthesizes current literature on sickness presenteeism and influenza transmission in the workplace and provides an overview of sick leave recommendations in Europe for influenza. Methods: A search was performed on Medline, Embase, PsychINFO, Cinahl, Web of Science, Scopus and SweMed to identify studies related to workplace contacts, -transmission, -interventions and compliance with recommendations to take sick leave. A web-based survey on national recommendations and policies for sick leave during influenza was issued to 31 European countries. Results: Twenty-two articles (9 surveys; 13 modelling articles) were eligible for this review. Results from social mixing studies suggest that 20–25% of weekly contacts are made in the workplace, while modelling studies suggest that on average 16% (range 9–33%) of influenza transmission occurs in the workplace. The effectiveness of interventions to reduce workplace presenteeism is largely unknown. Finally, estimates from studies reporting expected compliance with sick leave recommendations ranged from 71 to 95%. Overall, 18 countries participated in the survey of which nine (50%) had issued recommendations encouraging sick employees to stay at home during the 2009 A(H1N1) pandemic, while only one country had official recommendations for seasonal influenza. Conclusions: During the 2009 A(H1N1) pandemic, many European countries recommended ill employees to take sick leave. Further research is warranted to quantify the effect of reduced presenteeism during influenza illness. PMID:27060594

The Use of Dexamethasone in Support of High-Altitude Ground Operations: Review of the Literature & Current Training of U.S. Special Operations Medical Members

Science.gov (United States)

2013-03-14

capacity even in normoxic conditions. For example, high dosages of dexamethasone are used in aerobic endurance sports to enhance physical performance. This...is why the World Anti- Doping Agency prohibits the administration of any glucosteroids during competitions [25]. Fischler and colleagues [24...Medicine; 2004. Technical Note TN04-05. 4. Bärtsch P, Saltin B. General introduction to altitude adaptation and mountain sickness. Scand J Med Sci Sports

Motion sickness: a negative reinforcement model.

Science.gov (United States)

Bowins, Brad

2010-01-15

Theories pertaining to the "why" of motion sickness are in short supply relative to those detailing the "how." Considering the profoundly disturbing and dysfunctional symptoms of motion sickness, it is difficult to conceive of why this condition is so strongly biologically based in humans and most other mammalian and primate species. It is posited that motion sickness evolved as a potent negative reinforcement system designed to terminate motion involving sensory conflict or postural instability. During our evolution and that of many other species, motion of this type would have impaired evolutionary fitness via injury and/or signaling weakness and vulnerability to predators. The symptoms of motion sickness strongly motivate the individual to terminate the offending motion by early avoidance, cessation of movement, or removal of oneself from the source. The motion sickness negative reinforcement mechanism functions much like pain to strongly motivate evolutionary fitness preserving behavior. Alternative why theories focusing on the elimination of neurotoxins and the discouragement of motion programs yielding vestibular conflict suffer from several problems, foremost that neither can account for the rarity of motion sickness in infants and toddlers. The negative reinforcement model proposed here readily accounts for the absence of motion sickness in infants and toddlers, in that providing strong motivation to terminate aberrant motion does not make sense until a child is old enough to act on this motivation.

Influence of surgical decompression on the expression of inflammatory and tissue repair biomarkers in periapical cysts.

Science.gov (United States)

Rodrigues, Janderson Teixeira; Dos Santos Antunes, Henrique; Armada, Luciana; Pires, Fábio Ramôa

2017-12-01

The biologic effects of surgical decompression on the epithelium and connective tissues of periapical cysts are not fully understood. The aim of this study was to evaluate the expression of tissue repair and inflammatory biomarkers in periapical cysts before and after surgical decompression. Nine specimens of periapical cysts treated with decompression before undergoing complete enucleation were immunohistochemically analyzed to investigate the expression of interleukin-1β, tumor necrosis factor-α, transforming growth factor-β1, matrix metalloproteinase-9, Ki-67, and epidermal growth factor receptor. Expression of the biomarkers was classified as positive, focal, or negative. Ki-67 immunoexpression was calculated as a cell proliferation index. The expression of the biomarkers was compared in the specimens from decompression and from the final surgical procedure. Computed tomography demonstrated that volume was reduced in all cysts after decompression. There were no differences in the immunoexpression of the proinflammatory and tissue repair biomarkers when comparing the specimens obtained before and after the decompression. Surgical decompression was efficient in reducing the volume of periapical cysts before complete enucleation. When comparing the specimens obtained from surgical decompression and from complete surgical removal, the immunohistochemical analysis did not show a decrease in proinflammatory biomarkers; neither did it show an increase in tissue repair biomarkers. Copyright © 2017 Elsevier Inc. All rights reserved.

Examining paid sickness absence by shift workers.

Science.gov (United States)

Catano, V M; Bissonnette, A B

2014-06-01

Shift workers are at greater risk than day workers with respect to psychological and physical health, yet little research has linked shift work to increased sickness absence. To investigate the relationship between shift work and sickness absence while controlling for organizational and individual characteristics and shift work attributes that have confounded previous research. The study used archive data collected from three national surveys in Canada, each involving over 20000 employees and 6000 private-sector firms in 14 different occupational groups. The employees reported the number of paid sickness absence days in the past 12 months. Data were analysed using both chi-squared statistics and hierarchical regressions. Contrary to previous research, shift workers took less paid sickness absence than day workers. There were no differences in the length of the sickness absence between both groups or in sickness absence taken by female and male workers whether working days or shifts. Only job tenure, the presence of a union in the workplace and working rotating shifts predicted sickness absence in shift workers. The results were consistent across all three samples. In general, shift work does not seem to be linked to increased sickness absence. However, such associations may be true for specific industries. Male and female workers did not differ in the amount of sickness absence taken. Rotating shifts, regardless of industry, predicted sickness absence among shift workers. Consideration should be given to implementing scheduled time off between shift changes. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Pottery Electric Kiln Using Decompression

Science.gov (United States)

Naoe, Nobuyuki; Yamada, Hirofumi; Nakayama, Tetsuo; Nakayama, Minoru; Minamide, Akiyuki; Takemata, Kazuya

This paper presents a novel type electric kiln which fires the pottery using the decompression. The electric kiln is suitable for the environment and the energy saving as the pottery furnace. This paper described the baking principle and the baking characteristic of the novel type electric kiln.

Parental availability for the care of sick children.

Science.gov (United States)

Heymann, S J; Earle, A; Egleston, B

1996-08-01

Parents have always played a critical role in the care of sick children. Although parents' roles remain crucial to children's health, parental availability has declined during the past half century. The percentage of women with preschool children who work has risen almost fivefold in 45 years from 12% in 1947 to 58% in 1992. The percentage of women in the paid work force with school-aged children has almost tripled in the same period, from 27.3% to 75.9%. Research has examined the effects of a variety of parental work conditions on children. However, past research has not examined how working conditions affect the ability of parents to care for their sick children. In this article, we examine how often the children of working parents get sick and whether parents receive enough paid leave to care for their sick children. This analysis makes use of two national surveys, which provide complementary information regarding the care of sick children. The National Longitudinal Survey of Youth is a longitudinal survey of a nationally representative probability sample of 12,686 men and women; the National Medical Expenditure Survey is a panel survey of 34,459 people. First, we estimated the family illness burden. Second, we looked in detail at the number of days of sick leave mothers had. Third, we examined whether mothers who had sick leave had it consistently during a 5-year period. Finally, we conducted a logistic regression to determine what factors were significant predictors of both lacking sick leave. More than one in three families faced a family illness burden of 2 weeks or more each year. Yet, 28% of mothers had sick leave none of the time they were employed between 1985 and 1990. Employed mothers of children with chronic conditions had less sick leave than other employed mothers. Thirty-six percent of mothers whose children had chronic conditions had sick leave none of the time they were employed. Although 20% of working parents who did not live in poverty lacked

Changes of body fluid and hematology in toad and their rehabilitation following intermittent exposure to simulated high altitude

Science.gov (United States)

Biswas, H. M.; Boral, M. C.

1986-06-01

Three groups of adult male toads were exposed intermittently in a decompression chamber for a daily period of 4 and 8 hours at a time for 6 consecutive days to an “altitude” of 12,000; 18,000 and 24,000 feet (3658; 5486; 7315 m) respectively. Most of the exposed animals were sacrificed immediately after the last exposure, but only a few animals experiencing 8 hours of exposure were sacrificed after a further 16 hours of exposure at normal atmospheric pressure. Eight hours of daily exposure for 6 days causes a decrease of body fluids and an increase of hematological parameters in all the altitude exposed animals compared with to the changes noted in the animals having 4 hours of daily exposure for 6 days at the same altitude levels. The animals that were exposed to pressures equivalent to altitudes of 12,000 and 18,000 feet daily for 8 hours were found to return nearly to their normal body fluids and hematological balance after 16 hours of exposure to normal atmospheric pressure, whereas the animals exposed for a similar period at an equivalent 24,000 feet failed to get back their normal balance of body fluids and hematology after 16 hours of exposure at normal atmospheric pressure. The present experiment shows that the body weight loss and changes of body fluid and hematological parameters in the toad after exposure to simulated high altitude are due not only to dehydration, but suggest that hypoxia may also have a role.

Industrial Sickness in Indian Manufacturing

OpenAIRE

Falk, Rahel

2005-01-01

In India, the term ‘sick units’ refers to economically unviable firms which are kept alive ‘in the public interest’ by means of subsidies of various kinds. Since this practice is common, and large parts of the industrial sector are affected, this phenomenon is referred to as industrial sickness. As of March 2001, the Reserve Bank of India counted over a quarter of a million of sick units with outstanding credit worth more than a quarter of a trillion of Indian Rupees, i.e. about 1.2 percent o...

[The sick individual as a concept].

Science.gov (United States)

Tejerizo López, Luis Carlos

2011-01-01

We start from the premise, shared by some current philosophical movements and by the author, which states that philosophy is not contemplation, or reflection, or introspection or communication. Philosophy is the art of shaping, inventing and creating concepts. It is an explicit way of introducing new differences in life, a different reading level, a specific jargon, which may imply revealing the flip side of the coin, or a dissimilar view of the side facing us. The philosopher is the friend of the concept, he holds it in his power, which means, basically and in all honesty, that philosophy is the discipline of creating concepts. Let us remember the brilliant idea of the Russian director Tarkovsky, who announced his greatest ambition as an artist: "To capture time". At the same time, we must recall one of the sayings of this director: "Every film I have directed and I intend to direct is always tied to characters who have something to overcome". The healthy individual lives in a specific time, with precise coordinates, aware that his life consists only of living that time. That is, living as defined by Josep María Esquirol: "Then we could also see that the best way of living the present is not to run after the fleeing time, but to see and live the opportunity that appears before us". One of the many circumstances that can intercept the way we see and live the opportunity that appears before us is sickness, one of those inescapable experiences we have not been taught how to pay an adequate attention to, and the meaning of which can, in a way, go unnoticed. As "time" goes by, the circumstance that we consider to be the basis on which existence is founded, sickness can appear, thus introducing a new dimension in the time of the healthy individual. For this reason we, as doctors and professionals, know that sickness "is tied to characters who have something to overcome". In view of the fact that a sickness invades a healthy individual and transforms him into a sick one

Autophagy Is a Promoter for Aerobic Exercise Performance during High Altitude Training

Directory of Open Access Journals (Sweden)

Ying Zhang

2018-01-01

Full Text Available High altitude training is one of the effective strategies for improving aerobic exercise performance at sea level via altitude acclimatization, thereby improving oxygen transport and/or utilization. But its underlying molecular mechanisms on physiological functions and exercise performance of athletes are still vague. More recent evidence suggests that the recycling of cellular components by autophagy is an important process of the body involved in the adaptive responses to exercise. Whether high altitude training can activate autophagy or whether high altitude training can improve exercise performance through exercise-induced autophagy is still unclear. In this narrative review article, we will summarize current research advances in the improvement of exercise performance through high altitude training and its reasonable molecular mechanisms associated with autophagy, which will provide a new field to explore the molecular mechanisms of adaptive response to high altitude training.

Explaining the gender gap in sickness absence.

Science.gov (United States)

Østby, K A; Mykletun, A; Nilsen, W

2018-04-17

In many western countries, women have a much higher rate of sickness absence than men. To what degree the gender differences in sickness absence are caused by gender differences in health is largely unknown. To assess to what degree the gender gap in sickness absence can be explained by health factors and work- and family-related stressors. Norwegian parents participating in the Tracking Opportunities and Problems (TOPP) study were asked about sickness absence and a range of factors possibly contributing to gender differences in sickness absence, including somatic and mental health, sleep problems, job control/demands, work-home conflicts, parent-child conflicts and stressful life events. Using a cross-sectional design, we did linear regression analyses, to assess the relative contribution from health and stressors. There were 557 study participants. Adjusting for health factors reduced the gender difference in sickness absence by 24%, while adjusting for stressors in the family and at work reduced the difference by 22%. A simultaneous adjustment for health factors and stressors reduced the difference in sickness absence by about 28%. Despite adjusting for a large number of factors, including both previously well-studied factors (e.g. health, job control/demands) and lesser-studied factors (parent-child conflict and sexual assault), this study found that most of the gender gap in sickness absence remains unexplained. Gender differences in health and stressors account for only part of the differences in sickness absence. Other factors must, therefore, exist outside the domains of health, work and family stressors.

Part-Time Sick Leave as a Treatment Method?

OpenAIRE

Andrén D; Andrén T

2009-01-01

This paper analyzes the effects of being on part-time sick leave compared to full-time sick leave on the probability of recovering (i.e., returning to work with full recovery of lost work capacity). Using a discrete choice one-factor model, we estimate mean treatment parameters and distributional treatment parameters from a common set of structural parameters. Our results show that part-time sick leave increases the likelihood of recovering and dominates full-time sick leave for sickness spel...

Deep lateral wall orbital decompression following strabismus surgery in patients with Type II ophthalmic Graves' disease.

Science.gov (United States)

Ellis, Michael P; Broxterman, Emily C; Hromas, Alan R; Whittaker, Thomas J; Sokol, Jason A

2018-01-10

Surgical management of ophthalmic Graves' disease traditionally involves, in order, orbital decompression, followed by strabismus surgery and eyelid surgery. Nunery et al. previously described two distinct sub-types of patients with ophthalmic Graves' disease; Type I patients exhibit no restrictive myopathy (no diplopia) as opposed to Type II patients who do exhibit restrictive myopathy (diplopia) and are far more likely to develop new-onset worsening diplopia following medial wall and floor decompression. Strabismus surgery involving extra-ocular muscle recession has, in turn, been shown to potentially worsen proptosis. Our experience with Type II patients who have already undergone medial wall and floor decompression and strabismus surgery found, when additional decompression is necessary, deep lateral wall decompression (DLWD) appears to have a low rate of post-operative primary-gaze diplopia. A case series of four Type II ophthalmic Graves' disease patients, all of whom had already undergone decompression and strabismus surgery, and went on to develop worsening proptosis or optic nerve compression necessitating further decompression thereafter. In all cases, patients were treated with DLWD. Institutional Review Board approval was granted by the University of Kansas. None of the four patients treated with this approach developed recurrent primary-gaze diplopia or required strabismus surgery following DLWD. While we still prefer to perform medial wall and floor decompression as the initial treatment for ophthalmic Graves' disease, for proptosis following consecutive strabismus surgery, DLWD appears to be effective with a low rate of recurrent primary-gaze diplopia.

On-the-Fly Decompression and Rendering of Multiresolution Terrain

Energy Technology Data Exchange (ETDEWEB)

Lindstrom, P; Cohen, J D

2009-04-02

We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

A variant of the endothelial nitric oxide synthase gene (NOS3) associated with AMS susceptibility is less common in the Quechua, a high altitude Native population.

Science.gov (United States)

Wang, Pei; Ha, Alice Y N; Kidd, Kenneth K; Koehle, Michael S; Rupert, Jim L

2010-01-01

Endothelial nitric oxide synthase (eNOS) is a vascular enzyme that produces nitric oxide, a transient signaling molecule that by vasodilatation regulates blood flow and pressure. Nitric oxide is believed to play roles in both short-term acclimatization and long-term evolutionary adaptation to environmental hypoxia. Several laboratories, including ours, have shown that variants in NOS3 (the gene encoding eNOS) are overrepresented in individuals with altitude-related illnesses such as high altitude pulmonary edema (HAPE) and acute mountain sickness (AMS), suggesting that NOS3 genotypes contribute to altitude tolerance. To further test our hypothesis that the G allele at the G894T polymorphism in NOS3 (dbSNP number: rs1799983; protein polymorphism Glu298Asp) is beneficial in hypoxic environments, we compared frequencies of this allele in an altitude-adapted Amerindian population, Quechua of the Andean altiplano, with those in a lowland Amerindian population, Maya of the Yucatan Peninsula. While common in both populations, the G allele was significantly more frequent in the highlanders. Taken together, our data suggest that this variant in NOS3, which has been previously associated with higher levels of nitric oxide, contributes to both acclimatization and adaptation to altitude.

EXPERIMENTAL STUDY OF DECOMPRESSION, PERMEABILITY AND HEALING OF SILICATE ROCKS IN FAULT ZONES

Directory of Open Access Journals (Sweden)

V. Ya. Medvedev

2014-01-01

Full Text Available The article presents results of petrophysical laboratory experiments in studies of decompression phenomena associated with consequences of abrupt displacements in fault zones. Decompression was studied in cases of controlled pressure drop that caused sharp changes of porosity and permeability parameters, and impacts of such decompression were analyzed. Healing of fractured-porous medium by newly formed phases was studied. After experiments with decompression, healing of fractures and pores in silicate rock samples (3×2×2 cm, 500 °C, 100 MPa took about 800–1000 hours, and strength of such rocks was restored to 0.6–0.7 of the original value. In nature, fracture healing is influenced by a variety of factors, such as size of discontinuities in rock masses, pressure and temperature conditions, pressure drop gradients, rock composition and saturation with fluid. Impacts of such factors are reviewed.

Managerial leadership is associated with self-reported sickness absence and sickness presenteeism among Swedish men and women.

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Nyberg, Anna; Westerlund, Hugo; Magnusson Hanson, Linda L; Theorell, Töres

2008-11-01

The objective of this study was to investigate the relationship between managerial leadership and self-reported sickness absence/presenteeism among Swedish men and women. Five thousand one hundred and forty-one Swedish employees, 56% of the participants in a nationally representative sample of the Swedish working population, were included in this cross-sectional questionnaire study. The leadership dimensions measured were five subscales of a standardized leadership questionnaire (Global Leadership and Organizational Behaviour Effectiveness Programme): Integrity, Team integration, Inspirational leadership, Autocratic leadership, and Self-centred leadership. Multiple logistic regression analyses were conducted, adjusting for factors in private life, employment category, labour-market sector, working conditions, self-reported general health, and satisfaction with life in general. Inspirational leadership was associated with a lower rate of short spells of sickness absence (women. Autocratic leadership was related to a greater amount of total sick days taken by men. Sometimes showing integrity was associated with higher rate of sickness absence >1 week among men, and seldom showing integrity was associated with more sickness presenteeism among women. Managers performing Team integration were sometimes associated with women taking fewer short (1 week) spells of sickness absence. Adjustment for self-reported general health did not alter these associations for men, but did so to some extent for women. Managerial leadership was found to be relevant for the understanding of sickness absence in the Swedish working population. There were distinctive gender differences.

Influence of Acute Normobaric Hypoxia on Hemostasis in Volunteers with and without Acute Mountain Sickness

Directory of Open Access Journals (Sweden)

Marc Schaber

2015-01-01

Full Text Available Introduction. The aim of the present study was to investigate whether a 12-hour exposure in a normobaric hypoxic chamber would induce changes in the hemostatic system and a procoagulant state in volunteers suffering from acute mountain sickness (AMS and healthy controls. Materials and Methods. 37 healthy participants were passively exposed to 12.6% FiO2 (simulated altitude hypoxia of 4,500 m. AMS development was investigated by the Lake Louise Score (LLS. Prothrombin time, activated partial thromboplastin time, fibrinogen, and platelet count were measured and specific methods (i.e., thromboelastometry and a thrombin generation test were used. Results. AMS prevalence was 62.2% (LLS cut off of 3. For the whole group, paired sample t-tests showed significant increase in the maximal concentration of generated thrombin. ROTEM measurements revealed a significant shortening of coagulation time and an increase of maximal clot firmness (InTEM test. A significant increase in maximum clot firmness could be shown (FibTEM test. Conclusions. All significant changes in coagulation parameters after exposure remained within normal reference ranges. No differences with regard to measured parameters of the hemostatic system between AMS-positive and -negative subjects were observed. Therefore, the hypothesis of the acute activation of coagulation by hypoxia can be rejected.

Sickness benefit cuts mainly affect blue-collar workers.

Science.gov (United States)

Aaviksoo, E; Kiivet, R-A

2014-08-01

To analyse the impact of sick-pay cuts on the use of sickness absence by employees of different socioeconomic groups. In 2009 cuts in sick pay were implemented in reaction to an economic crisis in Estonia. Nationwide health survey data from the years 2004, 2006, 2008, and 2010 were used to evaluate sickness absence among blue-collar and white-collar workers. The dataset comprised 7,449 employees of 20-64 years of age. Difference in prevalence of absentees before and after the reform was assessed using the chi-squared test. Odds ratios (OR) for sickness absence were calculated in a multivariate logistic regression model. After the reform, the proportion of blue-collar workers who had been on sick leave decreased from 51% to 40% (pgender, age, self-rated health, and presence of chronic disease, especially among those with low incomes; in white-collar employees it reached statistical significance only in those with good self-rated health (p=0.033). In a multivariate model the odds of having lower sickness absence were highly significant only in blue-collar employees (OR 0.63; 95% confidence interval 0.51-0.77, p<0.001). The cuts in sickness benefits had a major impact on the use of sickness absence by blue-collar employees with low salaries. This indicates that lower income was a major factor hindering the use of sick leave as these employees are most vulnerable to the loss of income. © 2014 the Nordic Societies of Public Health.

Sick-visit immunizations and delayed well-baby visits.

Science.gov (United States)

Robison, Steve G

2013-07-01

Giving recommended immunizations during sick visits for minor and acute illness such as acute otitis media has long been an American Academy of Pediatrics/Advisory Committee on Immunization Practice recommendation. An addition to the American Academy of Pediatrics policy in 2010 advised considering whether giving immunizations at the sick visit would discourage making up missed well-baby visits. This study quantifies the potential tradeoff between sick-visit immunizations and well-baby visits. This study was a retrospective cohort analysis with a case-control component of sick visits for acute otitis media that supplanted normal well-baby visits at age 2, 4, or 6 months. Infants were stratified for sick-visit immunization, no sick-visit immunization but quick makeup well-baby visits, or no sick-visit immunizations or quick makeup visits. Immunization rates and well-baby visit rates were assessed through 24 months of age. For 1060 study cases, no significant difference was detected in immunization rates or well-baby visits through 24 months of age between those with or without sick-visit immunizations. Thirty-nine percent of infants without a sick-visit shot failed to return for a quick makeup well-baby visit; this delayed group was significantly less likely to be up-to-date for immunizations (relative risk: 0.66) and had fewer well-baby visits (mean: 3.8) from 2 through 24 months of age compared with those with sick-visit shots (mean: 4.7). The substantial risk that infants will not return for a timely makeup well-baby visit after a sick visit should be included in any consideration of whether to delay immunizations.

Persistent aryl hydrocarbon receptor inducers increase with altitude, and estrogen-like disrupters are low in soils of the Alps.

Science.gov (United States)

Levy, Walkiria; Henkelmann, Bernhard; Bernhöft, Silke; Bovee, Toine; Buegger, Franz; Jakobi, Gert; Kirchner, Manfred; Bassan, Rodolfo; Kräuchi, Norbert; Moche, Wolfgang; Offenthaler, Ivo; Simončič, Primoz; Weiss, Peter; Schramm, Karl-Werner

2011-01-01

Soil samples from remote Alpine areas were analyzed for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and polychlorinated biphenyls by high-resolution gas chromatography/high-resolution gas spectrometry. Additionally, the EROD micro-assay and a genetically modified yeast estrogen bioassay were carried out to determine persistent aryl hydrocarbon receptors (AhR) and estrogen receptors (ER) agonists, respectively. Regarding the AhR agonists, the toxicity equivalents of analytical and EROD determined values were compared, targeting both altitude of samples and their soil organic content. The ratio between bioassay derived equivalents and analytical determinations suggested no significant contribution of unknown AhR inducers in these sampling sites and some antagonism in soils with relatively high PCB loading. More CYP1A1 expression was induced at the highest sites or about 1400-1500 m a.s.l. along the altitude profiles. Surprisingly, no clear tendencies with the soil organic content were found for dioxin-like compounds. Mean values obtained in the present study were for ER agonists, 2: 0.37±0.12ng 17ß-estradiol EQ g-1 dry soil [corrected] and 6.1 ± 4.2 pg TCDD-EQ g⁻¹ dry soil for AhR agonists. Low bioassay responses with a higher relative amount of ER disrupters than AhR inducers were detected,indicating the higher abundance of estrogen-like than persistent dioxin-like compounds in these forested areas [corrected].

Sickness and love: an introduction

NARCIS (Netherlands)

van der Geest, S.; Vandamme, S.

2008-01-01

Love is a neglected topic in anthropology, for good reasons: it has always resisted scientific definition and analysis. By associating love with sickness seven authors attempt to capture various meanings and experiences of love. Two broad concepts arise: love as sickness and love in response to

Evaluation of hepatic metabolism and pharmacokinetics of ibuprofen in rats under chronic hypobaric hypoxia for targeted therapy at high altitude.

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Gola, Shefali; Gupta, Asheesh; Keshri, Gaurav K; Nath, Madhu; Velpandian, Thirumurthy

2016-03-20

With studies indicative of altered drug metabolism and pharmacokinetics (DMPK) under high altitude (HA)-induced hypobaric hypoxia, consideration of better therapeutic approaches has continuously been aimed in research for HA related illness management. DMPK of drugs like ibuprofen may get affected under hypoxia which establishes the requirement of different therapeutic dose regimen to ensure safe and effective therapy at HA. This study examined the effects of the chronic hypobaric hypoxia (CHH) on hepatic DMPK of ibuprofen in rats. Experimental animals were exposed to simulated altitude of 7620 m (∼25,000 ft) for CHH exposure (7 or 14 days) in decompression chamber and administered with ibuprofen (80 mg/kg, body weight, p.o.). Results demonstrated that CHH significantly altered PK variables of ibuprofen and activities of both phase-I and II hepatic metabolic enzymes as compared to the animals under normoxic conditions. Hepatic histopathological observations also revealed marked alterations. Increase in pro-inflammatory cytokines/chemokines viz. IL-1β, IL-2, IFN-γ, TNF-α exhibited close relevance with diminished CYP2C9 expression under CHH. Moreover, the down-regulated CYP2C9 level further supported the underlying mechanism for reduced metabolism of ibuprofen and as a result, increased retention of parent drug in the system. Increased mean retention time, Vd, T½ of ibuprofen, and decreased AUC, Cmax and clearance during CHH further strengthened the present findings. In conclusion, CHH exposure significantly affects hepatic DMPK of ibuprofen, which may further influence the usual therapeutic dose-regimen. Further, there is requirement of human studies to evaluate their susceptibility toward hypobaric hypoxia. Copyright © 2016 Elsevier B.V. All rights reserved.

Severe traumatic brain injury managed with decompressive ...

African Journals Online (AJOL)

2012-05-29

May 29, 2012 ... Patients with severe taumatic brain injury may develop intractable raised ICP resulting in high mortality ... Glasgow coma score was 8/15 (E1V3M4) and he had left ... An emergency right fronto-temporo-parietal decompressive.

Analysis of direct costs of decompressive craniectomy in victims of traumatic brain injury.

Science.gov (United States)

Badke, Guilherme Lellis; Araujo, João Luiz Vitorino; Miura, Flávio Key; Guirado, Vinicius Monteiro de Paula; Saade, Nelson; Paiva, Aline Lariessy Campos; Avelar, Tiago Marques; Pedrozo, Charles Alfred Grander; Veiga, José Carlos Esteves

2018-04-01

Decompressive craniectomy is a procedure required in some cases of traumatic brain injury (TBI). This manuscript evaluates the direct costs and outcomes of decompressive craniectomy for TBI in a developing country and describes the epidemiological profile. A retrospective study was performed using a five-year neurosurgical database, taking a sample of patients with TBI who underwent decompressive craniectomy. Several variables were considered and a formula was developed for calculating the total cost. Most patients had multiple brain lesions and the majority (69.0%) developed an infectious complication. The general mortality index was 68.8%. The total cost was R$ 2,116,960.22 (US$ 661,550.06) and the mean patient cost was R$ 66,155.00 (US$ 20,673.44). Decompressive craniectomy for TBI is an expensive procedure that is also associated with high morbidity and mortality. This was the first study performed in a developing country that aimed to evaluate the direct costs. Prevention measures should be a priority.

Medically certified sickness absence among health care workers.

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Khawaja, Rajab Ali; Sikander, Raheel; Khawaja, Asad Ali; Jareno, Rechel Joy Macadaan; Halepota, Aurangzeb Taj

2012-09-01

To compare the days and spells of sickness absence among males versus females and Saudi nationals versus expatriate employees of King Khalid University Hospital, Riyadh, and to identify the cause of sickness absence. The cross-sectional, descriptive study comprised 3117 King Khalid University Hospital employees. Records of physician-certified sickness absence from January 1 to June 30, 2009, were obtained from the employee health clinic's register. Absence rate, frequency, duration and severity were assessed and compared between genders and nationalities, and causes were noted. SPSS version 16 and student's t test were used for statistical analyses and comparison. A total of 377 (12.1 %) employees had 416 spells of sickness absence with 639 sick-off days (mean: 1.54 +/- 0.85). The probability of sickness absence was higher among Saudi (OR=1.33) and female (OR=1.39) employees. The association of sickness absence was not found among the absentees with either gender (p= 0.335) or nationality (p = 0.086). Almost all spells of sick-off days were of short duration. Longer spells were mainly due to chicken pox which was found to be more among the expatriates. Heavy absenteeism was found only among the Saudis. The most common causes of sickness absence were acute upper respiratory infection, diseases of musculoskeletal system and the digestive system. The rate, frequency and duration of absence due to sickness in the study were higher among Saudi and female employees. The rate of absence, with passage of time, has increased significantly among Saudi nationals.

Changes in alcohol drinking and subsequent sickness absence.

Science.gov (United States)

Salonsalmi, Aino; Rahkonen, Ossi; Lahelma, Eero; Laaksonen, Mikko

2015-06-01

The aim was to examine whether changes in alcohol drinking are associated with sickness absence. Repeated postal questionnaires on alcohol drinking were conducted among employees of the City of Helsinki in 2000-2 and 2007 to assess changes in drinking habits between these two time points. Data on the number of self-certified and medically confirmed sickness absences were derived from the employer's register. Sickness absences were followed from 2007 until the end of 2010 among employees participating in both questionnaire surveys. The study includes 3252 female and 682 male employees 40-60 years old at baseline. Poisson regression was used in the data analysis and population attributable fractions (PAFs) were calculated. Alcohol drinking was associated especially with self-certified sickness absence. Rate ratios (RRs) and 95% confidence intervals (CIs) for increasing weekly average drinking were 1.38, 1.18-1.62 among women and 1.58, 1.18-2.12 among men. Also stable problem drinking (for women 1.39, 1.26-1.54, for men 1.44, 1.10-1.87) and among women stable heavy drinking (1.53, 1.20-1.94) increased self-certified sickness absence. There were associations between alcohol drinking and medically confirmed sickness absence but these were mainly explained by health and health behaviours. Also, a decrease in weekly average drinking was associated with sickness absence among women whereas among men former problem drinking increased sickness absence. According to the PAF values, problem drinking had a stronger contribution to sickness absence than weekly average drinking. Alcohol drinking is particularly associated with self-certified sickness absence. Reducing adverse drinking habits is likely to prevent sickness absence. © 2015 the Nordic Societies of Public Health.

Nerve Decompression and Restless Legs Syndrome: A Retrospective Analysis

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James C. Anderson

2017-07-01

Full Text Available IntroductionRestless legs syndrome (RLS is a prevalent sleep disorder affecting quality of life and is often comorbid with other neurological diseases, including peripheral neuropathy. The mechanisms related to RLS symptoms remain unclear, and treatment options are often aimed at symptom relief rather than etiology. RLS may present in distinct phenotypes often described as “primary” vs. “secondary” RLS. Secondary RLS is often associated with peripheral neuropathy. Nerve decompression surgery of the common and superficial fibular nerves is used to treat peripheral neuropathy. Anecdotally, surgeons sometimes report improved RLS symptoms following nerve decompression for peripheral neuropathy. The purpose of this retrospective analysis was to quantify the change in symptoms commonly associated with RLS using visual analog scales (VAS.MethodsForty-two patients completed VAS scales (0–10 for pain, burning, numbness, tingling, weakness, balance, tightness, aching, pulling, cramping, twitchy/jumpy, uneasy, creepy/crawly, and throbbing, both before and 15 weeks after surgical decompression.ResultsSubjects reported significant improvement among all VAS categories, except for “pulling” (P = 0.14. The change in VAS following surgery was negatively correlated with the pre-surgery VAS for both the summed VAS (r = −0.58, P < 0.001 and the individual VAS scores (all P < 0.01, such that patients who reported the worst symptoms before surgery exhibited relatively greater reductions in symptoms after surgery.ConclusionThis is the first study to suggest improvement in RLS symptoms following surgical decompression of the common and superficial fibular nerves. Further investigation is needed to quantify improvement using RLS-specific metrics and sleep quality assessments.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma

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Javier Flores-Preciado

2016-11-01

Full Text Available Case Report: We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Discussion: Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity.

Needle Decompression of Tension Pneumothorax Tactical Combat Casualty Care Guideline Recommendations

Science.gov (United States)

2012-07-06

suspected torso trauma , consider a tension pneumothorax and decompress the chest on the side of the injury with a 14-gauge, 3.25 inch (8cm) needle...and known or suspected torso trauma , consider a tension pneumothorax and decompress the chest on the side of the injury with a 14-gauge, 3.25 inch...these studies used civilian volunteers, retrospective trauma database analysis and cadavers to measure the mean chest wall thickness. This population

Sagittal imbalance in patients with lumbar spinal stenosis and outcomes after simple decompression surgery.

Science.gov (United States)

Shin, E Kyung; Kim, Chi Heon; Chung, Chun Kee; Choi, Yunhee; Yim, Dahae; Jung, Whei; Park, Sung Bae; Moon, Jung Hyeon; Heo, Won; Kim, Sung-Mi

2017-02-01

Lumbar spinal stenosis (LSS) is the most common lumbar degenerative disease, and sagittal imbalance is uncommon. Forward-bending posture, which is primarily caused by buckling of the ligamentum flavum, may be improved via simple decompression surgery. The objectives of this study were to identify the risk factors for sagittal imbalance and to describe the outcomes of simple decompression surgery. This is a retrospective nested case-control study PATIENT SAMPLE: This was a retrospective study that included 83 consecutive patients (M:F=46:37; mean age, 68.5±7.7 years) who underwent decompression surgery and a minimum of 12 months of follow-up. The primary end point was normalization of sagittal imbalance after decompression surgery. Sagittal imbalance was defined as a C7 sagittal vertical axis (SVA) ≥40 mm on a 36-inch-long lateral whole spine radiograph. Logistic regression analysis was used to identify the risk factors for sagittal imbalance. Bilateral decompression was performed via a unilateral approach with a tubular retractor. The SVA was measured on serial radiographs performed 1, 3, 6, and 12 months postoperatively. The prognostic factors for sagittal balance recovery were determined based on various clinical and radiological parameters. Sagittal imbalance was observed in 54% (45/83) of patients, and its risk factors were old age and a large mismatch between pelvic incidence and lumbar lordosis. The 1-year normalization rate was 73% after decompression surgery, and the median time to normalization was 1 to 3 months. Patients who did not experience SVA normalization exhibited low thoracic kyphosis (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.02-1.10) (pimbalance was observed in more than 50% of LSS patients, but this imbalance was correctable via simple decompression surgery in 70% of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

[Microvascular decompression for hemifacial spasm. Ten years of experience].

Science.gov (United States)

Revuelta-Gutiérrez, Rogelio; Vales-Hidalgo, Lourdes Olivia; Arvizu-Saldaña, Emiliano; Hinojosa-González, Ramón; Reyes-Moreno, Ignacio

2003-01-01

Hemifacial spasm characterized by involuntary paroxistic contractions of the face is more frequent on left side and in females. Evolution is progressive and in a few cases may disappear. Management includes medical treatment, botulinum toxin, and microvascular decompression of the nerve. We present the results of 116 microvascular decompressions performed in 88 patients over 10 years. All patients had previous medical treatment. All patients were operated on with microsurgical technique by asterional craniotomy. Vascular compression was present in all cases with one exception. Follow-up was from 1 month to 133 months. Were achieved excellent results in 70.45% of cases after first operation, good results in 9.09%, and poor results in 20.45% of patients. Long-term results were excellent in 81.82%, good in 6.82%, and poor in 11.36% of patients. Hypoacusia and transitory facial palsy were the main complications. Hemifacial spasm is a painless but disabling entity. Medical treatment is effective in a limited fashion. Injection of botulinum toxin has good response but benefit is transitory. Microvascular decompression is treatment of choice because it is minimally invasive, not destructive, requires minimum technical support, and yields best long-term results.

Physiological aspects of altitude training and the use of altitude simulators

OpenAIRE

Ranković Goran; Radovanović Dragan

2005-01-01

Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training thr...

Prediction of sickness absenteeism, disability pension and sickness presenteeism among employees with back pain.

Science.gov (United States)

Bergström, Gunnar; Hagberg, Jan; Busch, Hillevi; Jensen, Irene; Björklund, Christina

2014-06-01

The primary aim of this study was to evaluate the predictive ability of the Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) concerning long-term sick leave, sickness presenteeism and disability pension during a follow-up period of 2 years. The study group consisted of 195 employees visiting the occupational health service (OHS) due to back pain. Using receiver operating characteristic (ROC) curves, the area under the curve (AUC) varied from 0.67 to 0.93, which was from less accurate for sickness presenteeism to highly accurate for the prediction of disability pension. For registered sick leave during 6 months following the baseline the AUC from the ROC analyses was moderately accurate (0.81) and a cut off score of 90 rendered a high sensitivity of 0.89 but a low specificity of 0.46 whereas a cut off score of 105 improves the specificity substantially but at the cost of some sensitivity. The predictive ability appears to decrease with time. Several workplace factors beyond those included in the ÖMPSQ were considered but only social support at the workplace was significantly related to future long-term sick leave besides the total score of the ÖMPSQ. The results of this study extend and confirm the findings of earlier research on the ÖMPSQ. Assessment of psychosocial risk factors among employees seeking help for back pain at the OHS could be helpful in the prevention of work disabling problems.

Evaluation on therapeutic effect of de-compressive craniectomies for patients with diffuse brain swelling

International Nuclear Information System (INIS)

Xiao Sanchao; Zhang Changrong; Zuo Yi; Zhou Xiaowei; Li Jian

2000-01-01

Objective: To evaluate the therapeutic effect of de-compressive craniectomies in acute traumatic patients with diffuse brain swelling. Methods: 23 patients with acute posttraumatic diffuse brain swelling admitted and confirmed by X-CT were randomly treated by surgical de-compressive craniectomies (operative group). Their treated results were compared with those of another 11 patients treated conservatively (non-operative group) at the same period. Results: The mortality rate was similar in both operative and nonoperative groups. Conclusion: The de-compressive craniectomy operation has no value and not valid for treatment of acute posttraumatic diffuse brain swelling

A Historical View of Motion Sickness-A Plague at Sea and on Land, Also with Military Impact.

Science.gov (United States)

Huppert, Doreen; Benson, Judy; Brandt, Thomas

2017-01-01

Seasickness and its triggers, symptoms, and preventive measures were well known in antiquity. This chapter is based on an analysis of descriptions of motion sickness, in particular seasickness, in ancient Greek, Roman, and Chinese literature. A systematic search was made from the Greek period beginning with Homer in 800 BC to the late Roman period and ending with Aetios Amidenos in 600 AD, as well as in the Chinese medical classics dating from around 300 AD. Major aspects are the following: body movements caused by waves were identified in all cultures as the critical stimuli. The ancient Greeks and Romans knew that other illnesses and the mental state could precipitate seasickness and that experienced sailors were highly resistant to it (habituation). The Chinese observed that children were particularly susceptible to motion sickness; they first described the type of motion sickness induced by traveling in carts (cart-sickness) or being transported on a litter or in a sedan chair (litter-sickness). The western classics recommended therapeutic measures like fasting or specific diets, pleasant fragrancies, medicinal plants like white hellebore (containing various alkaloids), or a mixture of wine and wormwood. The East knew more unusual measures, such as drinking the urine of young boys, swallowing white sand-syrup, collecting water drops from a bamboo stick, or hiding earth from the kitchen hearth under the hair. The Greek view of the pathophysiology of seasickness was based on the humoral theory of Empedokles and Aristoteles and differed from the Chinese medicine of correspondences, which attributed malfunctions to certain body substances and the life force Qi. Many sources emphasized the impact of seasickness on military actions and famous naval battles such as the Battle of the Red Cliff, which marked the end of the Han dynasty in China, or the defeat of the Spanish Armada by the English in 1588. A peculiar form of motion sickness is associated with Napoleon

Job satisfaction and sickness absence: a questionnaire survey.

Science.gov (United States)

Roelen, Corné A M; Koopmans, Petra C; Notenbomer, Annette; Groothoff, Johan W

2008-12-01

When dissatisfaction with work precedes sickness absence, screening for satisfaction levels might usefully detect workers at risk of sickness absence. To investigate whether job satisfaction was associated with subsequent sickness absence days or episodes. A sample of workers was randomly drawn from a population of employees who had an episode of absence between January and April 2003. Job satisfaction was measured using a validated single question with a Likert-type scale ranging from 1 (very dissatisfied) to 7 (very satisfied). Job satisfaction levels were linked to the number of recorded sickness absence days and episodes in 2003, distinguishing between short (1-7 days) episodes and long (>7 days) episodes. Of 898 questionnaires distributed, 518 (58%) were returned. The mean+/-standard deviation job satisfaction level was 5.1+/-1.4 and negatively related to the number of sickness absence days. Job satisfaction was also negatively related to the number of short episodes and long episodes of absence, but these associations were not significant. Job satisfaction was significantly related to total sickness absence duration. The association with the number of sickness absence episodes was weak and just below the level of statistical significance. Assessing work satisfaction levels might usefully identify those workers most likely to have the greatest sickness absence duration.

General Automatic Components of Motion Sickness

Science.gov (United States)

Suter, S.; Toscano, W. B.; Kamiya, J.; Naifeh, K.

1985-01-01

A body of investigations performed in support of experiments aboard the space shuttle, and designed to counteract the symptoms of Space Adaptation Syndrome, which resemble those of motion sickness on Earth is reviewed. For these supporting studies, the automatic manifestations of earth-based motion sickness was examined. Heart rate, respiration rate, finger pulse volume and basal skin resistance were measured on 127 men and women before, during and after exposure to nauseogenic rotating chair tests. Significant changes in all autonomic responses were observed across the tests. Significant differences in autonomic responses among groups divided according to motion sickness susceptibility were also observed. Results suggest that the examination of autonomic responses as an objective indicator of motion sickness malaise is warranted and may contribute to the overall understanding of the syndrome on Earth and in Space.

Motion in images is essential to cause motion sickness symptoms, but not to increase postural sway

NARCIS (Netherlands)

Lubeck, A.J.A.; Bos, J.E.; Stins, J.F.

2015-01-01

Abstract Objective It is generally assumed that motion in motion images is responsible for increased postural sway as well as for visually induced motion sickness (VIMS). However, this has not yet been tested. To that end, we studied postural sway and VIMS induced by motion and still images. Method

Spontaneous extracranial decompression of epidural hematoma

International Nuclear Information System (INIS)

Neely, John C.; Jones, Blaise V.; Crone, Kerry R.

2008-01-01

Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

Spontaneous extracranial decompression of epidural hematoma

Energy Technology Data Exchange (ETDEWEB)

Neely, John C. [Marshall University School of Medicine, Huntington, WV (United States); Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Crone, Kerry R. [Cincinnati Children' s Hospital Medical Center, Division of Neurosurgery, Cincinnati, OH (United States)

2008-03-15

Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma. (orig.)

Altitude training induced alterations in erythrocyte rheological properties: a controlled comparison study in rats.

Science.gov (United States)

Bor-Kucukatay, Melek; Colak, Ridvan; Erken, Gülten; Kilic-Toprak, Emine; Kucukatay, Vural

2014-01-01

Altitude training is frequently used by athletes to improve sea-level performance. However, the objective benefits of altitude training are controversial. This study aimed to investigate the possible alterations in hemorheological parameters in response to altitude training. Sprague Dawley rats, were divided into 6 groups: live low-train low (LLTL), live high-train high (LHTH), live high-train low (LHTL) and their controls live high and low (LHALC), live high (LHC), live low (LLC). LHC and LHTH groups were exposed to hypoxia (15% O2, altitudes of 3000 m), 4 weeks. LHALC and LHTL were exposed to 12 hours hypoxia/normoxia per day, 4 weeks. Hypoxia was maintained by a hypoxic tent. The training protocol corresponded to 60-70% of maximal exercise capacity. Rats of training groups ran on treadmill for 20-30 min/day, 4 days/week, 4 weeks. Erythrocyte deformability of LHC group was increased compared to LHALC and LLC. Deformability of LHTH group was higher than LHALC and LLTL groups. No statistically significant alteration in erythrocyte aggregation parameters was observed. There were no significant relationships between RBC deformability and exercise performance. The results of this study show that, living (LHC) and training at altitude (LHTH) seems more advantageous in hemorheological point of view.

System for analysing sickness absenteeism in Poland.

Science.gov (United States)

Indulski, J A; Szubert, Z

1997-01-01

The National System of Sickness Absenteeism Statistics has been functioning in Poland since 1977, as the part of the national health statistics. The system is based on a 15-percent random sample of copies of certificates of temporary incapacity for work issued by all health care units and authorised private medical practitioners. A certificate of temporary incapacity for work is received by every insured employee who is compelled to stop working due to sickness, accident, or due to the necessity to care for a sick member of his/her family. The certificate is required on the first day of sickness. Analyses of disease- and accident-related sickness absenteeism carried out each year in Poland within the statistical system lead to the main conclusions: 1. Diseases of the musculoskeletal and peripheral nervous systems accounting, when combined, for 1/3 of the total sickness absenteeism, are a major health problem of the working population in Poland. During the past five years, incapacity for work caused by these diseases in males increased 2.5 times. 2. Circulatory diseases, and arterial hypertension and ischaemic heart disease in particular (41% and 27% of sickness days, respectively), create an essential health problem among males at productive age, especially, in the 40 and older age group. Absenteeism due to these diseases has increased in males more than two times.

Driving simulator sickness: Impact on driving performance, influence of blood alcohol concentration, and effect of repeated simulator exposures.

Science.gov (United States)

Helland, Arne; Lydersen, Stian; Lervåg, Lone-Eirin; Jenssen, Gunnar D; Mørland, Jørg; Slørdal, Lars

2016-09-01

Simulator sickness is a major obstacle to the use of driving simulators for research, training and driver assessment purposes. The purpose of the present study was to investigate the possible influence of simulator sickness on driving performance measures such as standard deviation of lateral position (SDLP), and the effect of alcohol or repeated simulator exposure on the degree of simulator sickness. Twenty healthy male volunteers underwent three simulated driving trials of 1h's duration with a curvy rural road scenario, and rated their degree of simulator sickness after each trial. Subjects drove sober and with blood alcohol concentrations (BAC) of approx. 0.5g/L and 0.9g/L in a randomized order. Simulator sickness score (SSS) did not influence the primary outcome measure SDLP. Higher SSS significantly predicted lower average speed and frequency of steering wheel reversals. These effects seemed to be mitigated by alcohol. Higher BAC significantly predicted lower SSS, suggesting that alcohol inebriation alleviates simulator sickness. The negative relation between the number of previous exposures to the simulator and SSS was not statistically significant, but is consistent with habituation to the sickness-inducing effects, as shown in other studies. Overall, the results suggest no influence of simulator sickness on SDLP or several other driving performance measures. However, simulator sickness seems to cause test subjects to drive more carefully, with lower average speed and fewer steering wheel reversals, hampering the interpretation of these outcomes as measures of driving impairment and safety. BAC and repeated simulator exposures may act as confounding variables by influencing the degree of simulator sickness in experimental studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Serum sickness

Science.gov (United States)

... the problem should be stopped. Avoid using that medicine or antiserum in the future. ... Call your provider if you received medicine or antiserum in the last 4 weeks and have symptoms of serum sickness.

Decompressive craniectomy following brain injury: factors important ...

African Journals Online (AJOL)

2010-01-07

Jan 7, 2010 ... Background: Decompressive craniectomy (DC) is often performed as an empirical lifesaving measure to protect the injured brain from the damaging effects of propagating oedema and intracranial hypertension. However, there are no clearly defined indications or specified guidelines for patient selection for ...

Surgical outcome after decompressive craniectomy in patients with extensive cerebral infarction

International Nuclear Information System (INIS)

Otani, Naoki; Takasato, Yoshio; Masaoka, Hiroyuki

2008-01-01

Extensive cerebral hemispheric infarction is a devastating condition leading to early death in nearly 80% of cases due to the rapid rise of intracranial pressure in spite of maximum medical treatment for brain edema and swelling. Recently, decompressive craniectomy has been reevaluated to prevent the brain herniation caused by extensive hemispheric cerebral infarction. We studied the surgical results after decompressive craniectomy for extensive cerebral infarction. Between December 1997 and August 2006, 13 consecutive patients (7 males and 6 females aged from 39 to 73 with a mean age of 59 years) with massive cerebral infarction of internal carotid (IC) (11 patients) and middle cerebral artery (MCA) (2 patients) territory were treated with decompressive craniectomy and dural plasty. Five patients had a left-sided stroke with severe aphasia. The cardioembolic source of stroke was seen in 5 patients. Surgery was performed at the point of neurological deterioration, anisocoria, and effacement of perimesencephalic cistern on CT findings. The mean time between stroke onset and surgery was 39.8 hr and ranged from 13 to 102 hr. Glasgow outcome scale (GOS) on discharge was moderately disabled (MD) 1, severe disabled (SD) 5, vegetative state (VS) 1, and dead (D) 3 (mortality rate 30.8%). Severe pneumoniae were the causes of death. All survivors underwent cranioplasty and were transferred with the aim of rehabilitation. In this study, we showed that the decompressive craniectomy reduced mortality after extensive cerebral infarction. However, the functional outcome and level of independence are poor. It seems that the early decompressive craniectomy should be aggressively performed for extensive cerebral infarction before neurological deterioration such as worsening of consciousness disturbance or pupil abnormalities. Further investigations will be needed to clarify the surgical indications, timing, and functional outcomes. (author)

Sickness absence: a systematic review and meta-analysis of psychological treatments for individuals on sick leave due to common mental disorders.

Science.gov (United States)

Salomonsson, Sigrid; Hedman-Lagerlöf, Erik; Öst, Lars-Göran

2018-01-30

Sick leave due to common mental disorders (CMDs) increase rapidly and present a major societal challenge. The overall effect of psychological interventions to reduce sick leave and symptoms has not been sufficiently investigated and there is a need for a systematic review and meta-analysis of the field. The aim of the present meta-analysis was to calculate the effect size of psychological interventions for CMDs on sick leave and psychiatric symptoms based on all published randomized controlled trials. Methodological quality, the risk of bias and publication bias were also assessed. The literature searches gave 2240 hits and 45 studies were included. The psychological interventions were more effective than care as usual on both reduced sick leave (g = 0.15) and symptoms (g = 0.21). There was no significant difference in effect between work focused interventions, problem-solving therapy, cognitive behavioural therapy or collaborative care. We conclude that psychological interventions are more effective than care as usual to reduce sick leave and symptoms but the effect sizes are small. More research is needed on psychological interventions that evaluate effects on sick leave. Consensual measures of sick leave should be established and quality of psychotherapy for patients on sick leave should be improved.

Dietary broccoli mildly improves neuroinflammation in aged mice but does not reduce lipopolysaccharide-induced sickness behavior.

Science.gov (United States)

Townsend, Brigitte E; Chen, Yung-Ju; Jeffery, Elizabeth H; Johnson, Rodney W

2014-11-01

Aging is associated with oxidative stress and heightened inflammatory response to infection. Dietary interventions to reduce these changes are therefore desirable. Broccoli contains glucoraphanin, which is converted to sulforaphane (SFN) by plant myrosinase during cooking preparation or digestion. Sulforaphane increases antioxidant enzymes including NAD(P)H quinone oxidoreductase and heme oxygenase I and inhibits inflammatory cytokines. We hypothesized that dietary broccoli would support an antioxidant response in brain and periphery of aged mice and inhibit lipopolysaccharide (LPS)-induced inflammation and sickness. Young adult and aged mice were fed control or 10% broccoli diet for 28 days before an intraperitoneal LPS injection. Social interactions were assessed 2, 4, 8, and 24 hours after LPS, and mRNA was quantified in liver and brain at 24 hours. Dietary broccoli did not ameliorate LPS-induced decrease in social interactions in young or aged mice. Interleukin-1β (IL-1β) expression was unaffected by broccoli consumption but was induced by LPS in brain and liver of adult and aged mice. In addition, IL-1β was elevated in brain of aged mice without LPS. Broccoli consumption decreased age-elevated cytochrome b-245 β, an oxidative stress marker, and reduced glial activation markers in aged mice. Collectively, these data suggest that 10% broccoli diet provides a modest reduction in age-related oxidative stress and glial reactivity, but is insufficient to inhibit LPS-induced inflammation. Thus, it is likely that SFN would need to be provided in supplement form to control the inflammatory response to LPS. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and sickness behavior

OpenAIRE

Morris, Gerwyn; Anderson, George; Galecki, Piotr; Berk, Michael; Maes, Michael

2013-01-01

It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation. There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gas...

Behavioral methods of alleviating motion sickness: effectiveness of controlled breathing and a music audiotape.

Science.gov (United States)

Yen Pik Sang, Fleur D; Billar, Jessica P; Golding, John F; Gresty, Michael A

2003-01-01

Behavioral countermeasures for motion sickness would be advantageous because of the side effects of antiemetic drugs, but few alternative treatments are available. The objective of this study was to compare the effectiveness of controlling breathing and listening to a music audiotape designed to reduce motion sickness symptoms, on increasing tolerance to motion-induced nausea. Twenty-four healthy subjects were exposed to nauseogenic Coriolis stimulation on a rotating turntable under three conditions: whilst focusing on controlling breathing; listening to a music audiotape; or without intervention (control). The three conditions were performed by each subject according to a replicated factorial design at 1-week intervals at the same time of day. Ratings of motion sickness were obtained every 30 seconds. Once a level of mild nausea was reached subjects commenced controlling breathing or listened to the music audiotape. Motion was stopped after the onset of moderate nausea. Mean (+/- SD) motion exposure time in minutes tolerated before the onset of moderate nausea was significantly longer (p music (10.4 +/- 5.6 min) compared with control (9.2 +/- 5.9 min). Both controlling breathing and the music audiotape provided significant protection against motion sickness and with similar effectiveness. These nonpharmacologic countermeasures are only half as effective as standard doses of anti-motion sickness drugs, such as oral scopolamine; however, they are easy to implement and free of side effects.

[Pharmacological prophylaxis of vestibulo-autonomous syndrome (motion sickness) in model investigations].

Science.gov (United States)

Shashkov, V S; Iasnetsov, V V; Shashkov, A V; Il'ina, S L; Galle, R R; Sabaev, V V; Potapov, M G

2000-01-01

The authors summarize results of multiyear investigations at the Institute of Biomedical Problems of induced motion sickness and development of prophylactic medicaments representing various classes of biologically active substances (choline blocking agents, sympathomimetics, antihistamines etc.) prescribed singularly or in an combination based on the knowledge of MS-provoking inter-receptor interactions and therapeutic effects of drugs.

Performance changes during a weeklong high-altitude alpine ski-racing training camp in lowlander young athletes.

Science.gov (United States)

Hydren, Jay R; Kraemer, William J; Volek, Jeff S; Dunn-Lewis, Courtenay; Comstock, Brett A; Szivak, Tunde K; Hooper, David R; Denegar, Craig R; Maresh, Carl M

2013-04-01

Thousands of youth athletes travel to high altitude to participate in lift-access alpine sports. The purpose of this study was to examine the impact of acute high-altitude exposure on balance, choice reaction time, power, quickness, flexibility, strength endurance, and V[Combining Dot Above]O2max in youth lowlander athletes during a weeklong preseason training camp in Summit County, CO, USA. Eleven youth ski racers (4 boys and 7 girls; age, 13.7 ± 0.5 years; height, 157.2 ± 12.6 cm; weight, 52.4 ± 6.8 kg) with 7.7 ± 2.2 skiing years of experience participated in baseline testing at 160 m one week before the camp and a set of daily tests in the morning and afternoon at 2,828 m and skied between 3,328 and 3,802 m during a 6-day camp. Balance and choice reaction time tests were stagnant or improved slightly during the first 3 days and then improved on days 4 and 6. Vertical jump, flexibility, T-agility test, and push-ups in 1 minute improved on day 6. The number of sit-ups in 1 minute did not improve, and scores on the multistage fitness test decreased 20.34%. There was no effect of Lake Louise acute mountain sickness (AMS) questionnaire scores on performance variables measured. Athletes sojourning to high altitude for ski camps can train on immediate ascent but should slowly increase training volume over the first 3 days. Athletes should expect improvements in balance and reaction time 3-6 days into acclimatization. Coaches and athletes should expect about 20% of youth lowlander athletes to have signs and symptoms of AMS during the first 3 days of altitude exposure for alpine lift access sports at altitudes of up to 3,800 m.

[Orbital decompression in Grave's disease: comparison of techniques].

Science.gov (United States)

Sellari-Franceschini, S; Berrettini, S; Forli, F; Bartalena, L; Marcocci, C; Tanda, M L; Nardi, M; Lepri, A; Pinchera, A

1999-12-01

Grave's ophthalmopathy is an inflammatory, autoimmune disorder often associated with Grave's disease. The inflammatory infiltration involves the retrobulbar fatty tissue and the extrinsic eye muscles, causing proptosis, extraocular muscle dysfunction and often diplopia. Orbital decompression is an effective treatment in such cases, particularly when resistant to drugs and external radiation therapy. This work compares the results of orbital decompression performed by removing: a) the medial and lateral walls (Mourits technique) in 10 patients (19 orbits) and b) the medial and lower walls (Walsh-Ogura technique) in 17 patients (31 orbits). The results show that removing the floor of the orbit enables better reduction of proptosis but more easily leads to post-operative diplopia. Thus it proves necessary to combine the two techniques, modifying the surgical approach on a case-by-case basis.

[Teacher sick leave: Prevalence, duration, reasons and covariates].

Science.gov (United States)

Vercambre-Jacquot, M-N; Gilbert, F; Billaudeau, N

2018-02-01

Absences from work have considerable social and economic impact. In the education sector, the phenomenon is particularly worrying since teacher sick leave has an impact on the overall performance of the education system. Yet, available data are scarce. In April-June 2013, 2653 teachers responded to a population-based postal survey on their quality of life (enquête Qualité de vie des enseignants, MGEN Foundation/Ministry of education, response rate 53 %). Besides questions on work environment and health, teachers were asked to describe their eventual sick leave(s) since the beginning of the school year: duration, type and medical reasons. Self-reported information was reinforced by administrative data from ministerial databases and weighted to be extrapolated to all French teachers. Tobit models adjusted for individual factors of a private nature were used to investigate different occupational risk factors of teacher sick leave, taking into account both the estimated effect on the probability of sick leave and the length of it. More than one in three teachers (36 %) reported having had at least one day of sick leave since the beginning of the school year. Respiratory/ENT diseases were the leading reason for sick leave (37 %). However, and because sick leave duration depended on the underlying health problem, such diseases came in third place among justifications of sick leave days (14 %), far behind musculoskeletal problems (27 %) and neurological and psychological disorders (25 %). Tobit models suggested that some occupational factors significantly associated with the risk of sick leave may represent promising preventive targets, including high psychological demand, workplace violence and unfavorable socio-environmental context. Our study provides objective evidence about the issue of sick leave among French teachers, highlighting the usefulness of implementing actions to minimize its weight. To this end, the study findings point-out the importance of

Relative deprivation and sickness absence in Sweden.

Science.gov (United States)

Helgertz, Jonas; Hess, Wolfgang; Scott, Kirk

2013-08-29

A high prevalence of sickness absence in many countries, at a substantial societal cost, underlines the importance to understand its determining mechanisms. This study focuses on the link between relative deprivation and the probability of sickness absence. 184,000 men and women in Sweden were followed between 1982 and 2001. The sample consists of working individuals between the ages of 19 and 65. The outcome is defined as experiencing more than 14 days of sickness absence during a year. Based on the complete Swedish population, an individual's degree of relative deprivation is measured through income compared to individuals of the same age, sex, educational level and type. In accounting for the possibility that sickness absence and socioeconomic status are determined by common factors, discrete-time duration models were estimated, accounting for unobserved heterogeneity through random effects. The results confirm that the failure to account for the dynamics of the individual's career biases the influence from socioeconomic characteristics. Results consistently suggest a major influence from relative deprivation, with a consistently lower risk of sickness absence among the highly educated. Altering individual's health behavior through education appears more efficient in reducing the reliance on sickness absence, rather than redistributive policies.

Is part-time sick leave helping the unemployed?

OpenAIRE

Andrén, Daniela

2011-01-01

Using a discrete choice one-factor model, we estimate mean treatment parameters and distributional treatment parameters to analyze the effects of degree of sick leave on the probability of full recovery of lost work capacity for employed and unemployed individuals, respectively. Our results indicate that one year after the sick leave spell started, the average potential impact of part-time sick listing on an individual randomly chosen from the population on sick leave was positive for both gr...

Age as a risk factor for acute mountain sickness upon rapid ascent to 3,700 m among young adult Chinese men.

Science.gov (United States)

Tang, Xu-Gang; Zhang, Ji-hang; Qin, Jun; Gao, Xu-bin; Li, Qian-ning; Yu, Jie; Ding, Xiao-han; Huang, Lan

2014-01-01

The aim of this study was to explore the relationship between age and acute mountain sickness (AMS) when subjects are exposed suddenly to high altitude. A total of 856 young adult men were recruited. Before and after acute altitude exposure, the Athens Insomnia Scale score (AISS) was used to evaluate the subjective sleep quality of subjects. AMS was assessed using the Lake Louise scoring system. Heart rate (HR) and arterial oxygen saturation (SaO2) were measured. Results showed that, at 500 m, AISS and insomnia prevalence were higher in older individuals. After acute exposure to altitude, the HR, AISS, and insomnia prevalence increased sharply, and the increase in older individuals was more marked. The opposite trend was observed for SaO2. At 3,700 m, the prevalence of AMS increased with age, as did severe AMS, and AMS symptoms (except gastrointestinal symptoms). Multivariate logistic regression analysis showed that age was a risk factor for AMS (adjusted odds ratio [OR] 1.07, 95% confidence interval [CI] 1.01-1.13, Psleep quality may be a contributor to increased AMS prevalence in older subjects.

"White Cord Syndrome" of Acute Hemiparesis After Posterior Cervical Decompression and Fusion for Chronic Cervical Stenosis.

Science.gov (United States)

Antwi, Prince; Grant, Ryan; Kuzmik, Gregory; Abbed, Khalid

2018-05-01

"White cord syndrome" is a very rare condition thought to be due to acute reperfusion of chronically ischemic areas of the spinal cord. Its hallmark is the presence of intramedullary hyperintense signal on T2-weighted magnetic resonance imaging sequences in a patient with unexplained neurologic deficits following spinal cord decompression surgery. The syndrome is rare and has been reported previously in 2 patients following anterior cervical decompression and fusion. We report an additional case of this complication. A 68-year-old man developed acute left-sided hemiparesis after posterior cervical decompression and fusion for cervical spondylotic myelopathy. The patient improved with high-dose steroid therapy. The rare white cord syndrome following either anterior cervical decompression and fusion or posterior cervical decompression and fusion may be due to ischemic-reperfusion injury sustained by chronically compressed parts of the spinal cord. In previous reports, patients have improved following steroid therapy and acute rehabilitation. Copyright © 2018 Elsevier Inc. All rights reserved.

[Vestibular testing abnormalities in individuals with motion sickness].

Science.gov (United States)

Ma, Yan; Ou, Yongkang; Chen, Ling; Zheng, Yiqing

2009-08-01

To evaluate the vestibular function of motion sickness. VNG, which tests the vestibular function of horizontal semicircular canal, and CPT, which tests vestibulospinal reflex and judge proprioceptive, visual and vestibular status, were performed in 30 motion sickness patients and 20 healthy volunteers (control group). Graybiel score was recorded at the same time. Two groups' Graybiel score (12.67 +/- 11.78 vs 2.10 +/- 6.23; rank test P<0.05), caloric test labyrinth value [(19.02 +/- 8.59) degrees/s vs (13.58 +/- 5.25) degrees/s; t test P<0.05], caloric test labyrinth value of three patients in motion sickness group exceeded 75 degrees/s. In computerized posturography testing (CPT), motion sickness patients were central type (66.7%) and disperse type (23.3%); all of control group were central type. There was statistical significance in two groups' CTP area, and motion sickness group was obviously higher than control group. While stimulating vestibulum in CPT, there was abnormality (35%-50%) in motion sickness group and none in control group. Generally evaluating CPT, there was only 2 proprioceptive hypofunction, 3 visual hypofunction, and no vestibular hypofunction, but none hypofunction in control group. Motion sickness patients have high vestibular susceptible, some with vestibular hyperfunction. In posturography, a large number of motion sickness patients are central type but no vestibular hypofunction, but it is hard to keep balance when stimulating vestibulum.

Motion sickness and postural sway in console video games.

Science.gov (United States)

Stoffregen, Thomas A; Faugloire, Elise; Yoshida, Ken; Flanagan, Moira B; Merhi, Omar

2008-04-01

We tested the hypotheses that (a) participants might develop motion sickness while playing "off-the-shelf" console video games and (b) postural motion would differ between sick and well participants, prior to the onset of motion sickness. There have been many anecdotal reports of motion sickness among people who play console video games (e.g., Xbox, PlayStation). Participants (40 undergraduate students) played a game continuously for up to 50 min while standing or sitting. We varied the distance to the display screen (and, consequently, the visual angle of the display). Across conditions, the incidence of motion sickness ranged from 42% to 56%; incidence did not differ across conditions. During game play, head and torso motion differed between sick and well participants prior to the onset of subjective symptoms of motion sickness. The results indicate that console video games carry a significant risk of motion sickness. Potential applications of this research include changes in the design of console video games and recommendations for how such systems should be used.

KAJIAN RISIKO CEDERA DAN MASALAH UMUM PENDAKI MAHASISWA UNIVERSITAS UDAYANA

Directory of Open Access Journals (Sweden)

Mohamad Izam Zahary

2015-04-01

Full Text Available There are many tourist activities that can be promoted in rural spaces, including the active experience of nature through outdoor sports, either challenging or, rather, calm and contemplative in nature and hiking is one of the most popular forms of enjoying an active nature experience. High‐altitude illness may be divided into the acute syndromes that affect lowland or highland residents ascending to altitudes greater than those to which they are accustomed and the chronic conditions that affect individual resident at high altitude for long periods. The acute adult syndromes of high altitude are acute mountain sickness, high‐ altitude pulmonary oedema (HAPE and high‐altitude cerebral oedema. Hypoxia is the main factor for the acute high‐altitude illnesses. The incidence and severity of acute mountain sickness, HAPE and high‐altitude cerebral oedema are related to the speed of ascent and the maximum height gained. Keywords: Hypoxia, High Altitude, High Altitude Pulmonary Edema, Sub‐acute mountain sickness

Cerebral pressure-flow relationship in lowlanders and natives at high altitude.

Science.gov (United States)

Smirl, Jonathan D; Lucas, Samuel J E; Lewis, Nia C S; duManoir, Gregory R; Dumanior, Gregory R; Smith, Kurt J; Bakker, Akke; Basnyat, Aperna S; Ainslie, Philip N

2014-02-01

We investigated if dynamic cerebral pressure-flow relationships in lowlanders are altered at high altitude (HA), differ in HA natives and after return to sea level (SL). Lowlanders were tested at SL (n=16), arrival to 5,050 m, after 2-week acclimatization (with and without end-tidal PO2 normalization), and upon SL return. High-altitude natives (n=16) were tested at 5,050 m. Testing sessions involved resting spontaneous and driven (squat-stand maneuvers at very low (VLF, 0.05 Hz) and low (LF, 0.10 Hz) frequencies) measures to maximize blood pressure (BP) variability and improve assessment of the pressure-flow relationship using transfer function analysis (TFA). Blood flow velocity was assessed in the middle (MCAv) and posterior (PCAv) cerebral arteries. Spontaneous VLF and LF phases were reduced and coherence was elevated with acclimatization to HA (Pflow coupling. However, when BP was driven, both the frequency- and time-domain metrics were unaltered and comparable with HA natives. Acute mountain sickness was unrelated to TFA metrics. In conclusion, the driven cerebral pressure-flow relationship (in both frequency and time domains) is unaltered at 5,050 m in lowlanders and HA natives. Our findings indicate that spontaneous changes in TFA metrics do not necessarily reflect physiologically important alterations in the capacity of the brain to regulate BP.

The Proceedings of the Hypobaric Decompression Sickness Workshop Held in Armstrong Laboratory, Brooks AFB, Texas on 16-18 October 1990.

Science.gov (United States)

1992-06-01

absence of Air in the Bloud iuyces. and soft parts of the Body. may by their Vast number. and their conspiring distension , variously streighten in...and vitiating the figure of others. disturb or hinder the due circulation of the Bloud? Not to mention the pains that such distensions may cause in...Effects of Altitude on Aviators. Aviation, 2, 145-147 (1917). 10. Barcroft, J.; C.G. Douglas; L.P. Kendall and R. Margaria. Muscular Exercise at Low

Superior vena caval obstruction - decompression with chemotherapy and subsequent irradiation

International Nuclear Information System (INIS)

Kolaric, K.; Maricic, Z.; Dujmovic, I.; Mrsic, Z.

1975-01-01

The clinical picture, pathogenesis and etiology of malignant vena caval obstruction are described. The importance of using modern methods to treat this critical condition is emphasized. Furthermore, the authors examine the principles of chemotherapeutic decompression followed by irradiation. A single dose of nitrogen mustard was applied intravenously, followed by irradiation, on 24 patients with malignant vena caval obstruction. The results of this treatment are presented. The effect of this treatment was controlled by measuring the venous blood pressure and with chest X-rays. The authors conclude, that this method of decompression is successful in the palliative treatment of this syndrom. (orig.) [de

Peripheral blood lymphocytes: a model for monitoring physiological adaptation to high altitude.

Science.gov (United States)

Mariggiò, Maria A; Falone, Stefano; Morabito, Caterina; Guarnieri, Simone; Mirabilio, Alessandro; Pilla, Raffaele; Bucciarelli, Tonino; Verratti, Vittore; Amicarelli, Fernanda

2010-01-01

Depending on the absolute altitude and the duration of exposure, a high altitude environment induces various cellular effects that are strictly related to changes in oxidative balance. In this study, we used in vitro isolated peripheral blood lymphocytes as biosensors to test the effect of hypobaric hypoxia on seven climbers by measuring the functional activity of these cells. Our data revealed that a 21-day exposure to high altitude (5000 m) (1) increased intracellular Ca(2+) concentration, (2) caused a significant decrease in mitochondrial membrane potential, and (3) despite possible transient increases in intracellular levels of reactive oxygen species, did not significantly change the antioxidant and/or oxidative damage-related status in lymphocytes and serum, assessed by measuring Trolox-equivalent antioxidant capacity, glutathione peroxidase activity, vitamin levels, and oxidatively modified proteins and lipids. Overall, these results suggest that high altitude might cause an impairment in adaptive antioxidant responses. This, in turn, could increase the risk of oxidative-stress-induced cellular damage. In addition, this study corroborates the use of peripheral blood lymphocytes as an easily handled model for monitoring adaptive response to environmental challenge.

Farris-Tang retractor in optic nerve sheath decompression surgery.

Science.gov (United States)

Spiegel, Jennifer A; Sokol, Jason A; Whittaker, Thomas J; Bernard, Benjamin; Farris, Bradley K

2016-01-01

Our purpose is to introduce the use of the Farris-Tang retractor in optic nerve sheath decompression surgery. The procedure of optic nerve sheath fenestration was reviewed at our tertiary care teaching hospital, including the use of the Farris-Tang retractor. Pseudotumor cerebri is a syndrome of increased intracranial pressure without a clear cause. Surgical treatment can be effective in cases in which medical therapy has failed and disc swelling with visual field loss progresses. Optic nerve sheath decompression surgery (ONDS) involves cutting slits or windows in the optic nerve sheath to allow cerebrospinal fluid to escape, reducing the pressure around the optic nerve. We introduce the Farris-Tang retractor, a retractor that allows for excellent visualization of the optic nerve sheath during this surgery, facilitating the fenestration of the sheath and visualization of the subsequent cerebrospinal fluid egress. Utilizing a medial conjunctival approach, the Farris-Tang retractor allows for easy retraction of the medial orbital tissue and reduces the incidence of orbital fat protrusion through Tenon's capsule. The Farris-Tang retractor allows safe, easy, and effective access to the optic nerve with good visualization in optic nerve sheath decompression surgery. This, in turn, allows for greater surgical efficiency and positive patient outcomes.

A study on models of the inhomogeneity of the decompression in a bubble chamber

International Nuclear Information System (INIS)

Badier, J.

1961-01-01

Before building a hydrogen bubble chamber with liquid decompression the 'Saturne' cyclotron department wished to study for this chamber a shape leading to a homogeneous decompression as far as possible, without the production of vortices even after prolonged operation. The 'Office National d'Etudes et de Recherches Aeronautiques' (ONERA) were ready to carry out experiments on a model by strioscopy. The model was filled with air but an attempt was made to simulate the actual conditions as far as possible by varying the speed of the piston. The model was placed at one end of a tunnel, at the other end of which were produced alternatively compression and decompression waves. The study made it possible to conclude that it was necessary to make the base of the chamber round and that, in the space between the decompression cylinder and the body of the chamber it was advantageous to use 5 fins instead of 3. (author) [fr

Physiotherapy after subacromial decompression surgery

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Falla, Deborah; Frost, Poul

2015-01-01

This paper describes the development and details of a standardised physiotherapy exercise intervention designed to address pain and disability in patients with difficulty returning to usual activities after arthroscopic decompression surgery for subacromial impingement syndrome. To develop...... the intervention, the literature was reviewed with respect to the effectiveness of postoperative exercises, components of previous exercise programmes were extracted, and input from clinical physiotherapists in the field was obtained through a series of workshops. The physiotherapy exercise intervention...

Long-Term Intermittent Work at High Altitude: Right Heart Functional and Morphological Status and Associated Cardiometabolic Factors.

Science.gov (United States)

Brito, Julio; Siques, Patricia; López, Rosario; Romero, Raul; León-Velarde, Fabiola; Flores, Karen; Lüneburg, Nicole; Hannemann, Juliane; Böger, Rainer H

2018-01-01

Background: Living at high altitude or with chronic hypoxia implies functional and morphological changes in the right ventricle and pulmonary vasculature with a 10% prevalence of high-altitude pulmonary hypertension (HAPH). The implications of working intermittently (day shifts) at high altitude (hypobaric hypoxia) over the long term are still not well-defined. The aim of this study was to evaluate the right cardiac circuit status along with potentially contributory metabolic variables and distinctive responses after long exposure to the latter condition. Methods: A cross-sectional study of 120 healthy miners working at an altitude of 4,400-4,800 m for over 5 years in 7-day commuting shifts was designed. Echocardiography was performed on day 2 at sea level. Additionally, biomedical and biochemical variables, Lake Louise scores (LLSs), sleep disturbances and physiological variables were measured at altitude and at sea level. Results: The population was 41.8 ± 0.7 years old, with an average of 14 ± 0.5 (range 5-29) years spent at altitude. Most subjects still suffered from mild to moderate symptoms of acute mountain sickness (mild was an LLS of 3-5 points, including cephalea; moderate was LLS of 6-10 points) (38.3%) at the end of day 1 of the shift. Echocardiography showed a 23% mean pulmonary artery pressure (mPAP) >25 mmHg, 9% HAPH (≥30 mmHg), 85% mild increase in right ventricle wall thickness (≥5 mm), 64% mild right ventricle dilation, low pulmonary vascular resistance (PVR) and fairly good ventricle performance. Asymmetric dimethylarginine (ADMA) (OR 8.84 (1.18-66.39); p Working intermittently at high altitude involves a distinctive pattern. The most relevant and novel characteristics are a greater prevalence of elevated mPAP and HAPH than previously reported at chronic intermittent hypobaric hypoxia (CIHH), which is accompanied by subsequent morphological characteristics. These findings are associated with cardiometabolic factors (insulin and ADMA

Measures of work-family conflict predict sickness absence from work.

Science.gov (United States)

Clays, Els; Kittel, France; Godin, Isabelle; Bacquer, Dirk De; Backer, Guy De

2009-08-01

To examine the relation between work-family conflict and sickness absence. The BELSTRESS III study comprised 2983 middle-aged workers. Strain-based work-home interference (WHI) and home-work interference (HWI) were assessed by means of self-administered questionnaires. Prospective data of registered sickness absence during 12-months follow-up were collected. Multiple logistic regression analysis was conducted. HWI was positively and significantly related to high sickness absence duration (at least 10 sick leave days) and high sickness absence frequency (at least 3 sick leave episodes) in men and women, also after adjustments were made for sociodemographic variables, health indicators, and environmental psychosocial factors. In multivariate analysis, no association between WHI and sickness absence was found. HWI was positively and significantly related to high sickness absence duration and frequency during 12-months follow-up in male and female workers.

Does decompression of odontogenic cysts and cystlike lesions change the histologic diagnosis?

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Schlieve, Thomas; Miloro, Michael; Kolokythas, Antonia

2014-06-01

The purpose of this study was to report the histopathologic findings after postdecompression definitive treatment of odontogenic cystlike lesions and determine whether the diagnosis was consistent with the pretreatment diagnosis, thereby answering the clinical question: does decompression change the histologic diagnosis? The authors implemented a retrospective cohort study from a sample of patients diagnosed with a benign odontogenic cystlike lesion and who underwent decompression followed by definitive surgery as part of their treatment. The predictor variable was treatment by decompression and the dependent variable was change in histologic diagnosis. Age, gender, and lesion location were included as variables. The χ(2) test was used for statistical analysis of the categorical data and P values less than .05 were considered statistically significant. Twenty-five cysts and cystlike lesions in 25 patients were treated with decompression followed by enucleation and curettage. The mean age was 34 years (range, 13 to 80 yr) and 56% (14) were male patients. Lesions were located in the mandible in 76% (19 of 25) of patients. Postdecompression histologic examination at the time of definitive surgical treatment was consistent with the preoperative biopsy diagnosis in 91% (10 of 11) of keratocystic odontogenic tumors, 67% (2 of 3) of glandular odontogenic cysts, 75% (3 of 4) of dentigerous cysts, and 100% (7 of 7) of cystic ameloblastomas. The histologic diagnosis at time of definitive treatment by enucleation and curettage is consistent with the predecompression diagnosis. Therefore, all lesions should be definitively treated after decompression based on the initial lesion diagnosis, with all patients placed on appropriate follow-up protocols. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. All rights reserved.

Do work-place initiated measures reduce sickness absence? Preventive measures and sickness absence among older workers in Norway.

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Midtsundstad, Tove I; Nielsen, Roy A

2014-03-01

The article examines whether preventive measures and work adjustments at the establishment level affects sickness absence among workers aged 50 years and older. We combine survey data from a representative sample of 713 Norwegian companies, mapping the prevalence of preventive health measures in the work place in 2005, with register data on sickness absence and demographic variables for workers aged 50 years or older in 2001 and 2007. By means of a difference-in-differences approach, we compare changes and differences in the likelihood of sickness absence among the sample group, with and without the various measures/ instruments in 2005 respectively. In general, work-place preventive measures at the establishment level have not contributed to reducing the probability for sickness absence among workers aged 50 years and older. However, analyses comparing differences between industries find that the work-place measures have had a positive effect on public administration employees. Whether work-place preventive initiatives influence levels of sickness absence seems to be contingent on sector and industry. Therefore, work-place measures may be more effective in the public administration sector where most employees have office jobs compared to sectors such as manufacturing, construction and transportation, where many employees have manual work and more physical demanding jobs. Work-place initiatives thus seem to have less effect on preventing sickness absence in sectors dominated by manual labour.

Sleeping Sickness Surveillance In The Abraka Sleeping Sickness ...

African Journals Online (AJOL)

Confirmation of sleeping sickness (ss) was by the detection of trypanosomes in blood, body fluids and biopsy tissues. Thirteen (0.8%) seropositive subjects were parasitologically confirmed and treated with melasoprol at the Baptist Medical Centre (BMC) Eku. One (0.06%) patient died during the course of treatment.

Relative Deprivation and Sickness Absence in Sweden

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Jonas Helgertz

2013-08-01

Full Text Available Background: A high prevalence of sickness absence in many countries, at a substantial societal cost, underlines the importance to understand its determining mechanisms. This study focuses on the link between relative deprivation and the probability of sickness absence. Methods: 184,000 men and women in Sweden were followed between 1982 and 2001. The sample consists of working individuals between the ages of 19 and 65. The outcome is defined as experiencing more than 14 days of sickness absence during a year. Based on the complete Swedish population, an individual’s degree of relative deprivation is measured through income compared to individuals of the same age, sex, educational level and type. In accounting for the possibility that sickness absence and socioeconomic status are determined by common factors, discrete-time duration models were estimated, accounting for unobserved heterogeneity through random effects. Results: The results confirm that the failure to account for the dynamics of the individual’s career biases the influence from socioeconomic characteristics. Results consistently suggest a major influence from relative deprivation, with a consistently lower risk of sickness absence among the highly educated. Conclusions: Altering individual’s health behavior through education appears more efficient in reducing the reliance on sickness absence, rather than redistributive policies.

Fever and sickness behavior: Friend or foe?

Science.gov (United States)

Harden, L M; Kent, S; Pittman, Q J; Roth, J

2015-11-01

Fever has been recognized as an important symptom of disease since ancient times. For many years, fever was treated as a putative life-threatening phenomenon. More recently, it has been recognized as an important part of the body's defense mechanisms; indeed at times it has even been used as a therapeutic agent. The knowledge of the functional role of the central nervous system in the genesis of fever has greatly improved over the last decade. It is clear that the febrile process, which develops in the sick individual, is just one of many brain-controlled sickness symptoms. Not only will the sick individual appear "feverish" but they may also display a range of behavioral changes, such as anorexia, fatigue, loss of interest in usual daily activities, social withdrawal, listlessness or malaise, hyperalgesia, sleep disturbances and cognitive dysfunction, collectively termed "sickness behavior". In this review we consider the issue of whether fever and sickness behaviors are friend or foe during: a critical illness, the common cold or influenza, in pregnancy and in the newborn. Deciding whether these sickness responses are beneficial or harmful will very much shape our approach to the use of antipyretics during illness. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of Simulated Intermittent Altitude on the Metabolic and Hematologic Parameters in Streptozotocin Induced Diabetic Rats

Directory of Open Access Journals (Sweden)

mehdi Faramoushi

2016-04-01

Full Text Available Background & objectives: Type II diabetes is a metabolic disorder accompanied with insulin resistance of the whole body cells and is considered be the fifth cause of death in the world. Adaptation to altitude can lead to tolerance to many diseases. Therefore, the aim of this study was to determine the effect of simulated intermittent altitude on the metabolic and hematologic parameters and liver function in streptozotocin induced diabetic rats. Methods: In the current experimental study, twenty four male Wistar rats weighing 220±20 gr were randomly divided into three groups; normal control group (NC, n=8, diabetic control group (D, n=8 received fat diet for 2 weeks then were injected with streptozotocin (37 mg/kg and diabetic+hypoxia group (D+H, n=8 including diabetic rat exposed to chronic intermittent hypoxia (PiO2≈106 mm Hg, simulated altitude≈3400 m, 14% oxygen for 8 weeks. Diabetic, hematologic and lipid parameters as well as ALT and AST activities were measured in peripheral blood. Results: Our findings showed that intermittent hypoxia significantly decreased serum total cholesterol, LDL ,VLDL and triglyceride in D+H group compared to D group (p<0.05. Serum levels of fasting blood glucose and homeostatic model assessment-insulin resistance HOMA-IR( index and ALT were decreased in D+H group vs. D group p<0.05. Also, hemoglubin and hematocrite level increased in D+H group in comparison to D group p<0.05. No significant difference was detected in red blood cell count in D+H vs. D group. Conclusion: Based on resultant data, it seems that intermittent exposure to hypoxia (simulated to chronic and intermittent lodgement in altitude can be used to control of type 2 diabetes by increasing hemoglobin, decreasing insulin resistance and improving liver function as well as lipid parameters.

Morning sickness

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... not predict how you will feel in future pregnancies. Causes The exact cause of morning sickness is unknown. It may be caused by hormone changes or lower blood sugar during early pregnancy. Emotional stress, fatigue, traveling, or some foods can ...

Predictors of sickness absence in pregnancy

DEFF Research Database (Denmark)

Hansen, Mette Lausten; Thulstrup, Ane Marie; Juhl, Mette

2014-01-01

OBJECTIVE: The aim of this cohort study was to investigate associations between parity, pre-pregnancy body mass index (BMI), assisted reproductive therapy (ART), time to pregnancy (TTP), and engagement in physical exercise and the risk of sickness absence in pregnancy from 10-29 completed pregnancy...... with higher HR of sickness absence. Physical exercise of >120 minutes per week was associated with lower HR 0.84 (95% CI 0.75-0.95). CONCLUSION: Risk for sickness absence was higher among women who were multiparous, overweight, obese, received ART, and had prolonged TTP, and lower among women engaged...

Motion sickness incidence during a round-the-world yacht race.

Science.gov (United States)

Turner, M; Griffin, M J

1995-09-01

Motion sickness experiences were obtained from participants in a 9 month, round the world yacht race. Race participants completed questionnaires on their motion sickness experience 1 week prior to the start of the race, during the race, and following the race. Yacht headings, sea states, and wind directions were recorded throughout the race. Illness and the occurrence of vomiting were related to the duration at sea and yacht encounter directions relative to the prevailing wind. Individual crewmember characteristics, the use of anti-motion sickness drugs, activity while at sea, and after-effects of yacht motion were also examined with respect to sickness occurrence. Sickness was greatest among females and younger crewmembers, and among crewmembers who used anti-motion sickness drugs. Sickness varied as a function of drug type and activity while at sea. Crewmembers who reported after-effects of yacht motion also reported greater sickness while at sea. The primary determinants of motion sickness were the duration of time spent at sea and yacht encounter direction to the prevailing wind.

Sickness certification difficulties in Ireland--a GP focus group study.

Science.gov (United States)

Foley, M; Thorley, K; Von Hout, M-C

2013-07-01

Sickness certification causes problems for general practitioners (GPs). Difficulty with the assessment of capacity to work, conflict with patients and other non-medical factors have been shown to influence GPs' decision-making. Inadequate leadership and management of certification issues add to GPs' difficulties. To explore problems associated with sickness certification, as part of a larger mixed method research project exploring GPs' experiences and perceptions of sickness certification in Ireland. A qualitative study in an urban region of Ireland. A focus group of four male and four female GPs explored problems encountered by GPs in certifying sickness absence. Thematic data analysis was used. Three major themes emerged: perception of the sickness certification system, organization of health care and cultural factors in sickness absence behaviour. Employment structures in public and private sectors and lack of communication with other health care providers and employers were identified as complicating sickness certification. GPs encounter a complexity of issues in sick certification and are dissatisfied with their role in certifying sickness absence. Our results open the debate for policy change and development in Ireland.

How physicians have learned to handle sickness-certification cases.

Science.gov (United States)

Löfgren, Anna; Silén, Charlotte; Alexanderson, Kristina

2011-05-01

Sickness absence is a common ''prescription'' in health care in many Western countries. Despite the significance of sick-listing for the life situation of patients, physicians have limited training in how to handle sickness-certification cases and the research about sickness-certification practices is scarce. Gain knowledge on physicians' learning regarding management of sickness certification of patients in formal, informal, and non-formal learning situations, respectively, and possible changes in this from 2004 to 2008. Data from two comprehensive questionnaires to physicians in Sweden about their sickness-certification practice in 2004 (n = 7665) and 2008 (n = 36,898); response rates: 71% and 61%, respectively. Answers from all the physicians ≤64 years old and who had sickness certification tasks (n = 4019 and n = 14,210) were analysed. ratings of importance of different types of learning situations for their sickness-certification competence. Few physicians stated that formal learning situations had contributed to a large or fairly large extent to their competence in sickness certification, e.g. undergraduate studies had done that for 17%, internship for 37%, and resident training for 46%, respectively. Contacts with colleagues had been helpful for 65%. One-third was helped by training arranged by social insurance offices. There was a significant increase between 2004 and 2008 in all items related to formal and non-formal learning situations, while there were no changes regarding informal learning situations. This study of all physicians in Sweden shows that physicians primarily attain competence in sickness certification in their daily clinical practice; through contacts with colleagues and patients.

Work health determinants in employees without sickness absence.

Science.gov (United States)

Schell, E; Theorell, T; Nilsson, B; Saraste, H

2013-01-01

Working ability is known to be related to good physical condition, clear work tasks, positive feedback and other occupational, organizational and psychosocial factors. In Sweden, high levels of sickness absence are due to stress-related disorders and musculoskeletal pain. To identify work health characteristics in a working population with a large variety of professional skills and occupational tasks. Employers' data on occupation, sickness absence, age and gender in a working population of 11 occupational groups and questionnaire responses regarding work-organization, environment, work stress, pain, health, and socio-demographic factors were collected. Employees with no history of sick-leave were compared with those with a history of sick-leave (1-182 days, mean 25 days). Of 2641 employees, 1961 participated. Those with no history of sick-leave reported less work-related pain, work-related stress, sleep disturbances, worry about their health, 'sick-presenteeism', monotonous work, bent and twisted working positions and exposure to disturbing noise than those with a history of sick-leave (P health, support from superiors, having influence on their working hours and evening and week-end working, longer working hours per week (P health and less neck, shoulder and back pain and more support from their superiors and influence on their working hours.

Motion sickness history, food neophobia, and sensation seeking.

Science.gov (United States)

Alley, Thomas R; Willet, Kathleen A; Muth, Eric R

2006-06-01

Motion sickness is believed to be caused by conflicting sensory signals, a situation that mimics the effects of ingesting certain toxins. Thus, one might suspect that individuals who have experienced a relatively high frequency of motion sickness may be particularly vigilant about avoiding anything that produces nausea, induding potentially nauseating toxins. Consequently, they may be more resistant to trying new foods, i.e., be more food neophobic, since unfamiliar foods can have unexpected adverse effects due to toxins or allergens. Likewise, many highly stimulating experiences can trigger motion sickness, so individuals who are more susceptible may be more prone to avoid such experiences, i.e., be less sensation seeking. Finally, it was expected that food neophobia would be more frequent in individuals low on sensation seeking tendencies. Self-reported motion sickness history in 308 adults (M= 18.8 yr.; SD = 1.6) was correlated with scores on the Arnett Inventory of Sensation Seeking and the Food Neophobia Scale. As predicted, greater history of motion sickness was associated with lower Sensation Seeking scores. Food Neophobia was not correlated with motion sickness history but, as expected, was negatively correlated (r = -.42) with scores on Sensation Seeking. Further research is recommended that measures actual sensitivity to motion sickness.

Health-related behaviours and sickness absence from work.

Science.gov (United States)

Laaksonen, M; Piha, K; Martikainen, P; Rahkonen, O; Lahelma, E

2009-12-01

To compare associations of health-related behaviours with self-certified and medically confirmed sickness absence, and to examine whether these associations can be explained by psychosocial and physical working conditions and occupational social class. The study included 5470 female and 1464 male employees of the City of Helsinki surveyed in 2000-2002. These data were linked to sickness absence records until the end of 2005, providing a mean follow-up time of 3.9 years. Poisson regression analysis was used to examine associations of smoking, alcohol use, physical activity, dietary habits and relative weight (body mass index) with self-certified (1-3 days) and medically confirmed (> or =4 days) absence spells. Population attributable fractions (PAFs) were calculated to quantify the sickness absence burden related to the behaviours. Smoking and high relative weight were most strongly associated with sickness absence, while the associations of other studied health-related behaviours were weaker. The associations were stronger for medically confirmed sickness absence spells for which heavy smoking and obesity more than doubled the risk of sickness absence in men and nearly doubled it in women. Adjusting for psychosocial working conditions had little or no effect on the associations. Physical working conditions and social class somewhat attenuated the associations, especially for smoking and relative weight. In self-certified sickness absence the PAF for smoking (16.4 in men, 10.3 in women) was largest, while in medically confirmed absence relative weight had the largest PAF (23.5 in men, 15.0 in women). Health-related behaviours, smoking and high relative weight in particular, were associated with subsequent sickness absence independently of psychosocial and physical working conditions and social class. Decreasing smoking and relative weight is likely to provide important gains in work ability and reduce sickness absence.

Expansion of Chiari I-associated syringomyelia after posterior-fossa decompression.

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Gil, Z; Rao, S; Constantini, S

2000-09-01

Chiari I malformation (CMI) is an abnormality that involves caudal herniation of the cerebellar tonsils into the foramen magnum. CMI has been shown to be closely associated with the development of syringomyelia (SM). Several theories have emerged to explain the apparent correlation between the existence of CMI with subsequent development of SM. However, the exact mechanism of the evolution of SM is still subject to controversy. We report here the case of a 12-year-old girl admitted to hospital with headache, vomiting, ataxia, and moderate pyramidal signs. Radiological evaluation revealed the presence of CMI, accompanied by a small SM. The patient underwent posterior fossa decompression and improved significantly. She was re-admitted 6 months later with clinical evidence of progressive spinal cord dysfunction. MR revealed gross expansion of the syrinx. This case raises questions regarding the pathophysiology of CMI and its association with SM. The case indicates the need for neurological and radiological follow-up for patients undergoing posterior fossa decompression due to CMI, even for those without an initial syrinx. This is the first report known to us of expansion of a syrinx following decompression of an associated CMI.

MEDEX2015: Greater Sea-Level Fitness Is Associated with Lower Sense of Effort During Himalayan Trekking Without Worse Acute Mountain Sickness.

Science.gov (United States)

Rossetti, Gabriella M K; Macdonald, Jamie H; Smith, Matthew; Jackson, Anna R; Callender, Nigel; Newcombe, Hannah K; Storey, Heather M; Willis, Sebastian; van den Beukel, Jojanneke; Woodward, Jonathan; Pollard, James; Wood, Benjamin; Newton, Victoria; Virian, Jana; Haswell, Owen; Oliver, Samuel J

2017-06-01

Rossetti, Gabriella M.K., Jamie H. Macdonald, Matthew Smith, Anna R. Jackson, Nigel Callender, Hannah K. Newcombe, Heather M. Storey, Sebastian Willis, Jojanneke van den Beukel, Jonathan Woodward, James Pollard, Benjamin Wood, Victoria Newton, Jana Virian, Owen Haswell, and Samuel J. Oliver. MEDEX2015: Greater sea-level fitness is associated with lower sense of effort during Himalayan trekking without worse acute mountain sickness. High Alt Med Biol. 18:152-162, 2017.-This study examined the complex relationships of fitness and hypoxic sensitivity with submaximal exercise responses and acute mountain sickness (AMS) at altitude. Determining these relationships is necessary before fitness or hypoxic sensitivity tests can be recommended to appraise individuals' readiness for altitude. Forty-four trekkers (26 men; 18 women; 20-67 years) completed a loaded walking test and a fitness questionnaire in normoxia to measure and estimate sea-level maximal aerobic capacity (maximum oxygen consumption [[Formula: see text]O 2max ]), respectively. Participants also completed a hypoxic exercise test to determine hypoxic sensitivity (cardiac, ventilatory, and arterial oxygen saturation responses to acute hypoxia, fraction of inspired oxygen [Fio 2 ] = 0.112). One month later, all participants completed a 3-week trek to 5085 m with the same ascent profile. On ascent to 5085 m, ratings of perceived exertion (RPE ascent ), fatigue by Brunel Mood Scale, and AMS were recorded daily. At 5085 m, RPE during a fixed workload step test (RPE fixed ) and step rate during perceptually regulated exercise (STEP RPE35 ) were recorded. Greater sea-level [Formula: see text]O 2max was associated with, and predicted, lower sense of effort (RPE ascent ; r = -0.43; p sea-level fitness reported less effort during simulated and actual trekking activities, had better mood (less fatigue), and chose a higher step rate during perceptually regulated exercise, but did not suffer from worse AMS

Albuminuria and overall capillary permeability of albumin in acute altitude hypoxia

DEFF Research Database (Denmark)

Hansen, J M; Olsen, Niels Vidiendal; Feldt-Rasmussen, B

1994-01-01

The mechanism of proteinuria at high altitude is unclear. Renal function and urinary excretion rate of albumin (Ualb) at rest and during submaximal exercise and transcapillary escape rate of 125I-labeled albumin (TERalb) were investigated in 12 normal volunteers at sea level and after rapid...... and passive ascent to 4,350 m. The calcium antagonist isradipine (5 mg/day; n = 6) or placebo (n = 6) was administered to abolish hypoxia-induced rises in blood pressure. Lithium clearance and urinary excretion of beta 2-microglobulin were used to evaluate renal tubular function. High altitude increased Ualb...... from 2.8 to > 5.0 micrograms/min in both groups (P high altitude significantly increased filtration fraction (P

Transcriptome and network changes in climbers at extreme altitudes

DEFF Research Database (Denmark)

Chen, Fang; Zhang, Wei; Liang, Yu

2012-01-01

Extreme altitude can induce a range of cellular and systemic responses. Although it is known that hypoxia underlies the major changes and that the physiological responses include hemodynamic changes and erythropoiesis, the molecular mechanisms and signaling pathways mediating such changes are lar...

Does self-efficacy predict return-to-work after sickness absence? A prospective study among 930 employees with sickness absence for three weeks or more

DEFF Research Database (Denmark)

Labriola, Merete; Lund, Thomas; Christensen, Karl B

2007-01-01

follows a cohort of 5357 working employees and 106 long-term sickness absent employees in Denmark. They were interviewed in 2000 regarding self-efficacy and various co-variates, and followed for 78 weeks in a national sickness absence register. Cox regression analysis was performed in order to assess...... or with Return-to-Work. CONCLUSION: The results may suggest that lower self-efficacy among employees with sickness absence is a result of the sickness absence itself rather than a precursor of it. This indicates a need to investigate the potential change in self-efficacy in relation to the employee's change......AIM: To compare levels of self-efficacy among the general working population and employees with sickness absence from work, and to examine if general self-efficacy measured before occurrence of sickness absence predicted subsequent onset of sickness absence and Return-to-Work. METHODS: The study...

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head.

Directory of Open Access Journals (Sweden)

Wei Wang

Full Text Available Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests.Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target. Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT. A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy.The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm.Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis.

Do lower vertebrates suffer from motion sickness?

Science.gov (United States)

Lychakov, Dmitri

The poster presents literature data and results of the author’s studies with the goal to find out whether the lower animals are susceptible to motion sickness (Lychakov, 2012). In our studies, fish and amphibians were tested for 2 h and more by using a rotating device (f = 0.24 Hz, a _{centrifugal} = 0.144 g) and a parallel swing (f = 0.2 Hz, a _{horizontal} = 0.059 g). The performed studies did not revealed in 4 fish species and in toads any characteristic reactions of the motion sickness (sopite syndrome, prodromal preparatory behavior, vomiting). At the same time, in toads there appeared characteristic stress reactions (escape response, an increase of the number of urinations, inhibition of appetite), as well as some other reactions not associated with motion sickness (regular head movements, eye retractions). In trout fry the used stimulation promoted division of the individuals into the groups differing by locomotor reaction to stress, as well as the individuals with the well-expressed compensatory reaction that we called the otolithotropic reaction. Analysis of results obtained by other authors confirms our conclusions. Thus, the lower vertebrates, unlike mammals, are immune to motion sickness either under the land conditions or under conditions of weightlessness. On the basis of available experimental data and theoretical concepts of mechanisms of development the motion sickness, formulated in several hypotheses (mismatch hypothesis, Traisman‘ s hypothesis, resonance hypothesis), there presented the synthetic hypothesis of motion sickness that has the conceptual significance. According to the hypothesis, the unusual stimulation producing sensor-motor or sensor-sensor conflict or an action of vestibular and visual stimuli of frequency of about 0.2 Hz is perceived by CNS as poisoning and causes the corresponding reactions. The motion sickness actually is a byproduct of technical evolution. It is suggested that in the lower vertebrates, unlike mammals

[Sickness absence associated with major life events].

Science.gov (United States)

Markussen, Simen; Røgeberg, Ole

2012-05-29

Sickness absence in the Norwegian workplace doubled in the period 1993-2003. However, the extent to which the driving factors were medical or non-medical remains unclear, as does the extent to which the cause may be found in the composition of the workforce. A differences-in-differences regression model was used to estimate the added sickness absence associated with major life events such as separation, death of spouse and pregnancy in the period 1993-2005. The data were obtained from administrative registers covering the entire Norwegian population, and include all absence periods of 16 days' duration or more reported by a doctor's medical certificate. The primary outcome measures were incidence (the proportion of absentees in a given time window) and absence (the proportion of sick days in a given time window). The level of absence among employees exposed to the specified life events was compared to control groups matched for gender, age, education and income. In 1993, people in each of the three groups exposed to major life events had more frequent and longer periods of absence than people in the control groups. This added sickness absence increased between 1993 and 2005. The changes in added sickness absence were at times significant, particularly for pregnant women. While sickness absence among pregnant women in 1993 was 15.4 percentage points higher than in the control group, the difference had increased to 24.8 percentage points in 2005. We find it improbable for the increase in added sickness absence to be caused by changes in the medical impact of life events or alterations in the workforce composition. We believe the increase is caused by changing attitudes among the working population and in the medical profession towards sickness absence on grounds that are not strictly medical, combined with improved social acceptance and diagnosis of mental health issues, and/or a medicalisation of natural health variations (pregnancy) and emotional distress (grief).

Reducing sick leave of Dutch vocational school students: adaptation of a sick leave protocol using the intervention mapping process.

Science.gov (United States)

de Kroon, Marlou L A; Bulthuis, Jozien; Mulder, Wico; Schaafsma, Frederieke G; Anema, Johannes R

2016-12-01

Since the extent of sick leave and the problems of vocational school students are relatively large, we aimed to tailor a sick leave protocol at Dutch lower secondary education schools to the particular context of vocational schools. Four steps of the iterative process of Intervention Mapping (IM) to adapt this protocol were carried out: (1) performing a needs assessment and defining a program objective, (2) determining the performance and change objectives, (3) identifying theory-based methods and practical strategies and (4) developing a program plan. Interviews with students using structured questionnaires, in-depth interviews with relevant stakeholders, a literature research and, finally, a pilot implementation were carried out. A sick leave protocol was developed that was feasible and acceptable for all stakeholders. The main barriers for widespread implementation are time constraints in both monitoring and acting upon sick leave by school and youth health care. The iterative process of IM has shown its merits in the adaptation of the manual 'A quick return to school is much better' to a sick leave protocol for vocational school students.

Anterior cervical decompression and fusion with caspar plate fixation

International Nuclear Information System (INIS)

Rehman, L.; Akbar, H.; Das, G.; Hashim, A.S.M.

2013-01-01

Objective: To evaluate the role of anterior cervical decompression and fixation with Caspar plating in cervical spine injury on neurological outcome. Study Design: A case series. Place and Duration of Study: Department of Neurosurgery, Jinnah Postgraduate Medical Centre, Karachi, from July 2008 to March 2011. Methodology: Thirty patients admitted with cervical spine injuries were inducted in the study. All cases were evaluated for their clinical features, level of injury and degree of neurological injury was assessed using Frankel grading. Pre and postoperative record with X-rays and MRI were maintained. Cervical traction was applied to patients with sub-luxation. All patients underwent anterior cervical decompression, fusion and Caspar plate fixation. The follow-up period was 6 months with clinical and radiological assessment. Results: Among 30 patients, 24 (80%) were males and 6 (20%) were females. Age ranged from 15 to 55 years. Causes of injury were road traffic accident (n = 20), fall (n = 8) and assault (n = 2). Commonest mode of injury was road traffic accident (66.6%). Postoperative follow-up showed that pain and neurological deficit were improved in 21 patients. There was no improvement in 7 patients, one patient deteriorated and one expired. All patients developed pain at donor site. Conclusion: Anterior decompression, fusion and fixation with Caspar plate is an effective method with good neurological and radiological outcome. However, it is associated with pain at donor site. (author)

The effect of rapid decompression on femur blood flow of rabbits

International Nuclear Information System (INIS)

Yu Shaoning; Tian Wuxun; Zhu Xiangqi

1997-01-01

PURPOSE: To study the influence of regional blood flow in femur trochanter (FT) of rabbits' under rapid decompression after exposure to hyperbaric air. METHODS: Rabbits were placed in a hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, and the pressure was reduced to the atmosphere pressure at a uniform rate of 0.03 mPa/min. The regional blood flow of FT in rabbits were measured with 133 Xe washout methods. RESULTS: The normal average regional blood flow in left and right FT were 14.5 +- 1.7 and 14.1 +- 1.9 ml/(min·100g) respectively. After exposure to hyperbaric air with rapid decompression, the average regional blood flow of left and right FT were 11.1 +- 1.2 and 10.5 +- 1.6 ml/(min·100g) respectively. But the symptoms of dysbarism in these rabbits were various each other. CONCLUSIONS: After being exposed to hyperbaric air with rapid decompression, the blood flow of rabbits' femur trochanter were noticeably reduced

Effect of active compression-decompression resuscitation (ACD-CPR) on survival: a combined analysis using individual patient data

DEFF Research Database (Denmark)

Mauer, Dietmar; Nolan, Jerry; Plaisance, Patrick

1999-01-01

Cardiopulmonary resuscitation, compression, decompression, cardiac arrest, emergency medical service, advanced cardiac life support, survival......Cardiopulmonary resuscitation, compression, decompression, cardiac arrest, emergency medical service, advanced cardiac life support, survival...

Men and women differ in inflammatory and neuroendocrine responses to endotoxin but not in the severity of sickness symptoms.

Science.gov (United States)

Engler, Harald; Benson, Sven; Wegner, Alexander; Spreitzer, Ingo; Schedlowski, Manfred; Elsenbruch, Sigrid

2016-02-01

Impaired mood and increased anxiety represent core symptoms of sickness behavior that are thought to be mediated by pro-inflammatory cytokines. Moreover, excessive inflammation seems to be implicated in the development of mood/affective disorders. Although women are known to mount stronger pro-inflammatory responses during infections and are at higher risk to develop depressive and anxiety disorders compared to men, experimental studies on sex differences in sickness symptoms are scarce. Thus, the present study aimed at comparing physiological and psychological responses to endotoxin administration between men and women. Twenty-eight healthy volunteers (14 men, 14 women) were intravenously injected with a low dose (0.4 ng/kg) of lipopolysaccharide (LPS) and plasma concentrations of cytokines and neuroendocrine factors as well as negative state emotions were measured before and until six hours after LPS administration. Women exhibited a more profound pro-inflammatory response with significantly higher increases in tumor necrosis factor (TNF)-α and interleukin (IL)-6. In contrast, the LPS-induced increase in anti-inflammatory IL-10 was significantly higher in men. The cytokine alterations were accompanied by changes in neuroendocrine factors known to be involved in inflammation regulation. Endotoxin injection induced a significant increase in noradrenaline, without evidence for sex differences. The LPS-induced increase in cortisol was significantly higher in woman, whereas changes in dehydroepiandrosterone were largely comparable. LPS administration also increased secretion of prolactin, but only in women. Despite these profound sex differences in inflammatory and neuroendocrine responses, men and women did not differ in endotoxin-induced alterations in mood and state anxiety or non-specific sickness symptoms. This suggests that compensatory mechanisms exist that counteract the more pronounced inflammatory response in women, preventing an exaggerated sickness

Management of sinonasal complications after endoscopic orbital decompression for Graves' orbitopathy.

Science.gov (United States)

Antisdel, Jastin L; Gumber, Divya; Holmes, Janalee; Sindwani, Raj

2013-09-01

Endoscopic orbital decompression (EnOD) has proven to be safe and effective for the treatment of Graves' orbitopathy; however, complications do occur. Although the literature focuses on orbital complications, sinonasal complications including postobstructive sinusitis, hemorrhage, and cerebrospinal fluid (CSF) leak can also be challenging to manage. This study examines the incidence and management of sinonasal complications in these patients. Retrospective review. Clinical data, surgical findings, and postoperative outcomes were reviewed of patients who underwent EnOD for Graves' disease between March 2004 and November 2010. The incidence and management of postoperative sinonasal complications requiring an intervention were examined. The study group consisted of 50 consecutive patients (86 decompression procedures): 11 males and 39 females with an average age of 48.6 years (SD = 12.9). Incidence of significant sinonasal complications was 3.5% (5/86): with one patient experiencing postoperative hemorrhage requiring operative management, three patients with postoperative obstructive sinusitis, and one patient with nasal obstruction secondary to nasal adhesions that required lysis. The maxillary sinus was the most commonly involved and was managed using the mega-antrostomy technique. In the case of frontal sinusitis, an endoscopic transaxillary approach was utilized to avoid injury to decompressed orbital contents. All complications were successfully managed without sequelae. Sinonasal complications following EnOD are uncommon. In the setting of a decompressed orbit, even routine types of postoperative issues can be challenging and require additional considerations. Successful management of postoperative sinusitis related to outflow obstruction may require more extensive approaches and novel techniques. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

[Arterial hypertension due to altitude].

Science.gov (United States)

Domej, Wolfgang; Trapp, Michael; Miggitsch, Eva Maria; Krakher, Tiziana; Riedlbauer, Rita; Roher, Peter; Schwaberger, Günther

2008-01-01

The behavior of blood pressure under hypoxic conditions depends on individual factors, altitude and duration of stay at altitude. While most humans are normotensive at higher altitudes, a few will react with moderate hypertension or hypotension. Excessive elevation of arterial blood pressure is not even to be expected below 4,000 m. Rather, several weeks' stay at higher altitude will decrease systolic and diastolic blood pressure at rest as well as during physical exertion. A high-altitude treatment for rehabilitation purposes at moderate altitude may be recommended for patients with cardio-circulatory disorders. Improvements can last several months even after returning to accustomed altitudes. Furthermore, endurance-trained hypertensive patients with pharmacologically controlled arterial blood pressure might be able to participate in mountain treks without additional health risk.

Immediate pain relief by microvascular decompression for idiopathic trigeminal neuralagia

International Nuclear Information System (INIS)

Haq, N.U.; Ali, M.; Khan, H.M.; Ishaq, M.; Khattak, M.I.

2016-01-01

Background: Trigeminal neuralgia is a common entity which is managed by neurosurgeons in day to day practice. Up-till now many treatment options have been adopted for it but micro-vascular decompression is much impressive in terms of pain control and recurrence rate in all of them. The objective of study was known the efficacy of micro vascular decompression for idiopathic trigeminal neuralgia by using muscle patch in terms of immediate pain relief. Methods: This descriptive study was carried out in Neurosurgery Department lady reading hospital, Peshawar from January 2010 to December 2012. All patients who underwent micro vascular decompression for idiopathic trigeminal neuralgia were included in the study. Patients were assessed 72 hours after the surgery by borrow neurological institute pain scale (BNIP scale) for pain relief and findings were documented on predesigned proforma. Data was analysed by SPSS-17. Results: Total 52 patients were included in this study. Among these 32 (61.53 percentage) were female and 20 (38.46 percentage) were males having age from 22-76 years (mean 49 years). Right side was involved in 36 (69.23 percentage) and left side in 16 (30.76 percentage) patients. Duration of symptoms ranged from 6 months to 16 years (mean 8 years). History of dental extraction and peripheral neurectomy was present in 20 (38 percentage) and 3(5.76 percentage) patients while V3 was most commonly involved branch with 28(57.69 percentage) frequency and combined V2,V3 involvement was 1 (11.53 percentage). Superior cerebellar artery was most common offending vessel in 46(88.46 percentage) while arachnoid adhesions were in 2(3.84 percentage) patients. We assessed patient immediate postoperatively using BNIP pain scale. Conclusion: Micro-vascular decompression is most effective mode of treatment for trigeminal neuralgia in terms of immediate pain relief. (author)

Brain Food at High Altitude.

Science.gov (United States)

Jain, Vishal

2016-01-01

Scenic view at high altitude is a pleasure to the eyes, but it has some shortcoming effects as well. High altitude can be divided into different categories, i.e., high altitude (3000-5000 ft), very high altitude (5000-8000 ft), and extreme altitude (above 8000 ft). Much of the population resides at high altitude, and others go there for tourism. Military personnel are also posted there to defend boundaries. As we ascent to high altitude, partial pressure of oxygen reduces, whereas concentration remains the same; this reduces the availability of oxygen to different body parts. This pathophysiological condition is known as hypobaric hypoxia (HH) which leads to oxidative stress and further causes cognitive dysfunction in some cases. Hypoxia causes neurodegeneration in different brain regions; however, the hippocampus is found to be more prone in comparison to other brain regions. As the hippocampus is affected most, therefore, spatial memory is impaired most during such condition. This chapter will give a brief review of the damaging effect of high altitude on cognition and also throw light on possible herbal interventions at high altitude, which can improve cognitive performance as well as provide protection against the deteriorating effect of hypobaric hypoxia at high altitude.

Self-reported and employer-recorded sickness absence in doctors.

Science.gov (United States)

Murphy, I J

2014-09-01

Doctors' sickness absence reduces the quality and continuity of patient care and is financially costly. Doctors have lower rates of sickness absence than other healthcare workers. To compare self-reported with recorded sickness absence in doctors in a UK National Health Service hospital trust. A retrospective questionnaire study. The main outcome measures were self-reported and trust-recorded sickness absence episodes of 4 days or more in two consecutive 6-month periods. The response rate was 82% (607/736). Self-reported sickness absence rates were 1.2% compared with a rate of 0.6% from trust-recorded data. There were 38 matched pairs of self-reported (mean duration: 18 days, standard deviation: 22 days) and trust-recorded (mean duration: 10 days, standard deviation: 17 days) sickness absence episodes of 4 days or more in the 12 months studied. A matched pairs t-test determined that the difference between the two means was significant (t = 2.57, P sickness absence was significantly under-recorded in this study population. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MRI-guidance in percutaneous core decompression of osteonecrosis of the femoral head

Energy Technology Data Exchange (ETDEWEB)

Kerimaa, Pekka; Vaeaenaenen, Matti; Ojala, Risto; Tervonen, Osmo; Blanco Sequeiros, Roberto [Oulu University Hospital, Department of Radiology (Finland); Hyvoenen, Pekka; Lehenkari, Petri [Oulu University Hospital, Department of Surgery (Finland)

2016-04-15

The purpose of this study was to evaluate the usefulness of MRI-guidance for core decompression of avascular necrosis of the femoral head. Twelve MRI-guided core decompressions were performed on patients with different stages of avascular necrosis of the femoral head. The patients were asked to evaluate their pain and their ability to function before and after the procedure and imaging findings were reviewed respectively. Technical success in reaching the target was 100 % without complications. Mean duration of the procedure itself was 54 min. All patients with ARCO stage 1 osteonecrosis experienced clinical benefit and pathological MRI findings were seen to diminish. Patients with more advanced disease gained less, if any, benefit and total hip arthroplasty was eventually performed on four patients. MRI-guidance seems technically feasible, accurate and safe for core decompression of avascular necrosis of the femoral head. Patients with early stage osteonecrosis may benefit from the procedure. (orig.)

MRI-guidance in percutaneous core decompression of osteonecrosis of the femoral head

International Nuclear Information System (INIS)

Kerimaa, Pekka; Vaeaenaenen, Matti; Ojala, Risto; Tervonen, Osmo; Blanco Sequeiros, Roberto; Hyvoenen, Pekka; Lehenkari, Petri

2016-01-01

The purpose of this study was to evaluate the usefulness of MRI-guidance for core decompression of avascular necrosis of the femoral head. Twelve MRI-guided core decompressions were performed on patients with different stages of avascular necrosis of the femoral head. The patients were asked to evaluate their pain and their ability to function before and after the procedure and imaging findings were reviewed respectively. Technical success in reaching the target was 100 % without complications. Mean duration of the procedure itself was 54 min. All patients with ARCO stage 1 osteonecrosis experienced clinical benefit and pathological MRI findings were seen to diminish. Patients with more advanced disease gained less, if any, benefit and total hip arthroplasty was eventually performed on four patients. MRI-guidance seems technically feasible, accurate and safe for core decompression of avascular necrosis of the femoral head. Patients with early stage osteonecrosis may benefit from the procedure. (orig.)

Autogenic feedback training experiment: A preventative method for space motion sickness

Science.gov (United States)

Cowings, Patricia S.

1993-01-01

Space motion sickness is a disorder which produces symptoms similar to those of motion sickness on Earth. This syndrome has affected approximately 50 percent of all astronauts and cosmonauts exposed to microgravity in space, but it differs from what is commonly known as motion sickness in a number of critical ways. There is currently no ground-based method for predicting susceptibility to motion sickness in space. Antimotion sickness drugs have had limited success in preventing or counteracting symptoms in space, and frequently caused debilitating side effects. The objectives were: (1) to evaluate the effectiveness of Autogenic-Feedback Training as a countermeasure for space motion sickness; (2) to compare physiological data and in-flight symptom reports to ground-based motion sickness data; and (3) to predict susceptibility to space motion sickness based on pre-flight data of each treatment group crew member.

Training at altitude in practice.

Science.gov (United States)

Dick, F W

1992-10-01

There can be little doubt that training at altitude is fundamental to preparing an athlete for competition at altitude. However the value of training at altitude for competition at sea level appears on the one hand to lack total acceptance amongst sports scientists; and on the other to hold some cloak of mystery for coaches who have yet to enjoy first hand experience. The fact is that very few endurance athletes will ignore the critical edge which altitude training affords. Each fraction of a percentage of performance advantage gained through methods which are within the rules of fair play in sport, may shift the balance between failure and achievement. Moreover, there is growing support for application of training at altitude for speed-related disciplines. This paper aims to demystify the subject by dealing with practical aspects of training at altitude. Such aspects include a checklist of what should and should not be done at altitude, when to use altitude relative to target competitions, and specific training examples.

Does Early Decompressive Craniectomy Improve Outcome? Experience from an Active UK Recruiter Centre

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E. García Vicente

2013-01-01

Full Text Available Introduction. The results of the recent DECRA study suggest that although craniectomy decreases ICP and ICU length of stay, it is also associated with worst outcomes. Our experience, illustrated by these two striking cases, supports that early decompressive craniectomy may significantly improve the outcome in selected patients. Case Reports. The first patient, a 20-year-old man who suffered severe brain contusion and subarachnoid haemorrhage after a fall downstairs, with refractory ICP of 35 mmHg, despite maximal medical therapy, eventually underwent decompressive craniectomy. After 18 days in intensive care, he was discharged for rehabilitation. The second patient, a 23-year-old man was found at the scene of a road accident with a GCS of 3 and fixed, dilated pupils who underwent extensive unilateral decompressive craniectomy for refractory intracranial hypertension. After three weeks of cooling, paralysis, and neuroprotection, he eventually left ICU for rehabilitation. Outcomes. Four months after leaving ICU, the first patient abseiled 40 m down the main building of St. Mary’s Hospital to raise money for the Trauma Unit. He has returned to part-time work. The second patient, was decannulated less than a month later and made a full cognitive recovery. A year later, with a titanium skull prosthesis, he is back to part-time work and to playing football. Conclusions. Despite the conclusions of the DECRA study, our experience of the use of early decompressive craniectomy has been associated with outstanding outcomes. We are currently actively recruiting patients into the RESCUEicp trial and have high hopes that it will clarify the role of the decompressive craniectomy in traumatic brain injury and whether it effectively improves outcomes.

Effects of repetitive training at low altitude on erythropoiesis in 400 and 800 m runners.

Science.gov (United States)

Frese, F; Friedmann-Bette, B

2010-06-01

Classical altitude training can cause an increase in total hemoglobin mass (THM) if a minimum "dose of hypoxia" is reached (altitude >or=2,000 m, >or=3 weeks). We wanted to find out if repetitive exposure to mild hypoxia during living and training at low altitude (training camps at low altitude interspersed by 3 weeks of sea-level training and at the same time points in a control group (CG) of 5 well-trained runners. EPO, sTfR and ferritin were also repeatedly measured during the altitude training camps. Repeated measures ANOVA revealed significant increases in EPO- and sTfR-levels during both training camps and a significant decrease in ferritin indicating enhanced erythropoietic stimulation during living and training at low altitude. Furthermore, significant augmentation of THM by 5.1% occurred in the course of the 2 altitude training camps. In conclusion, repetitive living and training at low altitude leads to a hypoxia-induced increase in erythropoietic stimulation in elite 400 m and 800 m runners and, apparently, might also cause a consecutive augmentation of THM.

Decompression of the facial nerve in cases of hemifacial spasm

Directory of Open Access Journals (Sweden)

Karsten Kettel

1954-12-01

Full Text Available Among 11 patients a complete cure was obtained in one case, a fair result in 4 cases, while in 6 cases the effect of the operation has only been temporary and full recurrence has taken place. Even if decompression has thus resulted in a few recoveries and improvements, the results in the majority of cases have been disappointing. Everything points to hemifacial spasm being due to a disorder of the lower motor neuron. Intracranial lesions in the vicinity of the facial nerve are known to have resulted in irritation and spasm. It may be perfectly true that the majority of cases of hemifacial spasm are due to a lesion, the nature of which may vary, in the Fallopian canal near the stylomastoid foramen, not least the postparalytic following Bell's palsy. But the disappointing results of decompression seems to indicate that at the time of operation irreparable damage to the nerve has in the majority of cases been already done. Consequently I gave up decompression in cases of hemifacial spasm some years ago. Good results from injections of alcohol into the nerve have been reported13 but I prefer selective sections of the branches to the muscles involved as described by German and Greenwood8.

Decompression syndrome (Caisson disease) in an Indian diver.

Science.gov (United States)

Phatak, Uday A; David, Eric J; Kulkarni, Pravin M

2010-07-01

Acute decompression syndrome (Caisson's disease) is an acute neurological emergency in divers. It is caused due to release of nitrogen gas bubbles that impinge the blood vessels of the spinal cord and brain and result in severe neurodeficit. There are very few case reports in Indian literature. There are multiple factors in the pathogenesis of Acute decompression syndrome (Caisson's disease) such as health problems in divers (respiratory problems or congenital heart diseases like atrial septal defect, patent ductus arteriosus etc), speed of ascent from the depth and habits like smoking that render divers susceptible for such neurological emergency. Usually, immediate diagnosis of such a condition with MRI is not possible in hospitals in the Coastal border. Even though, MRI is performed, it has very low specificity and sensitivity. Facilities like hyperbaric oxygen treatment are virtually non-existent in these hospitals. Therefore, proper education of the divers and appropriate preventive measures in professional or recreational divers is recommended.

Decompression syndrome (Caisson disease in an Indian diver

Directory of Open Access Journals (Sweden)

Phatak Uday

2010-01-01

Full Text Available Acute decompression syndrome (Caisson′s disease is an acute neurological emergency in divers. It is caused due to release of nitrogen gas bubbles that impinge the blood vessels of the spinal cord and brain and result in severe neurodeficit. There are very few case reports in Indian literature. There are multiple factors in the pathogenesis of Acute decompression syndrome (Caisson′s disease such as health problems in divers (respiratory problems or congenital heart diseases like atrial septal defect, patent ductus arteriosus etc, speed of ascent from the depth and habits like smoking that render divers susceptible for such neurological emergency. Usually, immediate diagnosis of such a condition with MRI is not possible in hospitals in the Coastal border. Even though, MRI is performed, it has very low specificity and sensitivity. Facilities like hyperbaric oxygen treatment are virtually non-existent in these hospitals. Therefore, proper education of the divers and appropriate preventive measures in professional or recreational divers is recommended.

General Purpose Graphics Processing Unit Based High-Rate Rice Decompression and Reed-Solomon Decoding

Energy Technology Data Exchange (ETDEWEB)

Loughry, Thomas A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-02-01

As the volume of data acquired by space-based sensors increases, mission data compression/decompression and forward error correction code processing performance must likewise scale. This competency development effort was explored using the General Purpose Graphics Processing Unit (GPGPU) to accomplish high-rate Rice Decompression and high-rate Reed-Solomon (RS) decoding at the satellite mission ground station. Each algorithm was implemented and benchmarked on a single GPGPU. Distributed processing across one to four GPGPUs was also investigated. The results show that the GPGPU has considerable potential for performing satellite communication Data Signal Processing, with three times or better performance improvements and up to ten times reduction in cost over custom hardware, at least in the case of Rice Decompression and Reed-Solomon Decoding.

Cerebral microdialysis and PtiO2 to decide unilateral decompressive craniectomy after brain gunshot

Directory of Open Access Journals (Sweden)

Boret Henry

2012-01-01

Full Text Available Decompressive craniectomy (DC following brain injury can induce complications (hemorrhage, infection, and hygroma. It is then considered as a last-tier therapy, and can be deleteriously delayed. Focal neuromonitoring (microdialysis and PtiO2 can help clinicians to decide bedside to perform DC in case of intracranial pressure (ICP around 20 to 25 mmHg despite maximal medical treatment. This was the case of a hunter, brain injured by gunshot. DC was performed at day 6, because of unstable ICP, ischemic trend of PtiO2, and decreased cerebral glucose but normal lactate/pyruvate ratio. His evolution was good despite left hemiplegia due to initial injury.

Anti-infection treatment of iatrogenic acute radiation sickness

International Nuclear Information System (INIS)

Zhang Shulan; Ke Xiaoyan; Jia Tengzhen

2006-01-01

Objective: To occumulatle experience of anti-infection treatment in acute radiation sickness (ARS) induced by medical treatment in order to provide beneficial help for victims of accidental of acute radiation sickness. Methods: The changes of peripheral blood indices, body temperature and clinical symptoms of 17 cases who were clinically irradiated with 6.0-7.2 Gy X-rays were observed both before peripheral blood stem cell transplantation(PBSCT) and after anti-infection treatment. Results: WBC count began to decrease to below 1 x 10 9 /L from the 8th to 10th days after irradiation and maintained at row level for 4 days or for 13.3 days if the patients had not received rhG-CSF treatment. In 29.4% of patients the body temperature was higher than 38.5 degree C. After comprehensive enviromental protection and anti-infection treatment, all patients could successfully tide over the period of bone marrow depression without appearance of the typical critical phase of ARS. Conclusion: PBSCT and rhG-CSF treatment can reduce the time span for reconstruction of bone marrow. Comprehensive enviromental protection and combined anti-infection treatment are key points fm successful treatment. (authors)

Determinants of sick-leave duration : A tool for managers?

NARCIS (Netherlands)

Flach, P.A.; Krol, B.; Groothoff, J.W.

AIMS: To provide managers with tools to manage episodes of sick-leave of their employees, the influence of factors such as age, gender, duration of tenure, working full-time or part-time, cause and history of sick-leave, salary and education on sick-leave duration was studied. METHOD: In a

Mechanisms of Memory Dysfunction during High Altitude Hypoxia Training in Military Aircrew.

Science.gov (United States)

Nation, Daniel A; Bondi, Mark W; Gayles, Ellis; Delis, Dean C

2017-01-01

Cognitive dysfunction from high altitude exposure is a major cause of civilian and military air disasters. Pilot training improves recognition of the early symptoms of altitude exposure so that countermeasures may be taken before loss of consciousness. Little is known regarding the nature of cognitive impairments manifesting within this critical window when life-saving measures may still be taken. Prior studies evaluating cognition during high altitude simulation have predominantly focused on measures of reaction time and other basic attention or motor processes. Memory encoding, retention, and retrieval represent critical cognitive functions that may be vulnerable to acute hypoxic/ischemic events and could play a major role in survival of air emergencies, yet these processes have not been studied in the context of high altitude simulation training. In a series of experiments, military aircrew underwent neuropsychological testing before, during, and after brief (15 min) exposure to high altitude simulation (20,000 ft) in a pressure-controlled chamber. Acute exposure to high altitude simulation caused rapid impairment in learning and memory with relative preservation of basic visual and auditory attention. Memory dysfunction was predominantly characterized by deficiencies in memory encoding, as memory for information learned during high altitude exposure did not improve after washout at sea level. Retrieval and retention of memories learned shortly before altitude exposure were also impaired, suggesting further impairment in memory retention. Deficits in memory encoding and retention are rapidly induced upon exposure to high altitude, an effect that could impact life-saving situational awareness and response. (JINS, 2017, 23, 1-10).

Effectiveness of early part-time sick leave in musculoskeletal disorders.

Science.gov (United States)

Martimo, Kari-Pekka; Kaila-Kangas, Leena; Kausto, Johanna; Takala, Esa-Pekka; Ketola, Ritva; Riihimäki, Hilkka; Luukkonen, Ritva; Karppinen, Jaro; Miranda, Helena; Viikari-Juntura, Eira

2008-02-25

The importance of staying active instead of bed rest has been acknowledged in the management of musculoskeletal disorders (MSDs). This emphasizes the potential benefits of adjusting work to fit the employee's remaining work ability. Despite part-time sick leave being an official option in many countries, its effectiveness has not been studied yet. We have designed a randomized controlled study to assess the health effects of early part-time sick leave compared to conventional full-day sick leave. Our hypothesis is that if work time is temporarily reduced and work load adjusted at the early stages of disability, employees with MSDs will have less disability days and faster return to regular work duties than employees on a conventional sick leave. The study population will consist of 600 employees, who seek medical advice from an occupational physician due to musculoskeletal pain. The inclusion requires that they have not been on a sick leave for longer than 14 days prior to the visit. Based on the physician's judgement, the severity of the symptoms must indicate a need for conventional sick leave, but the employee is considered to be able to work part-time without any additional risk. Half of the employees are randomly allocated to part-time sick leave group and their work time is reduced by 40-60%, whereas in the control group work load is totally eliminated with conventional sick leave. The main outcomes are the number of days from the initial visit to return to regular work activities, and the total number of sick leave days during 12 and 24 months of follow-up. The costs and benefits as well as the feasibility of early part-time sick leave will also be evaluated. This is the first randomised trial to our knowledge on the effectiveness of early part-time sick leave compared to conventional full-time sick leave in the management of MSDs. The data collection continues until 2011, but preliminary results on the feasibility of part-time sick leave will be available

Indoor air pollution and sick building syndrome

Energy Technology Data Exchange (ETDEWEB)

Robertson, J P

1997-12-31

The topics discussed in this paper are accept that SBS (Sick building syndrome) is a reality ; understand the dimensions of the problem ; differentiate between sick building syndrome and building related illness ; introduce standards ; understanding the economics ; act pro-actively not re-actively.

Job demands, health perception and sickness absence

NARCIS (Netherlands)

Roelen, C.A.; Koopmans, P.C.; de Graaf, J.H.; van Zandbergen, J.W.; Groothoff, J.W.

2007-01-01

Background Investigation of the relations between job demands, health and sickness absence is required to design a strategy for the prevention of absence and disability. Aim To study the relationships between (physical and psychological) job demands, health perception and sickness absence. Methods

Indoor air pollution and sick building syndrome

International Nuclear Information System (INIS)

Robertson, J.P.

1996-01-01

The topics discussed in this paper are accept that SBS (Sick building syndrome) is a reality ; understand the dimensions of the problem ; differentiate between sick building syndrome and building related illness ; introduce standards ; understanding the economics ; act pro-actively not re-actively

GPs' negotiation strategies regarding sick leave for subjective health complaints

DEFF Research Database (Denmark)

Nilsen, Stein Tore; Malterud, Kirsti; Werner, Erik L.

2015-01-01

Objectives: To explore general practitioners ’(GPs’) specific negotiation strategies regarding sick-leave issues with patientssuffering from subjective health complaints. Design: Focus-group study. Setting: Nine focus-group interviews in three citiesin different regions of Norway. Participants: 48...... GPs (31 men, 17 women; age 32–65), participating in a course dealing with diagnostic practice and assessment of sickness certifi cates related to patients with subjective health complaints. Results: TheGPs identified some specific strategies that they claimed to apply when dealing with the question...... to sick leave. Conclusions and implications: GPs seem to have a conscious approach to negotiations of sickness certification, as they report applying specific strategies to limit the duration of sick leave due to subjective health complaints. This give-and-take way of handling sick leave negotiations has...

Atrial natriuretic peptide and red cell 2,3-diphosphoglycerate in patients with chronic mountain sickness.

Science.gov (United States)

Ge, R L; Shai, H R; Takeoka, M; Hanaoka, M; Koizumi, T; Matsuzawa, Y; Kubo, K; Kobayashi, T

2001-01-01

Individuals with chronic mountain sickness (CMS) show severe hypoxemia, excessive polycythemia, and marked pulmonary hypertension. The pathophysiologic mechanisms of CMS are still not completely understood. We determined plasma atrial natriuretic peptide (ANP), red cell 2,3-diphosphoglycerate (2,3-DPG), hematocrit, hemoglobin, and arterialized ear lobe blood gas values in 13 patients with CMS (9 Hans, 4 Tibetans) and 18 control Han Chinese men of similar age, height, and weight who had been living at 4300 m on the Tibetan plateau of Qinghai Province, China, for approximately 14 years. A significantly higher level of ANP was found in the CMS patients compared to the non-CMS patients (113.4+/-5.5 pg/mL vs 87.6+/-4.7 pg/mL, P levels of ANP correlated positively with the hemoglobin concentration (r = 0.8282, P levels in the CMS patients were significantly increased compared to the non-CMS subjects (5.23+/-0.16 mmol/L vs 4.40+/-0.12 mmol/L, P levels, lower pH values, lower PaO2 levels, and greater alveolar-arterial oxygen differences (PAO2 - PaO2) compared to the non-CMS subjects. These findings suggest that overproduction of ANP and 2,3-DPG at high altitudes may play an important role in the pathophysiology of chronic mountain sickness.

Long-Term Intermittent Work at High Altitude: Right Heart Functional and Morphological Status and Associated Cardiometabolic Factors

Directory of Open Access Journals (Sweden)

Julio Brito

2018-03-01

Full Text Available Background: Living at high altitude or with chronic hypoxia implies functional and morphological changes in the right ventricle and pulmonary vasculature with a 10% prevalence of high-altitude pulmonary hypertension (HAPH. The implications of working intermittently (day shifts at high altitude (hypobaric hypoxia over the long term are still not well-defined. The aim of this study was to evaluate the right cardiac circuit status along with potentially contributory metabolic variables and distinctive responses after long exposure to the latter condition.Methods: A cross-sectional study of 120 healthy miners working at an altitude of 4,400–4,800 m for over 5 years in 7-day commuting shifts was designed. Echocardiography was performed on day 2 at sea level. Additionally, biomedical and biochemical variables, Lake Louise scores (LLSs, sleep disturbances and physiological variables were measured at altitude and at sea level.Results: The population was 41.8 ± 0.7 years old, with an average of 14 ± 0.5 (range 5–29 years spent at altitude. Most subjects still suffered from mild to moderate symptoms of acute mountain sickness (mild was an LLS of 3–5 points, including cephalea; moderate was LLS of 6–10 points (38.3% at the end of day 1 of the shift. Echocardiography showed a 23% mean pulmonary artery pressure (mPAP >25 mmHg, 9% HAPH (≥30 mmHg, 85% mild increase in right ventricle wall thickness (≥5 mm, 64% mild right ventricle dilation, low pulmonary vascular resistance (PVR and fairly good ventricle performance. Asymmetric dimethylarginine (ADMA (OR 8.84 (1.18–66.39; p < 0.05 and insulin (OR: 1.11 (1.02–1.20; p < 0.05 were associated with elevated mPAP and were defined as a cut-off. Interestingly, the correspondence analysis identified association patterns of several other variables (metabolic, labor, and biomedical with higher mPAP.Conclusions: Working intermittently at high altitude involves a distinctive pattern. The most relevant and

How Safe Is Measles Immunization Of Sick Children? | Ogbonna ...

African Journals Online (AJOL)

A prospective study to ascertain how safe is maeales immunization of sick children was carried out in Jos University Teaching Hospital, Family Health Centre. Out of 125 children who were vaccinated against measles 17(16%) were sick at the time of vaccination. Two (12%) of the sick children had post vaccination reaction.

Strategies and methodologies to develop techniques for computer-assisted analysis of gas phase formation during altitude decompression

Science.gov (United States)

Powell, Michael R.; Hall, W. A.

1993-01-01

It would be of operational significance if one possessed a device that would indicate the presence of gas phase formation in the body during hypobaric decompression. Automated analysis of Doppler gas bubble signals has been attempted for 2 decades but with generally unfavorable results, except with surgically implanted transducers. Recently, efforts have intensified with the introduction of low-cost computer programs. Current NASA work is directed towards the development of a computer-assisted method specifically targeted to EVA, and we are most interested in Spencer Grade 4. We note that Spencer Doppler Grades 1 to 3 have increased in the FFT sonogram and spectrogram in the amplitude domain, and the frequency domain is sometimes increased over that created by the normal blood flow envelope. The amplitude perturbations are of very short duration, in both systole and diastole and at random temporal positions. Grade 4 is characteristic in the amplitude domain but with modest increases in the FFT sonogram and spectral frequency power from 2K to 4K over all of the cardiac cycle. Heart valve motion appears to characteristic display signals: (1) the demodulated Doppler signal amplitude is considerably above the Doppler-shifted blow flow signal (even Grade 4); and (2) demodulated Doppler frequency shifts are considerably greater (often several kHz) than the upper edge of the blood flow envelope. Knowledge of these facts will aid in the construction of a real-time, computer-assisted discriminator to eliminate cardiac motion artifacts. There could also exist perturbations in the following: (1) modifications of the pattern of blood flow in accordance with Poiseuille's Law, (2) flow changes with a change in the Reynolds number, (3) an increase in the pulsatility index, and/or (4) diminished diastolic flow or 'runoff.' Doppler ultrasound devices have been constructed with a three-transducer array and a pulsed frequency generator.

Are environmental characteristics in the municipal eldercare, more closely associated with frequent short sick leave spells among employees than with total sick leave: a cross-sectional study

Science.gov (United States)

2013-01-01

Background It has been suggested that frequent-, short-term sick leave is associated with work environment factors, whereas long-term sick leave is associated mainly with health factors. However, studies of the hypothesis of an association between a poor working environment and frequent short spells of sick leave are few and results are inconsistent. Therefore, we aimed to explore associations between self-reported psychosocial work factors and workplace-registered frequency and length of sick leave in the eldercare sector. Methods Employees from the municipal eldercare in Aarhus (N = 2,534) were included. In 2005, they responded to a work environment questionnaire. Sick leave records from 2005 were dichotomised into total sick leave days (0–14 and above 14 days) and into spell patterns (0–2 short, 3–9 short, and mixed spells and 1–3 long spells). Logistic regression models were used to analyse associations; adjusted for age, gender, occupation, and number of spells or sick leave length. Results The response rate was 76%; 96% of the respondents were women. Unfavourable mean scores in work pace, demands for hiding emotions, poor quality of leadership and bullying were best indicated by more than 14 sick leave days compared with 0–14 sick leave days. For work pace, the best indicator was a long-term sick leave pattern compared with a non-frequent short-term pattern. A frequent short-term sick leave pattern was a better indicator of emotional demands (1.62; 95% CI: 1.1-2.5) and role conflict (1.50; 95% CI: 1.2-1.9) than a short-term non-frequent pattern. Age (= 40 years) statistically significantly modified the association between the 1–3 long-term sick leave spell pattern and commitment to the workplace compared with the 3–9 frequent short-term pattern. Conclusions Total sick leave length and a long-term sick leave spell pattern were just as good or even better indicators of unfavourable work factor scores than a frequent short-term sick leave

Some problems of antibiotic therapy in radiation sickness

International Nuclear Information System (INIS)

Shalnova, G.A.

1975-01-01

Data on the application of antibiotics and the mechanism of their action in radiation sickness are reviewed. Questions are discussed, such as the effect of antibiotics on the course and outcome of radiation sickness, the development of dysbacteriosis following irradiation, the effect of antibiotics on endogenic infection, the development of resistance of autoflora microbes to antibiotics in an irradiated organism and various aspects of the mechanism of action of antibiotics in radiation sickness. (author)

Sick leave patterns as predictors of disability pension or long-term sick leave: a 6.75-year follow-up study in municipal eldercare workers

Science.gov (United States)

Stapelfeldt, Christina Malmose; Nielsen, Claus Vinther; Andersen, Niels Trolle; Krane, Line; Borg, Vilhelm; Fleten, Nils; Jensen, Chris

2014-01-01

Objectives The aim was to study whether a workplace-registered frequent short-term sick leave spell pattern was an early indicator of future disability pension or future long-term sick leave among municipal eldercare workers. Setting The municipal healthcare sector in the city of Aarhus, which is the second largest city in Denmark. Participants All elder care employees who worked the entire year of 2004 in the municipality of Aarhus, Denmark (N=2774). The employees’ sick leave days during 2004 were categorised into: 0–2 and 3–17 short (1–7 days) spells, 2–13 mixed short and long (8+ days) spells and long spells only. Student workers (n=180), employees who were absent due to maternal/paternal leave (n=536) and employees who did not work the entire year of 2004 (n=1218) were not included. Primary outcome Disability pension and long-term sick leave (≥8 weeks) were subsequently identified in a National register. The cumulative incidence proportion as a function of follow-up weeks was estimated using the Kaplan-Meier curve. The relative cumulative incidence (RR) of experiencing events within 352 weeks was analysed in a generalised linear regression model using the pseudo values method adjusted for age, occupation, unfavourable work factors and sick leave length. Results A frequent short-term and a mixed sick leave pattern showed RRs of being granted a disability pension of 2.08 (95% CI 1.00 to 4.35) and 2.61 (95% CI 1.33 to 5.12) compared with 0–2 short spells. The risk of long-term sick leave was significantly increased for all sick leave patterns compared with 0–2 short spells. Adding sick leave length to the models attenuated all RRs and they became non-significant. Conclusions Sick leave length was a better indicator of future workability than spell frequency. Preventive actions should target employees engaged in homecare. The more sick leave days the greater the preventive potential seems, irrespective of spell frequency. PMID:24508850

Early versus Late Decompression for Traumatic Spinal Cord Injuries; a Systematic Review and Meta-analysis

Directory of Open Access Journals (Sweden)

Mahmoud Yousefifard

2017-01-01

Full Text Available Introduction: Despite the vast number of surveys, no consensus has been reached on the optimum timing of spinal decompression surgery. This systematic review and meta-analysis aimed to compare the effects of early and late spinal decompression surgery on neurologic improvement and post-surgical complications in patients with traumatic spinal cord injuries.Methods: Two independent reviewers carried out an extended search in electronic databases. Data of neurological outcome and post-surgery complication were extracted. Finally, pooled relative risk (RR with a 95% confidence interval (CI was reported for comparing of efficacy of early and late surgical decompression.Results: Eventually 22 studies were included. The pooled RR was 0.77 (95% CI: 0.68-0.89 for at least one grade neurological improvement, and 0.84 (95% CI: 0.77-0.92 for at least two grade improvement. Pooled RR for surgical decompression performed within 12 hours after the injury was 0.26 (95% CI: 0.13-0.52; p<0.001, while it was 0.75 (95% CI: 0.63-0.90; p=0.002 when the procedure was performed within 24 hours, and 0.93 (95% CI: 0.76-1.14; p=0.48 when it was carried out in the first 72 hours after the injury. Surgical decompression performed within 24 hours after injury was found to be associated with significantly lower rates of post-surgical complications (RR=0.77; 95% CI: 0.68-0.86; p<0.001.Conclusion: The findings of this study indicate that early spinal decompression surgery can improve neurologic recovery and is associated with less post-surgical complications. The optimum efficacy is observed when the procedure is performed within 12 hours of the injury.

Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

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Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

2016-01-01

The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05–0.45 MPa s−1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

Science.gov (United States)

Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

2016-10-01

The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05-0.45 MPa s-1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

DSP accelerator for the wavelet compression/decompression of high- resolution images

Energy Technology Data Exchange (ETDEWEB)

Hunt, M.A.; Gleason, S.S.; Jatko, W.B.

1993-07-23

A Texas Instruments (TI) TMS320C30-based S-Bus digital signal processing (DSP) module was used to accelerate a wavelet-based compression and decompression algorithm applied to high-resolution fingerprint images. The law enforcement community, together with the National Institute of Standards and Technology (NISI), is adopting a standard based on the wavelet transform for the compression, transmission, and decompression of scanned fingerprint images. A two-dimensional wavelet transform of the input image is computed. Then spatial/frequency regions are automatically analyzed for information content and quantized for subsequent Huffman encoding. Compression ratios range from 10:1 to 30:1 while maintaining the level of image quality necessary for identification. Several prototype systems were developed using SUN SPARCstation 2 with a 1280 {times} 1024 8-bit display, 64-Mbyte random access memory (RAM), Tiber distributed data interface (FDDI), and Spirit-30 S-Bus DSP-accelerators from Sonitech. The final implementation of the DSP-accelerated algorithm performed the compression or decompression operation in 3.5 s per print. Further increases in system throughput were obtained by adding several DSP accelerators operating in parallel.

Complicated Pseudomeningocele Repair After Chiari Decompression: Case Report and Review of the Literature.

Science.gov (United States)

De Tommasi, Claudio; Bond, Aaron E

2016-04-01

Pseudomeningocele is a recognised complication after posterior fossa decompression for Chiari malformation. Its management can be challenging and treatment options vary in literature. A difficult-to-treat case of a pseudomeningocele after posterior fossa decompression for a Chiari I malformation is presented. A 34-year-old woman underwent an initial decompression followed by multiple revision surgeries after the development of a symptomatic pseudomeningocele and a low-grade infection. Complications associated with standard treatment modalities, including lumbar drainage and dural repair, are discussed. A review of the existing literature is presented. The reported case ultimately required complete removal of all dural repair materials to eliminate the patient's low-grade infection, a muscular flap, and placement of a ventricular-peritoneal shunt for definitive treatment after a trial of a lumbar drain led to herniation and development of a syrinx. Copyright © 2016 Elsevier Inc. All rights reserved.

ORACLE Stroke Study: Opinion Regarding Acceptable Outcome Following Decompressive Hemicraniectomy for Ischemic Stroke.

Science.gov (United States)

Honeybul, Stephen; Ho, Kwok M; Blacker, David W

2016-08-01

There continues to be considerable interest in the use of decompressive hemicraniectomy in the management of malignant cerebral artery infarction; however, concerns remain about long-term outcome. To assess opinion on consent and acceptable outcome among a wide range of healthcare workers. Seven hundred seventy-three healthcare workers at the 2 major public neurosurgical centers in Western Australia participated. Participants were asked to record their opinion on consent and acceptable outcome based on the modified Rankin Score (mRS). The evidence for clinical efficacy of the procedure was presented, and participants were then asked to reconsider their initial responses. Of the 773 participants included in the study, 407 (52.7%) initially felt that they would provide consent for a decompressive craniectomy as a lifesaving procedure, but only a minority of them considered an mRS score of 4 or 5 an acceptable outcome (for mRS score ≤4, n = 67, 8.7%; for mRS score = 4, n = 57, 7.4%). After the introduction of the concept of the disability paradox and the evidence for the clinical efficacy of decompressive craniectomy, more participants were unwilling to accept decompressive craniectomy (18.1% vs 37.8%), but at the same time, more were willing to accept an mRS score ≤4 as an acceptable outcome (for mRS score ≤4, n = 92, 11.9%; for mRS score = 4, n = 79, 10.2%). Most participants felt survival with dependency to be unacceptable. However, many would be willing to provide consent for surgery in the hopes that they may survive with some degree of independence. DESTINY, Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral ArterymRS, modified Rankin Scale.

The effects of venting and decompression on Yellow Tang (Zebrasoma flavescens in the marine ornamental aquarium fish trade