The Bayesian group lasso for confounded spatial data

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Hefley, Trevor J.; Hooten, Mevin B.; Hanks, Ephraim M.; Russell, Robin E.; Walsh, Daniel P.

2017-01-01

Generalized linear mixed models for spatial processes are widely used in applied statistics. In many applications of the spatial generalized linear mixed model (SGLMM), the goal is to obtain inference about regression coefficients while achieving optimal predictive ability. When implementing the SGLMM, multicollinearity among covariates and the spatial random effects can make computation challenging and influence inference. We present a Bayesian group lasso prior with a single tuning parameter that can be chosen to optimize predictive ability of the SGLMM and jointly regularize the regression coefficients and spatial random effect. We implement the group lasso SGLMM using efficient Markov chain Monte Carlo (MCMC) algorithms and demonstrate how multicollinearity among covariates and the spatial random effect can be monitored as a derived quantity. To test our method, we compared several parameterizations of the SGLMM using simulated data and two examples from plant ecology and disease ecology. In all examples, problematic levels multicollinearity occurred and influenced sampling efficiency and inference. We found that the group lasso prior resulted in roughly twice the effective sample size for MCMC samples of regression coefficients and can have higher and less variable predictive accuracy based on out-of-sample data when compared to the standard SGLMM.

Large-deflection statics analysis of active cardiac catheters through co-rotational modelling.

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Peng Qi; Chen Qiu; Mehndiratta, Aadarsh; I-Ming Chen; Haoyong Yu

2016-08-01

This paper presents a co-rotational concept for large-deflection formulation of cardiac catheters. Using this approach, the catheter is first discretized with a number of equal length beam elements and nodes, and the rigid body motions of an individual beam element are separated from its deformations. Therefore, it is adequate for modelling arbitrarily large deflections of a catheter with linear elastic analysis at the local element level. A novel design of active cardiac catheter of 9 Fr in diameter at the beginning of the paper is proposed, which is based on the contra-rotating double helix patterns and is improved from the previous prototypes. The modelling section is followed by MATLAB simulations of various deflections when the catheter is exerted different types of loads. This proves the feasibility of the presented modelling approach. To the best knowledge of the authors, it is the first to utilize this methodology for large-deflection static analysis of the catheter, which will enable more accurate control of robot-assisted cardiac catheterization procedures. Future work would include further experimental validations.

LES ARM Symbiotic Simulation and Observation (LASSO) Implementation Strategy

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Gustafson Jr., WI [Pacific Northwest National Laboratory; Vogelmann, AM [Brookhaven National Laboratory

2015-09-01

This document illustrates the design of the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) workflow to provide a routine, high-resolution modeling capability to augment the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s high-density observations. LASSO will create a powerful new capability for furthering ARM’s mission to advance understanding of cloud, radiation, aerosol, and land-surface processes. The combined observational and modeling elements will enable a new level of scientific inquiry by connecting processes and context to observations and providing needed statistics for details that cannot be measured. The result will be improved process understanding that facilitates concomitant improvements in climate model parameterizations. The initial LASSO implementation will be for ARM’s Southern Great Plains site in Oklahoma and will focus on shallow convection, which is poorly simulated by climate models due in part to clouds’ typically small spatial scale compared to model grid spacing, and because the convection involves complicated interactions of microphysical and boundary layer processes.

OPTIMAL WAVELENGTH SELECTION ON HYPERSPECTRAL DATA WITH FUSED LASSO FOR BIOMASS ESTIMATION OF TROPICAL RAIN FOREST

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T. Takayama

2016-06-01

Full Text Available Above-ground biomass prediction of tropical rain forest using remote sensing data is of paramount importance to continuous large-area forest monitoring. Hyperspectral data can provide rich spectral information for the biomass prediction; however, the prediction accuracy is affected by a small-sample-size problem, which widely exists as overfitting in using high dimensional data where the number of training samples is smaller than the dimensionality of the samples due to limitation of require time, cost, and human resources for field surveys. A common approach to addressing this problem is reducing the dimensionality of dataset. Also, acquired hyperspectral data usually have low signal-to-noise ratio due to a narrow bandwidth and local or global shifts of peaks due to instrumental instability or small differences in considering practical measurement conditions. In this work, we propose a methodology based on fused lasso regression that select optimal bands for the biomass prediction model with encouraging sparsity and grouping, which solves the small-sample-size problem by the dimensionality reduction from the sparsity and the noise and peak shift problem by the grouping. The prediction model provided higher accuracy with root-mean-square error (RMSE of 66.16 t/ha in the cross-validation than other methods; multiple linear analysis, partial least squares regression, and lasso regression. Furthermore, fusion of spectral and spatial information derived from texture index increased the prediction accuracy with RMSE of 62.62 t/ha. This analysis proves efficiency of fused lasso and image texture in biomass estimation of tropical forests.

Determination of lesion size by ultrasound during radiofrequency catheter ablation.

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Awad, S; Eick, O

2003-01-01

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

Fast empirical Bayesian LASSO for multiple quantitative trait locus mapping

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Xu Shizhong

2011-05-01

Full Text Available Abstract Background The Bayesian shrinkage technique has been applied to multiple quantitative trait loci (QTLs mapping to estimate the genetic effects of QTLs on quantitative traits from a very large set of possible effects including the main and epistatic effects of QTLs. Although the recently developed empirical Bayes (EB method significantly reduced computation comparing with the fully Bayesian approach, its speed and accuracy are limited by the fact that numerical optimization is required to estimate the variance components in the QTL model. Results We developed a fast empirical Bayesian LASSO (EBLASSO method for multiple QTL mapping. The fact that the EBLASSO can estimate the variance components in a closed form along with other algorithmic techniques render the EBLASSO method more efficient and accurate. Comparing with the EB method, our simulation study demonstrated that the EBLASSO method could substantially improve the computational speed and detect more QTL effects without increasing the false positive rate. Particularly, the EBLASSO algorithm running on a personal computer could easily handle a linear QTL model with more than 100,000 variables in our simulation study. Real data analysis also demonstrated that the EBLASSO method detected more reasonable effects than the EB method. Comparing with the LASSO, our simulation showed that the current version of the EBLASSO implemented in Matlab had similar speed as the LASSO implemented in Fortran, and that the EBLASSO detected the same number of true effects as the LASSO but a much smaller number of false positive effects. Conclusions The EBLASSO method can handle a large number of effects possibly including both the main and epistatic QTL effects, environmental effects and the effects of gene-environment interactions. It will be a very useful tool for multiple QTL mapping.

Sparse inverse covariance estimation with the graphical lasso.

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Friedman, Jerome; Hastie, Trevor; Tibshirani, Robert

2008-07-01

We consider the problem of estimating sparse graphs by a lasso penalty applied to the inverse covariance matrix. Using a coordinate descent procedure for the lasso, we develop a simple algorithm--the graphical lasso--that is remarkably fast: It solves a 1000-node problem ( approximately 500,000 parameters) in at most a minute and is 30-4000 times faster than competing methods. It also provides a conceptual link between the exact problem and the approximation suggested by Meinshausen and Bühlmann (2006). We illustrate the method on some cell-signaling data from proteomics.

Factors associated with performing tuberculosis screening of HIV-positive patients in Ghana: LASSO-based predictor selection in a large public health data set

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Susanne Mueller-Using

2016-07-01

Full Text Available Abstract Background The purpose of this study is to propose the Least Absolute Shrinkage and Selection Operators procedure (LASSO as an alternative to conventional variable selection models, as it allows for easy interpretation and handles multicollinearities. We developed a model on the basis of LASSO-selected parameters in order to link associated demographical, socio-economical, clinical and immunological factors to performing tuberculosis screening in HIV-positive patients in Ghana. Methods Applying the LASSO method and multivariate logistic regression analysis on a large public health data set, we selected relevant predictors related to tuberculosis screening. Results One Thousand Ninety Five patients infected with HIV were enrolled into this study with 691 (63.2 % of them having tuberculosis screening documented in their patient folders. Predictors found to be significantly associated with performance of tuberculosis screening can be classified into factors related to the clinician’s perception of the clinical state, as well as those related to PLHIV’s awareness. These factors include newly diagnosed HIV infections (n = 354 (32.42 %, aOR 1.84, current CD4+ T cell count (aOR 0.92, non-availability of HIV type (n = 787 (72.07 %, aOR 0.56, chronic cough (n = 32 (2.93 %, aOR 5.07, intake of co-trimoxazole (n = 271 (24.82 %, aOR 2.31, vitamin supplementation (n = 220 (20.15 %, aOR 2.64 as well as the use of mosquito bed nets (n = 613 (56.14 %, aOR 1.53. Conclusions Accelerated TB screening among newly diagnosed HIV-patients indicates that application of the WHO screening form for intensifying tuberculosis case finding among HIV-positive individuals in resource-limited settings is increasingly adopted. However, screening for TB in PLHIV is still impacted by clinician’s perception of patient’s health state and PLHIV’s health awareness. Education of staff, counselling of PLHIV and sufficient financing are

LASSO-ligand activity by surface similarity order: a new tool for ligand based virtual screening.

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Reid, Darryl; Sadjad, Bashir S; Zsoldos, Zsolt; Simon, Aniko

2008-01-01

Virtual Ligand Screening (VLS) has become an integral part of the drug discovery process for many pharmaceutical companies. Ligand similarity searches provide a very powerful method of screening large databases of ligands to identify possible hits. If these hits belong to new chemotypes the method is deemed even more successful. eHiTS LASSO uses a new interacting surface point types (ISPT) molecular descriptor that is generated from the 3D structure of the ligand, but unlike most 3D descriptors it is conformation independent. Combined with a neural network machine learning technique, LASSO screens molecular databases at an ultra fast speed of 1 million structures in under 1 min on a standard PC. The results obtained from eHiTS LASSO trained on relatively small training sets of just 2, 4 or 8 actives are presented using the diverse directory of useful decoys (DUD) dataset. It is shown that over a wide range of receptor families, eHiTS LASSO is consistently able to enrich screened databases and provides scaffold hopping ability.

Malfunctioning and infected tunneled infusion catheters: over-the-wire catheter exchange versus catheter removal and replacement.

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Guttmann, David M; Trerotola, Scott O; Clark, Timothy W; Dagli, Mandeep; Shlansky-Goldberg, Richard D; Itkin, Maxim; Soulen, Michael C; Mondschein, Jeffrey I; Stavropoulos, S William

2011-05-01

To compare the safety and effectiveness of over-the-wire catheter exchange (catheter-exchange) with catheter removal and replacement (removal-replacement) at a new site for infected or malfunctioning tunneled infusion catheters. Using a quality assurance database, 61 patients with tunneled infusion catheters placed during the period July 2001 to June 2009 were included in this study. Patients receiving hemodialysis catheters were excluded. Catheter-exchange was performed in 25 patients, and same-day removal-replacement was performed in 36 patients. Data collected included demographic information, indication for initial catheter placement and replacement, dwell time for the new catheter, and ultimate fate of the new device. Statistical comparisons between the two cohorts were analyzed using the Kaplan-Meier technique and Fisher exact test. Catheters exchanged over the wire remained functional without infection for a median of 102 days (range, 2-570 days), whereas catheters removed and replaced were functional for a median 238 days (range, 1-292 days, P = .12). After catheter replacement, there were 11 instances of subsequent infection in the catheter-exchange group and 7 instances in the removal-replacement cohort, accounting for infection rates of 4.4 and 2.3 per 1,000 catheter days (P = .049). Patients in the catheter-exchange group had 3.2 greater odds of infection compared with patients in the removal-replacement group. Five malfunction events occurred in each group, accounting for 2.0 and 1.7 malfunctions per 1,000 catheter days in the catheter-exchange and removal-replacement groups (P = .73). Catheter-exchange of tunneled infusion catheters results in a higher infection rate compared with removal-replacement at a new site. The rate of catheter malfunction is not significantly different between the two groups. Catheter-exchange is an alternative for patients with tunneled infusion catheters who have limited venous access, but this technique should not be

Bayesian LASSO, scale space and decision making in association genetics.

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Pasanen, Leena; Holmström, Lasse; Sillanpää, Mikko J

2015-01-01

LASSO is a penalized regression method that facilitates model fitting in situations where there are as many, or even more explanatory variables than observations, and only a few variables are relevant in explaining the data. We focus on the Bayesian version of LASSO and consider four problems that need special attention: (i) controlling false positives, (ii) multiple comparisons, (iii) collinearity among explanatory variables, and (iv) the choice of the tuning parameter that controls the amount of shrinkage and the sparsity of the estimates. The particular application considered is association genetics, where LASSO regression can be used to find links between chromosome locations and phenotypic traits in a biological organism. However, the proposed techniques are relevant also in other contexts where LASSO is used for variable selection. We separate the true associations from false positives using the posterior distribution of the effects (regression coefficients) provided by Bayesian LASSO. We propose to solve the multiple comparisons problem by using simultaneous inference based on the joint posterior distribution of the effects. Bayesian LASSO also tends to distribute an effect among collinear variables, making detection of an association difficult. We propose to solve this problem by considering not only individual effects but also their functionals (i.e. sums and differences). Finally, whereas in Bayesian LASSO the tuning parameter is often regarded as a random variable, we adopt a scale space view and consider a whole range of fixed tuning parameters, instead. The effect estimates and the associated inference are considered for all tuning parameters in the selected range and the results are visualized with color maps that provide useful insights into data and the association problem considered. The methods are illustrated using two sets of artificial data and one real data set, all representing typical settings in association genetics.

Controlling the local false discovery rate in the adaptive Lasso

KAUST Repository

Sampson, J. N.

2013-04-09

The Lasso shrinkage procedure achieved its popularity, in part, by its tendency to shrink estimated coefficients to zero, and its ability to serve as a variable selection procedure. Using data-adaptive weights, the adaptive Lasso modified the original procedure to increase the penalty terms for those variables estimated to be less important by ordinary least squares. Although this modified procedure attained the oracle properties, the resulting models tend to include a large number of "false positives" in practice. Here, we adapt the concept of local false discovery rates (lFDRs) so that it applies to the sequence, λn, of smoothing parameters for the adaptive Lasso. We define the lFDR for a given λn to be the probability that the variable added to the model by decreasing λn to λn-δ is not associated with the outcome, where δ is a small value. We derive the relationship between the lFDR and λn, show lFDR =1 for traditional smoothing parameters, and show how to select λn so as to achieve a desired lFDR. We compare the smoothing parameters chosen to achieve a specified lFDR and those chosen to achieve the oracle properties, as well as their resulting estimates for model coefficients, with both simulation and an example from a genetic study of prostate specific antigen.

Lasso and probabilistic inequalities for multivariate point processes

DEFF Research Database (Denmark)

Hansen, Niels Richard; Reynaud-Bouret, Patricia; Rivoirard, Vincent

2015-01-01

Due to its low computational cost, Lasso is an attractive regularization method for high-dimensional statistical settings. In this paper, we consider multivariate counting processes depending on an unknown function parameter to be estimated by linear combinations of a fixed dictionary. To select...... for multivariate Hawkes processes are proven, which allows us to check these assumptions by considering general dictionaries based on histograms, Fourier or wavelet bases. Motivated by problems of neuronal activity inference, we finally carry out a simulation study for multivariate Hawkes processes and compare our...... methodology with the adaptive Lasso procedure proposed by Zou in (J. Amer. Statist. Assoc. 101 (2006) 1418–1429). We observe an excellent behavior of our procedure. We rely on theoretical aspects for the essential question of tuning our methodology. Unlike adaptive Lasso of (J. Amer. Statist. Assoc. 101 (2006...

Multivariate sparse group lasso for the multivariate multiple linear regression with an arbitrary group structure.

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Li, Yanming; Nan, Bin; Zhu, Ji

2015-06-01

We propose a multivariate sparse group lasso variable selection and estimation method for data with high-dimensional predictors as well as high-dimensional response variables. The method is carried out through a penalized multivariate multiple linear regression model with an arbitrary group structure for the regression coefficient matrix. It suits many biology studies well in detecting associations between multiple traits and multiple predictors, with each trait and each predictor embedded in some biological functional groups such as genes, pathways or brain regions. The method is able to effectively remove unimportant groups as well as unimportant individual coefficients within important groups, particularly for large p small n problems, and is flexible in handling various complex group structures such as overlapping or nested or multilevel hierarchical structures. The method is evaluated through extensive simulations with comparisons to the conventional lasso and group lasso methods, and is applied to an eQTL association study. © 2015, The International Biometric Society.

Surface-Treated versus Untreated Large-Bore Catheters as Vascular Access in Hemodialysis and Apheresis Treatments

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Rolf Bambauer

2012-01-01

Full Text Available Background. Catheter-related infections, thrombosis, and stenosis are among the most frequent complications associated with catheters, which are inserted in vessels. Surface treatment processes of the outer surface, such as ion-beam-assisted deposition, can be used to mitigate such complications. Methods. This retrospective study (1992–2007 evaluated silver-coated (54 patients and noncoated (105 patients implanted large-bore catheters used for extracorporeal detoxification. The catheters were inserted into the internal jugular or subclavian veins. After removal, the catheters were cultured for bacterial colonization using standard microbiologic assays. They also were examined using scanning electron microscope. Results. The silver coated catheters showed a tendency towards longer in situ time. The microbiologic examinations of the catheter tips were in both catheter types high positive, but not significant. Conclusion. The silver-coated catheters showed no significantly reduction in infection rate by evaluation of all collected data in this retrospective study. There was no association between both catheters in significantly reducing savings in treatment costs and in reducing patient discomfort. Other new developed catheter materials such as the microdomain-structured inner and outer surface are considered more biocompatible because they mimic the structure of natural biological surface.

The Los Alamos Space Science Outreach (LASSO) Program

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Barker, P. L.; Skoug, R. M.; Alexander, R. J.; Thomsen, M. F.; Gary, S. P.

2002-12-01

The Los Alamos Space Science Outreach (LASSO) program features summer workshops in which K-14 teachers spend several weeks at LANL learning space science from Los Alamos scientists and developing methods and materials for teaching this science to their students. The program is designed to provide hands-on space science training to teachers as well as assistance in developing lesson plans for use in their classrooms. The program supports an instructional model based on education research and cognitive theory. Students and teachers engage in activities that encourage critical thinking and a constructivist approach to learning. LASSO is run through the Los Alamos Science Education Team (SET). SET personnel have many years of experience in teaching, education research, and science education programs. Their involvement ensures that the teacher workshop program is grounded in sound pedagogical methods and meets current educational standards. Lesson plans focus on current LANL satellite projects to study the solar wind and the Earth's magnetosphere. LASSO is an umbrella program for space science education activities at Los Alamos National Laboratory (LANL) that was created to enhance the science and math interests and skills of students from New Mexico and the nation. The LASSO umbrella allows maximum leveraging of EPO funding from a number of projects (and thus maximum educational benefits to both students and teachers), while providing a format for the expression of the unique science perspective of each project.

The joint graphical lasso for inverse covariance estimation across multiple classes.

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Danaher, Patrick; Wang, Pei; Witten, Daniela M

2014-03-01

We consider the problem of estimating multiple related Gaussian graphical models from a high-dimensional data set with observations belonging to distinct classes. We propose the joint graphical lasso , which borrows strength across the classes in order to estimate multiple graphical models that share certain characteristics, such as the locations or weights of nonzero edges. Our approach is based upon maximizing a penalized log likelihood. We employ generalized fused lasso or group lasso penalties, and implement a fast ADMM algorithm to solve the corresponding convex optimization problems. The performance of the proposed method is illustrated through simulated and real data examples.

Large-volume paracentesis with indwelling peritoneal catheter and albumin infusion: a community hospital study

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Daniel K. Martin

2016-10-01

Full Text Available Background: The management of ascites can be problematic. This is especially true in patients with diuretic refractory ascites who develop a tense abdomen. This often results in hypotension and decreased venous return with resulting renal failure. In this paper, we further examine the risks and benefits of utilizing an indwelling peritoneal catheter to remove large-volume ascites over a 72-h period while maintaining intravascular volume and preventing renal failure. Methods: We retrospectively reviewed charts and identified 36 consecutive patients undergoing continuous large-volume paracentesis with an indwelling peritoneal catheter. At the time of drain placement, no patients had signs or laboratory parameters suggestive of spontaneous bacterial peritonitis. The patients underwent ascitic fluid removal through an indwelling peritoneal catheter and were supported with scheduled albumin throughout the duration. The catheter was used to remove up to 3 L every 8 h for a maximum of 72 h. Regular laboratory and ascitic fluid testing was performed. All patients had a clinical follow-up within 3 months after the drain placement. Results: An average of 16.5 L was removed over the 72-h time frame of indwelling peritoneal catheter maintenance. The albumin infusion utilized correlated to 12 mg/L removed. The average creatinine trend improved in a statistically significant manner from 1.37 on the day of admission to 1.21 on the day of drain removal. No patients developed renal failure during the hospital course. There were no documented episodes of neutrocytic ascites or bacterial peritonitis throughout the study review. Conclusion: Large-volume peritoneal drainage with an indwelling peritoneal catheter is safe and effective for patients with tense ascites. Concomitant albumin infusion allows for maintenance of renal function, and no increase in infectious complications was noted.

Toward Probabilistic Diagnosis and Understanding of Depression Based on Functional MRI Data Analysis with Logistic Group LASSO.

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Yu Shimizu

Full Text Available Diagnosis of psychiatric disorders based on brain imaging data is highly desirable in clinical applications. However, a common problem in applying machine learning algorithms is that the number of imaging data dimensions often greatly exceeds the number of available training samples. Furthermore, interpretability of the learned classifier with respect to brain function and anatomy is an important, but non-trivial issue. We propose the use of logistic regression with a least absolute shrinkage and selection operator (LASSO to capture the most critical input features. In particular, we consider application of group LASSO to select brain areas relevant to diagnosis. An additional advantage of LASSO is its probabilistic output, which allows evaluation of diagnosis certainty. To verify our approach, we obtained semantic and phonological verbal fluency fMRI data from 31 depression patients and 31 control subjects, and compared the performances of group LASSO (gLASSO, and sparse group LASSO (sgLASSO to those of standard LASSO (sLASSO, Support Vector Machine (SVM, and Random Forest. Over 90% classification accuracy was achieved with gLASSO, sgLASSO, as well as SVM; however, in contrast to SVM, LASSO approaches allow for identification of the most discriminative weights and estimation of prediction reliability. Semantic task data revealed contributions to the classification from left precuneus, left precentral gyrus, left inferior frontal cortex (pars triangularis, and left cerebellum (c rus1. Weights for the phonological task indicated contributions from left inferior frontal operculum, left post central gyrus, left insula, left middle frontal cortex, bilateral middle temporal cortices, bilateral precuneus, left inferior frontal cortex (pars triangularis, and left precentral gyrus. The distribution of normalized odds ratios further showed, that predictions with absolute odds ratios higher than 0.2 could be regarded as certain.

Sparse EEG/MEG source estimation via a group lasso.

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Michael Lim

Full Text Available Non-invasive recordings of human brain activity through electroencephalography (EEG or magnetoencelphalography (MEG are of value for both basic science and clinical applications in sensory, cognitive, and affective neuroscience. Here we introduce a new approach to estimating the intra-cranial sources of EEG/MEG activity measured from extra-cranial sensors. The approach is based on the group lasso, a sparse-prior inverse that has been adapted to take advantage of functionally-defined regions of interest for the definition of physiologically meaningful groups within a functionally-based common space. Detailed simulations using realistic source-geometries and data from a human Visual Evoked Potential experiment demonstrate that the group-lasso method has improved performance over traditional ℓ2 minimum-norm methods. In addition, we show that pooling source estimates across subjects over functionally defined regions of interest results in improvements in the accuracy of source estimates for both the group-lasso and minimum-norm approaches.

Identifying the Prognosis Factors in Death after Liver Transplantation via Adaptive LASSO in Iran

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Hadi Raeisi Shahraki

2016-01-01

Full Text Available Despite the widespread use of liver transplantation as a routine therapy in liver diseases, the effective factors on its outcomes are still controversial. This study attempted to identify the most effective factors on death after liver transplantation. For this purpose, modified least absolute shrinkage and selection operator (LASSO, called Adaptive LASSO, was utilized. One of the best advantages of this method is considering high number of factors. Therefore, in a historical cohort study from 2008 to 2013, the clinical findings of 680 patients undergoing liver transplant surgery were considered. Ridge and Adaptive LASSO regression methods were then implemented to identify the most effective factors on death. To compare the performance of these two models, receiver operating characteristic (ROC curve was used. According to the results, 12 factors in Ridge regression and 9 ones in Adaptive LASSO regression were significant. The area under the ROC curve (AUC of Adaptive LASSO was equal to 89% (95% CI: 86%–91%, which was significantly greater than Ridge regression (64%, 95% CI: 61%–68% (p<0.001. As a conclusion, the significant factors and the performance criteria revealed the superiority of Adaptive LASSO method as a penalized model versus traditional regression model in the present study.

Supervised group Lasso with applications to microarray data analysis

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Huang Jian

2007-02-01

Full Text Available Abstract Background A tremendous amount of efforts have been devoted to identifying genes for diagnosis and prognosis of diseases using microarray gene expression data. It has been demonstrated that gene expression data have cluster structure, where the clusters consist of co-regulated genes which tend to have coordinated functions. However, most available statistical methods for gene selection do not take into consideration the cluster structure. Results We propose a supervised group Lasso approach that takes into account the cluster structure in gene expression data for gene selection and predictive model building. For gene expression data without biological cluster information, we first divide genes into clusters using the K-means approach and determine the optimal number of clusters using the Gap method. The supervised group Lasso consists of two steps. In the first step, we identify important genes within each cluster using the Lasso method. In the second step, we select important clusters using the group Lasso. Tuning parameters are determined using V-fold cross validation at both steps to allow for further flexibility. Prediction performance is evaluated using leave-one-out cross validation. We apply the proposed method to disease classification and survival analysis with microarray data. Conclusion We analyze four microarray data sets using the proposed approach: two cancer data sets with binary cancer occurrence as outcomes and two lymphoma data sets with survival outcomes. The results show that the proposed approach is capable of identifying a small number of influential gene clusters and important genes within those clusters, and has better prediction performance than existing methods.

Pierced Lasso Bundles are a new class of knot-like motifs.

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Ellinor Haglund

2014-06-01

Full Text Available A four-helix bundle is a well-characterized motif often used as a target for designed pharmaceutical therapeutics and nutritional supplements. Recently, we discovered a new structural complexity within this motif created by a disulphide bridge in the long-chain helical bundle cytokine leptin. When oxidized, leptin contains a disulphide bridge creating a covalent-loop through which part of the polypeptide chain is threaded (as seen in knotted proteins. We explored whether other proteins contain a similar intriguing knot-like structure as in leptin and discovered 11 structurally homologous proteins in the PDB. We call this new helical family class the Pierced Lasso Bundle (PLB and the knot-like threaded structural motif a Pierced Lasso (PL. In the current study, we use structure-based simulation to investigate the threading/folding mechanisms for all the PLBs along with three unthreaded homologs as the covalent loop (or lasso in leptin is important in folding dynamics and activity. We find that the presence of a small covalent loop leads to a mechanism where structural elements slipknot to thread through the covalent loop. Larger loops use a piercing mechanism where the free terminal plugs through the covalent loop. Remarkably, the position of the loop as well as its size influences the native state dynamics, which can impact receptor binding and biological activity. This previously unrecognized complexity of knot-like proteins within the helical bundle family comprises a completely new class within the knot family, and the hidden complexity we unraveled in the PLBs is expected to be found in other protein structures outside the four-helix bundles. The insights gained here provide critical new elements for future investigation of this emerging class of proteins, where function and the energetic landscape can be controlled by hidden topology, and should be take into account in ab initio predictions of newly identified protein targets.

Building interpretable predictive models for pediatric hospital readmission using Tree-Lasso logistic regression.

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Jovanovic, Milos; Radovanovic, Sandro; Vukicevic, Milan; Van Poucke, Sven; Delibasic, Boris

2016-09-01

Quantification and early identification of unplanned readmission risk have the potential to improve the quality of care during hospitalization and after discharge. However, high dimensionality, sparsity, and class imbalance of electronic health data and the complexity of risk quantification, challenge the development of accurate predictive models. Predictive models require a certain level of interpretability in order to be applicable in real settings and create actionable insights. This paper aims to develop accurate and interpretable predictive models for readmission in a general pediatric patient population, by integrating a data-driven model (sparse logistic regression) and domain knowledge based on the international classification of diseases 9th-revision clinical modification (ICD-9-CM) hierarchy of diseases. Additionally, we propose a way to quantify the interpretability of a model and inspect the stability of alternative solutions. The analysis was conducted on >66,000 pediatric hospital discharge records from California, State Inpatient Databases, Healthcare Cost and Utilization Project between 2009 and 2011. We incorporated domain knowledge based on the ICD-9-CM hierarchy in a data driven, Tree-Lasso regularized logistic regression model, providing the framework for model interpretation. This approach was compared with traditional Lasso logistic regression resulting in models that are easier to interpret by fewer high-level diagnoses, with comparable prediction accuracy. The results revealed that the use of a Tree-Lasso model was as competitive in terms of accuracy (measured by area under the receiver operating characteristic curve-AUC) as the traditional Lasso logistic regression, but integration with the ICD-9-CM hierarchy of diseases provided more interpretable models in terms of high-level diagnoses. Additionally, interpretations of models are in accordance with existing medical understanding of pediatric readmission. Best performing models have

The use of vector bootstrapping to improve variable selection precision in Lasso models

NARCIS (Netherlands)

Laurin, C.; Boomsma, D.I.; Lubke, G.H.

2016-01-01

The Lasso is a shrinkage regression method that is widely used for variable selection in statistical genetics. Commonly, K-fold cross-validation is used to fit a Lasso model. This is sometimes followed by using bootstrap confidence intervals to improve precision in the resulting variable selections.

Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio.

Science.gov (United States)

Spencer, Timothy R; Mahoney, Keegan J

2017-11-01

In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33 to 45% of the vessels diameter. There has been evidence on larger diameter catheters and increased thrombosis risk in recent literature, while insufficient information established on what relationship to vessel size is appropriate for any intra-vascular device. Earlier references to clinical standards and guidelines did not clearly address vessel size in relation to the area consumed or external catheter diameter. The aim of this manuscript is to present catheter-related thrombosis evidence and develop a standardized process of ultrasound-guided vessel assessment, integrating CVR, Virchow's triad phenomenon and vessel health and preservation strategies, empowering an evidence-based approach to device placement. Through review, calculation and assessment on the areas of the 33 and 45% rule, a preliminary clinical tool was developed to assist clinicians make cognizant decisions when placing intravascular devices relating to target vessel size, focusing on potential reduction in catheter-related thrombosis. Increasing the understanding and utilization of CVRs will lead to a safer, more consistent approach to device placement, with potential thrombosis reduction strategies. The future of evidence-based data relies on the clinician to capture accurate vessel measurements and device-related outcomes. This will lead to a more dependable data pool, driving the relationship of catheter-related thrombosis and vascular assessment.

Inference for feature selection using the Lasso with high-dimensional data

DEFF Research Database (Denmark)

Brink-Jensen, Kasper; Ekstrøm, Claus Thorn

2014-01-01

Penalized regression models such as the Lasso have proved useful for variable selection in many fields - especially for situations with high-dimensional data where the numbers of predictors far exceeds the number of observations. These methods identify and rank variables of importance but do...... not generally provide any inference of the selected variables. Thus, the variables selected might be the "most important" but need not be significant. We propose a significance test for the selection found by the Lasso. We introduce a procedure that computes inference and p-values for features chosen...... by the Lasso. This method rephrases the null hypothesis and uses a randomization approach which ensures that the error rate is controlled even for small samples. We demonstrate the ability of the algorithm to compute $p$-values of the expected magnitude with simulated data using a multitude of scenarios...

Genetic risk prediction using a spatial autoregressive model with adaptive lasso.

Science.gov (United States)

Wen, Yalu; Shen, Xiaoxi; Lu, Qing

2018-05-31

With rapidly evolving high-throughput technologies, studies are being initiated to accelerate the process toward precision medicine. The collection of the vast amounts of sequencing data provides us with great opportunities to systematically study the role of a deep catalog of sequencing variants in risk prediction. Nevertheless, the massive amount of noise signals and low frequencies of rare variants in sequencing data pose great analytical challenges on risk prediction modeling. Motivated by the development in spatial statistics, we propose a spatial autoregressive model with adaptive lasso (SARAL) for risk prediction modeling using high-dimensional sequencing data. The SARAL is a set-based approach, and thus, it reduces the data dimension and accumulates genetic effects within a single-nucleotide variant (SNV) set. Moreover, it allows different SNV sets having various magnitudes and directions of effect sizes, which reflects the nature of complex diseases. With the adaptive lasso implemented, SARAL can shrink the effects of noise SNV sets to be zero and, thus, further improve prediction accuracy. Through simulation studies, we demonstrate that, overall, SARAL is comparable to, if not better than, the genomic best linear unbiased prediction method. The method is further illustrated by an application to the sequencing data from the Alzheimer's Disease Neuroimaging Initiative. Copyright © 2018 John Wiley & Sons, Ltd.

Dictionary-Based Image Denoising by Fused-Lasso Atom Selection

Directory of Open Access Journals (Sweden)

Ao Li

2014-01-01

Full Text Available We proposed an efficient image denoising scheme by fused lasso with dictionary learning. The scheme has two important contributions. The first one is that we learned the patch-based adaptive dictionary by principal component analysis (PCA with clustering the image into many subsets, which can better preserve the local geometric structure. The second one is that we coded the patches in each subset by fused lasso with the clustering learned dictionary and proposed an iterative Split Bregman to solve it rapidly. We present the capabilities with several experiments. The results show that the proposed scheme is competitive to some excellent denoising algorithms.

The Bayesian Covariance Lasso.

Science.gov (United States)

Khondker, Zakaria S; Zhu, Hongtu; Chu, Haitao; Lin, Weili; Ibrahim, Joseph G

2013-04-01

Estimation of sparse covariance matrices and their inverse subject to positive definiteness constraints has drawn a lot of attention in recent years. The abundance of high-dimensional data, where the sample size ( n ) is less than the dimension ( d ), requires shrinkage estimation methods since the maximum likelihood estimator is not positive definite in this case. Furthermore, when n is larger than d but not sufficiently larger, shrinkage estimation is more stable than maximum likelihood as it reduces the condition number of the precision matrix. Frequentist methods have utilized penalized likelihood methods, whereas Bayesian approaches rely on matrix decompositions or Wishart priors for shrinkage. In this paper we propose a new method, called the Bayesian Covariance Lasso (BCLASSO), for the shrinkage estimation of a precision (covariance) matrix. We consider a class of priors for the precision matrix that leads to the popular frequentist penalties as special cases, develop a Bayes estimator for the precision matrix, and propose an efficient sampling scheme that does not precalculate boundaries for positive definiteness. The proposed method is permutation invariant and performs shrinkage and estimation simultaneously for non-full rank data. Simulations show that the proposed BCLASSO performs similarly as frequentist methods for non-full rank data.

Catheter-related bloodstream infection.

Science.gov (United States)

Goede, Matthew R; Coopersmith, Craig M

2009-04-01

Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed.

Validating the LASSO algorithm by unmixing spectral signatures in multicolor phantoms

Science.gov (United States)

Samarov, Daniel V.; Clarke, Matthew; Lee, Ji Yoon; Allen, David; Litorja, Maritoni; Hwang, Jeeseong

2012-03-01

As hyperspectral imaging (HSI) sees increased implementation into the biological and medical elds it becomes increasingly important that the algorithms being used to analyze the corresponding output be validated. While certainly important under any circumstance, as this technology begins to see a transition from benchtop to bedside ensuring that the measurements being given to medical professionals are accurate and reproducible is critical. In order to address these issues work has been done in generating a collection of datasets which could act as a test bed for algorithms validation. Using a microarray spot printer a collection of three food color dyes, acid red 1 (AR), brilliant blue R (BBR) and erioglaucine (EG) are mixed together at dierent concentrations in varying proportions at dierent locations on a microarray chip. With the concentration and mixture proportions known at each location, using HSI an algorithm should in principle, based on estimates of abundances, be able to determine the concentrations and proportions of each dye at each location on the chip. These types of data are particularly important in the context of medical measurements as the resulting estimated abundances will be used to make critical decisions which can have a serious impact on an individual's health. In this paper we present a novel algorithm for processing and analyzing HSI data based on the LASSO algorithm (similar to "basis pursuit"). The LASSO is a statistical method for simultaneously performing model estimation and variable selection. In the context of estimating abundances in an HSI scene these so called "sparse" representations provided by the LASSO are appropriate as not every pixel will be expected to contain every endmember. The algorithm we present takes the general framework of the LASSO algorithm a step further and incorporates the rich spatial information which is available in HSI to further improve the estimates of abundance. We show our algorithm's improvement

LASSO observations at McDonald and OCA/CERGA: A preliminary analysis

Science.gov (United States)

Veillet, CH.; Fridelance, P.; Feraudy, D.; Boudon, Y.; Shelus, P. J.; Ricklefs, R. L.; Wiant, J. R.

1993-01-01

The Laser Synchronization from Synchronous Orbit (LASSO) observations between USA and Europe were made possible with the move of Meteosat 3/P2 toward 50 deg W. Two Lunar Laser Ranging stations participated into the observations: the MLRS at McDonald Observatory (Texas, USA) and OCA/CERGA (Grasse, France). Common sessions were performed since 30 Apr. 1992, and will be continued up to the next Meteosat 3/P2 move further West (planned for January 1993). The preliminary analysis made with the data already collected by the end of Nov. 1992 shows that the precision which can be obtained from LASSO is better than 100 ps, the accuracy depending on how well the stations maintain their time metrology, as well as on the quality of the calibration (still to be made.) For extracting such a precision from the data, the processing has been drastically changed compared to the initial LASSO data analysis. It takes into account all the measurements made, timings on board, and echoes at each station. This complete use of the data increased dramatically the confidence into the synchronization results.

Radiologic placement of tunneled central catheters: rates of success and of immediate complications in a large series.

Science.gov (United States)

Docktor, B L; Sadler, D J; Gray, R R; Saliken, J C; So, C B

1999-08-01

The objective was to examine the success and immediate complication rates in a large series of radiologically placed tunneled central venous catheters. We prospectively recorded the success and immediate complication rates in 880 consecutive radiologically placed tunneled central venous catheters. We also recorded the indication for placement, the success of placement, the number of passes required, and whether a double- or single-wall puncture occurred. Hemodialysis was the most common indication for long-term venous access. Venous access was successful in all patients, and catheter placement was successful in 99.4% of patients, with only five failed placements. All patients in whom placement was initially unsuccessful underwent successful placement the same day. All catheters were placed using real-time sonographic guidance. Most were placed in an internal jugular vein, with 87.4% requiring only a single needle pass. The immediate complication rate was only 4.0%, and no major complications occurred. To our knowledge, this series is the largest for which the immediate complication and success rates for radiologically placed central venous catheters have been reported. Our results suggest that radiologic placement of tunneled central venous catheters is a safe and effective alternative to surgery.

Development of A MEMS Based Manometric Catheter for Diagnosis of Functional Swallowing Disorders

International Nuclear Information System (INIS)

Hsu, H Y; Hariz, A J; Omari, T; Teng, M F; Sii, D; Chan, S; Lau, L; Tan, S; Lin, G; Haskard, M; Mulcahy, D; Bakewell, M

2006-01-01

Silicon pressure sensors based on micro-electro-mechanical-systems (MEMS) technologies are gaining popularity for applications in bio-medical devices. In this study, a silicon piezo-resistive pressure sensor die is used in a feasibility study of developing a manometric catheter for functional swallowing disorders diagnosis. The function of a manometric catheter is to measure the peak and intrabolus pressures along the esophageal segment during the swallowing action. Previous manometric catheters used the water perfusion technique to measure the pressure changes. This type of catheter is reusable, large in size and the pressure reading is recorded by an external transducer. Current manometric catheters use a solid state pressure sensor on the catheter itself to measure the pressure changes. This type of catheter reduces the discomfort to the patient but it is reusable and is very expensive. We carried out several studies and experiments on the MEMS-based pressure sensor die, and the results show the MEMS-based pressure sensors have a good stability and a good linearity output response, together with the advantage of low excitation biasing voltage and extremely small size. The MEMS-based sensor is the best device to use in the new generation of manometric catheters. The concept of the new MEMS-based manometric catheter consists of a pressure sensing sensor, supporting ring, the catheter tube and a data connector. Laboratory testing shows that the new calibrated catheter is capable of measuring pressure in the range from 0 to 100mmHg and maintaining stable condition on the zero baseline setting when no pressure is applied. In-vivo tests are carried out to compare the new MEMS based catheter with the current version of catheters used in the hospital

Association between biomarkers and clinical characteristics in chronic subdural hematoma patients assessed with lasso regression.

Directory of Open Access Journals (Sweden)

Are Hugo Pripp

Full Text Available Chronic subdural hematoma (CSDH is characterized by an "old" encapsulated collection of blood and blood breakdown products between the brain and its outermost covering (the dura. Recognized risk factors for development of CSDH are head injury, old age and using anticoagulation medication, but its underlying pathophysiological processes are still unclear. It is assumed that a complex local process of interrelated mechanisms including inflammation, neomembrane formation, angiogenesis and fibrinolysis could be related to its development and propagation. However, the association between the biomarkers of inflammation and angiogenesis, and the clinical and radiological characteristics of CSDH patients, need further investigation. The high number of biomarkers compared to the number of observations, the correlation between biomarkers, missing data and skewed distributions may limit the usefulness of classical statistical methods. We therefore explored lasso regression to assess the association between 30 biomarkers of inflammation and angiogenesis at the site of lesions, and selected clinical and radiological characteristics in a cohort of 93 patients. Lasso regression performs both variable selection and regularization to improve the predictive accuracy and interpretability of the statistical model. The results from the lasso regression showed analysis exhibited lack of robust statistical association between the biomarkers in hematoma fluid with age, gender, brain infarct, neurological deficiencies and volume of hematoma. However, there were associations between several of the biomarkers with postoperative recurrence requiring reoperation. The statistical analysis with lasso regression supported previous findings that the immunological characteristics of CSDH are local. The relationship between biomarkers, the radiological appearance of lesions and recurrence requiring reoperation have been inclusive using classical statistical methods on these data

The Spike-and-Slab Lasso Generalized Linear Models for Prediction and Associated Genes Detection.

Science.gov (United States)

Tang, Zaixiang; Shen, Yueping; Zhang, Xinyan; Yi, Nengjun

2017-01-01

Large-scale "omics" data have been increasingly used as an important resource for prognostic prediction of diseases and detection of associated genes. However, there are considerable challenges in analyzing high-dimensional molecular data, including the large number of potential molecular predictors, limited number of samples, and small effect of each predictor. We propose new Bayesian hierarchical generalized linear models, called spike-and-slab lasso GLMs, for prognostic prediction and detection of associated genes using large-scale molecular data. The proposed model employs a spike-and-slab mixture double-exponential prior for coefficients that can induce weak shrinkage on large coefficients, and strong shrinkage on irrelevant coefficients. We have developed a fast and stable algorithm to fit large-scale hierarchal GLMs by incorporating expectation-maximization (EM) steps into the fast cyclic coordinate descent algorithm. The proposed approach integrates nice features of two popular methods, i.e., penalized lasso and Bayesian spike-and-slab variable selection. The performance of the proposed method is assessed via extensive simulation studies. The results show that the proposed approach can provide not only more accurate estimates of the parameters, but also better prediction. We demonstrate the proposed procedure on two cancer data sets: a well-known breast cancer data set consisting of 295 tumors, and expression data of 4919 genes; and the ovarian cancer data set from TCGA with 362 tumors, and expression data of 5336 genes. Our analyses show that the proposed procedure can generate powerful models for predicting outcomes and detecting associated genes. The methods have been implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). Copyright © 2017 by the Genetics Society of America.

IPF-LASSO: Integrative L1-Penalized Regression with Penalty Factors for Prediction Based on Multi-Omics Data

Directory of Open Access Journals (Sweden)

Anne-Laure Boulesteix

2017-01-01

Full Text Available As modern biotechnologies advance, it has become increasingly frequent that different modalities of high-dimensional molecular data (termed “omics” data in this paper, such as gene expression, methylation, and copy number, are collected from the same patient cohort to predict the clinical outcome. While prediction based on omics data has been widely studied in the last fifteen years, little has been done in the statistical literature on the integration of multiple omics modalities to select a subset of variables for prediction, which is a critical task in personalized medicine. In this paper, we propose a simple penalized regression method to address this problem by assigning different penalty factors to different data modalities for feature selection and prediction. The penalty factors can be chosen in a fully data-driven fashion by cross-validation or by taking practical considerations into account. In simulation studies, we compare the prediction performance of our approach, called IPF-LASSO (Integrative LASSO with Penalty Factors and implemented in the R package ipflasso, with the standard LASSO and sparse group LASSO. The use of IPF-LASSO is also illustrated through applications to two real-life cancer datasets. All data and codes are available on the companion website to ensure reproducibility.

Laser welding of balloon catheters

Science.gov (United States)

Flanagan, Aidan J.

2003-03-01

The balloon catheter is one of the principal instruments of non-invasive vascular surgery. It is used most commonly for angioplasty (and in recent years for delivering stents) at a multitude of different sites in the body from small arteries in the heart to the bilary duct. It is composed of a polymer balloon that is attached to a polymer shaft at two points called the distal and proximal bonds. The diverse utility of balloon catheters means a large range of component sizes and materials are used during production; this leads to a complexity of bonding methods and technology. The proximal and distal bonds have been conventionally made using cyanoacrylate or UV curing glue, however with performance requirements of bond strength, flexibility, profile, and manufacturing costs these bonds are increasingly being made by welding using laser, RF, and Hot Jaw methods. This paper describes laser welding of distal and proximal balloon bonds and details beam delivery, bonding mechanisms, bond shaping, laser types, and wavelength choice.

Old habits die hard; does early urinary catheter removal affect kidney size, bacteriuria and UTI after renal transplantation?

Science.gov (United States)

Akbari, Roghayeh; Rahmani Firouzi, Sedigheh; Akbarzadeh-Pasha, Abazar

2017-01-01

Introduction: Renal transplantation is the treatment of choice in chronic renal failure patients. Objectives: The purpose of this study was to evaluate the impact of urinary catheter removal time on transplanted kidney size and incidence of asymptomatic bacteriuria and urinary tract infections (UTIs). Patients and Methods: This retrospective cohort study evaluated the clinical outcomes of 109 consecutive live donor renal transplant recipients from December 2011 to July 2014. Routine ultrasound examinations were performed on donor's kidney prior to operation and one month later. Kidney volume was calculated. UTI and bacteriuria were evaluated one month later. Patients were divided into two groups based on time of Foley catheter removal (before and after fifth day posttransplantation). Results: In this study 74 males (67.9%) and 35 females (32.1%) were evaluated. Sixty-six patients (57.92%) were in group 1. None of the patients with positive urine culture had UTI but bacteriuria occurred in all of them (21.1%). Bacteriuria time after transplantation and catheter removal was significantly later in group 1 and it was not different in female group but they were later in male group. The mean renal volume increase was positively correlated to renal transplant recipient and donor's age and donor's body mass index (BMI) ( P UTI but increases the probability of bacteria in men whose catheter was removed within 5 days after transplantation. We also found that the renal volume change is not associated with catheter removal time and bacteriuria.

Detection of radionuclides from weak and poorly resolved spectra using Lasso and subsampling techniques

Energy Technology Data Exchange (ETDEWEB)

Bai, Er-Wei, E-mail: er-wei-bai@uiowa.edu [Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA 52242 (United States); Chan, Kung-sik, E-mail: kung-sik-chan@uiowa.edu [Department of Statistical and Actuarial Science, University of Iowa, Iowa City, IA 52242 (United States); Eichinger, William, E-mail: william-eichinger@uiowa.edu [Department of Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States); Kump, Paul [Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA 52242 (United States)

2011-10-15

We consider a problem of identification of nuclides from weak and poorly resolved spectra. A two stage algorithm is proposed and tested based on the principle of majority voting. The idea is to model gamma-ray counts as Poisson processes. Then, the average part is taken to be the model and the difference between the observed gamma-ray counts and the average is considered as random noise. In the linear part, the unknown coefficients correspond to if isotopes of interest are present or absent. Lasso types of algorithms are applied to find non-vanishing coefficients. Since Lasso or any prediction error based algorithm is inconsistent with variable selection for finite data length, an estimate of parameter distribution based on subsampling techniques is added in addition to Lasso. Simulation examples are provided in which the traditional peak detection algorithms fail to work and the proposed two stage algorithm performs well in terms of both the False Negative and False Positive errors. - Highlights: > Identification of nuclides from weak and poorly resolved spectra. > An algorithm is proposed and tested based on the principle of majority voting. > Lasso types of algorithms are applied to find non-vanishing coefficients. > An estimate of parameter distribution based on sub-sampling techniques is included. > Simulations compare the results of the proposed method with those of peak detection.

Detection of radionuclides from weak and poorly resolved spectra using Lasso and subsampling techniques

International Nuclear Information System (INIS)

Bai, Er-Wei; Chan, Kung-sik; Eichinger, William; Kump, Paul

2011-01-01

We consider a problem of identification of nuclides from weak and poorly resolved spectra. A two stage algorithm is proposed and tested based on the principle of majority voting. The idea is to model gamma-ray counts as Poisson processes. Then, the average part is taken to be the model and the difference between the observed gamma-ray counts and the average is considered as random noise. In the linear part, the unknown coefficients correspond to if isotopes of interest are present or absent. Lasso types of algorithms are applied to find non-vanishing coefficients. Since Lasso or any prediction error based algorithm is inconsistent with variable selection for finite data length, an estimate of parameter distribution based on subsampling techniques is added in addition to Lasso. Simulation examples are provided in which the traditional peak detection algorithms fail to work and the proposed two stage algorithm performs well in terms of both the False Negative and False Positive errors. - Highlights: → Identification of nuclides from weak and poorly resolved spectra. → An algorithm is proposed and tested based on the principle of majority voting. → Lasso types of algorithms are applied to find non-vanishing coefficients. → An estimate of parameter distribution based on sub-sampling techniques is included. → Simulations compare the results of the proposed method with those of peak detection.

Non-Asymptotic Oracle Inequalities for the High-Dimensional Cox Regression via Lasso.

Science.gov (United States)

Kong, Shengchun; Nan, Bin

2014-01-01

We consider finite sample properties of the regularized high-dimensional Cox regression via lasso. Existing literature focuses on linear models or generalized linear models with Lipschitz loss functions, where the empirical risk functions are the summations of independent and identically distributed (iid) losses. The summands in the negative log partial likelihood function for censored survival data, however, are neither iid nor Lipschitz.We first approximate the negative log partial likelihood function by a sum of iid non-Lipschitz terms, then derive the non-asymptotic oracle inequalities for the lasso penalized Cox regression using pointwise arguments to tackle the difficulties caused by lacking iid Lipschitz losses.

Sclerosing encapsulating peritonitis in chronic ambulatory peritoneal dialysis;preoperative catheter drainage : a case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Hoon [Dankook Univ. Hospital, Seoul (Korea, Republic of)

1996-10-01

Sclerosing encapsulating peritonitis is a well recognized, but uncommon, complication of chronic ambulatory peritoneal dialysis. I report a case of sclerosing encapsulating peritonitis in which percutaneous catheter drainage was performed preoperatively. Ultrasonography(US) and computed tomography(CT) showed a large multi-septated cystic mass which occupied nearly all the peritoneal cavity. Percutaneous drainage with two 8.5 French catheters was preoperatively performed under fluoroscopy and about 2100 ml of bloody fluid was drained for 20 days. On follow-up CT, the size of the cyst had significantly decreased and anoperation was performed. It is considered that percutaneous catheter drainage is useful in the preoperative decompression of sclerosing encapsulating peritonitis.

Sclerosing encapsulating peritonitis in chronic ambulatory peritoneal dialysis;preoperative catheter drainage : a case report

International Nuclear Information System (INIS)

Kim, Tae Hoon

1996-01-01

Sclerosing encapsulating peritonitis is a well recognized, but uncommon, complication of chronic ambulatory peritoneal dialysis. I report a case of sclerosing encapsulating peritonitis in which percutaneous catheter drainage was performed preoperatively. Ultrasonography(US) and computed tomography(CT) showed a large multi-septated cystic mass which occupied nearly all the peritoneal cavity. Percutaneous drainage with two 8.5 French catheters was preoperatively performed under fluoroscopy and about 2100 ml of bloody fluid was drained for 20 days. On follow-up CT, the size of the cyst had significantly decreased and anoperation was performed. It is considered that percutaneous catheter drainage is useful in the preoperative decompression of sclerosing encapsulating peritonitis

Fused Adaptive Lasso for Spatial and Temporal Quantile Function Estimation

KAUST Repository

Sun, Ying; Wang, Huixia J.; Fuentes, Montserrat

2015-01-01

and temporal data with a fused adaptive Lasso penalty to accommodate the dependence in space and time. This method penalizes the difference among neighboring quantiles, hence it is desirable for applications with features ordered in time or space without

Sungsanpin, a lasso peptide from a deep-sea streptomycete.

Science.gov (United States)

Um, Soohyun; Kim, Young-Joo; Kwon, Hyuknam; Wen, He; Kim, Seong-Hwan; Kwon, Hak Cheol; Park, Sunghyouk; Shin, Jongheon; Oh, Dong-Chan

2013-05-24

Sungsanpin (1), a new 15-amino-acid peptide, was discovered from a Streptomyces species isolated from deep-sea sediment collected off Jeju Island, Korea. The planar structure of 1 was determined by 1D and 2D NMR spectroscopy, mass spectrometry, and UV spectroscopy. The absolute configurations of the stereocenters in this compound were assigned by derivatizations of the hydrolysate of 1 with Marfey's reagents and 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate, followed by LC-MS analysis. Careful analysis of the ROESY NMR spectrum and three-dimensional structure calculations revealed that sungsanpin possesses the features of a lasso peptide: eight amino acids (-Gly(1)-Phe-Gly-Ser-Lys-Pro-Ile-Asp(8)-) that form a cyclic peptide and seven amino acids (-Ser(9)-Phe-Gly-Leu-Ser-Trp-Leu(15)) that form a tail that loops through the ring. Sungsanpin is thus the first example of a lasso peptide isolated from a marine-derived microorganism. Sungsanpin displayed inhibitory activity in a cell invasion assay with the human lung cancer cell line A549.

Lasso and probabilistic inequalities for multivariate point processes

OpenAIRE

Hansen, Niels Richard; Reynaud-Bouret, Patricia; Rivoirard, Vincent

2012-01-01

Due to its low computational cost, Lasso is an attractive regularization method for high-dimensional statistical settings. In this paper, we consider multivariate counting processes depending on an unknown function parameter to be estimated by linear combinations of a fixed dictionary. To select coefficients, we propose an adaptive $\\ell_{1}$-penalization methodology, where data-driven weights of the penalty are derived from new Bernstein type inequalities for martingales. Oracle inequalities...

Catheter Angiography

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography uses a catheter, x-ray ... are the limitations of Catheter Angiography? What is Catheter Angiography? Angiography is a minimally invasive medical test ...

Similarity regularized sparse group lasso for cup to disc ratio computation.

Science.gov (United States)

Cheng, Jun; Zhang, Zhuo; Tao, Dacheng; Wong, Damon Wing Kee; Liu, Jiang; Baskaran, Mani; Aung, Tin; Wong, Tien Yin

2017-08-01

Automatic cup to disc ratio (CDR) computation from color fundus images has shown to be promising for glaucoma detection. Over the past decade, many algorithms have been proposed. In this paper, we first review the recent work in the area and then present a novel similarity-regularized sparse group lasso method for automated CDR estimation. The proposed method reconstructs the testing disc image based on a set of reference disc images by integrating the similarity between testing and the reference disc images with the sparse group lasso constraints. The reconstruction coefficients are then used to estimate the CDR of the testing image. The proposed method has been validated using 650 images with manually annotated CDRs. Experimental results show an average CDR error of 0.0616 and a correlation coefficient of 0.7, outperforming other methods. The areas under curve in the diagnostic test reach 0.843 and 0.837 when manual and automatically segmented discs are used respectively, better than other methods as well.

Urinary catheters

Science.gov (United States)

Catheter - urine; Foley catheter; Indwelling catheter; Suprapubic catheters ... stones Blood infections ( septicemia ) Blood in the urine (hematuria) Kidney damage (usually only with long-term, indwelling ...

Comparison of partial least squares and lasso regression techniques as applied to laser-induced breakdown spectroscopy of geological samples

International Nuclear Information System (INIS)

Dyar, M.D.; Carmosino, M.L.; Breves, E.A.; Ozanne, M.V.; Clegg, S.M.; Wiens, R.C.

2012-01-01

A remote laser-induced breakdown spectrometer (LIBS) designed to simulate the ChemCam instrument on the Mars Science Laboratory Rover Curiosity was used to probe 100 geologic samples at a 9-m standoff distance. ChemCam consists of an integrated remote LIBS instrument that will probe samples up to 7 m from the mast of the rover and a remote micro-imager (RMI) that will record context images. The elemental compositions of 100 igneous and highly-metamorphosed rocks are determined with LIBS using three variations of multivariate analysis, with a goal of improving the analytical accuracy. Two forms of partial least squares (PLS) regression are employed with finely-tuned parameters: PLS-1 regresses a single response variable (elemental concentration) against the observation variables (spectra, or intensity at each of 6144 spectrometer channels), while PLS-2 simultaneously regresses multiple response variables (concentrations of the ten major elements in rocks) against the observation predictor variables, taking advantage of natural correlations between elements. Those results are contrasted with those from the multivariate regression technique of the least absolute shrinkage and selection operator (lasso), which is a penalized shrunken regression method that selects the specific channels for each element that explain the most variance in the concentration of that element. To make this comparison, we use results of cross-validation and of held-out testing, and employ unscaled and uncentered spectral intensity data because all of the input variables are already in the same units. Results demonstrate that the lasso, PLS-1, and PLS-2 all yield comparable results in terms of accuracy for this dataset. However, the interpretability of these methods differs greatly in terms of fundamental understanding of LIBS emissions. PLS techniques generate principal components, linear combinations of intensities at any number of spectrometer channels, which explain as much variance in the

Implementations of geographically weighted lasso in spatial data with multicollinearity (Case study: Poverty modeling of Java Island)

Science.gov (United States)

Setiyorini, Anis; Suprijadi, Jadi; Handoko, Budhi

2017-03-01

Geographically Weighted Regression (GWR) is a regression model that takes into account the spatial heterogeneity effect. In the application of the GWR, inference on regression coefficients is often of interest, as is estimation and prediction of the response variable. Empirical research and studies have demonstrated that local correlation between explanatory variables can lead to estimated regression coefficients in GWR that are strongly correlated, a condition named multicollinearity. It later results on a large standard error on estimated regression coefficients, and, hence, problematic for inference on relationships between variables. Geographically Weighted Lasso (GWL) is a method which capable to deal with spatial heterogeneity and local multicollinearity in spatial data sets. GWL is a further development of GWR method, which adds a LASSO (Least Absolute Shrinkage and Selection Operator) constraint in parameter estimation. In this study, GWL will be applied by using fixed exponential kernel weights matrix to establish a poverty modeling of Java Island, Indonesia. The results of applying the GWL to poverty datasets show that this method stabilizes regression coefficients in the presence of multicollinearity and produces lower prediction and estimation error of the response variable than GWR does.

Temperature-controlled irrigated tip radiofrequency catheter ablation

DEFF Research Database (Denmark)

Petersen, H H; Chen, X; Pietersen, Adrian

1998-01-01

INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

Clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy for large impacted proximal ureteral calculi: a prospective, randomized study.

Science.gov (United States)

Qi, Shiyong; Li, Yanni; Liu, Xu; Zhang, Changwen; Zhang, Hongtuan; Zhang, Zhihong; Xu, Yong

2014-09-01

To evaluate the clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy (POBC-URSL) for large impacted proximal ureteral calculi. 156 patients with impacted proximal ureteral stones ≥1.5 cm in size were randomized to ureteroscopic lithotripsy (URSL), POBC-URSL, and percutaneous nephrolithotomy (PNL) group between May 2010 and May 2013. For URSL, the calculi were disintegrated with the assistance of anti-retropulsion devices. POBC-URSL was performed with the assistance of an 8F percutaneous occlusive balloon catheter. PNL was finished with the combination of an ultrasonic and a pneumatic lithotripter. A flexible ureteroscope and a 200 μm laser fiber were used to achieve stone-free status to a large extent for each group. Variables studied were mean operative time, auxiliary procedure, postoperative hospital stay, operation-related complications, stone clearance rate, and treatment costs. The mean lithotripsy time for POBC-URSL was shorter than URSL, but longer than PNL (42.6±8.9 minutes vs 66.7±15.3 minutes vs 28.1±6.3 minutes, p=0.014). The auxiliary procedure rate and postoperative fever rate for POBC-URSL were significantly lower than URSL and comparable to PNL (pPNL (98.1% vs 75.0% vs 96.2%, pPNL group and similar to URSL group (p=0.016, pPNL.

Improving the prediction of going concern of Taiwanese listed companies using a hybrid of LASSO with data mining techniques.

Science.gov (United States)

Goo, Yeung-Ja James; Chi, Der-Jang; Shen, Zong-De

2016-01-01

The purpose of this study is to establish rigorous and reliable going concern doubt (GCD) prediction models. This study first uses the least absolute shrinkage and selection operator (LASSO) to select variables and then applies data mining techniques to establish prediction models, such as neural network (NN), classification and regression tree (CART), and support vector machine (SVM). The samples of this study include 48 GCD listed companies and 124 NGCD (non-GCD) listed companies from 2002 to 2013 in the TEJ database. We conduct fivefold cross validation in order to identify the prediction accuracy. According to the empirical results, the prediction accuracy of the LASSO-NN model is 88.96 % (Type I error rate is 12.22 %; Type II error rate is 7.50 %), the prediction accuracy of the LASSO-CART model is 88.75 % (Type I error rate is 13.61 %; Type II error rate is 14.17 %), and the prediction accuracy of the LASSO-SVM model is 89.79 % (Type I error rate is 10.00 %; Type II error rate is 15.83 %).

Dose requirements for UVC disinfection of catheter biofilms

DEFF Research Database (Denmark)

Bak, Jimmy; Ladefoged, Søren D.; Tvede, Michael

2009-01-01

Bacterial biofilms on permanent catheters are the major sources of infection. Exposure to ultraviolet-C (UVC) light has been proposed as a method for disinfecting the inner surface of catheters. Specification of a UVC-based device for in vivo disinfection is based on the knowledge of the required...... doses to kill catheter biofilm. Given these doses and the power of available UVC light sources, calculation of the necessary treatment times is then possible. To determine the required doses, contaminated urinary catheters were used as test samples and UVC treated in vitro. Patient catheters (n = 67......) were collected and cut into segments of equal size and treated with various UVC doses. After treatment, the biofilm was removed by scraping and quantified by counting colony forming units. Percentage killing rates were determined by calculating ratios between UVC-treated samples and controls (no UVC...

Central venous catheters: detection of catheter complications and therapeutical options

International Nuclear Information System (INIS)

Gebauer, B.; Beck, A.; Wagner, H.J.; Vivantes-Kliniken, Hellersdorf und Prenzlauer Berg

2008-01-01

For modern medicine central venous catheters play an important role for diagnostic and therapeutic options. Catheter implantation, complication detection and therapy of catheter complications are an increasing demand for the radiologist. The review article provides an overview of different catheter types, their indications, advantages and disadvantages. Catheter malpositions are usually detectable in conventional X-ray. Most malpositions are correctable using interventional-radiological techniques. In addition therapeutical options for thrombotic complications (venous thrombosis, catheter occlusion, fibrin sheath) are discussed. In case of an infectious catheter complication, usually a catheter extraction and re-implantation is necessary

Detection of electrophysiology catheters in noisy fluoroscopy images.

Science.gov (United States)

Franken, Erik; Rongen, Peter; van Almsick, Markus; ter Haar Romeny, Bart

2006-01-01

Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust image analysis method that can detect the catheters in X-ray fluoroscopy images. Our method uses steerable tensor voting in combination with a catheter-specific multi-step extraction algorithm. The evaluation on clinical fluoroscopy images shows that especially the extraction of the catheter tip is successful and that the use of tensor voting accounts for a large increase in performance.

Assessment of right liver graft perfusion effectiveness between one and two-catheter infusion methods.

Science.gov (United States)

Jung, Bo-Hyun; Hwang, Shin; Ha, Tae-Yong; Song, Gi-Won; Jung, Dong-Hwan; Kim, Ki-Hun; Ahn, Chul-Soo; Moon, Deok-Bog; Park, Gil-Chun; Kang, Sung-Hwa; Yoon, Young-In; Lee, Sung-Gyu

2014-05-01

Conventional graft perfusion method using one small-caliber catheter takes a relatively long time for right liver graft perfusion, thus some modification is needed. In this study, we intended to assess the effectiveness of right liver graft perfusion methods through comparison of different infusion catheters. The study consisted of two parts including one bench experiment to obtain data of hydraulic infusion and one clinical trial of 40 cases on graft perfusion with one- versus two-catheter infusion methods. These two graft infusion methods were compared in terms of the perfusion time and washing-out efficiency. At bench experiment, the infusion flow rate and infusion pressure were 3.3 ml/sec and 1.9 cmH20 in one blood transfusion catheter group, and 11.7 ml/sec and 3.1 cmH20 in single transurethral resection of prostate irrigation catheter group, and 6.6 ml/sec and 2.0 cmH20 in two blood transfusion catheters group, respectively. In clinical trial with 40 right liver grafts, two-catheter group had a shorter graft portal perfusion time for the first 2 L of histidine-tryptophan-ketoglutarate (HTK) solution than the conventional one-catheter group (375±25 seconds vs. 662±34 seconds; p=0.001) and a lower rate of incomplete blood washing-out after the initial 2 L portal perfusion (40% vs. 85%; p=0.03). The two-catheter infusion method appears to be more effective than the conventional one-catheter infusion method for right liver graft perfusion at the back table. Large size of right liver grafts seems to be its good indication.

Catheter Calibration Using Template Matching Line Interpolation Algorithm

National Research Council Canada - National Science Library

Nagy, L

2001-01-01

..., such as: image resolution, type of the calibration, algorithm used for contour detection, size of the FOV, other parameters of the image The studied calibration method is the one using catheter size...

Catheter Angiography

Medline Plus

Full Text Available ... Z Catheter Angiography Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material ... vessels in the body. Angiography is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging ( ...

Incidence of catheter-related complications in patients with central venous or hemodialysis catheters: a health care claims database analysis.

Science.gov (United States)

Napalkov, Pavel; Felici, Diana M; Chu, Laura K; Jacobs, Joan R; Begelman, Susan M

2013-10-16

Central venous catheter (CVC) and hemodialysis (HD) catheter usage are associated with complications that occur during catheter insertion, dwell period, and removal. This study aims to identify and describe the incidence rates of catheter-related complications in a large patient population in a United States-based health care claims database after CVC or HD catheter placement. Patients in the i3 InVision DataMart® health care claims database with at least 1 CVC or HD catheter insertion claim were categorized into CVC or HD cohorts using diagnostic and procedural codes from the US Renal Data System, American College of Surgeons, and American Medical Association's Physician Performance Measures. Catheter-related complications were identified using published diagnostic and procedural codes. Incidence rates (IRs)/1000 catheter-days were calculated for complications including catheter-related bloodstream infections (CRBSIs), thrombosis, embolism, intracranial hemorrhage (ICH), major bleeding (MB), and mechanical catheter-related complications (MCRCs). Thirty percent of the CVC cohort and 54% of the HD cohort had catheter placements lasting <90 days. Catheter-related complications occurred most often during the first 90 days of catheter placement. IRs were highest for CRBSIs in both cohorts (4.0 [95% CI, 3.7-4.3] and 5.1 [95% CI, 4.7-5.6], respectively). Other IRs in CVC and HD cohorts, respectively, were thrombosis, 1.3 and 0.8; MCRCs, 0.6 and 0.7; embolism, 0.4 and 0.5; MB, 0.1 and 0.3; and ICH, 0.1 in both cohorts. Patients with cancer at baseline had significantly higher IRs for CRBSIs and thrombosis than non-cancer patients. CVC or HD catheter-related complications were most frequently seen in patients 16 years or younger. The risk of catheter-related complications is highest during the first 90 days of catheter placement in patients with CVCs and HD catheters and in younger patients (≤16 years of age) with HD catheters. Data provided in this study can be applied

Urinary catheter - infants

Science.gov (United States)

Bladder catheter - infants; Foley catheter - infants; Urinary catheter - neonatal ... A urinary catheter is a small, soft tube placed in the bladder. This article addresses urinary catheters in babies. WHY IS ...

On the Oracle Property of the Adaptive LASSO in Stationary and Nonstationary Autoregressions

DEFF Research Database (Denmark)

Kock, Anders Bredahl

We show that the Adaptive LASSO is oracle efficient in stationary and non-stationary autoregressions. This means that it estimates parameters consistently, selects the correct sparsity pattern, and estimates the coefficients belonging to the relevant variables at the same asymptotic efficiency...

Comparison of partial least squares and lasso regression techniques as applied to laser-induced breakdown spectroscopy of geological samples

Energy Technology Data Exchange (ETDEWEB)

Dyar, M.D., E-mail: mdyar@mtholyoke.edu [Dept. of Astronomy, Mount Holyoke College, 50 College St., South Hadley, MA 01075 (United States); Carmosino, M.L.; Breves, E.A.; Ozanne, M.V. [Dept. of Astronomy, Mount Holyoke College, 50 College St., South Hadley, MA 01075 (United States); Clegg, S.M.; Wiens, R.C. [Los Alamos National Laboratory, P.O. Box 1663, MS J565, Los Alamos, NM 87545 (United States)

2012-04-15

A remote laser-induced breakdown spectrometer (LIBS) designed to simulate the ChemCam instrument on the Mars Science Laboratory Rover Curiosity was used to probe 100 geologic samples at a 9-m standoff distance. ChemCam consists of an integrated remote LIBS instrument that will probe samples up to 7 m from the mast of the rover and a remote micro-imager (RMI) that will record context images. The elemental compositions of 100 igneous and highly-metamorphosed rocks are determined with LIBS using three variations of multivariate analysis, with a goal of improving the analytical accuracy. Two forms of partial least squares (PLS) regression are employed with finely-tuned parameters: PLS-1 regresses a single response variable (elemental concentration) against the observation variables (spectra, or intensity at each of 6144 spectrometer channels), while PLS-2 simultaneously regresses multiple response variables (concentrations of the ten major elements in rocks) against the observation predictor variables, taking advantage of natural correlations between elements. Those results are contrasted with those from the multivariate regression technique of the least absolute shrinkage and selection operator (lasso), which is a penalized shrunken regression method that selects the specific channels for each element that explain the most variance in the concentration of that element. To make this comparison, we use results of cross-validation and of held-out testing, and employ unscaled and uncentered spectral intensity data because all of the input variables are already in the same units. Results demonstrate that the lasso, PLS-1, and PLS-2 all yield comparable results in terms of accuracy for this dataset. However, the interpretability of these methods differs greatly in terms of fundamental understanding of LIBS emissions. PLS techniques generate principal components, linear combinations of intensities at any number of spectrometer channels, which explain as much variance in the

A National Implementation Project to Prevent Catheter-Associated Urinary Tract Infection in Nursing Home Residents.

Science.gov (United States)

Mody, Lona; Greene, M Todd; Meddings, Jennifer; Krein, Sarah L; McNamara, Sara E; Trautner, Barbara W; Ratz, David; Stone, Nimalie D; Min, Lillian; Schweon, Steven J; Rolle, Andrew J; Olmsted, Russell N; Burwen, Dale R; Battles, James; Edson, Barbara; Saint, Sanjay

2017-08-01

Catheter-associated urinary tract infection (UTI) in nursing home residents is a common cause of sepsis, hospital admission, and antimicrobial use leading to colonization with multidrug-resistant organisms. To develop, implement, and evaluate an intervention to reduce catheter-associated UTI. A large-scale prospective implementation project was conducted in community-based nursing homes participating in the Agency for Healthcare Research and Quality Safety Program for Long-Term Care. Nursing homes across 48 states, Washington DC, and Puerto Rico participated. Implementation of the project was conducted between March 1, 2014, and August 31, 2016. The project was implemented over 12-month cohorts and included a technical bundle: catheter removal, aseptic insertion, using regular assessments, training for catheter care, and incontinence care planning, as well as a socioadaptive bundle emphasizing leadership, resident and family engagement, and effective communication. Urinary catheter use and catheter-associated UTI rates using National Healthcare Safety Network definitions were collected. Facility-level urine culture order rates were also obtained. Random-effects negative binomial regression models were used to examine changes in catheter-associated UTI, catheter utilization, and urine cultures and adjusted for covariates including ownership, bed size, provision of subacute care, 5-star rating, presence of an infection control committee, and an infection preventionist. In 4 cohorts over 30 months, 568 community-based nursing homes were recruited; 404 met inclusion criteria for analysis. The unadjusted catheter-associated UTI rates decreased from 6.78 to 2.63 infections per 1000 catheter-days. With use of the regression model and adjustment for facility characteristics, the rates decreased from 6.42 to 3.33 (incidence rate ratio [IRR], 0.46; 95% CI, 0.36-0.58; P project. Catheter utilization remained unchanged (4.50 at baseline, 4.45 at conclusion of project; IRR, 0

The large sample size fallacy.

Science.gov (United States)

Lantz, Björn

2013-06-01

Significance in the statistical sense has little to do with significance in the common practical sense. Statistical significance is a necessary but not a sufficient condition for practical significance. Hence, results that are extremely statistically significant may be highly nonsignificant in practice. The degree of practical significance is generally determined by the size of the observed effect, not the p-value. The results of studies based on large samples are often characterized by extreme statistical significance despite small or even trivial effect sizes. Interpreting such results as significant in practice without further analysis is referred to as the large sample size fallacy in this article. The aim of this article is to explore the relevance of the large sample size fallacy in contemporary nursing research. Relatively few nursing articles display explicit measures of observed effect sizes or include a qualitative discussion of observed effect sizes. Statistical significance is often treated as an end in itself. Effect sizes should generally be calculated and presented along with p-values for statistically significant results, and observed effect sizes should be discussed qualitatively through direct and explicit comparisons with the effects in related literature. © 2012 Nordic College of Caring Science.

Balloon catheter dilatation in esophageal achalasia: long term follow-up

Energy Technology Data Exchange (ETDEWEB)

Shin, Cheol Yong; Park, Hyun Mee; Kim, So Eun; Lee, Shin Hyung; Kim, Seung Hyeon; Lee, Chang Joon [National Medical Center, Seoul (Korea, Republic of)

1994-12-15

To evaluate the clinical efficacy of balloon catheter dilatation in the treatment of esophageal achalasia. Seven patients(three males and four females) with esopha-geal achalasia were treated with balloon catheter dilatation. Balloon catheters of variable sizes were used depending on patient's conditions. The patients were followed up over a period of 12-39 months. Balloon catheter dilatation in esophageal achalasia was successful in all patients without esophageal perforation. All patients were relieved from dysphagia. Recurrence was not found in 5 patients on long term follow-up study, but was seen in 2 patients after 18 and 21 months, respectively. Balloon catheter dilatation was a safe and effective method in the treatment of esophageal achalasia with low recurrence rate of 29% on follow-up study.

Balloon catheter dilatation in esophageal achalasia: long term follow-up

International Nuclear Information System (INIS)

Shin, Cheol Yong; Park, Hyun Mee; Kim, So Eun; Lee, Shin Hyung; Kim, Seung Hyeon; Lee, Chang Joon

1994-01-01

To evaluate the clinical efficacy of balloon catheter dilatation in the treatment of esophageal achalasia. Seven patients(three males and four females) with esopha-geal achalasia were treated with balloon catheter dilatation. Balloon catheters of variable sizes were used depending on patient's conditions. The patients were followed up over a period of 12-39 months. Balloon catheter dilatation in esophageal achalasia was successful in all patients without esophageal perforation. All patients were relieved from dysphagia. Recurrence was not found in 5 patients on long term follow-up study, but was seen in 2 patients after 18 and 21 months, respectively. Balloon catheter dilatation was a safe and effective method in the treatment of esophageal achalasia with low recurrence rate of 29% on follow-up study

Flow Rate Through Pigtail Catheter Used for Left Heart Decompression in an Artificial Model of Extracorporeal Membrane Oxygenation Circuit.

Science.gov (United States)

Kim, Won Ho; Hong, Tae Hee; Byun, Joung Hun; Kim, Jong Woo; Kim, Sung Hwan; Moon, Sung Ho; Park, Hyun Oh; Choi, Jun Young; Yang, Jun Ho; Jang, In Seok; Lee, Chung Eun; Yun, Jeong Hee

In refractory cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (ECMO) can be initiated. Although left heart decompression can be accomplished by insertion of a left atrial (LA) or left ventricular (LV) cannula using a percutaneous pigtail catheter, the venting flow rate according to catheter size and ECMO flow rate is unknown. We developed an artificial ECMO circuit. One liter saline bag with its pressure set to 20 mm Hg was connected to ECMO to mimic LV failure. A pigtail catheter was inserted into the 1 L saline bag to simulate LV unloading. For each pigtail catheter size (5-8 Fr) and ECMO flow rate (2.0-4.0 L/min), the moving distance of an air bubble that was injected through a three-way stopcock was measured in the arterial pressure line between the pigtail catheter and ECMO inflow limb. The flow rate was then calculated. We obtained the following equation to estimate the pigtail catheter flow rate.Pigtail vent catheter flow rate (ml/min) = 8×ECMOflow rate(L /min)+9×pigtail catheter size(Fr)- 57This equation would aid in designing of a further study to determine optimal venting flow rate. To achieve optimal venting flow, our equation would enable selection of an adequate catheter size.

Catheter Angiography

Medline Plus

Full Text Available ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. Catheter angiography ... of a catheter makes it possible to combine diagnosis and treatment in a single procedure. An example ...

Catheter Angiography

Medline Plus

Full Text Available ... few millimeters) in the skin where the catheter can be inserted into an artery. The catheter is ... need for surgery. If surgery remains necessary, it can be performed more accurately. Catheter angiography presents a ...

Catheter Angiography

Medline Plus

Full Text Available ... resonance imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an ... The catheter used in angiography is a long plastic tube about as thick as a strand of ...

Catheter Angiography

Medline Plus

Full Text Available ... using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a thin plastic ... called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a catheter makes it ...

Catheter indwell time and phlebitis development during peripheral intravenous catheter administration.

Science.gov (United States)

Pasalioglu, Kadriye Burcu; Kaya, Hatice

2014-07-01

Intravenous catheters have been indispensable tools of modern medicine. Although intravenous applications can be used for a multitude of purposes, these applications may cause complications, some of which have serious effects. Of these complications, the most commonly observed is phlebitis. This study was conducted to determine the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. This study determined the effect of catheter indwell time on phlebitis development during peripheral intravenous catheter administration. The study included a total of 103 individuals who were administered 439 catheters and satisfied the study enrollment criteria at one infectious diseases clinic in Istanbul/Turkey. Data were compiled from Patient Information Forms, Peripheral Intravenous Catheter and Therapy Information Forms, reported grades based on the Visual Infusion Phlebitis Assessment Scale, and Peripheral Intravenous Catheter Nurse Observation Forms. The data were analyzed using SPSS. Results : The mean patient age was 53.75±15.54 (standard deviation) years, and 59.2% of the study participants were men. Phlebitis was detected in 41.2% of peripheral intravenous catheters, and the rate decreased with increased catheter indwell time. Analyses showed that catheter indwell time, antibiotic usage, sex, and catheterization sites were significantly associated with development of phlebitis. The results of this study show that catheters can be used for longer periods of time when administered under optimal conditions and with appropriate surveillance.

Consistent and Conservative Model Selection with the Adaptive LASSO in Stationary and Nonstationary Autoregressions

DEFF Research Database (Denmark)

Kock, Anders Bredahl

2016-01-01

We show that the adaptive Lasso is oracle efficient in stationary and nonstationary autoregressions. This means that it estimates parameters consistently, selects the correct sparsity pattern, and estimates the coefficients belonging to the relevant variables at the same asymptotic efficiency...

Matlab implementation of LASSO, LARS, the elastic net and SPCA

DEFF Research Database (Denmark)

2005-01-01

There are a number of interesting variable selection methods available beside the regular forward selection and stepwise selection methods. Such approaches include LASSO (Least Absolute Shrinkage and Selection Operator), least angle regression (LARS) and elastic net (LARS-EN) regression. There al...... exists a method for calculating principal components with sparse loadings. This software package contains Matlab implementations of these functions. The standard implementations of these functions are available as add-on packages in S-Plus and R....

The balloon dilatation and large profile catheter maintenance method for the management of the bile duct stricture following liver transplantation

Energy Technology Data Exchange (ETDEWEB)

Choo, Sung Wook; Shin, Sung Wook; Do, Young Soo; Park, Kwang Bo; Sung, Yon Mi; Choo, In Wook [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Liu, Wei Chiang [Sungae General Hospital, Seoul (Korea, Republic of)

2006-03-15

We wanted to evaluate the therapeutic efficacy of the percutaneous balloon dilatation and large profile catheter maintenance method for the management of patients with anastomotic biliary strictures following liver transplant. From May 1999 to June 2003, 12 patients with symptomatic benign biliary stricture complicated by liver transplantation were treated with the percutaneous balloon dilatation and large profile catheter maintenance method (1-6 months). The patients were eight males and four females, and their ages ranged from 20 to 62 years (mean age: 44 years). Ten patients underwent living donor liver transplantation and two underwent cadaveric liver transplantation. Postoperative biliary strictures occurred from two to 21 months (mean age: 18 months) after liver transplantation. The initial technical success rate was 92%. Patency of the bile duct was preserved for eight to 40 months (mean period: 19 months) in 10 of 12 (84%) patients. When reviewing two patients (17%), secondary balloon dilatations were needed for treating the delayed recurrence of biliary stricture. In one patients, no recurrent stenosis was seen during the further 10 months follow-up after secondary balloon dilatation. Another patient did not response to secondary balloon dilatation, and he was treated by surgery. Eleven of 12 patients (92%) showed good biliary patency for 8-40 months (mean period: 19 months) of follow-up. The percutaneous balloon dilatation and large profile catheter maintenance method is an effective therapeutic alterative for the treatment of most biliary strictures that complicate liver transplantation. It has a high success rate and it should be considered before surgery.

Infraclavicular versus axillary nerve catheters: A retrospective comparison of early catheter failure rate.

Science.gov (United States)

Quast, Michaela B; Sviggum, Hans P; Hanson, Andrew C; Stoike, David E; Martin, David P; Niesen, Adam D

2018-05-01

Continuous brachial plexus catheters are often used to decrease pain following elbow surgery. This investigation aimed to assess the rate of early failure of infraclavicular (IC) and axillary (AX) nerve catheters following elbow surgery. Retrospective study. Postoperative recovery unit and inpatient hospital floor. 328 patients who received IC or AX nerve catheters and underwent elbow surgery were identified by retrospective query of our institution's database. Data collected included unplanned catheter dislodgement, catheter replacement rate, postoperative pain scores, and opioid administration on postoperative day 1. Catheter failure was defined as unplanned dislodging within 24 h of placement or requirement for catheter replacement and evaluated using a covariate adjusted model. 119 IC catheters and 209 AX catheters were evaluated. There were 8 (6.7%) failed IC catheters versus 13 (6.2%) failed AX catheters. After adjusting for age, BMI, and gender there was no difference in catheter failure rate between IC and AX nerve catheters (p = 0.449). These results suggest that IC and AX nerve catheters do not differ in the rate of early catheter failure, despite differences in anatomic location and catheter placement techniques. Both techniques provided effective postoperative analgesia with median pain scores < 3/10 for patients following elbow surgery. Reasons other than rate of early catheter failure should dictate which approach is performed. Copyright © 2018. Published by Elsevier Inc.

Logistic LASSO regression for the diagnosis of breast cancer using clinical demographic data and the BI-RADS lexicon for ultrasonography.

Science.gov (United States)

Kim, Sun Mi; Kim, Yongdai; Jeong, Kuhwan; Jeong, Heeyeong; Kim, Jiyoung

2018-01-01

The aim of this study was to compare the performance of image analysis for predicting breast cancer using two distinct regression models and to evaluate the usefulness of incorporating clinical and demographic data (CDD) into the image analysis in order to improve the diagnosis of breast cancer. This study included 139 solid masses from 139 patients who underwent a ultrasonography-guided core biopsy and had available CDD between June 2009 and April 2010. Three breast radiologists retrospectively reviewed 139 breast masses and described each lesion using the Breast Imaging Reporting and Data System (BI-RADS) lexicon. We applied and compared two regression methods-stepwise logistic (SL) regression and logistic least absolute shrinkage and selection operator (LASSO) regression-in which the BI-RADS descriptors and CDD were used as covariates. We investigated the performances of these regression methods and the agreement of radiologists in terms of test misclassification error and the area under the curve (AUC) of the tests. Logistic LASSO regression was superior (Pcomparable to the AUC with CDD (0.873 vs. 0.880, P=0.141). Logistic LASSO regression based on BI-RADS descriptors and CDD showed better performance than SL in predicting the presence of breast cancer. The use of CDD as a supplement to the BI-RADS descriptors significantly improved the prediction of breast cancer using logistic LASSO regression.

Catheter Angiography

Medline Plus

Full Text Available ... lessen your anxiety during the procedure. The area of the groin or arm where the catheter will be inserted is shaved, ... contrast material is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is ...

Peripheral intravenous catheter-related phlebitis and related risk factors.

Science.gov (United States)

Nassaji-Zavareh, M; Ghorbani, R

2007-08-01

Peripheral intravenous catheter-related phlebitis is a common and significant problem in clinical practice. This study aims to investigate the incidence of phlebitis and to evaluate some important related factors. 300 patients admitted to medical and surgical wards of hospitals in Semnan, Iran from April 2003 to February 2004 were prospectively studied. Variables evaluated were age, gender, site and size of catheter, type of insertion and underlying conditions (diabetes mellitus, trauma, infectious disease and burns). Phlebitis was defined when at least four criteria were fulfilled (erythema, pain, tenderness, warmth, induration, palpable cord and swelling). Any patient who was discharged or their catheter removed before three days were excluded. Phlebitis occurred in 26 percent (95 percent confidence interval [CI] 21- 31 percent) of patients. There was no significant relationship between age, catheter bore size, trauma and phlebitis. Related risk factors were gender (odds-ratio [OR] 1.50, 95 percent CI 1.01-2.22), site (OR 3.25, 95 percent CI 2.26-4.67) and type of insertion (OR 2.04, 95 percent CI 1.36-3.05) of catheter, diabetes mellitus (OR 7.78, 95 percent CI 4.59-13.21), infectious disease (OR 6.21, 95 percent CI 4.27-9.03) and burns (OR 3.96, 95 percent CI 3.26-4.82). Phlebitis is still an important and ongoing problem in medical practice. In patients with diabetes mellitus and infectious diseases, more attention is needed.

Isolated Calyx Mistaken for a Cyst: Inappropriately Performed Catheter-Directed Sclerotherapy and Safe Removal of the Catheter After Selective Embolization

Energy Technology Data Exchange (ETDEWEB)

Gwak, Jng Won, E-mail: jjungwonie@hanmail.net; Lee, Seung Hwa, E-mail: gareureung@daum.net; Chung, Hwan Hoon, E-mail: chungmic@korea.ac.kr; Je, Bo Kyung, E-mail: purity21@hanmail.net; Yeom, Suk kyu, E-mail: pagoda20@hanmail.net [Korea University College of Medicine, Department of Radiology, Ansan Hospital (Korea, Republic of); Sung, Deuk Jae, E-mail: urora@korea.ac.kr [Korea University College of Medicine, Department of Radiology, Anam Hospital (Korea, Republic of)

2015-02-15

We present a case of isolated calyx that was mistaken for a large cyst. A 47-year-old woman was referred for sclerotherapy of a large cystic lesion on her left kidney. Computed tomography (CT) and ultrasound showed that the cystic lesion was a large cyst. We noticed that the cystic lesion was not a typical simple cyst, even after two sessions of catheter-mediated sclerotherapy. Isolated calyx was presumed by medical history review and was confirmed by aspirated fluid analysis and far delayed-phase CT after intravenous contrast injection. We performed meticulous selective arterial embolization for an isolated calyx and inserted a catheter that could be removed without complication.

Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

International Nuclear Information System (INIS)

Cunha, J. A. M.; Hsu, I-C.; Pouliot, J.

2009-01-01

Purpose: To determine whether alternative high dose rate prostate brachytherapy catheter patterns can result in similar or improved dose distributions while providing better access and reducing trauma. Materials and Methods: Standard prostate cancer high dose rate brachytherapy uses a regular grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. This study used CT datasets with 3 mm slice spacing from ten previously treated patients and digitized new catheters following three hypothetical catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a plan must fulfill the RTOG-0321 dose criteria for target dose coverage (V 100 Prostate >90%) and organ-at-risk dose sparing (V 75 Bladder 75 Rectum 125 Urethra <<1 cc). Results: The three nonstandard catheter patterns used 16 nonparallel, straight divergent catheters, with entry points in the perineum. Thirty plans from ten patients with prostate sizes ranging from 26 to 89 cc were optimized. All nonstandard patterns fulfilled the RTOG criteria when the clinical plan did. In some cases, the dose distribution was improved by better sparing the organs-at-risk. Conclusion: Alternative catheter patterns can provide the physician with additional ways to treat patients previously considered unsuited for brachytherapy treatment (pubic arch interference) and facilitate robotic guidance of catheter insertion. In addition, alternative catheter

Percutaneous transfemoral repositioning of malpositioned central venous catheters.

Science.gov (United States)

Hartnell, G G; Roizental, M

1995-04-01

Central venous catheters inserted by blind surgical placement may not advance into a satisfactory position and may require repositioning. Malpositioning via surgical insertion is common in patients in whom central venous catheters have previously been placed, as these patients are more likely to have central venous thrombosis and distortion of central venous anatomy. This is less of a problem when catheter placement is guided by imaging; however, even when insertion is satisfactory, central venous catheters may become displaced spontaneously after insertion (Fig. 1). Repositioning can be effected by direct manipulation using guidewires or tip-deflecting wires [1, 2], by manipulation via a transfemoral venous approach [3-5], and by injection of contrast material or saline [6]. Limitations of the direct approach include (1) the number and type of maneuvers that can be performed to effect repositioning when anatomy is distorted, (2) difficulty in accessing the catheter, and (3) the risk of introducing infection. Moreover, these patients are often immunosuppressed, and there is a risk of introducing infection by exposing and directly manipulating the venous catheter. Vigorous injection of contrast material or saline may be unsuccessful for the same reasons: It seldom exerts sufficient force to reposition large-caliber central venous catheters and may cause vessel damage or rupture if injection is made into a small or thrombosed vessel. We illustrate several alternative methods for catheter repositioning via a transfemoral venous approach.

Structural Graphical Lasso for Learning Mouse Brain Connectivity

KAUST Repository

Yang, Sen

2015-08-07

Investigations into brain connectivity aim to recover networks of brain regions connected by anatomical tracts or by functional associations. The inference of brain networks has recently attracted much interest due to the increasing availability of high-resolution brain imaging data. Sparse inverse covariance estimation with lasso and group lasso penalty has been demonstrated to be a powerful approach to discover brain networks. Motivated by the hierarchical structure of the brain networks, we consider the problem of estimating a graphical model with tree-structural regularization in this paper. The regularization encourages the graphical model to exhibit a brain-like structure. Specifically, in this hierarchical structure, hundreds of thousands of voxels serve as the leaf nodes of the tree. A node in the intermediate layer represents a region formed by voxels in the subtree rooted at that node. The whole brain is considered as the root of the tree. We propose to apply the tree-structural regularized graphical model to estimate the mouse brain network. However, the dimensionality of whole-brain data, usually on the order of hundreds of thousands, poses significant computational challenges. Efficient algorithms that are capable of estimating networks from high-dimensional data are highly desired. To address the computational challenge, we develop a screening rule which can quickly identify many zero blocks in the estimated graphical model, thereby dramatically reducing the computational cost of solving the proposed model. It is based on a novel insight on the relationship between screening and the so-called proximal operator that we first establish in this paper. We perform experiments on both synthetic data and real data from the Allen Developing Mouse Brain Atlas; results demonstrate the effectiveness and efficiency of the proposed approach.

Bacterial Biofilms and Catheters: A Key to Understanding Bacterial Strategies in Catheter-Associated Urinary Tract Infection

Directory of Open Access Journals (Sweden)

J Curtis Nickel

1992-01-01

Full Text Available Despite major technological improvements in catheter drainage systems, the indwelling Foley catheter remains the most common cause of nosocomial infection in medical practice. By approaching this common complicated urinary tract infection from the perspective of the biofilm strategy bacteria appear to use to overcome obstacles to produce bacteriuria, one appreciates a new understanding of these infections. An adherent biofilm of bacteria in their secretory products ascends the luminal and external surface of the catheter and drainage system from a contaminated drainage spigot or urethral meatus into the bladder. If the intraluminal route of bacterial ascent is delayed by strict sterile closed drainage or addition of internal modifications to the system, the extraluminal or urethral route assumes greater importance in the development of bacteriuria, but takes significantly longer. Bacterial growth within these thick coherent biofilms confers a large measure of relative resistance to antibiotics even though the individual bacterium remains sensitive, thus accounting for the failure of antibiotic therapy. With disruption of the protective mucous layer of the bladder by mechanical irritation, the bacteria colonizing the catheter can adhere to the bladder’s mucosal surface and cause infection. An appreciation of the role of bacterial biofilms in these infections should suggest future directions for research that may ultimately reduce the risk of catheter-associated infection.

Indwelling catheter care

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Foley catheter ... You will need to make sure your indwelling catheter is working properly. You will also need to ... not get an infection or skin irritation. Make catheter and skin care part of your daily routine. ...

Balloon-tipped flow-directed catheters

International Nuclear Information System (INIS)

Ganz, P.; Swan, H.J.C.; Ganz, W.

1986-01-01

Diagnostic catheterization of the right side of the heart with semirigid cardiac catheters requires fluoroscopic guidance and substantial skill. Abnormal positions of the heart chambers and of the great vessels associated with cardiac dilatation or with congenital malformation present difficulties even to experienced laboratory cardiologists. These problems have been largely overcome by the introduction of balloon tipped flow directed catheters, which allow for rapid and relatively safe catheterization of the pulmonary artery without fluoroscopy. It was through the application of these catheters in the intensive care unit that the many pitfalls in the clinical assessment of hemodynamic disturbances became apparent. Although S3 gallop sounds may be useful in the clinical recognition of chronic ventricular failure, their presence or absence has limited predictive value in estimating left ventricular filling pressure in myocardial infarction. Information derived from right heart catheterization is often pivotal in the evaluation of hemodynamic disorders, in directing treatment, and in monitoring the results of therapy in critically ill patients

Translumbar aortography by catheter technique

International Nuclear Information System (INIS)

Hagen, B.; Honemeyer, U.; Meier-Duis, H.

1982-01-01

400 examinations performed during the last three years by TLA (only catheter technique) were subjected to critical analysis and studied particularly in respect to the rate of complications. We observed 13 complications (3.25%) of moderate severity, including 3 large hematomas (documented by CT), 3 paravasations and 7 dissections, but no fatal complication. Two (0.5%) of these complications had clinical evidence. The advantages of the catheter technique of TLA are described. Injections through rigid metal cannula should be avoided because of the high incidence of complications (mainly the increased risk of dissection). Downstream injection resulted in excellent visualization of peripheral occluding vascular disease. Upstream injection should be preferred to demonstrate the major abdominal arteries as well as supraceliac collateral circulation in the case of high Leriche syndrome. The low or intermediate puncture of the aorta is preferable to facilitate caudad direction of the catheter and to diminish the risk of damaging other vessels or puncturing an organ. (orig.) [de

A simple method of using a Foley catheter to drain pleural effusion.

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Ben-Nun, Alon; Best, Lael Anson

2008-01-01

Pleural effusion is a common problem, and various techniques of pleural fluid drainage have been described. We report our experience of using a Foley-type catheter to drain pleural effusion. After the injection of local anesthesia, the catheter is inserted, usually through the 7th intercostal space, with the patient sitting upright. The size of the catheter is selected according to the predicted fluid characteristics, and ranges from 18 to 24 F. Once the catheter is positioned in the pleural space, the balloon is inflated with diluted soluble contrast material and connected to a urine collection bag. During the last 10 years, we have used 3500 catheters for this purpose. The catheter site can be used as a port for various procedures, including needle biopsy of the parietal pleura, talc-slurry pleurodesis, and intra-pleural fibrinolysis. This method of pleural drainage is simple, reliable, and inexpensive.

Feedforward Coordinate Control of a Robotic Cell Injection Catheter.

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Cheng, Weyland; Law, Peter K

2017-08-01

Remote and robotically actuated catheters are the stepping-stones toward autonomous catheters, where complex intravascular procedures may be performed with minimal intervention from a physician. This article proposes a concept for the positional, feedforward control of a robotically actuated cell injection catheter used for the injection of myogenic or undifferentiated stem cells into the myocardial infarct boundary zones of the left ventricle. The prototype for the catheter system was built upon a needle-based catheter with a single degree of deflection, a 3-D printed handle combined with actuators, and the Arduino microcontroller platform. A bench setup was used to mimic a left ventricle catheter procedure starting from the femoral artery. Using Matlab and the open-source video modeling tool Tracker, the planar coordinates ( y, z) of the catheter position were analyzed, and a feedforward control system was developed based on empirical models. Using the Student's t test with a sample size of 26, it was determined that for both the y- and z-axes, the mean discrepancy between the calibrated and theoretical coordinate values had no significant difference compared to the hypothetical value of µ = 0. The root mean square error of the calibrated coordinates also showed an 88% improvement in the z-axis and 31% improvement in the y-axis compared to the unmodified trial run. This proof of concept investigation leads to the possibility of further developing a feedfoward control system in vivo using catheters with omnidirectional deflection. Feedforward positional control allows for more flexibility in the design of an automated catheter system where problems such as systemic time delay may be a hindrance in instances requiring an immediate reaction.

Ultrasound-guided pigtail catheters for drainage of various pleural diseases.

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Liu, Yi-Heng; Lin, Yu-Chao; Liang, Shinn-Jye; Tu, Chih-Yen; Chen, Chia-Hung; Chen, Hung-Jen; Chen, Wei; Shih, Chuen-Ming; Hsu, Wu-Huei

2010-10-01

Little is known about the efficacy and safety of ultrasound-guided pigtail catheters for the management of various pleural diseases in the emergency department, ward, and intensive care unit. We conducted a retrospective study in a university hospital during a 1-year interval. A total of 276 patients (178 men and 98 women) underwent 332 pigtail catheters (the drain size ranged from 10F to 16F) under ultrasound guidance. The mean ± SEM patient age was 59 ± 18 years, and mean duration of drainage was 6.1 ± 2 days. A total of 64 drains (19.2%) were inserted for pneumothoraces; 98 drains (29.5%), for malignant effusions; 119 drains (35.8%), for parapneumonic effusions/empyemas; and 38 drains (11.4%), for massive transudate pleural effusions. The overall success rate was 72.9%. The success rate was highest when the drain was used to treat massive transudate effusions (81.6%) and malignant pleural effusions (75.5%), followed by parapneumonic effusions/empyemas (72.2%), hemothoraces (66.6%), and pneumothoraces (64.0%). Only 10 (3.0%) drains had complications due to the procedure, including infection (n = 4, 1.2%), dislodgment (n = 4, 1.2%), wound bleeding at the pigtail catheter puncture area complicated with hemothoraces (n = 1, 0.3%), and lung puncture (n = 1, 0.3%). There was no significant difference in success rate when different catheter sizes were used to treat pleural diseases. Ultrasound-guided pigtail catheters provide a safe and effective method of draining various pleural diseases. We strongly suggest that ultrasound-guided pigtail catheters be considered as the initial draining method for a variety of pleural diseases. Copyright © 2010 Elsevier Inc. All rights reserved.

A pilot study to assess adductor canal catheter tip migration in a cadaver model.

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Leng, Jody C; Harrison, T Kyle; Miller, Brett; Howard, Steven K; Conroy, Myles; Udani, Ankeet; Shum, Cynthia; Mariano, Edward R

2015-04-01

An adductor canal catheter may facilitate early ambulation after total knee arthroplasty, but there is concern over preoperative placement since intraoperative migration of catheters may occur from surgical manipulation and result in ineffective analgesia. We hypothesized that catheter type and subcutaneous tunneling may influence tip migration for preoperatively inserted adductor canal catheters. In a male unembalmed human cadaver, 20 catheter insertion trials were divided randomly into one of four groups: flexible epidural catheter either tunneled or not tunneled; or rigid stimulating catheter either tunneled or not tunneled. Intraoperative patient manipulation was simulated by five range-of-motion exercises of the knee. Distance and length measurements were performed by a blinded regional anesthesiologist. Changes in catheter tip to nerve distance (p = 0.225) and length of catheter within the adductor canal (p = 0.467) were not different between the four groups. Two of five non-tunneled stimulating catheters (40 %) were dislodged compared to 0/5 in all other groups (p = 0.187). A cadaver model may be useful for assessing migration of regional anesthesia catheters; catheter type and subcutaneous tunneling may not affect migration of adductor canal catheters based on this preliminary study. However, future studies involving a larger sample size, actual patients, and other catheter types are warranted.

Intracoronary stent implantation: new approach using a monorail system and new large-lumen 7F catheters from the brachial route.

Science.gov (United States)

Jenny, D B; Robert, G P; Fajadet, J C; Cassagneau, B G; Marco, J

1992-04-01

In this brief report we describe a case of successful multivessel PTCA with intracoronary stent implantation using a new large-lumen 7F catheter from the left brachial approach. The application of this technique should be considered for intravascular stent implantation when anticoagulation ideally should not be interrupted or in anatomical situations limiting femoral vascular access.

Transbronchial Catheter Drainage via Fiberoptic Bronchoscope in Intractable Lung Abscess

Science.gov (United States)

Jeong, Man Pyo; Kim, Woo Sung; Han, Sung Koo; Shim, Young Soo; Kim, Keun Youl; Han, Yong Chol

1989-01-01

The use of the fiberoptic bronchoscope as a drainage procedure for lung abscess has become more and more widespread. We have recently adopted the technique of inserting a simple polyethylene catheter through the flexible fiberoptic bronchoscope into the abscess cavity of 11 patients with lung absess. All cases had not responded to aggressive postural drainage and adequate antibiotic therapy for at least a week. The results were as follows: Among 11 patients, the therapeutic response was dramatic in 6 patients.In the successful group, the abscess sizes were greater than 8cm in diameter and the air-fluid levels were higher than two-thirds of the cavity.Additional diagnoses, other than bacterial lung abscess, could be made in 2 cases when otherwise the diagnosis would have remained in doubt. The authors suggest that catheter drainage via fiberoptic bronchoscpope is an effective treatment modality in the large lung abscess with a high air-fluid level which is intractable to other medical approaches, and it is also a safe procedure. PMID:2487405

Improved Variable Selection Algorithm Using a LASSO-Type Penalty, with an Application to Assessing Hepatitis B Infection Relevant Factors in Community Residents

Science.gov (United States)

Guo, Pi; Zeng, Fangfang; Hu, Xiaomin; Zhang, Dingmei; Zhu, Shuming; Deng, Yu; Hao, Yuantao

2015-01-01

Objectives In epidemiological studies, it is important to identify independent associations between collective exposures and a health outcome. The current stepwise selection technique ignores stochastic errors and suffers from a lack of stability. The alternative LASSO-penalized regression model can be applied to detect significant predictors from a pool of candidate variables. However, this technique is prone to false positives and tends to create excessive biases. It remains challenging to develop robust variable selection methods and enhance predictability. Material and methods Two improved algorithms denoted the two-stage hybrid and bootstrap ranking procedures, both using a LASSO-type penalty, were developed for epidemiological association analysis. The performance of the proposed procedures and other methods including conventional LASSO, Bolasso, stepwise and stability selection models were evaluated using intensive simulation. In addition, methods were compared by using an empirical analysis based on large-scale survey data of hepatitis B infection-relevant factors among Guangdong residents. Results The proposed procedures produced comparable or less biased selection results when compared to conventional variable selection models. In total, the two newly proposed procedures were stable with respect to various scenarios of simulation, demonstrating a higher power and a lower false positive rate during variable selection than the compared methods. In empirical analysis, the proposed procedures yielding a sparse set of hepatitis B infection-relevant factors gave the best predictive performance and showed that the procedures were able to select a more stringent set of factors. The individual history of hepatitis B vaccination, family and individual history of hepatitis B infection were associated with hepatitis B infection in the studied residents according to the proposed procedures. Conclusions The newly proposed procedures improve the identification of

Phlebitis risk varies by peripheral venous catheter site and increases after 96 hours: a large multi-centre prospective study.

Science.gov (United States)

Cicolini, Giancarlo; Manzoli, Lamberto; Simonetti, Valentina; Flacco, Maria Elena; Comparcini, Dania; Capasso, Lorenzo; Di Baldassarre, Angela; Eltaji Elfarouki, Ghaleb

2014-11-01

This multi-centre prospective field study evaluated whether peripheral venous catheter site of insertion influences the risk of catheter-related phlebitis. Potential predictors of phlebitis were also investigated. Millions of patients worldwide use peripheral venous catheters, which frequently cause local complications including phlebitis, infection and obstruction. Although phlebitis predictors have been broadly investigated, uncertainties remain on the potential effect of cannulation anatomical site, duration and the appropriate time for catheter removal. A prospective cohort design was carried out from January-June 2012. The clinical course of each patient who received a new peripheral venous catheter for any cause in five Italian hospitals was followed by trained nurses until catheter removal. The presence of phlebitis was assessed every 24 hours using the Visual Infusion Phlebitis score. Analyses were based upon multilevel mixed-effects regression. The final sample consisted of 1498 patients. The average time for catheters in situ was 65·6 hours and 23·6% of the catheters were in place beyond 96 hours. Overall phlebitis incidence was 15·4%, 94·4% of which were grade 1. The likelihood of phlebitis independently increased with increasing catheter duration, being highest after 96 hours. Compared with patients with catheter placed in the dorsum of the hand (22·8% of the sample), those with the catheter located in the antecubital fossa (34·1%) or forearm were less likely to have a phlebitis of any grade. Antecubital fossa and forearm veins may be preferential sites for peripheral venous cannulation. Our results support Centers for Disease Control and Prevention recommendations to replace catheters in adults no later than 96 hours. A relevant proportion of healthcare personnel did not adhere to such guidelines - more attention to this issue is required. © 2014 John Wiley & Sons Ltd.

Catheter visualisation in MR tomography: first animal experimental experiences with field inhomogeneity catheters

International Nuclear Information System (INIS)

Adam, G.; Glowinski, A.; Neuerburg, J.; Buecker, A.; Vaals, J.J. van; Hurtak, W.; Guenther, R.W.

1997-01-01

Purpose: To assess the feasibility of a new developed field inhomogeneity catheter for interventional MR imaging in vivo. Materials and methods: Three different prototypes of a field inhomogeneity catheter were investigated in 6 pigs. The catheters were introduced in Seldinger technique via the femoral vessels over a guide wire on an interventional MR system (Philips Gyroscan NT combined with a C-arm fluoroscopy unit [Philips BV 212[). Catheters were placed in veins and arteries. The catheter position was controlled by a fast gradient echo sequence (Turbo Field Echo [TEF[). Results: Catheters were introduced over a guide wire without complications in all cases. Using the field inhomogeneity concept, catheters were easily visualised in the inferior vena cava and the aorta by the fast gradient echo technique on MR in all cases. Although aortic branches were successfully cannulated, the catheters were not displayed by the TFE technique due to the complex and tortuous anatomy. All animals survived the experiments without complications. Conclusion: MR guided visualisation of a field inhomogeneity catheter is a simple concept which can be realised on each MR scanner and may allow intravascular MR guided interventions in future. (orig.) [de

Catheter Angiography

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Catheter Angiography Catheter angiography ...

Catheter Angiography

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Full Text Available ... imaging (MRI) In catheter angiography, a thin plastic tube, called a catheter , is inserted into an artery ... examined, a contrast material is injected through the tube and images are captured using a small dose ...

Catheter Angiography

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Full Text Available ... incision in the skin. Once the catheter is guided to the area being examined, a contrast material ... inserted into an artery. The catheter is then guided through the arteries to the area to be ...

Catheter Angiography

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Full Text Available ... catheter , is inserted into an artery through a small incision in the skin. Once the catheter is ... the tube and images are captured using a small dose of ionizing radiation ( x-rays ). top of ...

Catheter Angiography

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Full Text Available ... it will make the rest of the procedure pain-free. You will not feel the catheter in ... nurse if you notice any bleeding, swelling or pain at the site where the catheter entered the ...

Catheter Angiography

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Full Text Available ... should inform the nurse if you notice any bleeding, swelling or pain at the site where the ... Rarely, the catheter punctures the artery, causing internal bleeding. It also is possible that the catheter tip ...

Catheter Angiography

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Full Text Available ... an artery through a small incision in the skin. Once the catheter is guided to the area ... small incision (usually a few millimeters) in the skin where the catheter can be inserted into an ...

Catheter Angiography

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Full Text Available ... or other procedures such as chemoembolization or selective internal radiation therapy. identify dissection or splitting in the ... days. Rarely, the catheter punctures the artery, causing internal bleeding. It also is possible that the catheter ...

Catheter Angiography

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Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of ...

Catheter Angiography

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Full Text Available ... Catheter angiography uses a catheter, x-ray imaging guidance and an injection of contrast material to examine ... removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x- ...

Catheter Angiography

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Full Text Available ... most cases, the kidneys will regain their normal function within five to seven days. Rarely, the catheter ... limitations of Catheter Angiography? Patients with impaired kidney function, especially those who also have diabetes, are not ...

Catheter Angiography

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Full Text Available ... lies. The catheter used in angiography is a long plastic tube about as thick as a strand of spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ...

Group spike-and-slab lasso generalized linear models for disease prediction and associated genes detection by incorporating pathway information.

Science.gov (United States)

Tang, Zaixiang; Shen, Yueping; Li, Yan; Zhang, Xinyan; Wen, Jia; Qian, Chen'ao; Zhuang, Wenzhuo; Shi, Xinghua; Yi, Nengjun

2018-03-15

Large-scale molecular data have been increasingly used as an important resource for prognostic prediction of diseases and detection of associated genes. However, standard approaches for omics data analysis ignore the group structure among genes encoded in functional relationships or pathway information. We propose new Bayesian hierarchical generalized linear models, called group spike-and-slab lasso GLMs, for predicting disease outcomes and detecting associated genes by incorporating large-scale molecular data and group structures. The proposed model employs a mixture double-exponential prior for coefficients that induces self-adaptive shrinkage amount on different coefficients. The group information is incorporated into the model by setting group-specific parameters. We have developed a fast and stable deterministic algorithm to fit the proposed hierarchal GLMs, which can perform variable selection within groups. We assess the performance of the proposed method on several simulated scenarios, by varying the overlap among groups, group size, number of non-null groups, and the correlation within group. Compared with existing methods, the proposed method provides not only more accurate estimates of the parameters but also better prediction. We further demonstrate the application of the proposed procedure on three cancer datasets by utilizing pathway structures of genes. Our results show that the proposed method generates powerful models for predicting disease outcomes and detecting associated genes. The methods have been implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). nyi@uab.edu. Supplementary data are available at Bioinformatics online.

Catheter Angiography

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Full Text Available ... is performed using: x-rays with catheters computed tomography (CT) magnetic resonance imaging (MRI) In catheter angiography, a ... tumor; this is called superselective angiography. Unlike computed tomography (CT) or magnetic resonance (MR) angiography , use of a ...

Balloon catheter dilation of benign esophageal stenosis in children

International Nuclear Information System (INIS)

Fan Guoping; Yu Juming; Zhong Weixing; Zhu Ming; Wu Yeming; Shi Chengren

2001-01-01

Objective: To evaluate the methods and effect of balloon catheter dilation of benign esophageal stenosis in children. Methods: 9 cases had an anastomotic stenosis after surgical correction of esophageal atresia; 11 cases of esophageal stenosis due to ingestion of caustics; one case had an lower esophageal stenosis after Nissen surgery and one case after gastro-esophagoplasty. Age ranged from 17 days to 7 years. Each case had a barium esophagram before balloon dilation. The balloon size varied from 3 to 10 mm in diameter. Results: 21 cases were successful after dilation of balloon catheter. There were no esophageal perforation and complications. The satisfactory results maintained from six months to thirty months. Conclusions: Balloon catheter dilation is a simple, safe and reliable method for the treatment of benign esophageal strictures in children as the first choice

A central venous catheter coated with benzalkonium chloride for the prevention of catheter-related microbial colonization.

Science.gov (United States)

Moss, H A; Tebbs, S E; Faroqui, M H; Herbst, T; Isaac, J L; Brown, J; Elliott, T S

2000-11-01

In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P = 0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.

Control of intravascular catheters using an array of active steering coils.

Science.gov (United States)

Gudino, N; Heilman, J A; Derakhshan, J J; Sunshine, J L; Duerk, J L; Griswold, M A

2011-07-01

To extend the concept of deflecting the tip of a catheter with the magnetic force created in an MRI system through the use of an array of independently controllable steering coils located in the catheter tip, and to present methods for visualization of the catheter and/or surrounding areas while the catheter is deflected. An array of steering coils made of 42-gauge wire was built over a 2.5 Fr (0.83 mm) fiber braided microcatheter. Two of the coils were 70 turn axial coils separated by 1 cm, and the third was a 15-turn square side coil that was 2 x 4 mm2. Each coil was driven independently by a pulse width modulation (PWM) current source controlled by a microprocessor that received commands from a MATLAB routine that dynamically set current amplitude and direction for each coil. The catheter was immersed in a water phantom containing 1% Gd-DTPA that was placed at the isocenter of a 1.5 T MRI scanner. Deflections of the catheter tip were measured from image-based data obtained with a real-time radio frequency (RF) spoiled gradient echo sequence (GRE). The small local magnetic fields generated by the steering coils were exploited to generate a hyperintense signal at the catheter tip by using a modified GRE sequence that did not include slice-select rewinding gradients. Imaging and excitation modes were implemented by synchronizing the excitation of the steering coil array with the scanner by ensuring that no current was driven through the coils during the data acquisition window; this allowed visualization of the surrounding tissue while not affecting the desired catheter position. Deflections as large as 2.5 cm were measured when exciting the steering coils sequentially with a 100 mA maximum current per coil. When exciting a single axial coil, the deflection was half this value with 30% higher current. A hyperintense catheter tip useful for catheter tracking was obtained by imaging with the modified GRE sequence. Clear visualization of the areas surrounding the

Clinical usefulness of catheter-drawn blood samples and catheter tip cultures for the diagnosis of catheter-related bloodstream infections in neonatology: A systematic review.

Science.gov (United States)

Ferreira, Janita; Camargos, Paulo Augusto Moreira; Clemente, Wanessa Trindade; Romanelli, Roberta Maia de Castro

2018-01-01

Neonatal sepsis is the most frequent health care-associated infection in neonatal units. This study aimed to analyze articles on the clinical usefulness of catheter-drawn blood samples and catheter tip cultures for the diagnosis of intravascular catheter-related bloodstream infection (CRBSI) in neonates. A systematic search was performed for studies published from 1987-2017, without language restriction. Observational studies carried out in neonates with CRBSI diagnosed using catheter-drawn blood samples or catheter tip cultures were included. A total of 412 articles were identified in the databases and 10 articles were included. The 7 studies that evaluated central venous catheter tip cultures and cultures of catheter fragments presented sensitivities ranging from 58.5%-100% and specificities ranging from 60%-95.7%. Three studies that evaluated catheter-drawn blood cultures, paired with peripheral blood cultures, reported sensitivity and specificity of 94% and 71% when evaluated for the differential time to positivity. When quantitative evaluation was performed, the sensitivity and specificity were 80% and 99.4%. Most of the studies analyzed cultures from the central venous catheter tip and catheter fragments for the diagnosis of CRBSI in neonatal populations. The results of this review suggest that the analysis of the catheter-drawn blood samples and catheter tip cultures, paired with peripheral blood cultures, are efficient methods for the diagnosis of CRBSI in neonates. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Dedicated radial ventriculography pigtail catheter

Energy Technology Data Exchange (ETDEWEB)

Vidovich, Mladen I., E-mail: miv@uic.edu

2013-05-15

A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

Large-sized seaweed monitoring based on MODIS

Science.gov (United States)

Ma, Long; Li, Ying; Lan, Guo-xin; Li, Chuan-long

2009-10-01

In recent years, large-sized seaweed, such as ulva lactuca, blooms frequently in coastal water in China, which threatens marine eco-environment. In order to take effective measures, it is important to make operational surveillance. A case of large-sized seaweed blooming (i.e. enteromorpha), occurred in June, 2008, in the sea near Qingdao city, is studied. Seaweed blooming is dynamically monitored using Moderate Resolution Imaging Spectroradiometer (MODIS). After analyzing imaging spectral characteristics of enteromorpha, MODIS band 1 and 2 are used to create a band ratio algorithm for detecting and mapping large-sized seaweed blooming. In addition, chlorophyll-α concentration is inversed based on an empirical model developed using MODIS. Chlorophyll-α concentration maps are derived using multitemporal MODIS data, and chlorophyll-α concentration change is analyzed. Results show that the presented methods are useful to get the dynamic distribution and the growth of large-sized seaweed, and can support contingency planning.

Catheter Angiography

Medline Plus

Full Text Available ... is injected through the catheter and reaches the blood vessels being studied, several sets of x-rays are taken. Then the catheter is removed and the incision site is closed by applying pressure on the area for approximately 10 to 20 ...

FACTORS AND COMPLICATIONS AFFECTING CATHETER AND TECHNIQUE SURVIVAL WITH PERMANENT SINGLE-LUMEN DIALYSIS CATHETERS

NARCIS (Netherlands)

DEMEESTER, J; VANHOLDER, R; DEROOSE, J; RINGOIR, S

1994-01-01

This long-term study on the outcome of permanent silicone single-lumen dialysis catheters consisted of 43 surgically inserted catheters in 33 patients. All catheters were attached to a pressure-pressure single-cannula dialysis system. Technique and catheter survival were 80 and 59% at 1 year, and 63

Catheter versus non-catheter angiography in isolated third nerve palsy

International Nuclear Information System (INIS)

Lee, A.G.

2007-01-01

To discuss the controversies surrounding the indications for catheter angiography versus non-catheter and less invasive angiography techniques (e.g. magnetic resonance angiography (MRA) and computerized tomography angiography (CTA)) in the evaluation of patients with a third nerve palsy. Clinical opinion-perspective and literature review. The patient with an isolated third nerve palsy might have a vasculopathic (and typically benign, self limited course) etiology or a life threatening intracranial posterior communicating artery aneurysm. Although it is clear that non-isolated third nerve palsies require imaging directed at the topographical localization of the clinical findings, the evaluation of the neurologically isolated third nerve palsy remains controversial. The completeness of the external (i.e. somatic) motor dysfunction and the presence or absence of internal (i.e. pupillary) dysfunction are generally used to guide the choice of initial neuroimaging. Advances in MRA and CTA technology have reduced but not eliminated our dependence upon catheter angiography in this setting. A properly performed and interpreted MRA or CTA probably will be able to detect greater than 95 % of aneurysms producing a third nerve palsy. The issues surrounding the use of catheter angiography in third nerve palsy are reviewed. If the clinician is highly confident in the capability, availability, and reliability of the neuroradiologist and of their institutional experience and quality of less invasive non-catheter MRA and CTA and if the risk of aneurysm is low or if the risk of angiography is high (e.g. elderly, renal failure, iodinated contrast allergy, risk of stroke) then MRI and MRA (or CTA) may be a reasonable alternative to catheter angiography. Patients with a moderate or uncertain risk of aneurysm and a lower risk for catheter angiography or if there is a low confidence in the quality or the interpretation of the institutional MRA (or CTA) may still require catheter

LASSO NTCP predictors for the incidence of xerostomia in patients with head and neck squamous cell carcinoma and nasopharyngeal carcinoma

Science.gov (United States)

Lee, Tsair-Fwu; Liou, Ming-Hsiang; Huang, Yu-Jie; Chao, Pei-Ju; Ting, Hui-Min; Lee, Hsiao-Yi

2014-01-01

To predict the incidence of moderate-to-severe patient-reported xerostomia among head and neck squamous cell carcinoma (HNSCC) and nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT). Multivariable normal tissue complication probability (NTCP) models were developed by using quality of life questionnaire datasets from 152 patients with HNSCC and 84 patients with NPC. The primary endpoint was defined as moderate-to-severe xerostomia after IMRT. The numbers of predictive factors for a multivariable logistic regression model were determined using the least absolute shrinkage and selection operator (LASSO) with bootstrapping technique. Four predictive models were achieved by LASSO with the smallest number of factors while preserving predictive value with higher AUC performance. For all models, the dosimetric factors for the mean dose given to the contralateral and ipsilateral parotid gland were selected as the most significant predictors. Followed by the different clinical and socio-economic factors being selected, namely age, financial status, T stage, and education for different models were chosen. The predicted incidence of xerostomia for HNSCC and NPC patients can be improved by using multivariable logistic regression models with LASSO technique. The predictive model developed in HNSCC cannot be generalized to NPC cohort treated with IMRT without validation and vice versa. PMID:25163814

Impact of short-term hemodialysis catheters on the central veins: a catheter venographic study

Energy Technology Data Exchange (ETDEWEB)

Oguzkurt, Levent E-mail: loguzkurt@yahoo.com; Tercan, Fahri; Torun, Dilek; Yildirim, Tuelin; Zuemruetdal, Ayseguel; Kizilkilic, Osman

2004-12-01

Objective: To determine the incidence of pericatheter sleeve formation, thrombus formation, and stenosis of the central veins in hemodialysis patients with temporary catheters. Methods and material: In this prospective study, 57 patients (40 males, 17 females) with temporary dialysis catheters had catheter venography by pulling back the catheter just before removal. Patient's age range was 25-87 years (mean age, 51 years). The venographic studies were evaluated for pericatheter sleeve formation, thrombus formation, and stenosis of the brachiocephalic vein (BCV) and the superior vena cava (SVC). The IJV could only be evaluated if there was adequate filling during contrast administration. In a subgroup of patients who had had only right IJV or only right SCV catheters, impact of these catheters on the central veins was compared. Results: The catheter location was right internal jugular vein (IJV) in 26 cases, right subclavian vein (SCV) in 27 cases, left IJV in 1 case, and left SCV in 3 cases. Thirty-two patients (56%) had had only one temporary catheter and the rest had had more than one inserted. The mean dwell time for the catheters was 21 days (range 7-59 days). A pericatheter sleeve was detected on venography in 32 (56%) patients and thrombus formation was noted in 16 patients (28%). A total of 41 patients (72%) exhibited pericatheter sleeve and/or thrombus formation. While 19 of the 32 patients (59%) without previous catheterization had a sleeve around the catheter, only 13 (52%) of 25 patients who had had multiple catheters inserted had a sleeve (P>0.05). Of the eight patients (14%) with BCV stenosis, two had >50% stenosis. Only one patient (2%) had mild stenosis of the SVC. Three patients out of 15 (20%) who had diagnostic venography for the IJV had severe stenosis of the vein. Pericatheter sleeve formation was more frequent in women (P<0.05). However, there were no statistical differences with respect to pericatheter sleeve formation, luminal filling

Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter

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Ming-Tsung Chuang

2011-11-01

Full Text Available The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010, a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days. The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days. All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

Pierced Lasso Proteins

Science.gov (United States)

Jennings, Patricia

Entanglement and knots are naturally occurring, where, in the microscopic world, knots in DNA and homopolymers are well characterized. The most complex knots are observed in proteins which are harder to investigate, as proteins are heteropolymers composed of a combination of 20 different amino acids with different individual biophysical properties. As new-knotted topologies and new proteins containing knots continue to be discovered and characterized, the investigation of knots in proteins has gained intense interest. Thus far, the principle focus has been on the evolutionary origin of tying a knot, with questions of how a protein chain `self-ties' into a knot, what the mechanism(s) are that contribute to threading, and the biological relevance and functional implication of a knotted topology in vivo gaining the most insight. Efforts to study the fully untied and unfolded chain indicate that the knot is highly stable, remaining intact in the unfolded state orders of magnitude longer than first anticipated. The persistence of ``stable'' knots in the unfolded state, together with the challenge of defining an unfolded and untied chain from an unfolded and knotted chain, complicates the study of fully untied protein in vitro. Our discovery of a new class of knotted proteins, the Pierced Lassos (PL) loop topology, simplifies the knotting approach. While PLs are not easily recognizable by the naked eye, they have now been identified in many proteins in the PDB through the use of computation tools. PL topologies are diverse proteins found in all kingdoms of life, performing a large variety of biological responses such as cell signaling, immune responses, transporters and inhibitors (http://lassoprot.cent.uw.edu.pl/). Many of these PL topologies are secreted proteins, extracellular proteins, as well as, redox sensors, enzymes and metal and co-factor binding proteins; all of which provide a favorable environment for the formation of the disulphide bridge. In the PL

[Coronary angioplasty with the Monorail system via 6 French diagnostic catheters].

Science.gov (United States)

Villavicencio, R; González, H; López, J; Zavala, E; Ban Hayashi, E B; Gaspar, J; Gil, M; Martínez Ríos, M A

1994-01-01

We studied the use of "Monorail" system with Express (Scimed) balloon catheters for coronary angioplasty through 6 French (F) "high-flow" diagnostic catheters (Novoste, USCI). Prospectively, from July 1992 to January 1993, angioplasty of 31 lesions in 24 patients was attempted (1.3 lesions/procedure). Twenty procedures were of a single lesion and four were multi-vessel angioplasty. Fourteen lesions were in the left anterior descending or in its branches, 10 in the left circumflex or in its branches, 6 in the right coronary artery, and one in the distal anastomosis of an internal mammary artery graft. Thirteen lesions (42%) were type A, 17 (55%) type B and one (3%) type C. Balloon sizes varied between 2.0 and 3.5 mm. Twenty-nine lesions could be successfully dilated (93.5%); two cases were unsuccessful due to an acute occlusion in one and residual stenosis of more than 50% in the other. For only one case, another balloon catheter different from the "Monorail" system was necessary to complete a multi-vessel angioplasty. Coronary visualization and manipulation of the balloon through the tip of the diagnostic catheter were satisfactory in all cases, except with the 3.5 mm balloon catheter. Coronary angioplasty with "Monorail" system balloon catheters through 6 F "high-flow" diagnostic catheters is feasible and provides a high success rate in simple and moderately complex selected lesions, including multivessel angioplasty with advantages of smaller artery punction and the feasibility of performing coronary angioplasty with the same catheter used for diagnostic angiography.

Effect of Foley catheters on seed positions and urethral dose in 125I and 103Pd prostate implants

International Nuclear Information System (INIS)

Brezovich, Ivan A.; Pareek, Prem N.; Duan, Jun; Fiveash, John

2001-01-01

Purpose: To estimate the perturbation of seed position and urethral dose, subsequent to withdrawal of urethral catheters. Methods and Materials: A mathematical model based on the volume incompressibility of tissues was used to compute seed positions and doses following removal of the Foley. The model assumed that the central axis of the urethra remains stationary, and that prostate tissue and seeds move radially toward the center of the urethra to fill the void left by the catheter. Seed motion has also been measured using transrectal ultrasound. Results: Based on the computations, seeds located originally close to the urethra travel relatively large distances toward the urethra upon Foley removal, whereas seeds located further away move substantially less. This seed motion leads to higher urethral doses than shown in a standard treatment plan. Dose enhancements increase with catheter size, decrease with increasing prostate volume, are more pronounced for 103 Pd than for 125 I, and range between 3.5% and 32.4%. Postimplant dosimetry is equally affected if images are taken with urethral catheters in place, showing lower urethral doses than actually delivered. Preliminary ultrasound based measurements of seed motion agree with the theory. Conclusion: During the implantation procedure, 12 fr or smaller urethral catheters are preferable to larger diameter catheters if urine drainage is sufficient. Treatment planners should avoid planning seeds at 5 mm or closer from the urethra. Special caution is indicated in prostates having about 20 cm 3 or smaller volumes, and when 103 Pd is used. Postimplant dosimetry is susceptible to the same errors

The efficacy of noble metal alloy urinary catheters in reducing catheter-associated urinary tract infection

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Alanood Ahmed Aljohi

2016-01-01

Results: A 90% relative risk reduction in the rate of CAUTI was observed with the noble metal alloy catheter compared to the standard catheter (10 vs. 1 cases, P = 0.006. When considering both catheter-associated asymptomatic bacteriuria and CAUTI, the relative risk reduction was 83% (12 vs. 2 cases, P = 0.005. In addition to CAUTI, the risk of acquiring secondary bacteremia was lower (100% for the patients using noble metal alloy catheters (3 cases in the standard group vs. 0 case in the noble metal alloy catheter group, P = 0.24. No adverse events related to any of the used catheters were recorded. Conclusion: Results from this study revealed that noble metal alloy catheters are safe to use and significantly reduce CAUTI rate in ICU patients after 3 days of use.

Button self-retaining drainage catheter

International Nuclear Information System (INIS)

Caridi, James G.; Hawkins, Irvin F.; Akins, E. William; Young, Ronald S.

1997-01-01

To help improve patient acceptance of long-term internal/external catheter access to the biliary tract in those with benign biliary obstruction, a simple design allows the catheter end to remain flush with the skin. It consists of a clothes button affixed to the drainage catheter with a wood screw after the catheter has been cut off at the skin exit. This button/screw device has been used successfully in 22 patients over the last 10 years; catheter exchanges were easily accomplished

Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

International Nuclear Information System (INIS)

Whitaker, May; Hruby, George; Lovett, Aimee; Patanjali, Nitya

2011-01-01

Background and purpose: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methods: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5 mm or more, indexer positions were adjusted prior to treatment delivery. Results: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81–367 min). Median catheter displacement was 7.5 mm (range −2.9–23.9 mm), 67% of implants had displacement of 5 mm or greater. Displacements were predominantly caudal. Conclusions: Catheter displacement can occur in the 1–3 h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

Large litter sizes

DEFF Research Database (Denmark)

Sandøe, Peter; Rutherford, K.M.D.; Berg, Peer

2012-01-01

This paper presents some key results and conclusions from a review (Rutherford et al. 2011) undertaken regarding the ethical and welfare implications of breeding for large litter size in the domestic pig and about different ways of dealing with these implications. Focus is primarily on the direct...... possible to achieve a drop in relative piglet mortality and the related welfare problems. However, there will be a growing problem with the need to use foster or nurse sows which may have negative effects on both sows and piglets. This gives rise to new challenges for management....

Modeling and Forecasting Large Realized Covariance Matrices and Portfolio Choice

NARCIS (Netherlands)

Callot, Laurent A.F.; Kock, Anders B.; Medeiros, Marcelo C.

2017-01-01

We consider modeling and forecasting large realized covariance matrices by penalized vector autoregressive models. We consider Lasso-type estimators to reduce the dimensionality and provide strong theoretical guarantees on the forecast capability of our procedure. We show that we can forecast

Multiscale Data Assimilation for Large-Eddy Simulations

Science.gov (United States)

Li, Z.; Cheng, X.; Gustafson, W. I., Jr.; Xiao, H.; Vogelmann, A. M.; Endo, S.; Toto, T.

2017-12-01

Large-eddy simulation (LES) is a powerful tool for understanding atmospheric turbulence, boundary layer physics and cloud development, and there is a great need for developing data assimilation methodologies that can constrain LES models. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) User Facility has been developing the capability to routinely generate ensembles of LES. The LES ARM Symbiotic Simulation and Observation (LASSO) project (https://www.arm.gov/capabilities/modeling/lasso) is generating simulations for shallow convection days at the ARM Southern Great Plains site in Oklahoma. One of major objectives of LASSO is to develop the capability to observationally constrain LES using a hierarchy of ARM observations. We have implemented a multiscale data assimilation (MSDA) scheme, which allows data assimilation to be implemented separately for distinct spatial scales, so that the localized observations can be effectively assimilated to constrain the mesoscale fields in the LES area of about 15 km in width. The MSDA analysis is used to produce forcing data that drive LES. With such LES workflow we have examined 13 days with shallow convection selected from the period May-August 2016. We will describe the implementation of MSDA, present LES results, and address challenges and opportunities for applying data assimilation to LES studies.

Evaluation of mupirocin ointment in control of central venous catheter related infections: a randomized clinical trial

Directory of Open Access Journals (Sweden)

Rezaei J

2009-09-01

Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 st1":*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Central venous catheter (CVC related infections are important complications of cathter application. This study assessed the usefulness of mupirocin in prevention and control of these infections."n"nMethods: In this randomized clinical trial, consecutive surgical patients requiring central venous catheter (for more than 2 days in Amir-Alam Hospital from 2006-2008 were enrolled. Patients were divided in two groups; in "case group" patients received topical mupirocin 2% every 48 hours at the time of insertion of catheter and dressing change and for "control group" mupirocin was not used. All of the patients received chlorhexidine and enoxoparin as complementary treatments. Two groups were comparable in regard of age, sex and risk factors."n"nResults: One hundred eighteen patients enrolled in the study (57 in case and 61 in control group completed the study. 84 catheters in case group and 88 catheters in control group were inserted. The catheters in 90% of patients were inserted in jugular vein. At the end of study 29(16.8% patients (16 in control versus 13 in case group had catheter colonization (p=NS. Catheter related bloodstream infection was observed in 16(9.3% patients (6 in

Exploring relationships of catheter-associated urinary tract infection and blockage in people with long-term indwelling urinary catheters.

Science.gov (United States)

Wilde, Mary H; McMahon, James M; Crean, Hugh F; Brasch, Judith

2017-09-01

To describe and explore relationships among catheter problems in long-term indwelling urinary catheter users, including excess healthcare use for treating catheter problems. Long-term urinary catheter users experience repeated problems with catheter-related urinary tract infection and blockage of the device, yet little has been reported of the patterns and relationships among relevant catheter variables. Secondary data analysis was conducted from a sample in a randomised clinical trial, using data from the entire sample of 202 persons over 12 months' participation. Descriptive statistics were used to characterise the sample over time. Zero-inflated negative binomial models were employed for logistic regressions to evaluate predictor variables of the presence/absence and frequencies of catheter-related urinary tract infection and blockage. Catheter-related urinary tract infection was marginally associated with catheter blockage. Problems reported at least once per person in the 12 months were as follows: catheter-related urinary tract infection 57%, blockage 34%, accidental dislodgment 28%, sediment 87%, leakage (bypassing) 67%, bladder spasms 59%, kinks/twists 42% and catheter pain 49%. Regression analysis demonstrated that bladder spasms were significantly related to catheter-related urinary tract infection and sediment amount, and catheter leakages were marginally significantly and positively related to catheter-related urinary tract infection. Frequencies of higher levels of sediment and catheter leakage were significantly associated with higher levels of blockage, and being female was associated with fewer blockages. Persons who need help with eating (more disabled) were also more likely to have blockages. Catheter-related urinary tract infection and blockage appear to be related and both are associated with additional healthcare expenditures. More research is needed to better understand how to prevent adverse catheter outcomes and patterns of problems in

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).

Science.gov (United States)

Pickard, R; Lam, T; Maclennan, G; Starr, K; Kilonzo, M; McPherson, G; Gillies, K; McDonald, A; Walton, K; Buckley, B; Glazener, C; Boachie, C; Burr, J; Norrie, J; Vale, L; Grant, A; N'dow, J

2012-11-01

outcome was incremental cost per quality-adjusted life-year (QALY). Health-care costs were estimated from NHS sources with QALYs calculated from participant completion of the European Quality of Life-5 Dimensions (EQ-5D). Outcome analyses encompassed 6394 (90%) of 7102 participants randomised. The rate of symptomatic UTI within 6 weeks of randomisation was 10.6% in the nitrofurazone group (n = 2153; -2.1% absolute risk difference), 12.5% in the silver alloy group (n = 2097; -0.1% absolute risk difference) and 12.6% in the PTFE group (n = 2144). The effect size {odds ratio (OR) [97.5% confidence interval (CI)]} was 0.82 (97.5% CI 0.66 to 1.01) for nitrofurazone (p = 0.037) and 0.99 (97.5% CI 0.81 to 1.22) for silver alloy (p = 0.92) catheters. The nitrofurazone catheters were more likely to cause discomfort during use and on removal. The primary economic analysis suggested that nitrofurazone-impregnated catheters would be, on average, the least costly (> £7 less than PTFE) and most effective option at current NHS prices. There was a 73% chance that nitrofurazone would be cost saving and an 84% chance that the incremental cost per QALY would be < £30,000. At the trial price (£6.46), silver alloy catheters were very unlikely to be cost-effective. These results were unchanged in sensitivity analyses, although when the length of stay cost was excluded the incremental cost per QALY for nitrofurazone against PTFE was £28,602. The trial estimate of clinical effectiveness for nitrofurazone-impregnated catheters was less than the pre-specified minimum absolute risk difference that we considered important (-3.3%), and the surrounding CI included zero, indicating that any reduction in catheter-associated UTI was uncertain. Economic analysis, although associated with uncertainty, suggested that nitrofurazone-impregnated catheters may be cost-effective for the NHS. The trial ruled out the possibility that silver alloy-coated catheters might reach the pre-set degree of clinical

Logistic LASSO regression for the diagnosis of breast cancer using clinical demographic data and the BI-RADS lexicon for ultrasonography

Directory of Open Access Journals (Sweden)

Sun Mi Kim

2018-01-01

Full Text Available Purpose The aim of this study was to compare the performance of image analysis for predicting breast cancer using two distinct regression models and to evaluate the usefulness of incorporating clinical and demographic data (CDD into the image analysis in order to improve the diagnosis of breast cancer. Methods This study included 139 solid masses from 139 patients who underwent a ultrasonography-guided core biopsy and had available CDD between June 2009 and April 2010. Three breast radiologists retrospectively reviewed 139 breast masses and described each lesion using the Breast Imaging Reporting and Data System (BI-RADS lexicon. We applied and compared two regression methods-stepwise logistic (SL regression and logistic least absolute shrinkage and selection operator (LASSO regression-in which the BI-RADS descriptors and CDD were used as covariates. We investigated the performances of these regression methods and the agreement of radiologists in terms of test misclassification error and the area under the curve (AUC of the tests. Results Logistic LASSO regression was superior (P<0.05 to SL regression, regardless of whether CDD was included in the covariates, in terms of test misclassification errors (0.234 vs. 0.253, without CDD; 0.196 vs. 0.258, with CDD and AUC (0.785 vs. 0.759, without CDD; 0.873 vs. 0.735, with CDD. However, it was inferior (P<0.05 to the agreement of three radiologists in terms of test misclassification errors (0.234 vs. 0.168, without CDD; 0.196 vs. 0.088, with CDD and the AUC without CDD (0.785 vs. 0.844, P<0.001, but was comparable to the AUC with CDD (0.873 vs. 0.880, P=0.141. Conclusion Logistic LASSO regression based on BI-RADS descriptors and CDD showed better performance than SL in predicting the presence of breast cancer. The use of CDD as a supplement to the BI-RADS descriptors significantly improved the prediction of breast cancer using logistic LASSO regression.

Evaluation of the safety of latrogenic lntestinal perforation during placement of percutaneous drainage catheter in rabbit

International Nuclear Information System (INIS)

Lee, Choon Hyeong; Oh, Joo Hyung; Park, Ga Young; Shin, Hong Sub; Kim, In Sub; Yoon, Yup; Lee, Dong Ho; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won

1996-01-01

To evaluate the safety of transgression of the bowel during intraperitoneal percutaneous catheter placement in an animal model. Eight 8-F straight catheters were percutaneously inserted into the small and large bowel of eight rabbits. In four animals, the catheters were left in place until autopsy, whereas in the remaining four, the catheters were withdrawn five days after insertion. Autopsy was performed in all animals ten days after catheter placement, and gross and microscopic examination was carried out. Transgressing the bowel during intraperitoneal percutaneous catheter placement did not contribute to any clinically significant complications. At autopsy, there was no bowel leakage, peritonitis, or abscess, although peritoneal adhesions were found around the catheter tract. Although further study is warranted, our study with an animal model indicated that transgression of the intestine during percutaneous placement of an intraabdominal catheter did not produce significant complications

Evaluation of the safety of latrogenic lntestinal perforation during placement of percutaneous drainage catheter in rabbit

Energy Technology Data Exchange (ETDEWEB)

Lee, Choon Hyeong; Oh, Joo Hyung; Park, Ga Young; Shin, Hong Sub; Kim, In Sub; Yoon, Yup; Lee, Dong Ho; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won [Kyunghee Univ. Hospital, Seoul (Korea, Republic of)

1996-10-01

To evaluate the safety of transgression of the bowel during intraperitoneal percutaneous catheter placement in an animal model. Eight 8-F straight catheters were percutaneously inserted into the small and large bowel of eight rabbits. In four animals, the catheters were left in place until autopsy, whereas in the remaining four, the catheters were withdrawn five days after insertion. Autopsy was performed in all animals ten days after catheter placement, and gross and microscopic examination was carried out. Transgressing the bowel during intraperitoneal percutaneous catheter placement did not contribute to any clinically significant complications. At autopsy, there was no bowel leakage, peritonitis, or abscess, although peritoneal adhesions were found around the catheter tract. Although further study is warranted, our study with an animal model indicated that transgression of the intestine during percutaneous placement of an intraabdominal catheter did not produce significant complications.

Peritoneal catheter fixation combined with straight upward tunnel and low implant position to prevent catheter malfunction.

Science.gov (United States)

Zhang, Qingyan; Jiang, Chunming; Zhu, Wei; Sun, Cheng; Xia, Yangyang; Tang, Tianfeng; Wan, Cheng; Shao, Qiuyuan; Liu, Jing; Jin, Bo; Zhang, Miao

2018-03-01

Catheter malfunction is the main reason for early peritoneal dialysis (PD) technique failure. This study aimed to evaluate the effect of a new surgery technique with catheter fixation to the lower abdominal wall combined with straight upward tunnel and low implant position in reducing catheter malfunction. Patients with end stage renal disease who received PD in our centre from January 2013 to December 2015 were involved in this study. They were randomly divided into three groups according to surgical technique: traditional open surgery group, modified open surgery group and modified open surgery with catheter fixation group. All patients were followed up for six months after surgery. Catheter- related complications were analyzed. A total of 152 patients were involved. Among them, 49 received traditional open surgery (TOS group), 49 received modified open surgery (MOS group), and 54 received modified open surgery with catheter fixation (MOS-F group). During follow-up, no patients (0%) in MOS-F group developed catheter malfunction which was significantly lower than that of the TOS group (0 vs 16.33%, P = 0.002). Although not statistically significant, the incidence of catheter malfunction was lower in MOS-F group than that in MOS group (0 vs 4.08%, P = 0.134). No significant difference was observed in the episodes of infection, bleeding, leakage, inflow or outflow pain, hernia and delayed wound healing among the three groups (all P > 0.05). Catheter fixation combined with straight upward tunnel and low implant position can effectively prevent catheter malfunction in PD catheter placement. © 2016 Asian Pacific Society of Nephrology.

A catheter malpositioned patient with pain and paresthesia

Directory of Open Access Journals (Sweden)

Akbar Fadaei Haghi

2017-01-01

Full Text Available We report a 54-year-old woman with the history of end-stage renal disease (ESRD who was admitted to our hospital because of volume overload. Due to long-term use of peripheral veins and arteriovenous fistula (AVF failure, central venous catheterization was the only choice for hemodialysis. She developed right upper extremiti’s pain and paresis during hemodialysis. A posteroanterior chest x-ray showed the catheter tip was accidently pushed from right internal jugular vein into right subclavian vein during hemodialysis by the dialysis center nurse. Therefore, we believe that the physician should be aware of any changes in the catheter size after insertion. And a chest x-ray should ensure the catheter’s correct position in any patient who develops complications.

[The role of the uretral catheter in the development of catheter- related urinary tract infection].

Science.gov (United States)

Vasilyev, A O; Govorov, A V; Shiryaev, A A; Pushkar, D Yu

2017-12-01

The most common source of nosocomial infection is the urinary tract, especially if they it is drained with a urethral catheter. Catheter-associated urinary tract infections account for at least 80% of all complicated urinary tract infections and are the most common type of hospital-acquired infection. Intestinal microflora plays the leading role in the pathogenesis of catheter-associated urinary tract infections, whereas the most important risk factor for their development is the long duration of urinary catheter drainage. In the case of short-term and intermittent catheterization, routine antibiotic prophylaxis is not required, but if a patient develops clinically significant infection, antibiotic therapy is required followed by definitive therapy based on culture. Urethral catheters coated with antimicrobial substances and anti-inflammatory agents can significantly reduce the adhesion and migration of bacteria, thereby reducing the incidence of urinary tract infections. Despite this, the incidence of catheter-associated infection remains high. We have reviewed recent literature related to catheter-associated urinary tract infections and the best means of preventing this condition.

Epidural Catheter Breakage In-Situ

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Geetanjali S Verma

2014-09-01

Full Text Available A 45yr old woman diagnosed with dysfunctional uterine bleeding and incisional hernia was planned for total abdominal hysterectomy with bilateral salpingo-oophorectomy and mesh repair under combined spinal and epidural anaesthesia. Using VYGON® epidural catheter with its recommended introducer, the catheter was inserted but it snapped off at 11cm mark while positioning the catheter. After radiological confirmation, the neurosurgeon removed the catheter under general anaesthesia, which was followed by the scheduled surgery.

A Case of Unrecognized Intrathoracic Placement of a Subclavian Central Venous Catheter in a Patient with Large Traumatic Hemothorax

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Dina Wallin

2015-01-01

Full Text Available Traditional recommendations suggest placement of a subclavian central venous catheter (CVC ipsilateral to a known pneumothorax to minimize risk of bilateral pneumothorax. We present the case of a 65-year-old male with a right hemopneumothorax who was found to have intrathoracic placement of his right subclavian CVC at thoracotomy despite successful aspiration of blood and transduction of central venous pressure (CVP. We thus recommend extreme caution with the interpretation of CVC placement by blood aspiration and CVP measurement alone in patients with large volume ipsilateral hemothorax.

Percutaneous transvenous retrieval of CVP catheter emboli in S. V. C.-A case report-

International Nuclear Information System (INIS)

Zeon, Seok Kil; Lee, Deock Hee; Kim, Hong; Kim, Ok Bae

1987-01-01

The increasing use of the indwelling venous catheters and cardiovascular catheters has led to many iatrogenic complications. One of the most serious complications is catheter embolization, caused by inadvertent fracture of a fragment of catheter remaining within cardiovascular systems. In the catheter embolization, there are serious consequence such as thromboembolism, sepsis, cardiac arrhythmia and others. Fisher and Ferreyro (1978) reported a 71% incidence of serious morbidity or death following to intravascular foreign bodies in patients without removal. The authors experienced a case of retained central venous pressure monitoring catheter (CVP catheter) fragment extending from superior vena cava to hepatic segment of inferior vena cava. CVP catheter wa introduced into right subclavian venous route for hyperalimentation, because of poor general condition for operation of afferent loop syndrome following to resection of the gastric carcinoma with Billoth II operation (5 years age). On attempting removal of CVP catheter on recovery from afferent loop syndrome, a large portion of the CVP catheter was cut off in S.V.C. Percutaneous puncture of right femoral vein with Seldinger technique was done and 9F introducer sheath was indwelled. The helical basket of Dotter intravascular retriever set was advance through the sheath up to retained CVP catheter, and it was grasped. The retrieved CVP catheter fragment showed several tiny blood clots on surface. The patient was uneventfully recovered and was discharged asymptomatic on second day of the procedure.

Laparoscopic management of a large ovarian cyst in an adolescent. A case report.

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Eltabbakh, G H; Kaiser, J R

2000-03-01

The safety of laparoscopic management of benign ovarian cysts has been demonstrated. The size of the benign ovarian cyst continues to be a limiting factor for laparoscopic surgery, with most surgeons choosing laparotomy for large cysts. A 15-year-old woman had a 22-cm, benign ovarian cyst extending above the umbilicus that was managed successfully with laparoscopy. We performed prelaparoscopy cyst drainage with a suprapubic Bonanno catheter (Becton Dickinson, Rutherford, New Jersey) followed by laparoscopic cystectomy. Because of its coiled end, the Bonanno catheter is less likely to result in cyst leakage around the aspiration site. With proper patient selection, laparoscopic surgery can be safely applied in a select group of patients with large, benign ovarian cysts.

Simultaneous Channel and Feature Selection of Fused EEG Features Based on Sparse Group Lasso

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Jin-Jia Wang

2015-01-01

Full Text Available Feature extraction and classification of EEG signals are core parts of brain computer interfaces (BCIs. Due to the high dimension of the EEG feature vector, an effective feature selection algorithm has become an integral part of research studies. In this paper, we present a new method based on a wrapped Sparse Group Lasso for channel and feature selection of fused EEG signals. The high-dimensional fused features are firstly obtained, which include the power spectrum, time-domain statistics, AR model, and the wavelet coefficient features extracted from the preprocessed EEG signals. The wrapped channel and feature selection method is then applied, which uses the logistical regression model with Sparse Group Lasso penalized function. The model is fitted on the training data, and parameter estimation is obtained by modified blockwise coordinate descent and coordinate gradient descent method. The best parameters and feature subset are selected by using a 10-fold cross-validation. Finally, the test data is classified using the trained model. Compared with existing channel and feature selection methods, results show that the proposed method is more suitable, more stable, and faster for high-dimensional feature fusion. It can simultaneously achieve channel and feature selection with a lower error rate. The test accuracy on the data used from international BCI Competition IV reached 84.72%.

Vascular access in neonatology: peripherally inserted central catheter and peripheral venous catheter

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Marcia Lienemann

2014-04-01

The objective of this paper is to present aspects of peripherally inserted central catheter and peripheral venous catheter, highlighting important points in choosing the type of access. For the passage of peripherally inserted central catheter is previously performing specific course necessary, while the primary indication occurs when it is necessary to access the patient's stay for a long period of time. Whereas peripheral venipuncture is the most appropriate in cases of needing an IV line quickly and safely, for the administration of fluids, blood collection, blood transfusion and other.

Emergency coronary angioplasty with stenting using Cordis® diagnostic coronary catheters when there is difficulty in engaging guide catheters and bench evaluation of diagnostic and guide catheters.

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Arokiaraj, Mark Christopher

2018-02-01

Difficulty in engaging with guide catheters is not uncommon in acute emergencies. We aimed to evaluate the use of Cordis ® INFINITI diagnostic catheters to perform angioplasty in patients in whom the coronaries cannot be engaged using standard guide catheters. In 34 cases of acute coronary syndrome, when difficulty in engagement with two standard guide catheters was encountered with reasonable manipulations, angioplasty was performed using diagnostic catheters. In total, 40 stents were placed by this technique. Pushability and trackability, distal tip flexion and three-point bending tests were performed to evaluate the performance of the guide and diagnostic catheters. Angioplasty was performed easily in a setting where it would have been very difficult to perform. Coronary dissection occurred in one patient, treated by a stent. The stent and dilatation balloons were easily passed through the diagnostic catheters. Pressure tracings were clearly preserved with certain stent delivery systems, and at angioplasty, although there was slightly reduced opacification of the respective artery, the coronary anatomy was sufficiently visualized to perform angioplasty. No periprocedural target lesion complications were seen in any cases. Pushability and trackability tests showed good force transmission along a tortuous path with diagnostic catheters, and balanced force-displacement curves from three-point bending tests and distal tip softness tests. Angioplasty with stenting can be performed safely through 6F Cordis ® infiniti diagnostic catheters when difficulty in engaging guide catheters is encountered. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Intracorporeal knotting of a femoral nerve catheter

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Ghanem, Mohamed

2015-01-01

Full Text Available Peripheral nerve catheters are effective and well-established tools to provide postoperative analgesia to patients undergoing orthopedic surgery. The performance of these techniques is usually considered safe. However, placement of nerve catheters may be associated with a considerable number of side effects and major complications have repeatedly been published. In this work, we report on a patient who underwent total knee replacement with spinal anesthesia and preoperative insertion of femoral and sciatic nerve catheters for postoperative analgesia. During insertion of the femoral catheter, significant resistance was encountered upon retracting the catheter. This occurred due to knotting of the catheter. The catheter had to be removed by operative intervention which has to be considered a major complication. The postoperative course was uneventful. The principles for removal of entrapped peripheral catheters are not well established, may differ from those for neuroaxial catheters, and range from cautious manipulation up to surgical intervention.

Discovery and replication of gene influences on brain structure using LASSO regression

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Omid eKohannim

2012-08-01

Full Text Available We implemented LASSO (least absolute shrinkage and selection operator regression to evaluate gene effects in genome-wide association studies (GWAS of brain images, using an MRI-derived temporal lobe volume measure from 729 subjects scanned as part of the Alzheimer’s Disease Neuroimaging Initiative (ADNI. Sparse groups of SNPs in individual genes were selected by LASSO, which identifies efficient sets of variants influencing the data. These SNPs were considered jointly when assessing their association with neuroimaging measures. We discovered 22 genes that passed genome-wide significance for influencing temporal lobe volume. This was a substantially greater number of significant genes compared to those found with standard, univariate GWAS. These top genes are all expressed in the brain and include genes previously related to brain function or neuropsychiatric disorders such as MACROD2, SORCS2, GRIN2B, MAGI2, NPAS3, CLSTN2, GABRG3, NRXN3, PRKAG2, GAS7, RBFOX1, ADARB2, CHD4 and CDH13. The top genes we identified with this method also displayed significant and widespread post-hoc effects on voxelwise, tensor-based morphometry (TBM maps of the temporal lobes. The most significantly associated gene was an autism susceptibility gene known as MACROD2. We were able to successfully replicate the effect of the MACROD2 gene in an independent cohort of 564 young, Australian healthy adult twins and siblings scanned with MRI (mean age: 23.8±2.2 SD years. In exploratory analyses, three selected SNPs in the MACROD2 gene were also significantly associated with performance intelligence quotient (PIQ. Our approach powerfully complements univariate techniques in detecting influences of genes on the living brain.

Radiologic placement of Hickman catheters

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Robertson, L.J.; Mauro, M.A.; Jaques, P.F.

1988-01-01

Hickman catheter inserter has previously been predominantly accomplished surgically by means of venous cutdown or percutaneous placement in the operating room. The authors describe their method and results for 55 consecutive percutaneous placements of Hickman catheters in the interventional radiology suite. Complication rates were comparable to those for surgical techniques. Radiologic placement resulted in increased convenience, decreased time and cost of insertion, and super fluoroscopic control of catheter placement and any special manipulations. Modern angiographic materials provide safer access to the subclavian vein than traditional methods. The authors conclude that radiologic placement of Hickman catheters offers significant advantages over traditional surgical placement

Comparative study of peripherally inserted central venous catheter and traditional central catheter assisted with X-ray

International Nuclear Information System (INIS)

Yu Jianchun; Wang Xiurong; Jiang Zhuming

1999-01-01

Objective: To study the feasibility, complications, mid- and long-term advantages of peripherally inserted central catheters (PICC) compared with central venous access assisted with X-ray. Methods: From Jan 1997 to Dec 1998, the authors conducted a study in 60 patients with placed PICC lines and 60 patients with central lines. Study variables included tip placement and complication rates. Results: Tere were on significant differences between PICC and CVC in the successful placement 95.0% and 88.3%, t = 1.745, P 0.19; the mean duration 13(6-98) days and 14 (7-104) days, F = 0.049, P = 0.83; the total occlusion rate 6.7% (4/60) and 5.0%(3/60), t = 0.152, P = 0.70. In PICC patients, the occlusion rate was slightly higher in 3 Fr (20-gauge) catheter (3/20, 15.0%) than in 4 Fr(18-gauge) catheters (1/20, 5.0%), t = 1.111, P=0.29. Phlebitis occurred in 5.0% of patients (3/60) and one catheter fracture was happened on the catheter hub junction (1.7%). In 3 catheter tips dislocation cases, the catheter tips were moved to the optional position assisted with X-ray image. In CVC group, pneumothorax happened in 1 case (1.7%). In 4 catheter dislocation cases, the catheters were with drawn. No catheter-related sepsis and hemo-pneumothorax happened in both group patients. Conclusions: Both PICC and CVC can be acceptable in clinical use. PICC assisted with X-ray possesses the advantages of less trauma, accurate localization preventing some possible severe complications of central venous access such as pneumothorax. The new method provides a reliable, effective venous access for mid-and long-term usage in patients receiving a variety of solutions, primarily parenteral alimentation, chemotherapy or antibiotic infusion

Using Multivariate Regression Model with Least Absolute Shrinkage and Selection Operator (LASSO) to Predict the Incidence of Xerostomia after Intensity-Modulated Radiotherapy for Head and Neck Cancer

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Ting, Hui-Min; Chang, Liyun; Huang, Yu-Jie; Wu, Jia-Ming; Wang, Hung-Yu; Horng, Mong-Fong; Chang, Chun-Ming; Lan, Jen-Hong; Huang, Ya-Yu; Fang, Fu-Min; Leung, Stephen Wan

2014-01-01

Purpose The aim of this study was to develop a multivariate logistic regression model with least absolute shrinkage and selection operator (LASSO) to make valid predictions about the incidence of moderate-to-severe patient-rated xerostomia among head and neck cancer (HNC) patients treated with IMRT. Methods and Materials Quality of life questionnaire datasets from 206 patients with HNC were analyzed. The European Organization for Research and Treatment of Cancer QLQ-H&N35 and QLQ-C30 questionnaires were used as the endpoint evaluation. The primary endpoint (grade 3+ xerostomia) was defined as moderate-to-severe xerostomia at 3 (XER3m) and 12 months (XER12m) after the completion of IMRT. Normal tissue complication probability (NTCP) models were developed. The optimal and suboptimal numbers of prognostic factors for a multivariate logistic regression model were determined using the LASSO with bootstrapping technique. Statistical analysis was performed using the scaled Brier score, Nagelkerke R2, chi-squared test, Omnibus, Hosmer-Lemeshow test, and the AUC. Results Eight prognostic factors were selected by LASSO for the 3-month time point: Dmean-c, Dmean-i, age, financial status, T stage, AJCC stage, smoking, and education. Nine prognostic factors were selected for the 12-month time point: Dmean-i, education, Dmean-c, smoking, T stage, baseline xerostomia, alcohol abuse, family history, and node classification. In the selection of the suboptimal number of prognostic factors by LASSO, three suboptimal prognostic factors were fine-tuned by Hosmer-Lemeshow test and AUC, i.e., Dmean-c, Dmean-i, and age for the 3-month time point. Five suboptimal prognostic factors were also selected for the 12-month time point, i.e., Dmean-i, education, Dmean-c, smoking, and T stage. The overall performance for both time points of the NTCP model in terms of scaled Brier score, Omnibus, and Nagelkerke R2 was satisfactory and corresponded well with the expected values. Conclusions

SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

International Nuclear Information System (INIS)

Li, J S; Ma, C

2014-01-01

Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system was used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use

[Incidence of phlebitis due to peripherally inserted venous catheters: impact of a catheter management protocol].

Science.gov (United States)

Ferrete-Morales, C; Vázquez-Pérez, M A; Sánchez-Berna, M; Gilabert-Cerro, I; Corzo-Delgado, J E; Pineda-Vergara, J A; Vergara-López, S; Gómez-Mateos, J

2010-01-01

To assess the impact on the incidence of PPIVC by implementing a catheter management protocol and to determine risk factors for PPIVC development in hospitalized patients. A total of 3978 episodes of venous catheterization were prospectively included from September 2002 to December 2007. A catheter management protocol was implemented during this period of time. The incidence and variables associated to the occurrence of PPIVC were determined. The incidence of PPIVC from 2002 to 2007 was 4.8%, 4.3%, 3.6%, 2.5%, 1.3% and 1.8% (phistory of phlebitis was the only factor independently associated to phlebitis due to peripherally inserted central venous catheters (AOR 3.24; CI at 95% CI= 1.05-9.98, p=0.04). A catheter management protocol decreases the incidence of PPIVC in hospitalized patients. The risk of PPIVC increases for peripherally inserted central venous catheters when the patients have a history of phlebitis and for peripheral venous catheters when amiodarone or cefotaxime are infused. Catheterization of peripheral veins performed during morning shifts is associated with a lower incidence of PPIVC when compared with night shift catheterizations.

Fused Adaptive Lasso for Spatial and Temporal Quantile Function Estimation

KAUST Repository

Sun, Ying

2015-09-01

Quantile functions are important in characterizing the entire probability distribution of a random variable, especially when the tail of a skewed distribution is of interest. This article introduces new quantile function estimators for spatial and temporal data with a fused adaptive Lasso penalty to accommodate the dependence in space and time. This method penalizes the difference among neighboring quantiles, hence it is desirable for applications with features ordered in time or space without replicated observations. The theoretical properties are investigated and the performances of the proposed methods are evaluated by simulations. The proposed method is applied to particulate matter (PM) data from the Community Multiscale Air Quality (CMAQ) model to characterize the upper quantiles, which are crucial for studying spatial association between PM concentrations and adverse human health effects. © 2016 American Statistical Association and the American Society for Quality.

Reinnervation following catheter-based radio-frequency renal denervation.

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Booth, Lindsea C; Nishi, Erika E; Yao, Song T; Ramchandra, Rohit; Lambert, Gavin W; Schlaich, Markus P; May, Clive N

2015-04-20

were normal, indicating reinnervation. Anatomical measures of renal innervation by sympathetic efferent nerves (tissue noradrenaline and tyrosine hydroxylase) and afferent sensory nerves (calcitonin gene-related peptide) demonstrated large decreases at 1 week postdenervation, but normal levels at 11 months postdenervation. In summary, catheter-based renal denervation is effective, but reinnervation occurs. Studies of central and renal changes postdenervation are required to understand the causes of the prolonged hypotensive response to catheter-based renal denervation in human hypertension. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

A comparison of plasma and electron beam-sterilization of PU catheters

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Mrad, O. [Univ Paris-Sud 11, EA 401, IFR 141, Faculte de pharmacie, F-92296 Chatenay Malabry (France); Saunier, J., E-mail: johanna.saunier@u-psud.f [Univ Paris-Sud 11, EA 401, IFR 141, Faculte de pharmacie, F-92296 Chatenay Malabry (France); Aymes Chodur, C. [Univ Paris-Sud 11, EA 401, IFR 141, Faculte de pharmacie, F-92296 Chatenay Malabry (France); Rosilio, V.; Agnely, F. [Univ Paris-Sud 11, UMR 8612, Faculte de pharmacie, F-92296 Chatenay Malabry (France); CNRS, UMR 8612, Faculte de pharmacie, F-92296 Chatenay Malabry (France); Aubert, P. [Univ Evry Val d' Essonne, LMN, F-91025 Evry (France); Vigneron, J.; Etcheberry, A. [Univ Versailles, ILV CNRS UMR 8180, Institut Lavoisier de Versailles, F-78035 Versailles (France); Yagoubi, N. [Univ Paris-Sud 11, EA 401, IFR 141, Faculte de pharmacie, F-92296 Chatenay Malabry (France)

2010-01-15

Polyurethane (PU) catheters made of Pellethane 2363-80AE were treated in two different ways: a new treatment with low temperature plasma that could be used to decontaminate reusable polymer devices in hospitals, and an e-beam (EB) irradiation. Polymer structure and bulk properties were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR) and size exclusion chromatography (SEC). Although PU was strongly modified by the e-beam irradiation leading to branching of polymer chains, it had no or little impact on the thermo-mechanical properties of the catheters and on the hard/soft segment organization of PU. For plasma-treated samples, no modification in the polymer bulk was observed, confirming that plasma treatment might be considered as an alternative to e-beam irradiation. The analysis of surface modifications showed an evolution of superficial topology and chemical composition (grafting of oxygen and nitrogen species) of the catheters after treatment, with a more polar and hydrophilic surface.

A comparison of plasma and electron beam-sterilization of PU catheters

International Nuclear Information System (INIS)

Mrad, O.; Saunier, J.; Aymes Chodur, C.; Rosilio, V.; Agnely, F.; Aubert, P.; Vigneron, J.; Etcheberry, A.; Yagoubi, N.

2010-01-01

Polyurethane (PU) catheters made of Pellethane 2363-80AE were treated in two different ways: a new treatment with low temperature plasma that could be used to decontaminate reusable polymer devices in hospitals, and an e-beam (EB) irradiation. Polymer structure and bulk properties were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR) and size exclusion chromatography (SEC). Although PU was strongly modified by the e-beam irradiation leading to branching of polymer chains, it had no or little impact on the thermo-mechanical properties of the catheters and on the hard/soft segment organization of PU. For plasma-treated samples, no modification in the polymer bulk was observed, confirming that plasma treatment might be considered as an alternative to e-beam irradiation. The analysis of surface modifications showed an evolution of superficial topology and chemical composition (grafting of oxygen and nitrogen species) of the catheters after treatment, with a more polar and hydrophilic surface.

Atrial fibrillation ablation using a closed irrigation radiofrequency ablation catheter.

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Golden, Keith; Mounsey, John Paul; Chung, Eugene; Roomiani, Pahresah; Morse, Michael Andew; Patel, Ankit; Gehi, Anil

2012-05-01

Catheter ablation is an effective therapy for symptomatic, medically refractory atrial fibrillation (AF). Open-irrigated radiofrequency (RF) ablation catheters produce transmural lesions at the cost of increased fluid delivery. In vivo models suggest closed-irrigated RF catheters create equivalent lesions, but clinical outcomes are limited. A cohort of 195 sequential patients with symptomatic AF underwent stepwise AF ablation (AFA) using a closed-irrigation ablation catheter. Recurrence of AF was monitored and outcomes were evaluated using Kaplan-Meier survival analysis and Cox proportional hazards models. Mean age was 59.0 years, 74.9% were male, 56.4% of patients were paroxysmal and mean duration of AF was 5.4 years. Patients had multiple comorbidities including hypertension (76.4%), tobacco abuse (42.1%), diabetes (17.4%), and obesity (mean body mass index 30.8). The median follow-up was 55.8 weeks. Overall event-free survival was 73.6% with one ablation and 77.4% after reablation (reablation rate was 8.7%). Median time to recurrence was 26.9 weeks. AF was more likely to recur in patients being treated with antiarrhythmic therapy at the time of last follow-up (recurrence rate 30.3% with antiarrhythmic drugs, 13.2% without antiarrhythmic drugs; hazard ratio [HR] 2.2, 95% confidence interval [CI] 1.1-4.4, P = 0.024) and in those with a history of AF greater than 2 years duration (HR 2.7, 95% CI 1.1-6.9, P = 0.038). Our study represents the largest cohort of patients receiving AFA with closed-irrigation ablation catheters. We demonstrate comparable outcomes to those previously reported in studies of open-irrigation ablation catheters. Given the theoretical benefits of a closed-irrigation system, a large head-to-head comparison using this catheter is warranted. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

An alternative method for determining particle-size distribution of forest road aggregate and soil with large-sized particles

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Hakjun Rhee; Randy B. Foltz; James L. Fridley; Finn Krogstad; Deborah S. Page-Dumroese

2014-01-01

Measurement of particle-size distribution (PSD) of soil with large-sized particles (e.g., 25.4 mm diameter) requires a large sample and numerous particle-size analyses (PSAs). A new method is needed that would reduce time, effort, and cost for PSAs of the soil and aggregate material with large-sized particles. We evaluated a nested method for sampling and PSA by...

Radiofrequency catheter oblation in atrial flutter

International Nuclear Information System (INIS)

Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

2002-01-01

Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

The effect of peripherally inserted central catheter (PICC) valve technology on catheter occlusion rates--the 'ELeCTRiC' study.

Science.gov (United States)

Johnston, Andrew J; Streater, Carmel T; Noorani, Remy; Crofts, Joanne L; Del Mundo, Aldwin B; Parker, Richard A

2012-01-01

Peripherally Inserted Central Catheters (PICCs) are increasingly being used to provide short to medium-term central venous access. The current study was designed to test the hypothesis that PICC valve technology does not influence PICC occlusion rates. Intensive care unit (ICU) patients who required a PICC were randomized to one of three types of dual lumen PICC (open ended non-valved, Groshong valve, PASV valve). PICC occlusions were recorded and managed with a protocol that used urokinase. A total of 102 patients were recruited to the study. The overall risk of occlusion per catheter was 35% (95% CI 26% to 44%). The overall rate of occlusion was 76 occlusions per 1000 catheter days (95% CI 61 to 95). Presence or type of valve did not significantly influence this rate (open-ended non-valved PICC 38% of catheters, 79 occlusions per 1000 catheter days; Groshong 38% of catheters, 60 occlusions per 1000 catheter days; PASV 27% of catheters, 99 occlusions per 1000 catheter days). The dose of urokinase required to treat PICC occlusions did not significantly differ between PICC types. Valved PICCs do not appear to influence PICC occlusion rates.

AN ANALYTIC OUTLOOK OF THE MADRIGAL MORO LASSO AL MIO DUOLO BY GESUALDO DA VENOSA

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MURARU AUREL

2015-09-01

Full Text Available The analysis of the madrigal Moro lasso al mio duolo reveals the melancholic, thoughtful and grieving atmosphere, gene­rating shady, silent, sometimes dark soundscapes. Gesualdo shapes the poliphony through chromatic licenses, in order to create a tense musical discourse, permanently yearning for stability and balance amidst a harmonic construction lacking any attempt for resolution. Thus the strange harmonies of Gesualdo are shaped, giving birth to a unique musical style, full of dissonances and endless musical tension.

The relationship between vacuum and hemolysis during catheter blood collection: a retrospective analysis of six large cohorts.

Science.gov (United States)

Mrazek, Cornelia; Simundic, Ana-Maria; Wiedemann, Helmut; Krahmer, Florian; Felder, Thomas Klaus; Kipman, Ulrike; Hoppe, Uta; Haschke-Becher, Elisabeth; Cadamuro, Janne

2017-07-26

Blood collection through intravenous (IV) catheters is a common practice at emergency departments (EDs). This technique is associated with higher in vitro hemolysis rates and may even be amplified by the use of vacuum collection tubes. Our aim was to investigate the association of five different vacuum tubes with hemolysis rates in comparison to an aspiration system under real-life conditions and to propose an equation to estimate the amount of hemolysis, depending on the vacuum collection tube type. We retrospectively evaluated hemolysis data of plasma samples from our ED, where blood is drawn through IV catheters. Over the past 5 years, we compared 19,001 hemolysis index values amongst each other and against the respective vacuum pressure (Pv) of the collection tubes, which were used within the six observational periods. The highest hemolysis rates were associated with full-draw evacuated tubes. Significantly reduced hemolysis was observed for two kinds of partial-draw tubes. The hemolysis rate of one partial-draw blood collection tube was comparable to those of the aspiration system. Regression analysis of Pv and mean free hemoglobin (fHb) values yielded the formula fHb (g/L)=0.0082*Pv2-0.1143*Pv+ 0.5314 with an R2 of 0.99. If IV catheters are used for blood collection, hemolysis rates directly correlate with the vacuum within the tubes and can be estimated by the proposed formula. By the use of partial-draw vacuum blood collection tubes, hemolysis rates in IV catheter collections can be reduced to levels comparable with collections performed by aspiration systems.

Previous PICC Placement May Be Associated With Catheter-Related Infections in Hemodialysis Patients

International Nuclear Information System (INIS)

Butler, Philip J.; Sood, Shreya; Mojibian, Hamid; Tal, Michael G.

2011-01-01

Background: Catheter-related infections (CRIs) are a significant source of morbidity and mortality in hemodialysis patients. The identification of novel, modifiable risk factors for CRIs may lead to improved outcomes in this population. Peripherally inserted central catheters (PICCs) have been hypothesized to compromise vascular access due to vascular damage and venous thrombosis, whereas venous thrombosis has been linked to the development of CRIs. Here we examine the association between PICC placement and CRIs. Methods: A retrospective review was performed of all chronic hemodialysis catheter placements and exchanges performed at a large university hospital from September 2003 to September 2008. History of PICC line use was determined by examining hospital radiologic records from December 1993 to September 2008. Catheter-related complications were assessed and correlated with PICC line history. Results: One hundred eighty-five patients with 713 chronic tunneled hemodialysis catheter placements were identified. Thirty-eight of those patients (20.5%) had a history of PICC placement; these patients were more likely to have CRIs (odds ratio = 2.46, 95% confidence interval = 1.71–3.53, p < .001) compared with patients without a history of PICC placement. There was no difference between the two groups in age or number of catheters placed. Conclusion: Previous PICC placement may be associated with catheter-related infections in hemodialysis patients.

Effect of Ultrasound-Guided Placement of Difficult-to-Place Peripheral Venous Catheters

DEFF Research Database (Denmark)

Partovi-Deilami, Kohyar; Nielsen, Jesper K.; Møller, Ann M.

2016-01-01

operated by nurse anesthetists for these patients. This prospective observational study with a pre/post design focused on inpatients with DIVA referred for PVC placement, a service provided by nurse anesthetists in most Scandinavian hospitals. The rate of success, procedure time, number of skin punctures......) with ultrasound. Procedure time was reduced from 20 to 10 minutes, discomfort was unchanged, and the median number of skin punctures decreased from 3 to 2. The incidence of central venous catheter placement dropped from 34% to 7%. Implementation of a training program and a mobile service in which nurse......, discomfort, catheter size, location, and incidence of central venous catheter placement are reported before and after implementation of a training program and a mobile service using ultrasound to place difficult-to-place PVCs. The success rate increased from 0% (0 of 33 patients) to 83% (58 of 70 patients...

Large size space construction for space exploitation

Science.gov (United States)

Kondyurin, Alexey

2016-07-01

Space exploitation is impossible without large space structures. We need to make sufficient large volume of pressurized protecting frames for crew, passengers, space processing equipment, & etc. We have to be unlimited in space. Now the size and mass of space constructions are limited by possibility of a launch vehicle. It limits our future in exploitation of space by humans and in development of space industry. Large-size space construction can be made with using of the curing technology of the fibers-filled composites and a reactionable matrix applied directly in free space. For curing the fabric impregnated with a liquid matrix (prepreg) is prepared in terrestrial conditions and shipped in a container to orbit. In due time the prepreg is unfolded by inflating. After polymerization reaction, the durable construction can be fitted out with air, apparatus and life support systems. Our experimental studies of the curing processes in the simulated free space environment showed that the curing of composite in free space is possible. The large-size space construction can be developed. A project of space station, Moon base, Mars base, mining station, interplanet space ship, telecommunication station, space observatory, space factory, antenna dish, radiation shield, solar sail is proposed and overviewed. The study was supported by Humboldt Foundation, ESA (contract 17083/03/NL/SFe), NASA program of the stratospheric balloons and RFBR grants (05-08-18277, 12-08-00970 and 14-08-96011).

In vitro analysis of balloon cuffing phenomenon: inherent biophysical properties of catheter material or mechanics of catheter balloon deflation?

Science.gov (United States)

Chung, Eric; So, Karina

2012-06-01

To investigates the different methods of balloon deflation, types of urinary catheters and exposure to urine media in catheter balloon cuffing. Bardex®, Bard-Lubri-Sil®, Argyle®, Releen® and Biocath® were tested in sterile and E.Coli inoculated urine at 0, 14 and 28 days. Catheter deflation was performed with active deflation; passive deflation; passive auto-deflation; and excision of the balloon inflow channel. Balloon cuffing was assessed objectively by running the deflated balloon over a plate of agar and subjectively by 3 independent observers. Bardex®, Argyle® and Biocath® showed greater degree of catheter balloon cuffing (p deflation was the worst method (p 0.05). Linear regression model analysis confirmed time as the most significant factor. The duration of catheters exposure, different deflation methods and types of catheters tested contributed significantly to catheter balloon cuffing (p < 0.01).

Prevention of catheter-related blood stream infection.

Science.gov (United States)

Byrnes, Matthew C; Coopersmith, Craig M

2007-08-01

Catheter-related blood stream infections are a morbid complication of central venous catheters. This review will highlight a comprehensive approach demonstrated to prevent catheter-related blood stream infections. Elements of prevention important to inserting a central venous catheter include proper hand hygiene, use of full barrier precautions, appropriate skin preparation with 2% chlorhexidine, and using the subclavian vein as the preferred anatomic site. Rigorous attention needs to be given to dressing care, and there should be daily assessment of the need for central venous catheters, with prompt removal as soon as is practicable. Healthcare workers should be educated routinely on methods to prevent catheter-related blood stream infections. If rates remain higher than benchmark levels despite proper bedside practice, antiseptic or antibiotic-impregnated catheters can also prevent infections effectively. A recent program utilizing these practices in 103 ICUs in Michigan resulted in a 66% decrease in infection rates. There is increasing recognition that a comprehensive strategy to prevent catheter-related blood stream infections can prevent most infections, if not all. This suggests that thousands of infections can potentially be averted if the simple practices outlined herein are followed.

YM2: Continuum expectations, lattice convergence, and lassos

International Nuclear Information System (INIS)

Driver, B.K.

1989-01-01

The two dimensional Yang-Mills theory (YM 2 ) is analyzed in both the continuum and the lattice. In the complete axial gauge the continuum theory may be defined in terms of a Lie algebra valued white noise, and parallel translation may be defined by stochastic differential equations. This machinery is used to compute the expectations of gauge invariant functions of the parallel translation operators along a collection of curves C. The expectation values are expressed as finite dimensional integrals with densities that are products of the heat kernel on the structure group. The time parameters of the heat kernels are determined by the areas enclosed by the collection C, and the arguments are determined by the crossing topologies of the curves in C. The expectations for the Wilson lattice models have a similar structure, and from this it follows that in the limit of small lattice spacing the lattice expectations converge to the continuum expectations. It is also shown that the lasso variables advocated by L. Gross exist and are sufficient to generate all the measurable functions on the YM 2 -measure space. (orig.)

Usefulness of gram staining of blood collected from total parenteral nutrition catheter for rapid diagnosis of catheter-related sepsis.

Science.gov (United States)

Moonens, F; el Alami, S; Van Gossum, A; Struelens, M J; Serruys, E

1994-01-01

The accuracy of Gram staining of blood drawn from catheters used to administer total parenteral nutrition was compared with paired quantitative blood cultures for the diagnosis of catheter-related sepsis. Gram staining was positive in 11 of 18 episodes of catheter-related sepsis documented by quantitative culture (sensitivity, 61%) but in none of the 5 episodes of fever unrelated to catheter infection. Thus, this procedure enabled the rapid presumptive diagnosis and guidance of antimicrobial therapy for total parenteral nutrition catheter sepsis, with a positive predictive value of 100% and a negative predictive value of 42%. PMID:7521359

Percutaneous catheter drainage of lung abscess

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub [Catholic University Medical college, Seoul (Korea, Republic of)

1993-09-15

From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess.

Percutaneous catheter drainage of lung abscess

International Nuclear Information System (INIS)

Kim, Young Shin; Chun, Kyung Ah; Choi, Hyo Sun; Ha, Hyun Kown; Shinn, Kyung Sub

1993-01-01

From March 1987 to July 1989, six patients (five adults and one child) with lung abscess (size, 5-13 cm in diameter) were treated with percutaneous aspiration and drainage. In each case, the puncture was made where the wall of the abscess was in contact with the pleural surface. An 8 to 10 Fr cartheter was inserted for drainage. Five of 6 had a dynamatic clinical response within 24 hours of the drainage. Percutaneous drainage was successful with complete abscess resolution in four and partial resolution in one patient. No response was seen in the rest one. The duration of drainage ranged from 7 to 18 days(average, 15.5 days) in successful cases. One case of the failure in drainage was due tio persistent aspiration of the neurologically impaired patient. In one patient, the abscess resolved after drainage but recurred after inadvertent removal of the catheter 7 days after insertion. In two patients, concurrent pleural empyema was resolved completely by the drainage. Computed tomography provide anatomic details necessary for choosing the puncture site and avoiding a puncture of the lung parenchyma. Percutaneous catheter drainage is safe and effective method for treating patient with lung abscess

[Peripheral intravenous catheter-related phlebitis].

Science.gov (United States)

van der Sar-van der Brugge, Simone; Posthuma, E F M Ward

2011-01-01

Phlebitis is a very common complication of the use of intravenous catheters. Two patients with an i.v. catheter complicated by thrombophlebitis are described. Patient A was immunocompromised due to chronic lymphatic leukaemia and developed septic thrombophlebitis with positive blood cultures for S. Aureus. Patient B was being treated with flucloxacillin because of an S. Aureus infection and developed chemical phlebitis. Septic phlebitis is rare, but potentially serious. Chemical or mechanical types of thrombophlebitis are usually less severe, but happen very frequently. Risk factors include: female sex, previous episode of phlebitis, insertion at (ventral) forearm, emergency placement and administration of antibiotics. Until recently, routine replacement of peripheral intravenous catheters after 72-96 h was recommended, but randomised controlled trials have not shown any benefit of this routine. A recent Cochrane Review recommends replacement of peripheral intravenous catheters when clinically indicated only.

Using central venous catheter for suprapubic catheterization in cardiac surgery

Directory of Open Access Journals (Sweden)

Bilehjani E

2017-01-01

Full Text Available Eissa Bilehjani,1 Solmaz Fakhari2 1Department of Cardiovascular Anesthesia, Tabriz University of Medical Sciences, Madani Heart Hospital, 2Department of Anesthesiology, Tabriz University of Medical Sciences, Madani Heart Hospital, Tabriz, Iran Abstract: Suprapubic catheterization is an alternative method for urinary drainage that is used when transurethral catheterization fails. Traditionally, inserted large-bore suprapubic catheters may cause fatal complications. During the past decade, we used a small central venous catheter (CVC suprapubicly in 16 male patients for the purpose of urinary drainage, when transurethral catheterization failed. The procedure is performed in no more than 10 minutes. Success rate was 100% and this approach did not lead to any complications. In conclusion, placing a CVC for suprapubic drainage is a safe method with a high success rate and we recommend it in patients with failed transurethral catheterization after a few attempts (2–3 attempts. Keywords: suprapubic catheterization complication, urethral catheterization, central venous catheter, Seldinger’s technique, cardiac surgery

Value of Micronester coils in port-catheter implantation for continuous hepatic arterial infusion chemotherapy with fixed catheter tip method

International Nuclear Information System (INIS)

Yamagami, Takuji; Kato, Takeharu; Hirota, Tatsuya; Yoshimatsu, Rika; Matsumoto, Tomohiro; Nishimura, Tsunehiko; White, Robert I.

2008-01-01

To retrospectively evaluate the use of Micronester coils in port-catheter implantation with the fixed catheter tip method in comparison with other previously used coils. The cohort of this study was 143 consecutive patients with unresectable advanced liver cancer for whom a port-catheter system was percutaneously implanted. In the most recent 32 patients, Micronester coils were used for catheter tip fixation. Details of embolic agents for fixation, persistent blood flow beyond the distal end of the indwelling catheter, and complications were compared between cases without and with Micronester coils. In all, percutaneous port-catheter placement was successful. Mean number of coils used for fixation was 4.2 without Micronester coils vs. 2.5 with Micronester coils. N-butyl cyanoacrylate (NBCA)-Lipiodol was additionally used for catheter tip fixation in 85.6% of 111 procedures without Micronester coils and in 50% of 32 using Micronester coils. The gastroduodenal artery beyond the distal end was not detected at the final examination after any procedure. Catheter dislocation occurred in five and hepatic arterial obstruction or severe stenosis in eight. The number of coils used and necessity of NBCA-Lipiodol could be decreased with usage of Micronester coils without decreasing fixation ability compared to other coils. (orig.)

Percutaneous catheter drainage of tuberculous psoas abscesses

International Nuclear Information System (INIS)

Pombo, F.; Martin-Egana, R.; Cela, A.; Diaz, J.L.; Linares-Mondejar, P.; Freire, M.

1993-01-01

Six patients with 7 tuberculous psoas or ilio-psoas abscesses were treated by CT-guided catheter drainage and chemotherapy. The abscesses (5 unilateral and 1 bilateral) were completely drained using a posterior or lateral approach. The abscess volume was 70 to 700 ml (mean 300 ml) and the duration of drainage 5 to 11 days (mean 7 days). Immediate local symptomatic improvement was achieved in all patients, and there were no procedural complications. CT follow-up at 3 to 9 months showed normalization in 5 patients, 2 of whom are still in medical therapy. One patient, who did not take the medication regularly, had a recurrent abscess requiring new catheter drainage after which the fluid collection disappeared. Percutaneous drainage represents an efficient and attractive alternative to surgical drainage as a supplement to medical therapy in the management of patients with large tuberculous psoas abscesses. (orig.)

21 CFR 868.5120 - Anesthesia conduction catheter.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to inject...

Agile and Bright Intracardiac Catheters

NARCIS (Netherlands)

M. Pekař (Martin)

2017-01-01

markdownabstractIntracardiac imaging catheters represent unique instruments to diagnose and treat a diseased heart. While there are imminent advances in medical innovation, many of the commercially available imaging catheters are outdated. Some of them have been designed more than 20 years and

21 CFR 876.5030 - Continent ileostomy catheter.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a form...

FAQs about Catheter-Associated Urinary Tract Infection

Science.gov (United States)

... do so. o Avoid disconnecting the catheter and drain tube. This helps to pre - vent germs from getting into the catheter tube. o The catheter is secured to the leg to prevent pulling on the ... regularly. The drainage spout should not touch any - thing while emptying ...

The dangers of long-term catheter drainage.

Science.gov (United States)

Lowthian, P

There are many dangers associated with long-term urinary bladder drainage by catheter. For various reasons, the choice of catheter is important, and its initial insertion can be particularly hazardous. All catheterizations should, however, be safer when there is some urine (or other fluid) in the bladder. The appropriate choice of drainage system attached to the catheter can delay bacterial invasion of the bladder. Great care is needed to prevent blockage of the system, particularly when bacteriuria is present. Recent evidence indicates that some bacteria encourage the development of encrustations, so that, in some circumstances, catheters may become blocked within 24 hours. This, together with other considerations, strongly suggests that indwelling catheters should be changed at intervals of not more than 5 days. The practical implications of this are considered, as are the benefits that may accrue. Accidental catheter traction is another danger, and some possible methods of avoiding this are discussed. Finally, the need for a new kind of drainage-bag support is highlighted.

Thoracic Nerve Root Entrapment by Intrathecal Catheter Coiling: Case Report and Review of the Literature.

Science.gov (United States)

Han, Jing L; Loriaux, Daniel B; Tybout, Caroline; Kinon, Merritt D; Rahimpour, Shervin; Runyon, Scott L; Hopkins, Thomas J; Boortz-Marx, Richard L; Lad, Shivanand P

2016-03-01

Intrathecal catheter placement has long-term therapeutic benefits in the management of chronic, intractable pain. Despite the diverse clinical applicability and rising prevalence of implantable drug delivery systems in pain medicine, the spectrum of complications associated with intrathecal catheterization remains largely understudied and underreported in the literature. To report a case of thoracic nerve root entrapment resulting from intrathecal catheter migration. Case report. Inpatient hospital service. A 60-year-old man status post implanted intrathecal (IT) catheter for intractable low back pain secondary to failed back surgery syndrome returned to the operating room for removal of IT pump trial catheter after experiencing relapse of preoperative pain and pump occlusion. Initial attempt at ambulatory removal of the catheter was aborted after the patient reported acute onset of lower extremity radiculopathic pain during the extraction. Noncontrast computed tomography (CT) subsequently revealed that the catheter had ascended and coiled around the T10 nerve root. The patient was taken back to the operating room for removal of the catheter under fluoroscopic guidance, with possible laminectomy for direct visualization. Removal was ultimately achieved with slow continuous tension, with complete resolution of the patient's new radicular symptoms. This report describes a single case report. This case demonstrates that any existing loops in the intrathecal catheter during initial implantation should be immediately re-addressed, as they can precipitate nerve root entrapment and irritation. Reduction of the loop or extrication of the catheter should be attempted under continuous fluoroscopic guidance to prevent further neurosurgical morbidity.

Biological safety evaluation of the modified urinary catheter

Energy Technology Data Exchange (ETDEWEB)

Kowalczuk, Dorota, E-mail: dorota.kowalczuk@umlub.pl [Department of Medicinal Chemistry, Medical University of Lublin, Jaczewskiego 4, 20-090 Lublin (Poland); Przekora, Agata; Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Chodzki 1, 20-093 Lublin (Poland)

2015-04-01

The purpose of this study was to evaluate in vitro safety of the novel tosufloxacin (TOS)-treated catheters with the prolonged antimicrobial activity. The test samples of silicone latex catheter were prepared by the immobilization of TOS on chitosan (CHIT)-coated catheter by means of covalent bonds and non-covalent interactions. Each step of the modification process of catheter surface was observed using ATR–Fourier transform infrared spectroscopy. In vitro cytotoxicity of the modified and unmodified catheters was assessed by direct and indirect tests in accordance with ISO standards using green monkey kidney (GMK) cell line. The MTT, lactate dehydrogenase activity (LDH), WST-8, Sulforhodamine B (SRB) test results and microscopic observation clearly indicated that unmodified silicone latex catheters decrease cell metabolic activity, act as a cytotoxic agent causing cell lysis and induce cell death through necrotic or apoptotic process. We suggest that chitosan coat with TOS immobilized limits leaching of harmful agents from silicone latex material, which significantly enhances survivability of GMK cells and therefore is quite a good protection against the cytotoxic effect of this material. - Highlights: • Characterization of the novel antimicrobial urinary catheters • Monitoring of the catheter modification by FTIR analysis • Confirmation of high cytotoxicity of latex-based catheter used in urological practice • Chitosan-coated and tosufloxacin-treated catheter is less toxic than the untreated one. • The proposed surface modification protects cells against latex-induced death.

The GuideLiner catheter: A supportive tool in percutaneous coronary intervention of chronic total occlusion

Directory of Open Access Journals (Sweden)

Jan-Erik Guelker

2018-04-01

Full Text Available Background: Failure of delivering a stent or a balloon across the target lesion during percutaneous coronary intervention (PCI of chronic total occlusion (CTO, especially in arteries with calcified tortuous anatomy, is often due to insufficient backup support from the guiding catheter. The purpose of this study was to assess the feasibility of the GuideLiner (GL catheter use. Methods: We examined 18 patients and used the GL catheter to overcome poor support and excessive friction in standardized antegrade and retrograde CTO procedures. The GL is a coaxial, monorail guiding catheter extension delivered through a standard guiding catheter and is available in different sizes. Results: Almost all lesions were classified as severely calcified (94.4 ± 0.24%. The Japanese CTO score reflecting lesion complexity was 3.56 ± 0.78. All procedures were performed femorally; the retrograde approach was used in 27.8 ± 0.46% of cases. The overall success rate was 88.9 ± 0.32%; there were no relevant complications. Conclusions: The GL catheter is an adjunctive interventional device which enhances and amplifies CTO-PCI. Its use is indicated in cases in which back-up force needs to be strengthened to pass a CTO despite advanced calcification. It can be recommended as an important additional tool in advanced interventional cardiology such as antegrade and retrograde CTO-PCI if other techniques like anchor balloon or anchor wire are not possible. Keywords: Chronic total occlusion, GuideLiner catheter, Percutaneous coronary intervention, Severe calcification

Low-angled peripheral intravenous catheter tip placement decreases phlebitis.

Science.gov (United States)

Tanabe, Hidenori; Murayama, Ryoko; Yabunaka, Koichi; Oe, Makoto; Takahashi, Toshiaki; Komiyama, Chieko; Sanada, Hiromi

2016-11-02

Peripheral intravenous catheters (PIVCs) are frequently removed due to phlebitis. We hypothesized that catheters made of polyurethane, which is more flexible than Teflon, would decrease phlebitis, and that flexibility could be estimated by measuring the catheter-tip angle. Ultrasonography in two groups of patients with different catheter types was then used to compare catheter-tip angles and phlebitis. Observational studies were carried out at a medical ward in a university hospital. Infusion therapy was administered to one group of patients in 2014 using Teflon catheters (control group, n = 200), and to another group of patients in 2015 using polyurethane catheters (investigational group, n = 207). The symptoms were assessed according to a scale developed by the Infusion Nurses Society. Long-axis ultrasonography images taken immediately before catheter removal were used to measure the angle between the central line of the catheter within 2 mm from the distal point and a tangent to the vessel wall. There were no significant differences between the two groups with respect to sex, age, and medical diagnosis. In the control and investigational groups, the rates of phlebitis were 37% (73/200) and 17% (36/207), respectively (pPhlebitis occurred more frequently when the catheter-tip was placed at angle >5.8°. The frequency of phlebitis was lower in the polyurethane, in which the catheter was placed at lower angle, almost parallel to the vessel. Our results will aid in developing new catheters and in improving PIVC-securement techniques.

Paravertebral block catheter breakage by electrocautery during thoracic surgery.

Science.gov (United States)

Saeki, Noboru; Sugimoto, Yuki; Mori, Yoko; Kato, Takahiro; Miyoshi, Hirotsugu; Nakamura, Ryuji; Koga, Tomomichi

2017-06-01

Advantages of thoracic paravertebral analgesia (TPA) include placement of the catheter closer to the surgical field; however, the catheter can become damaged during the operation. We experienced a case of intraoperative TPA catheter breakage that prompted us to perform an experiment to investigate possible causes. A 50-year-old male underwent a thoracoscopic lower lobectomy under general anesthesia with TPA via an intercostal approach. Following surgery, it was discovered that the catheter had become occluded, as well as cut and fused, so we reopened the incision and removed the residual catheter. From that experience, we performed an experiment to examine electrocautery-induced damage in normal (Portex™, Smith's Medical), radiopaque (Perifix SoftTip™, BBraun), and reinforced (Perifix FX™, BBraun) epidural catheters (n = 8 each). Chicken meat was penetrated by each catheter and then cut by electrocautery. In the normal group, breakage occurred in 8 and occlusion in 6 of the catheters, and in the radiopaque group breakage occurred in 8 and occlusion in 7. In contrast, breakage occurred in only 3 and occlusion in none in the reinforced group, with the 5 without breakage remaining connected only by the spring coil. Furthermore, in 7 of the reinforced catheters, electric arc-induced thermal damage was observed at the tip of the catheter. A TPA catheter for thoracic surgery should be inserted via the median approach, or it should be inserted after surgery to avoid catheter damage during surgery.

Antifouling coating with controllable and sustained silver release for long-term inhibition of infection and encrustation in urinary catheters.

Science.gov (United States)

Wang, Rong; Neoh, Koon Gee; Kang, En-Tang; Tambyah, Paul Anantharajah; Chiong, Edmund

2015-04-01

Urinary tract infections constitute a large proportion of nosocomial infections, and the urinary catheter is the most important predisposing factor. Encrustation induced by urease-producing uropathogens like Proteus mirabilis causes further complications. In the present work, a strategy for controllable and sustained release of silver over several weeks has been developed for combating bacterial infection and encrustation in urinary devices. Silver nanoparticles (AgNPs) were first immobilized on polydopamine (PDA) pre-treated silicone catheter surface and this was followed by another PDA coating. The number of AgNP-PDA bilayers could be manipulated to control the amount of silver loaded and its subsequent release. Poly(sulfobetaine methacrylate-co-acrylamide) was then grafted to provide an antifouling outer layer, and to ensure free diffusion of Ag from the surface. The micron-scale combination of an antifouling coating with AgNP-PDA bilayers reduced colonization of the urinary catheter by uropathogens by approximately two orders of magnitude. With one and two AgNP-PDA bilayers, the coated catheter could resist encrustation for 12 and 45 days, respectively, compared with approximately 6 days with the Dover™ silver-coated catheter. Such anti-infective and anti-encrustation catheters can potentially have a large impact on reducing patient morbidity and healthcare expenditure. © 2014 Wiley Periodicals, Inc.

Spinal canal extension of hyperalimentation catheter without neurologic sequela

International Nuclear Information System (INIS)

Glasier, M.; Arkansas Children's Hospital, Little Rock; Hassell, D.R.

1989-01-01

An attempt at placement of a left femoral vein hyperalimentation catheter resulted in entrance of the catheter into the spinal canal. Catheter location was documented by injections of nonionic contrast material into the catheter without neurologic sequellae. (orig.)

Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal

Directory of Open Access Journals (Sweden)

Janete de Souza Urbanetto

Full Text Available ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC and following their removal - (post-infusion phlebitis in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective.

SU-E-T-362: Automatic Catheter Reconstruction of Flap Applicators in HDR Surface Brachytherapy

International Nuclear Information System (INIS)

Buzurovic, I; Devlin, P; Hansen, J; O'Farrell, D; Bhagwat, M; Friesen, S; Damato, A; Lewis, J; Cormack, R

2014-01-01

Purpose: Catheter reconstruction is crucial for the accurate delivery of radiation dose in HDR brachytherapy. The process becomes complicated and time-consuming for large superficial clinical targets with a complex topology. A novel method for the automatic catheter reconstruction of flap applicators is proposed in this study. Methods: We have developed a program package capable of image manipulation, using C++class libraries of The-Visualization-Toolkit(VTK) software system. The workflow for automatic catheter reconstruction is: a)an anchor point is placed in 3D or in the axial view of the first slice at the tip of the first, last and middle points for the curved surface; b)similar points are placed on the last slice of the image set; c)the surface detection algorithm automatically registers the points to the images and applies the surface reconstruction filter; d)then a structured grid surface is generated through the center of the treatment catheters placed at a distance of 5mm from the patient's skin. As a result, a mesh-style plane is generated with the reconstructed catheters placed 10mm apart. To demonstrate automatic catheter reconstruction, we used CT images of patients diagnosed with cutaneous T-cell-lymphoma and imaged with Freiburg-Flap-Applicators (Nucletron™-Elekta, Netherlands). The coordinates for each catheter were generated and compared to the control points selected during the manual reconstruction for 16catheters and 368control point Results: The variation of the catheter tip positions between the automatically and manually reconstructed catheters was 0.17mm(SD=0.23mm). The position difference between the manually selected catheter control points and the corresponding points obtained automatically was 0.17mm in the x-direction (SD=0.23mm), 0.13mm in the y-direction (SD=0.22mm), and 0.14mm in the z-direction (SD=0.24mm). Conclusion: This study shows the feasibility of the automatic catheter reconstruction of flap applicators with a high

Using optical coherence tomography to detect bacterial biofilms on foley catheters (Conference Presentation)

Science.gov (United States)

Heidari, Andrew E.; Oh, Kyungjin; Chen, Zhongping

2017-02-01

Urinary tract infections(UTI) pose a serious problem for hospital patients accounting for 33% of all hospital acquired(nosocomial) infections with indwelling foley catheters. The presence of an indwelling foley catheter provides a scaffolding for circulating planktonic bacteria to adhere to and to form microbial biofilm communities that would typically be hindered by the body's innate immune system response. It is these biofilm communities that form on the inner lumen of foley catheters that provide a reservoir of pathogenic bacteria that could dislodge or disperse from the biofilm and infect urethra or bladder mucosal tissue in the urinary tract. Current diagnostic techniques of urine microbiological cultures are lacking in differentiating asymptomatic bacteriuria and symptomatic catheter-associated urinary tract infection(CAUTI) since almost all patients with chronic indwelling catheters are almost universally bacteriuruic. There is an unmet need of a diagnostic tool to assess the difference between the pathogenesis of asymptomatic bacteriuria and CAUTI, specifically at the site of the native biofilm formation. Optical Coherence Tomography(OCT) is an emerging high resolution, minimally invasive tomographic imaging technique that has shown promise in imaging biofilm structures previously in an endoscopic setting of the airway in-vivo and in microfluidic chambers. OCT can be adapted to image various sized biological surfaces and orifices such as airway branches and blood vessels by using a variety of minature endoscopic probes. In this work OCT will be used to image biofilm structure in-vitro on the inner lumen of extravasated critical care patient's foley catheters. Scanning electron microscopy will be conducted post OCT to confirm the presence of bacterial biofilm in OCT images.

Repositioning of malpositioned or flipped central venous catheters

Energy Technology Data Exchange (ETDEWEB)

Thalhammer, A.; Jacobi, V.; Balzer, J.; Vogl, T.J. [Institute for Diagnostic and Interventional Radiology, Central Radiology Clinic, J.W. Goethe University, Frankfurt am Main (Germany)

2002-03-01

Primary misplaced or secondary flipped implanted catheters are located mostly in the right jugular vein. We demonstrate an effective method to replace fix implanted catheters such as Ports, Grochomg or Hickman catheters. Using a femoral venous approach, replacement into the superior vena cava can easily be done with a Sidewinder 1 catheter which is hooked over the misplaced central venous approach. In all our patients the method was successful. The repositioning technique described is simple, fast and has low costs. We can keep sterile conditions and do not need to solve the catheters' fixation. (orig.)

Pacemaker implantation after catheter ablation for atrial fibrillation.

Science.gov (United States)

Deshmukh, Abhishek J; Yao, Xiaoxi; Schilz, Stephanie; Van Houten, Holly; Sangaralingham, Lindsey R; Asirvatham, Samuel J; Friedman, Paul A; Packer, Douglas L; Noseworthy, Peter A

2016-01-01

Sinus node dysfunction requiring pacemaker implantation is commonly associated with atrial fibrillation (AF), but may not be clinically apparent until restoration of sinus rhythm with ablation or cardioversion. We sought to determine frequency, time course, and predictors for pacemaker implantation after catheter ablation, and to compare the overall rates to a matched cardioversion cohort. We conducted a retrospective analysis using a large US commercial insurance database and identified 12,158 AF patients who underwent catheter ablation between January 1, 2005 and December 31, 2012. Over an average of 2.4 years of follow-up, 5.6 % of the patients underwent pacemaker implantation. Using the Cox proportional hazards models, we found that risk of risks of pacemaker implantation was associated with older age (50-64 and ≥65 versus pacemaker implantation between ablation patients and propensity score (PS)-matched cardioversion groups (3.5 versus. 4.1 % at 1 year and 8.8 versus 8.3 % at 5 years). Overall, pacemaker implantation occurs in about 1/28 patients within 1 year of catheter ablation. The overall implantation rate decreased between 2005 and 2012. Furthermore, the risk after ablation is similar to cardioversion, suggesting that patients require pacing due to a common underlying electrophysiologic substrate, rather than the ablation itself.

Indication of the radiofrequency induced lesion size by pre-ablation measurements

DEFF Research Database (Denmark)

Stagegaard, Niels; Petersen, Helen Høgh; Chen, Xu

2005-01-01

BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool for asses......BACKGROUND: During radiofrequency ablation of arrhythmias tissue heating and hence lesion size depend on electrode-tissue contact and cooling of the electrode tip caused by cavitary blood flow. These factors are unique and unknown for each catheter placement in the beating heart. A tool...... for assessing these factors prior to ablation may indicate the lesion size which will be obtained for any given catheter position. METHODS AND RESULTS: Radiofrequency ablation was performed in vitro on strips of left ventricular porcine myocardium during two different levels of convective cooling (0 or 0.1 m....../s), two different contact pressures (10 or 30 g) and parallel or perpendicular electrode-tissue orientation using 7F 4 mm tip catheters. Prior to ablation the impedance rise (DeltaIMP) caused by the obtained contact and the temperature rise with a 0.6 W 5 s test pulse (DeltaT) were measured. Subsequently...

CATHETER DURATION AND THE RISK OF SEPSIS IN PREMATURE BABIES WITH UMBILICAL VEIN CATHETERS

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Hartojo Hartojo

2012-01-01

Full Text Available Umbilical catheters are frequently required in the management of severely ill premature babies. The risk of complications may increase with duration of UVC use. Objective: To determine whether the risk of central line-associated bloodstream infections (CLA-BSIs and sepsis remained constant over the duration of umbilical vein catheters (UVCs in high-risk premature neonates. Methods:retrospective analysis. The data were collected from the medical record of high risk premature neonates who had a UVC placed in neonatal care unit of Husada Utama Hospital between April 1st 2008 to April 30th 2011 with purposive sampling. Catheter duration was observed before and after 14 days on placement. Blood and UVC culture was performed to establish the risk of CLA-BSIs and sepsis. Chi-square and logistic regression analysis were performed in the laboratorium data. Result: A total 44 high risk premature babies with UVCs were enrolled (sepsis group: n = 23 and non sepsis group: n = 21. Baseline demographics were similar between the groups. 15 babies in sepsis group have UVCs duration > 14 days, and 8 babies have UVCs 14 days show blood culture performance in 11 babies with positive evidence, UVCs culture performance is negative in 18 babies (p = 0.456. Burkholderia cepacia and Klebsiella pneumonia mostly appeared in blood culture performance. 25% of UVC culture performance shows Pseudomonas aeroginosa. Conclusions: The catheter duration have no significant difference in risk of sepsis in premature babies with Umbilical Vein Catheters.

Obstruction of peritoneal dialysis catheter is associated with catheter type and independent of omentectomy: A comparative data analysis from a transplant surgical and a pediatric surgical department.

Science.gov (United States)

Radtke, Josephine; Schild, Raphael; Reismann, Marc; Ridwelski, Robert-Richard; Kempf, Caroline; Nashan, Bjoern; Rothe, Karin; Koch, Martina

2018-04-01

Peritoneal dialysis (PD) catheter occlusion is a common complication with up to 36% of catheter obstructions described in the literature. We present a comparison of complications and outcome after implantation of PD catheters in a transplant surgical and a pediatric surgical department. We retrospectively analyzed 154 PD catheters, which were implanted during 2009-2015 by transplant surgeons (TS, University Medical Center Hamburg-Eppendorf, Germany, n=85 catheters) and pediatric surgeons (PS, Charité University Medicine Berlin, Germany, n=69 catheters) in 122 children (median (range) age 3.0 (0.01-17.1) years) for acute (n=65) or chronic (n=89) renal failure. All catheters were one-cuffed or double-cuffed curled catheters, except that straight catheters were implanted into smaller children (n=19) by TS in Hamburg. Patient characteristics and operation technique did not differ between the departments. Peritonitis was the most common complication (33 catheters, 21.4%). Leakage (n=18 catheters, 11.7%) occurred more often in children weighing <10kg (p<0.001). The incidence of obstruction and dysfunction was significantly higher in catheters used in PS than catheters used in TS (30.4% vs. 11.8%, p=0.004). Omentectomy did not reduce the incidence of catheter obstruction (p=1.0). Perforation at the catheter tips was larger and appeared to be rougher in catheters used in PS than the catheters in TS. The type of catheter and presumably the type of perforation at the catheter tip may influence the incidence of peritoneal dialysis catheter obstruction. Copyright © 2017 Elsevier Inc. All rights reserved.

Tunneled dialysis catheter exchange with fibrin sheath disruption is not associated with increased rate of bacteremia.

Science.gov (United States)

Valliant, Amanda M; Chaudhry, Muhammad K; Yevzlin, Alexander S; Astor, Brad; Chan, Micah R

2015-01-01

Tunneled dialysis catheters are the most common form of vascular access among incident dialysis patients in the United States. Fibrin sheath formation is a frequent cause of late catheter dysfunction requiring an exchange procedure with balloon disruption of the fibrin sheath. It is unknown whether fibrin sheath disruption is associated with increased incidence of bacteremia or catheter failure. We reviewed all tunneled dialysis catheter exchange procedures at the University of Wisconsin between January 2008 and December 2011. The primary outcome was incidence of bacteremia, defined as positive blood cultures within 2 weeks of the procedure. Catheter failure, requiring intervention or replacement, was examined as a secondary outcome. Baseline characteristics examined included diabetic status, gender, race and age. A total of 163 procedures were reviewed; 67 (41.1%) had fibrin sheath disruption and 96 did not. Bacteremia occurred in 4.5% (3/67) of those with and 3.1% (3/97) of those without fibrin sheath disruption (p=0.65). Fibrin sheath disruption was not significantly associated with the risk of catheter failure (adjusted hazard ratio [aHR]=1.34; 95% confidence interval [CI]: 0.87-2.10; p=0.18). Diabetes was associated with greater risk of catheter failure (aHR=1.88; 95% CI: 1.19-2.95; p=0.006), whereas higher age was associated with a lower risk of catheter failure (aHR per 10 years=0.83; 95% CI: 0.72-0.96; p=0.01). This study demonstrates that there is no significant increase in bacteremia and subsequent catheter dysfunction rates after fibrin sheath disruption compared to simple over the wire exchange. These results are encouraging given the large numbers of patients utilizing tunneled catheters for initial hemodialysis access and the known rates of fibrin sheath formation leading to catheter failure.

Experimental study on propagation properties of large size TEM antennas

International Nuclear Information System (INIS)

Zhang Guowei; Wang Haiyang; Chen Weiqing; Wang Wei; Zhu Xiangqin; Xie Linshen

2014-01-01

The propagation properties of large size TEM antennas were studied by experiment. The size of the TEM antennas is 60 m × 20 m × 10 m and the character Impedance is 120 Ω. A kind of dielectric foil switch is designed compactly with TEM antennas which can generate double exponential waveform with altitude of 10 kV and rise time of l.2 ns. The radiated field distribution was measured. The relationship between rise time/altitude and distance were provided, and the propagation properties of large size TEM antennas were summarized. (authors)

Closed-loop helium circulation system for actuation of a continuously operating heart catheter pump.

Science.gov (United States)

Karabegovic, Alen; Hinteregger, Markus; Janeczek, Christoph; Mohl, Werner; Gföhler, Margit

2017-06-09

Currently available, pneumatic-based medical devices are operated using closed-loop pulsatile or open continuous systems. Medical devices utilizing gases with a low atomic number in a continuous closed loop stream have not been documented to date. This work presents the construction of a portable helium circulation addressing the need for actuating a novel, pneumatically operated catheter pump. The design of its control system puts emphasis on the performance, safety and low running cost of the catheter pump. Static and dynamic characteristics of individual elements in the circulation are analyzed to ensure a proper operation of the system. The pneumatic circulation maximizes the working range of the drive unit inside the catheter pump while reducing the total size and noise production.Separate flow and pressure controllers position the turbine's working point into the stable region of the pressure creation element. A subsystem for rapid gas evacuation significantly decreases the duration of helium removal after a leak, reaching subatmospheric pressure in the intracorporeal catheter within several milliseconds. The system presented in the study offers an easy control of helium mass flow while ensuring stable behavior of its internal components.

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

Science.gov (United States)

Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Attitudes Towards Catheter Ablation for Atrial Fibrillation

DEFF Research Database (Denmark)

Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis

2015-01-01

BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...... cardiologists towards catheter ablation for AF, using a nationwide survey. METHODS AND RESULTS: We developed a purpose-designed questionnaire to evaluate attitudes towards catheter ablation for AF that was sent to all Danish cardiologists (n = 401; response n = 272 (67.8%)). There was no association between...... attitudes towards ablation and the experience or age of the cardiologist with respect to patients with recurrent AF episodes with a duration of 7 days and/or need for cardioversion. The majority (69%) expected a recurrence of AF after catheter ablation in more than 30% of the cases...

Catheter Angiography

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Technique of Peritoneal Catheter Placement under Fluoroscopic Guidance

International Nuclear Information System (INIS)

Abdel-Aal, A.K.; Gaddikeri, S.; Saddekni, S.

2011-01-01

Peritoneal catheters are mainly used for peritoneal dialysis in patients with end-stage renal disease. Other uses of this catheter include intraperitoneal chemotherapy and gene therapy for ovarian cancer and draining of uncontrolled refractory ascites in patients with liver cirrhosis. Traditionally, surgeons place most of these peritoneal catheters either by laparoscopy or open laparotomy. We detail our percutaneous approach to placing peritoneal catheters using fluoroscopic guidance. We emphasize the use of additional ultrasound guidance, including gray scale and color Doppler ultrasound, to determine the safest puncture site and to guide the initial needle puncture in order to avoid bowel perforation and injury to epigastric artery. We present our experience in placing peritoneal catheters using this technique in 95 patients with various indications. Fluoroscopic guided percutaneous placement of peritoneal catheters is a safe, minimally invasive, and effective alternative to open surgical or laparoscopic placement.

Processing and properties of large-sized ceramic slabs

Energy Technology Data Exchange (ETDEWEB)

Raimondo, M.; Dondi, M.; Zanelli, C.; Guarini, G.; Gozzi, A.; Marani, F.; Fossa, L.

2010-07-01

Large-sized ceramic slabs with dimensions up to 360x120 cm{sup 2} and thickness down to 2 mm are manufactured through an innovative ceramic process, starting from porcelain stoneware formulations and involving wet ball milling, spray drying, die-less slow-rate pressing, a single stage of fast drying-firing, and finishing (trimming, assembling of ceramic-fiberglass composites). Fired and unfired industrial slabs were selected and characterized from the technological, compositional (XRF, XRD) and microstructural (SEM) viewpoints. Semi-finished products exhibit a remarkable microstructural uniformity and stability in a rather wide window of firing schedules. The phase composition and compact microstructure of fired slabs are very similar to those of porcelain stoneware tiles. The values of water absorption, bulk density, closed porosity, functional performances as well as mechanical and tribological properties conform to the top quality range of porcelain stoneware tiles. However, the large size coupled with low thickness bestow on the slab a certain degree of flexibility, which is emphasized in ceramic-fiberglass composites. These outstanding performances make the large-sized slabs suitable to be used in novel applications: building and construction (new floorings without dismantling the previous paving, ventilated facades, tunnel coverings, insulating panelling), indoor furnitures (table tops, doors), support for photovoltaic ceramic panels. (Author) 24 refs.

Processing and properties of large-sized ceramic slabs

International Nuclear Information System (INIS)

Raimondo, M.; Dondi, M.; Zanelli, C.; Guarini, G.; Gozzi, A.; Marani, F.; Fossa, L.

2010-01-01

Large-sized ceramic slabs with dimensions up to 360x120 cm 2 and thickness down to 2 mm are manufactured through an innovative ceramic process, starting from porcelain stoneware formulations and involving wet ball milling, spray drying, die-less slow-rate pressing, a single stage of fast drying-firing, and finishing (trimming, assembling of ceramic-fiberglass composites). Fired and unfired industrial slabs were selected and characterized from the technological, compositional (XRF, XRD) and microstructural (SEM) viewpoints. Semi-finished products exhibit a remarkable microstructural uniformity and stability in a rather wide window of firing schedules. The phase composition and compact microstructure of fired slabs are very similar to those of porcelain stoneware tiles. The values of water absorption, bulk density, closed porosity, functional performances as well as mechanical and tribological properties conform to the top quality range of porcelain stoneware tiles. However, the large size coupled with low thickness bestow on the slab a certain degree of flexibility, which is emphasized in ceramic-fiberglass composites. These outstanding performances make the large-sized slabs suitable to be used in novel applications: building and construction (new floorings without dismantling the previous paving, ventilated facades, tunnel coverings, insulating panelling), indoor furnitures (table tops, doors), support for photovoltaic ceramic panels. (Author) 24 refs.

Technological Aspects of Creating Large-size Optical Telescopes

Directory of Open Access Journals (Sweden)

V. V. Sychev

2015-01-01

Full Text Available A concept of the telescope creation, first of all, depends both on a choice of the optical scheme to form optical radiation and images with minimum losses of energy and information and on a choice of design to meet requirements for strength, stiffness, and stabilization characteristics in real telescope operation conditions. Thus, the concept of creating large-size telescopes, certainly, involves the use of adaptive optics methods and means.The level of technological capabilities to realize scientific and engineering ideas define a successful development of large-size optical telescopes in many respects. All developers pursue the same aim that is to raise an amount of information by increasing a main mirror diameter of the telescope.The article analyses the adaptive telescope designs developed in our country. Using a domestic ACT-25 telescope as an example, it considers creation of large-size optical telescopes in terms of technological aspects. It also describes the telescope creation concept features, which allow reaching marginally possible characteristics to ensure maximum amount of information.The article compares a wide range of large-size telescopes projects. It shows that a domestic project to create the adaptive ACT-25 super-telescope surpasses its foreign counterparts, and there is no sense to implement Euro50 (50m and OWL (100m projects.The considered material gives clear understanding on a role of technological aspects in development of such complicated optic-electronic complexes as a large-size optical telescope. The technological criteria of an assessment offered in the article, namely specific informational content of the telescope, its specific mass, and specific cost allow us to reveal weaknesses in the project development and define a reserve regarding further improvement of the telescope.The analysis of results and their judgment have shown that improvement of optical largesize telescopes in terms of their maximum

UK Renal Registry 15th annual report: Chapter 8 UK multisite peritoneal dialysis access catheter audit for first PD catheters 2011.

Science.gov (United States)

Briggs, Victoria; Pitcher, David; Braddon, Fiona; Fogarty, Damian; Wilkie, Martin

2013-01-01

The central paradigm of effective peritoneal dialysis (PD) is an appropriate standard of PD catheter function. The aim of the project was to develop an effective national PD access audit which would identify an 'appropriate standard' of PD catheter function. The UK Renal Registry collected centre specific information on various PD access outcome measures including catheter functionality and post-insertion complications. The first PD access audit covering England, Northern Ireland and Wales was conducted during April to June 2012 looking at incident dialysis patients in 2011. Forty three data collection spreadsheets were returned from a total of 65 centres describing 917 PD catheter placements. The median age of PD patients was 61 years and 61.5% were male. The proportion of patients initiated on PD in comparison to HD was lower in socially deprived areas. There was a relationship between the timing of nephrology referral and the likelihood of surgical assessment regarding PD catheter placement. Patients with diabetes did not have higher rates of PD catheter failure or of early peritonitis. A comparative PD catheter audit has the potential to provide valuable information on an important patient related outcome measure and lead to an improvement in patient experience. There was wide variation between centres of PD catheter use for late presenting patients. Overall patients were more likely to get a PD catheter if they had been known to the service for more than 1 year. The percutaneous insertion technique was associated with a higher early (less than 2 week) peritonitis rate and more catheter flow problems. Copyright © 2013 S. Karger AG, Basel.

Systematic review and meta-analysis: reminder systems to reduce catheter-associated urinary tract infections and urinary catheter use in hospitalized patients.

Science.gov (United States)

Meddings, Jennifer; Rogers, Mary A M; Macy, Michelle; Saint, Sanjay

2010-09-01

Prolonged catheterization is the primary risk factor for catheter-associated urinary tract infection (CAUTI). Reminder systems are interventions used to prompt the removal of unnecessary urinary catheters. To summarize the effect of urinary catheter reminder systems on the rate of CAUTI, urinary catheter use, and the need for recatheterization, we performed a systematic review and meta-analysis. Studies were identified in MEDLINE, the Cochrane Library, Biosis, the Web of Science, EMBASE, and CINAHL through August 2008. Only interventional studies that used reminders to physicians or nurses that a urinary catheter was in use or stop orders to prompt catheter removal in hospitalized adults were included. A total of 6679 citations were identified; 118 articles were reviewed, and 14 articles met the selection criteria. The rate of CAUTI (episodes per 1000 catheter-days) was reduced by 52% (P SMD) in the duration of catheterization was -1.11 overall (P = 070), including a statistically significant decrease in studies that used a stop order (SMD, -0.30; P = .001) but not in those that used a reminder (SMD, -1.54; P = .071). Recatheterization rates were similar in control and intervention groups. Urinary catheter reminders and stop orders appear to reduce the rate of CAUTI and should be strongly considered to enhance the safety of hospitalized patients.

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner catheter to deliver stents for anomalous right coronary artery

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Toshiki Kuno

2015-10-01

Full Text Available Objective: Percutaneous coronary intervention for anomalous right coronary artery (RCA originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. Methods: We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. Results: We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. Conclusions: We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

[A new port catheter system of aluminum oxide ceramics].

Science.gov (United States)

Haindl, H; Schmoll, E; Willmann, G

1995-03-01

Implantable port catheter systems are becoming increasingly important, as they often permit out-patient treatment for many indications that would otherwise require hospitalization. Moreover, they also increase the safety/reliability of infusion therapy in critical inpatients. For a variety of reasons, the materials used so far, i.e. steel, titanium and various plastics have not been completely satisfactory. The main disadvantage of metallic systems is the formation of artefacts in tomographic images, while the shortcomings of plastics are mechanical, e.g. chip formation and early membrane failure. Against this background, a port catheter system made of alumina ceramic, which is largely free of the disadvantages of the other materials, was developed. The expected advantages in terms of complication rate and radiological artefacts, were fully confirmed by the evaluation of 160 monitored patients.

Cryo-balloon catheter localization in fluoroscopic images

Science.gov (United States)

Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

2013-03-01

Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

Catheter ablation of epicardial ventricular tachycardia

Directory of Open Access Journals (Sweden)

Takumi Yamada, MD, PhD

2014-08-01

Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

Robustness of IPSA optimized high-dose-rate prostate brachytherapy treatment plans to catheter displacements.

Science.gov (United States)

Poder, Joel; Whitaker, May

2016-06-01

Inverse planning simulated annealing (IPSA) optimized brachytherapy treatment plans are characterized with large isolated dwell times at the first or last dwell position of each catheter. The potential of catheter shifts relative to the target and organs at risk in these plans may lead to a more significant change in delivered dose to the volumes of interest relative to plans with more uniform dwell times. This study aims to determine if the Nucletron Oncentra dwell time deviation constraint (DTDC) parameter can be optimized to improve the robustness of high-dose-rate (HDR) prostate brachytherapy plans to catheter displacements. A set of 10 clinically acceptable prostate plans were re-optimized with a DTDC parameter of 0 and 0.4. For each plan, catheter displacements of 3, 7, and 14 mm were retrospectively applied and the change in dose volume histogram (DVH) indices and conformity indices analyzed. The robustness of clinically acceptable prostate plans to catheter displacements in the caudal direction was found to be dependent on the DTDC parameter. A DTDC value of 0 improves the robustness of planning target volume (PTV) coverage to catheter displacements, whereas a DTDC value of 0.4 improves the robustness of the plans to changes in hotspots. The results indicate that if used in conjunction with a pre-treatment catheter displacement correction protocol and a tolerance of 3 mm, a DTDC value of 0.4 may produce clinically superior plans. However, the effect of the DTDC parameter in plan robustness was not observed to be as strong as initially suspected.

Catheter Angiography

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Full Text Available ... you are pregnant and discuss any recent illnesses, medical conditions, medications you're taking and allergies, especially ... is Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical ...

Catheter Angiography

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Full Text Available ... a catheter, x-ray imaging guidance and an injection of contrast material to examine blood vessels in ... technologies and, in most cases, a contrast material injection is needed to produce pictures of blood vessels ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... angiogram may be performed in less than an hour; however, it may last several hours. top of ...

Catheter Angiography

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Full Text Available ... the American College of Radiology (ACR) and the European Society of Urogenital Radiology note that the available ... will regain their normal function within five to seven days. Rarely, the catheter punctures the artery, causing ...

Catheter Angiography

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Full Text Available ... diagnosis and treatment in a single procedure. An example is finding an area of severe arterial narrowing, ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

Catheter Angiography

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Full Text Available ... possible to combine diagnosis and treatment in a single procedure. Catheter angiography produces very detailed, clear and ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

Catheter Angiography

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Full Text Available ... far outweighs the risk. If you have a history of allergy to x-ray contrast material, your ... Angiography (CTA) X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored ...

Catheter Angiography

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Full Text Available ... examine blood vessels in key areas of the body for abnormalities such as aneurysms and disease such ... to produce pictures of blood vessels in the body. Angiography is performed using: x-rays with catheters ...

Catheter Angiography

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Full Text Available ... rare, and radiology departments are well-equipped to deal with them. There is a small risk that ... standard x-ray contrast. Catheter angiography should be done very cautiously—if at all—in patients who ...

Catheter Angiography

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Full Text Available ... atherosclerosis (plaque). The use of a catheter makes it possible to combine diagnosis and treatment in a ... the aorta in the chest or abdomen or its major branches. show the extent and severity of ...

Catheter Angiography

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Full Text Available ... 20 minutes (or by using a special closure device). When the examination is complete, you may be ... contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography ...

Catheter Angiography

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Full Text Available ... rays ). top of page What are some common uses of the procedure? Catheter angiography is used to ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... and x-rays. Manufacturers of intravenous contrast indicate mothers should not breastfeed their babies for 24-48 ...

Catheter Angiography

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Full Text Available ... spaghetti. top of page How does the procedure work? Catheter angiography works much the same as a ... possible to combine diagnosis and treatment in a single procedure. An example is finding an area of ...

Catheter Angiography

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Full Text Available ... Once the catheter is guided to the area being examined, a contrast material is injected through the ... You should inform your physician of any medications being taken and if there are any allergies, especially ...

A prospective interventional study to examine the effect of a silver alloy and hydrogel-coated catheter on the incidence of catheter-associated urinary tract infection.

Science.gov (United States)

Chung, P Hy; Wong, C Wy; Lai, C Kc; Siu, H K; Tsang, D Nc; Yeung, K Y; Ip, D Km; Tam, P Kh

2017-06-01

Catheter-associated urinary tract infection is a major hospital-acquired infection. This study aimed to analyse the effect of a silver alloy and hydrogel-coated catheter on the occurrence of catheter-associated urinary tract infection. This was a 1-year prospective study conducted at a single centre in Hong Kong. Adult patients with an indwelling urinary catheter for longer than 24 hours were recruited. The incidence of catheter-associated urinary tract infection in patients with a conventional latex Foley catheter without hydrogel was compared with that in patients with a silver alloy and hydrogel-coated catheter. The most recent definition of urinary tract infection was based on the latest surveillance definition of the National Healthcare Safety Network managed by Centers for Disease Control and Prevention. A total of 306 patients were recruited with a similar ratio between males and females. The mean (standard deviation) age was 81.1 (10.5) years. The total numbers of catheter-days were 4352 and 7474 in the silver-coated and conventional groups, respectively. The incidences of catheter-associated urinary tract infection per 1000 catheter-days were 6.4 and 9.4, respectively (P=0.095). There was a 31% reduction in the incidence of catheter-associated urinary tract infection per 1000 catheter-days in the silver-coated group. Escherichia coli was the most commonly involved pathogen (36.7%) of all cases. Subgroup analysis revealed that the protective effect of silver-coated catheter was more pronounced in long-term users as well as female patients with a respective 48% (P=0.027) and 42% (P=0.108) reduction in incidence of catheter-associated urinary tract infection. The mean catheterisation time per person was the longest in patients using a silver-coated catheter (17.0 days) compared with those using a conventional (10.8 days) or both types of catheter (13.6 days) [P=0.01]. Silver alloy and hydrogel-coated catheters appear to be effective in preventing catheter

Coronary angioplasty with second generation Monorail catheters.

Science.gov (United States)

Pande, A K; Meier, B; Urban, P; Villavicencio, R; de la Serna, F; Moles, V

1991-07-01

The Monorail system (Schneider) consists of a balloon catheter in which the guidewire passes through the balloon itself, exits the catheter proximal to the balloon, and runs alongside its small shaft (3 French) through the length of the guiding catheter. It offers distinct advantages over conventional systems of coronary angioplasty. It facilitates contrast injections and permits rapid balloon exchanges. This system was used for coronary angioplasty in 273 unselected consecutive patients (age 59 +/- 10, mean 35 to 73 years). There were 216 patients (84%) undergoing single-vessel and 57 patients (16%) with multi-vessel coronary angioplasty. A total of 335 coronary stenoses were dilated, which included 35 total occlusions. The size of balloon used ranged from 2.0 to 4.25 mm (3.0 +/- 0.5 mm) and the severity of stenosis was 85 +/- 11%. Technical success was defined as a residual stenosis of less than 50% as determined angiographically. Clinical success was defined as technical success, and absence of a major inhospital complication defined as absence of myocardial infarction, lack of need for coronary arterial bypass surgery, and survival. The Monorail system was technically successful in 294/300 stenotic lesions (98%). It was clinically successful for 281 lesions (94%). Of the 35 total occlusions, technical success was obtained in 25 (71%). The residual stenosis of successful cases was 26 +/- 21%. The Monorail system was also successful in 5 patients with stenosis of more than 90% in whom conventional systems failed. The complications included acute occlusion causing acute myocardial infarction in 13 cases (5%), emergency coronary arterial bypass surgery in 1 patient (0.4%), and death in 4 patients (1.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Removal of non-deflatable retained foley catheter in the bladder by percutaneous puncture of catheter balloon

International Nuclear Information System (INIS)

Yoo, Jae Duk; Kim, Jae Kyu; Park, Jin Gyun; Chung, Hyon De

1988-01-01

Nondeflatable Foley catheter in the bladder is an uncommon event. We recently experienced a patient in whom the urologist were unable to remove a Foley catheter with cystoscope due to public bone fractures. The procedure, which was successfully carried out, consists of puncturing the ballon under fluoroscope.

Ultrasound-Guided Percutaneous Catheter Drainage of Large Breast Abscesses in Lactating Women: How to Preserve Breastfeeding Safely.

Science.gov (United States)

Falco, Giuseppe; Foroni, Monica; Castagnetti, Fabio; Marano, Luigi; Bordoni, Daniele; Rocco, Nicola; Marchesi, Vanessa; Iotti, Valentina; Vacondio, Rita; Ferrari, Guglielmo

2016-12-01

Management of breast abscess in lactating women remains controversial. During pregnancy, women may develop different kinds of benign breast lesions that could require a surgical incision performed under general anesthesia with consequent breastfeeding interruption. The purpose of this study was to prospectively evaluate the management of large breast abscesses with ultrasound-assisted drainage aiming at breastfeeding preservation. 34 lactating women with a diagnosis of unilateral breast abscess have been treated with an ultrasound (US)-assisted drainage of the abscess. A pigtail catheter was inserted into the fluid collection using the Seldinger technique under US guide and connected to a three stop way to allow drainage and irrigation of the cavity until its resolution. All procedures have been found safe and well tolerated. No recurrence was observed and breastfeeding was never interrupted. The described technique allows to avoid surgery and to preserve breastfeeding in well-selected patients with a safe, well-tolerated and cost-effective procedure.

Iatrogenic Bowel Injury at Exchange of Supra-Pubic Catheter

LENUS (Irish Health Repository)

Foran, AT

2018-04-01

Suprapubic catheter insertion and exchange is a common urological procedure, but it is not without risks and complications. While bowel perforation is a recognised complication at suprapubic catheter insertion, it is not commonly reported at suprapubic catheter exchange. We report our experience of recognition, diagnosis and subsequent successful management of the most important complication related to suprapubic catheters.

Analog experiment of transarterial catheter hyperthermic infusion in vitro

International Nuclear Information System (INIS)

Fan Shufeng Li Zheng; Gu Weizhong; Ru Fuming

2006-01-01

Objective: To investigate the factors related to the heating effect by transarterial catheter hyperthermic infusion with the evaluation of the feasibility in controlling the tumor temperature. Methods: Infusing 55-68 degree C liquid at the speed of 10-40 ml/min through 6F, 5F or 3F catheter with different length respectively under the similar clinical condition. The liquid temperature at the terminal exit of the catheter was measured with a digital thermometer. The factors related to the liquid temperature at the exit of the catheter were analyzed by multiple regression analysis. Results: The infusion temperature , rate and the catheter length were the main related factors to the liquid temperature at the exit of the catheter as the condition similar in clinical use. When 60-65 degree C liquid was infused at the rate of 20-40 ml/min through 5F catheter with length of 80 cm, the mean and 95% confident interval of the liquid temperature at the catheter exit were (47.55±0.44) degree C and 44.61-48.49 degree C respectively. Conclusions: The liquid temperature at the exit of infusion catheter can be regulated and controlled through adjusting the liquid perfusion temperature and speed. (authors)

Statistically Modeling I-V Characteristics of CNT-FET with LASSO

Science.gov (United States)

Ma, Dongsheng; Ye, Zuochang; Wang, Yan

2017-08-01

With the advent of internet of things (IOT), the need for studying new material and devices for various applications is increasing. Traditionally we build compact models for transistors on the basis of physics. But physical models are expensive and need a very long time to adjust for non-ideal effects. As the vision for the application of many novel devices is not certain or the manufacture process is not mature, deriving generalized accurate physical models for such devices is very strenuous, whereas statistical modeling is becoming a potential method because of its data oriented property and fast implementation. In this paper, one classical statistical regression method, LASSO, is used to model the I-V characteristics of CNT-FET and a pseudo-PMOS inverter simulation based on the trained model is implemented in Cadence. The normalized relative mean square prediction error of the trained model versus experiment sample data and the simulation results show that the model is acceptable for digital circuit static simulation. And such modeling methodology can extend to general devices.

The bowed catheter sign: a risk for pericardial tamponade

Energy Technology Data Exchange (ETDEWEB)

Towbin, Richard [Phoenix Children' s Hospital, Department of Radiology, Phoenix, AZ (United States)

2008-03-15

The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

The bowed catheter sign: a risk for pericardial tamponade

International Nuclear Information System (INIS)

Towbin, Richard

2008-01-01

The use of a central venous catheter (CVC) has become commonplace in the care of children with a wide variety of medical and surgical problems. Complications resulting from the insertion of these catheters are well recognized and can be life-threatening. When a temporary CVC or other catheter is inserted into the central venous system it is secured to the skin with a combination of sutures and sterile dressing. This fixes the catheter in place and does not allow it to retract, thereby putting pressure on the right atrial wall via the catheter tip if it is too long. The probability of wall penetration is increased if a catheter or device is tapered at the point of contact. The purpose of this case report is to present the bowed catheter sign and to review the anatomy of the cavotricuspid isthmus, a possible predisposing factor to cardiac perforation and tamponade. (orig.)

Steam-deformed Judkins-left guiding catheter with use of the GuideLiner(®) catheter to deliver stents for anomalous right coronary artery.

Science.gov (United States)

Kuno, Toshiki; Fujisawa, Taishi; Yamazaki, Hiroyuki; Motoda, Hiroyuki; Kodaira, Masaki; Numasawa, Yohei

2015-01-01

Percutaneous coronary intervention for anomalous right coronary artery (RCA) originating from the left coronary cusp is challenging because of our current inability to coaxially engage the guiding catheter. We report a case of an 88-year-old woman with non-ST segment elevation myocardial infarction, with an anomalous RCA origin. Using either the Judkins-Left catheter or Amplatz-Left catheter was difficult because of RCA ostium tortuosity. Thus, we used steam to deform the Judkins-Left catheter, but back-up support was insufficient to deliver the stent. We used GuideLiner®, a novel pediatric catheter with rapid exchange/monorail systems, to enhance back-up support. We were able to successfully stent with both the deformed Judkins-Left guiding catheter and GuideLiner® for an anomalous RCA origin.

Catheter Associated Urinary Tract Infection Prevention bundle

Directory of Open Access Journals (Sweden)

O. Zarkotou

2017-01-01

Full Text Available Catheter-associated urinary tract infections (CAUTI are among the most common healthcare-associated infections, and potentially lead to significant morbidity and mortality. Multifaceted infection control strategies implemented as bundles can prevent nosocomial infections associated with invasive devices such as CAUTIs. The components of the CAUTI bundle proposed herein, include appropriate indications for catheterization and recommendations for the procedures of catheter insertion and catheter maintenance and care. Avoiding unnecessary urinary catheter use is the most effective measure for their prevention. To minimize the risk of CAUTI, urinary catheters should be placed only when a clinical valid indication is documented and they should be removed as soon as possible; alternatives to catheterization should also be considered. Aseptic insertion technique, maintenance of closed drainage system and strict adherence to hand hygiene are essential for preventing CAUTI. The successful implementation of the bundle requires education and training for all healthcare professionals and evaluation of surveillance data.

Scoring relevancy of features based on combinatorial analysis of Lasso with application to lymphoma diagnosis

Directory of Open Access Journals (Sweden)

Zare Habil

2013-01-01

Full Text Available Abstract One challenge in applying bioinformatic tools to clinical or biological data is high number of features that might be provided to the learning algorithm without any prior knowledge on which ones should be used. In such applications, the number of features can drastically exceed the number of training instances which is often limited by the number of available samples for the study. The Lasso is one of many regularization methods that have been developed to prevent overfitting and improve prediction performance in high-dimensional settings. In this paper, we propose a novel algorithm for feature selection based on the Lasso and our hypothesis is that defining a scoring scheme that measures the "quality" of each feature can provide a more robust feature selection method. Our approach is to generate several samples from the training data by bootstrapping, determine the best relevance-ordering of the features for each sample, and finally combine these relevance-orderings to select highly relevant features. In addition to the theoretical analysis of our feature scoring scheme, we provided empirical evaluations on six real datasets from different fields to confirm the superiority of our method in exploratory data analysis and prediction performance. For example, we applied FeaLect, our feature scoring algorithm, to a lymphoma dataset, and according to a human expert, our method led to selecting more meaningful features than those commonly used in the clinics. This case study built a basis for discovering interesting new criteria for lymphoma diagnosis. Furthermore, to facilitate the use of our algorithm in other applications, the source code that implements our algorithm was released as FeaLect, a documented R package in CRAN.

Central venous catheter insertion problem solving using intravenous catheter: technical communication

Directory of Open Access Journals (Sweden)

Alemohammad M

2013-02-01

Full Text Available Insertion of central venous catheter is an accepted method for hemodynamic monitor-ring, drug and fluid administration, intravenous access, hemodialysis and applying cardiac pace-maker in hospitalized patients. This procedure can be associated with severe complications. The aim of this article is to provide a practical approach to prevent catheter malposition in states that the guide wire will not pass freely.During central venous insertion in internal jugular vein using modified seldinger technique, when after venous insertion, the passage of the guide wire shows difficulties and don’t pass freely, insertion of an intravenous cannula over the wire and re-insertion of the wire can help to prevent malposition of the wire and the catheter. Use of an intravenous cannula over the guide, in situations that the guide wire cannot pass freely among the needle inserted in internal jugular vein, and re-insertion of the guide can probably prevent or reduce the tissue or vascular trauma and the associated complica-tions. This simple maneuver can be helpful in difficult cases especially in cardiac surgery patients who receive high dose heparin and it is necessary to avoid traumatize-tion of carotid artery.

Catheter Angiography

Medline Plus

Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Interventional radiologist performing an angiography exam View ... ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Catheter Angiography Sponsored by Please note ...

Three-dimensional tracking of cardiac catheters using an inverse geometry x-ray fluoroscopy system

International Nuclear Information System (INIS)

Speidel, Michael A.; Tomkowiak, Michael T.; Raval, Amish N.; Van Lysel, Michael S.

2010-01-01

tracking precision of ablation and diagnostic catheter tips ranged from ±0.2 mm at the highest image fluence to ±0.9 mm at the lowest fluence. Tracking precision depended on image fluence, the size of the tracked catheter electrode, and the contrast of the electrode. Conclusions: High speed multiplanar tomosynthesis with an inverse geometry x-ray fluoroscopy system enables 3D tracking of multiple high-contrast objects at the rate of fluoroscopic imaging. The SBDX system is capable of tracking electrodes in standard cardiac catheters with approximately 1 mm accuracy and precision.

Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies.

Science.gov (United States)

Robinson, Eric; Oldham, Melissa; Cuckson, Imogen; Brunstrom, Jeffrey M; Rogers, Peter J; Hardman, Charlotte A

2016-03-01

Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study 3 participants were exposed to images of large or small portions of a snack food before selecting a portion size of snack food to consume. Across the three studies, visual exposure to larger as opposed to smaller portion sizes resulted in participants considering a normal portion of food to be larger than a reference intermediate sized portion. In studies 1 and 2 visual exposure to larger portion sizes also increased the size of self-reported ideal meal size. In study 3 visual exposure to larger portion sizes of a snack food did not affect how much of that food participants subsequently served themselves and ate. Visual exposure to larger portion sizes may adjust visual perceptions of what constitutes a 'normal' sized portion. However, we did not find evidence that visual exposure to larger portions altered snack food intake. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

An epidural catheter removal after recent percutaneous coronary intervention and coronary artery stenting: Epidural catheter and antiaggregation therapy

Directory of Open Access Journals (Sweden)

Joksić Nikola

2016-01-01

Full Text Available Introduction: Anticoagulation and antiplatelet therapy in the presence of the epidural catheter is still controversial. It is well known that dual antiplatelet therapy is indicated for 12 months after the placement of drug-eluting stents (DES. Removal of an epidural catheter during that period is related to an increased risk of stent occlusion in case of discontinuation of platelet function inhibitors or, on the other hand, increased risk of epidural hematoma associated with neurological deficit if suppressed platelet function is still present. Case Report: Here we present a case of a 63-year-old man who was admitted to Institute for Cardiovascular Diseases Dedinje for elective aortic surgery. Before the induction, an epidural catheter was inserted at the Th10-Th11 epidural space. Uneventful surgery was performed under the combined epidural and general anesthesia. On the 2nd postoperative day, the patient sustained a ST depression myocardial infarction treated with percutaneous coronary intervention with DES placement, while epidural catheter was still in place. Dual antiplatelet therapy with 600mg of clopidogrel, 100 mg of acetilsalicylic acid (ASA and low molecular weight heparin (LMWH were started during the procedure. The next day, clopidogrel (75 mg and ASA (100 mg were continued as well as LMWH. The decision to remove the epidural catheter was made on the 9th postoperative day, after platelet aggregation assays were performed. Six hours after catheter removal the patient again received clopidogrel, ASA and LMWH. There were no signs of epidural hematoma. Conclusion: This case shows that point-of-care testing with platelet aggregation assays may be useful in increasing the margin of safety for epidural catheter removal during dual antiplatelet therapy.

Urethral catheters: can we reduce use?

NARCIS (Netherlands)

Broek, P.J. van den; Wille, J.C.; Benthem, B.H.B. van; Perenboom, R.J.M.; Akker-van Marle, M.E. van den; Nielen, A.M.A.

2011-01-01

Indwelling urinary catheters are the main cause of healthcare-associated urinary tract infections. It can be expected that reduction of the use of urinary catheters will lead to decreased numbers of urinary tract infection. The efficacy of an intervention programme to improve adherence to

Spontaneous rotation of the monorail-type guide extension support catheter during advancement of a curved guiding catheter: the potential hazard of twisting with the coronary guidewire.

Science.gov (United States)

Hashimoto, Sho; Takahashi, Akihiko; Yamada, Takeshi; Mizuguchi, Yukio; Taniguchi, Norimasa; Hata, Tetsuya; Nakajima, Shunsuke

2017-11-20

The extension support guiding catheter has been used to perform complex percutaneous coronary intervention to increase back-up support for the guiding catheter or to ensure deep intubation for device delivery. However, because of its monorail design, advancement of the stent into the distal extension tubing segment is sometimes problematic. Although this problem is considered due to simple collision of the stent, operators have observed tangling between a monorail extension catheter and coronary guidewire in some patients. To examine movement of the collar of the extension guide catheter during advancement of the guiding catheter, we set up an in vitro model in which the guiding catheter had two curves. Rotation of the extension guide catheter was examined by both fluoroscopic imaging and movement of the hub of the proximal end of the catheter. During advancement in the first curve, the collar moved toward the outer side of the curve of the guiding catheter as the operator pushed the shaft of the extension guiding catheter, which overrode the guidewire. After crossing the first curve, the collar moved again to the outer side of the second curve (the inner side of the first curve) of the mother catheter, and then, another clockwise rotation was observed in the proximal hub. Consequently, the collar and tubing portion of the extension guide catheter rotated 360° around the coronary guidewire, and the monorail extension catheter and guidewire became tangled. There is a potential risk of unintentional twisting with the guidewire during advancement into the curved guiding catheter because of its monorail design.

Catheter placement for lysis of spontaneous intracerebral hematomas: does a catheter position in the core of the hematoma allow more effective and faster hematoma lysis?

Science.gov (United States)

Malinova, Vesna; Schlegel, Anna; Rohde, Veit; Mielke, Dorothee

2017-07-01

For the fibrinolytic therapy of intracerebral hematomas (ICH) using recombinant tissue plasminogen activator (rtPA), a catheter position in the core of the hematoma along the largest clot diameter was assumed to be optimal for an effective clot lysis. However, it never had been proven that core position indeed enhances clot lysis if compared with less optimal catheter positions. In this study, the impact of the catheter position on the effectiveness and on the time course of clot lysis was evaluated. We analyzed the catheter position using a relative error calculating the distance perpendicular to the catheter's center in relation to hematoma's diameter and evaluated the relative hematoma volume reduction (RVR). The correlation of the RVR with the catheter position was evaluated. Additionally, we tried to identify patterns of clot lysis with different catheter positions. The patient's outcome at discharge was evaluated using the Glasgow outcome score. A total of 105 patients were included in the study. The mean hematoma volume was 56 ml. The overall RVR was 62.7 %. In 69 patients, a catheter position in the core of the clot was achieved. We found no significant correlation between catheter position and hematoma RVR (linear regression, p = 0.14). Core catheter position leads to more symmetrical hematoma RVR. Faster clot lysis happens in the vicinity of the catheter openings. We found no significant difference in the patient's outcome dependent on the catheter position (linear regression, p = 0.90). The catheter position in the core of the hematoma along its largest diameter does not significantly influence the effectiveness of clot lysis after rtPA application.

Catheter Angiography

Medline Plus

Full Text Available ... key areas of the body for abnormalities such as aneurysms and disease such as atherosclerosis (plaque). The use of a catheter makes ... including the: brain neck heart chest abdomen (such as the kidneys and liver) pelvis legs and feet ...

Catheter Angiography

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. ...

Radiologic Placement of Tunneled Central Venous Catheters in Pediatric Patients

International Nuclear Information System (INIS)

Kim, Eun Ji; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jeong, Woo Kyoung; Lee, Yong Ho

2010-01-01

We evaluated the technical success and complication rates associated with the radiological placement of tunneled central venous catheters in pediatric patients. Between May 1, 2005 and March 31, 2008, a total of 46 tunneled central venous catheters were placed in 34 children (M:F = 22:12; mean age, 9.9 years [9 months to 16.8 years]). All procedures were performed under ultrasonographic and fluoroscopic guidance. Follow-up data were obtained through the retrospective review of the medical records. We used the Kaplan-Meier survival method for the evaluation of survival rate of the catheters. All procedures were technically successful. The observed periprocedural complications included hematoma formation in three patients. The mean catheter life was 189.3 days (total, 8710 days; range, 7-810). Catheters were removed due to death (n=9), the end of treatment (n=8), catheter sepsis (n=4), malfunction (n=8), and accidental removal (n=4). The rate of catheter sepsis and malfunction was 0.459 and 0.919 for every 1000 catheter days, respectively. The expected mean catheter life was 479.6 days as per the Kaplan- Meier analysis. The results suggest that the radiologic placement of a tunneled central venous catheter is an effective technique with a high technical success rate and low complication rate

Radiologic Placement of Tunneled Central Venous Catheters in Pediatric Patients

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ji; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jeong, Woo Kyoung; Lee, Yong Ho [Hanyang University College of Medicine, Seoul (Korea, Republic of)

2010-08-15

We evaluated the technical success and complication rates associated with the radiological placement of tunneled central venous catheters in pediatric patients. Between May 1, 2005 and March 31, 2008, a total of 46 tunneled central venous catheters were placed in 34 children (M:F = 22:12; mean age, 9.9 years [9 months to 16.8 years]). All procedures were performed under ultrasonographic and fluoroscopic guidance. Follow-up data were obtained through the retrospective review of the medical records. We used the Kaplan-Meier survival method for the evaluation of survival rate of the catheters. All procedures were technically successful. The observed periprocedural complications included hematoma formation in three patients. The mean catheter life was 189.3 days (total, 8710 days; range, 7-810). Catheters were removed due to death (n=9), the end of treatment (n=8), catheter sepsis (n=4), malfunction (n=8), and accidental removal (n=4). The rate of catheter sepsis and malfunction was 0.459 and 0.919 for every 1000 catheter days, respectively. The expected mean catheter life was 479.6 days as per the Kaplan- Meier analysis. The results suggest that the radiologic placement of a tunneled central venous catheter is an effective technique with a high technical success rate and low complication rate.

Management of Non- Deflating Foley Suprapubic Catheters - A ...

African Journals Online (AJOL)

The procedure described uses a 10 ml syringe and needle passed through the lumen of the catheter to puncture the inner surface of the catheter balloon and thus deflate it. Because the catheter balloon does not burst in this procedure there is no risk of balloon fragmentation or subsequent stone formation. The technique is ...

Urethral catheters: can we reduce use?

Directory of Open Access Journals (Sweden)

van den Akker-van Marle M Elske

2011-05-01

Full Text Available Abstract Background Indwelling urinary catheters are the main cause of healthcare-associated urinary tract infections. It can be expected that reduction of the use of urinary catheters will lead to decreased numbers of urinary tract infection. Methods The efficacy of an intervention programme to improve adherence to recommendations to reduce the use of urethral catheters was studied in a before-after comparison in ten Dutch hospitals. The programme detected barriers and facilitators and each individual facility was supported with developing their own intervention strategy. Outcome was evaluated by the prevalence of catheters, alternatives such as diapers, numbers of urinary tract infections, the percentage of correct indications and the duration of catheterization. The costs of the implementation as well as the catheterization were evaluated. Results Of a population of 16,495 hospitalized patients 3335 patients of whom 2943 were evaluable for the study, had a urethral catheter. The prevalence of urethral catheters decreased insignificantly in neurology (OR 0.93; 95% CI 0.77 - 1.13 and internal medicine wards (OR 0.97; 95% CI 0.83 - 1.13, decreased significantly in surgical wards (OR 0.84; 95% CI 0.75 - 0.96, but increased significantly in intensive care (IC and coronary care (CC units (OR 1.48; 95% CI 1.01 - 2.17. The use of alternatives was limited and remained so after the intervention. Duration of catheterization decreased insignificantly in IC/CC units (ratio after/before 0.95; 95% CI 0.78 - 1.16 and neurology (ratio 0.97; 95% CI 0.80 - 1.18 and significantly in internal medicine (ratio 0.81; 95% CI 0.69 - 0.96 and surgery wards (ratio 0.80; 95% CI 0.71 - 0.90. The percentage of correct indications on the day of inclusion increased from 50 to 67% (p Conclusion Targeted implementation of recommendations from an existing guideline can lead to better adherence and cost savings. Especially, hospitals which use a lot of urethral catheters or

21 CFR 880.5200 - Intravascular catheter.

Science.gov (United States)

2010-04-01

... Devices § 880.5200 Intravascular catheter. (a) Identification. An intravascular catheter is a device that consists of a slender tube and any necessary connecting fittings and that is inserted into the patient's vascular system for short term use (less than 30 days) to sample blood, monitor blood pressure, or...

Synthesis of mesoporous carbon nanoparticles with large and tunable pore sizes

Science.gov (United States)

Liu, Chao; Yu, Meihua; Li, Yang; Li, Jiansheng; Wang, Jing; Yu, Chengzhong; Wang, Lianjun

2015-07-01

Mesoporous carbon nanoparticles (MCNs) with large and adjustable pores have been synthesized by using poly(ethylene oxide)-b-polystyrene (PEO-b-PS) as a template and resorcinol-formaldehyde (RF) as a carbon precursor. The resulting MCNs possess small diameters (100-126 nm) and high BET surface areas (up to 646 m2 g-1). By using home-designed block copolymers, the pore size of MCNs can be tuned in the range of 13-32 nm. Importantly, the pore size of 32 nm is the largest among the MCNs prepared by the soft-templating route. The formation mechanism and structure evolution of MCNs were studied by TEM and DLS measurements, based on which a soft-templating/sphere packing mechanism was proposed. Because of the large pores and small particle sizes, the resulting MCNs were excellent nano-carriers to deliver biomolecules into cancer cells. MCNs were further demonstrated with negligible toxicity. It is anticipated that this carbon material with large pores and small particle sizes may have excellent potential in drug/gene delivery.Mesoporous carbon nanoparticles (MCNs) with large and adjustable pores have been synthesized by using poly(ethylene oxide)-b-polystyrene (PEO-b-PS) as a template and resorcinol-formaldehyde (RF) as a carbon precursor. The resulting MCNs possess small diameters (100-126 nm) and high BET surface areas (up to 646 m2 g-1). By using home-designed block copolymers, the pore size of MCNs can be tuned in the range of 13-32 nm. Importantly, the pore size of 32 nm is the largest among the MCNs prepared by the soft-templating route. The formation mechanism and structure evolution of MCNs were studied by TEM and DLS measurements, based on which a soft-templating/sphere packing mechanism was proposed. Because of the large pores and small particle sizes, the resulting MCNs were excellent nano-carriers to deliver biomolecules into cancer cells. MCNs were further demonstrated with negligible toxicity. It is anticipated that this carbon material with large pores and

Reducing unnecessary urinary catheter use and other strategies to prevent catheter-associated urinary tract infection: an integrative review.

Science.gov (United States)

Meddings, Jennifer; Rogers, Mary A M; Krein, Sarah L; Fakih, Mohamad G; Olmsted, Russell N; Saint, Sanjay

2014-04-01

Catheter-associated urinary tract infections (CAUTI) are costly, common and often preventable by reducing unnecessary urinary catheter (UC) use. To summarise interventions to reduce UC use and CAUTIs, we updated a prior systematic review (through October 2012), and a meta-analysis regarding interventions prompting UC removal by reminders or stop orders. A narrative review summarises other CAUTI prevention strategies including aseptic insertion, catheter maintenance, antimicrobial UCs, and bladder bundle implementation. 30 studies were identified and summarised with interventions to prompt removal of UCs, with potential for inclusion in the meta-analyses. By meta-analysis (11 studies), the rate of CAUTI (episodes per 1000 catheter-days) was reduced by 53% (rate ratio 0.47; 95% CI 0.30 to 0.64, pSMD) in catheterisation duration (days) was -1.06 overall (p=0.065) including a statistically significant decrease in stop-order studies (SMD -0.37; pSMD, -1.54; p=0.071). No significant harm from catheter removal strategies is supported. Limited research is available regarding the impact of UC insertion and maintenance technique. A recent randomised controlled trial indicates antimicrobial catheters provide no significant benefit in preventing symptomatic CAUTIs. UC reminders and stop orders appear to reduce CAUTI rates and should be used to improve patient safety. Several evidence-based guidelines have evaluated CAUTI preventive strategies as well as emerging evidence regarding intervention bundles. Implementation strategies are important because reducing UC use involves changing well-established habits.

Local Intravascular Drug Delivery: In Vitro Comparison of Three Catheter Systems

International Nuclear Information System (INIS)

Alfke, Heiko; Wagner, Hans-Joachim; Calmer, Christian; Klose, Klaus Jochen

1998-01-01

Purpose: The aim of this in vitro study was to compare different catheter systems for local drug delivery with respect to the penetration depth of a biotin marker solution delivered into the vessel wall. Methods: Post-mortem carotid arteries from pigs were locally infused with a biotin solution using three different catheter systems. With all catheters (microporous balloon catheter, hydrogel-coated balloon catheter, and spiral balloon catheter) we used the same pressure of 405 kPa (4 atm) and infusion times of 60, 90, and 300 sec. After infusion the arteries were histologically prepared and stained using a biotin-specific method. With a light microscope an observer, blinded to the catheter type, scored the amount of biotin within the vessel wall, measured as staining intensity, and the penetration depth of the biotin. Results: Delivery with the hydrogel-coated balloon catheter was limited to the intima and the innermost parts of the media. The spiral balloon and microporous balloon catheter showed both a deeper penetration and a larger amount of delivered biotin compared with the hydrogel catheter, with a slightly deeper penetration using the microporous catheter. The penetration depth showed a correlation with infusion time for the spiral balloon and microporous catheters, but not for the hydrogel-coated catheter. Conclusion: Different catheter designs lead to different patterns of local drug delivery. The differences in penetration depth and amount of the substance delivered to the vessel wall should be known and might be useful for targeting specific areas within the vessel wall

Pigtail Catheter: A Less Invasive Option for Pleural Drainage in Egyptian Patients with Recurrent Hepatic Hydrothorax

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Mohamed Sharaf-Eldin

2016-01-01

Full Text Available Background and Aims. Treatment of hepatic hydrothorax is a clinical challenge. Chest tube insertion for hepatic hydrothorax is associated with high complication rates. We assessed the use of pigtail catheter as a safe and practical method for treatment of recurrent hepatic hydrothorax as it had not been assessed before in a large series of patients. Methods. This study was conducted on 60 patients admitted to Tanta University Hospital, Egypt, suffering from recurrent hepatic hydrothorax. The site of pigtail catheter insertion was determined by ultrasound guidance under complete aseptic measures and proper local anesthesia. Insertion was done by pushing the trocar and catheter until reaching the pleural cavity and then the trocar was withdrawn gradually while inserting the catheter which was then connected to a collecting bag via a triple way valve. Results. The use of pigtail catheter was successful in pleural drainage in 48 (80% patients with hepatic hydrothorax. Complications were few and included pain at the site of insertion in 12 (20% patients, blockage of the catheter in only 2 (3.3% patients, and rapid reaccumulation of fluid in 12 (20% patients. Pleurodesis was performed on 38 patients with no recurrence of fluid within three months of observation. Conclusions. Pigtail catheter insertion is a practical method for treatment of recurrent hepatic hydrothorax with a low rate of complications. This trial is registered with ClinicalTrials.gov Identifier: NCT02119169.

Miniaturization of catheter systems for angiography

International Nuclear Information System (INIS)

Hawkins, I.F. Jr.; Akins, E.W.

1988-01-01

The authors discuss the use of small catheters and needles in angiography and interventional procedures to improve the quality of the procedures and increase the success rate and safety. This philosophy was initially poorly received, both by operators and by industry; however, more recently microtechniques have become more acceptable primarily because of the changing economic climate requiring procedures with shorter or no hospitalization time. Since 1970, the authors have performed well over 10,000 angiographic procedures using 5 French catheters, or smaller. During the last 12 years, they have used almost exclusively 4 French catheters, primarily with standard filming techniques which have resulted in no thrombosed arteries, or significant hematoma formation

Cryoballoon Catheter Ablation in Atrial Fibrillation

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Cevher Ozcan

2011-01-01

Full Text Available Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

[Prevention of catheter-related infection: usefulness and cost-effectiveness of antiseptic catheters in children].

Science.gov (United States)

Lenz, Ana M; Vassallo, Juan C; Moreno, Guillermo E; Althabe, María; Gómez, Silvia; Magliola, Ricardo; Casimir, Lidia; Bologna, Rosa; Barretta, Jorge; Ruffa, Pablo

2010-06-01

To evaluate the cost-effectiveness of the antiseptic-impregnated catheter compared with conventional catheters in preventing catheter- related blood stream infections (CR-BSI). Cost-effectiveness analysis; clinical trial, experimental, randomized, controlled, prospective, open label. Patients and methods. A 172 patient cohort, under 1-year-old or less than 10 kg, postoperative cardiovascular children with central venous catheters (CVC) admitted to Cardiac Intensive Care Unit (UCI 35) at Hospital Nacional de Pediatría "Prof. Dr. Juan P. Garrahan", since September 2005 to December 2007. Demographic and CVC data were retrieved to compare: age, gender, weight, diagnosis, surgery, CVC days, costs and complications. Intervention. CVC Arrow, double-lumen, > 48 h of duration; intervention group: antiseptic-impregnated CVC vs. control group: CVC without antiseptics (conventional). The incidence of CR-IE (CR-Infected Events: colonization, local infection and/or CRBSI; combined end point) was 27% for antiseptic- impregnated CVC vs. 31% for conventional catheters (p= 0.6) with similar accumulated incidence of CR- BSI: 2.8 vs. 3.3 per 1000 dayscatheter. We found no differences between groups, except in weight: median 4.0 kg (r 2-17) vs. 4.7 kg (r 2-9) p= 0.0002 and age, median 2 months (r 1- 48) vs. 5 months (r 1- 24) p= 0.0019 in antiseptic-impregnated CVC group. These differences, though statistically significant were clinically non relevant. Median cost per patient during intensive care stay in the conventional CVC group was $3.417 (359-9.453) and in the antiseptic-impregnated-CVC group was $4.962 (239-24.532), p= 0.10. The use of antiseptic-impregnated CVC compared with conventional CVC did not decrease CR-BSI in this population. The cost per patients was higher in the antiseptic impregnated CVC group. These results do not support the routine use of this type of CVC in our population.

Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

International Nuclear Information System (INIS)

Burton, Kirsteen R.; Guo, Lancia L. Q.; Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K.

2012-01-01

Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

Use of monorail PTCA balloon catheter for local drug delivery.

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Trehan, Vijay; Nair, Girish M; Gupta, Mohit D

2007-01-01

We report the use of monorail coronary balloon as an infusion catheter to give bailout abciximab selectively into the site of stent thrombosis as an adjunct to plain old balloon angioplasty (POBA) in a patient of subacute stent thrombosis of the left anterior descending coronary artery. The balloon component (polyamide material) of the monorail balloon catheter was shaved off the catheter so that abciximab injected through the balloon port of the catheter exited out the shaft of the balloon catheter at the site from where the balloon material was shaved off. We believe that selective infusion with abciximab along with POBA established antegrade flow and relieved the patient's ischemia. In the absence of essential hardware to give intracoronary drugs in an emergency situation, one may employ our technique of infusion through a monorail balloon catheter after shaving the balloon component from the catheter.

Radiologically placed tunneled peritoneal catheter in palliation of malignant ascites

International Nuclear Information System (INIS)

Akinci, Devrim; Erol, Bekir; Ciftci, Tuerkmen T.; Akhan, Okan

2011-01-01

The purpose of this study was to evaluate retrospectively the safety and effectiveness of radiologically placed tunneled peritoneal catheter in palliation of malignant ascites. Between July 2005 and June 2009, 41 tunneled peritoneal catheters were placed under ultrasonographic and fluoroscopic guidance in 40 patients (mean age, 55 years; 22 women) who had symptomatic malignant ascites. No procedure related mortality was observed. Major complication occurred in one patient (2.5%) in the form of serious bacterial peritonitis that necessitated catheter removal. Minor complications such as minor bacterial peritonitis, catheter dislodgement, tunnel infection, and catheter blockage occurred in 11 patients (27.5%). The mean duration of survival after catheter placement was 11.8 weeks. All patients expired of their primary malignancies in the follow-up. Radiologically placed tunneled peritoneal catheter is safe and effective in palliation of symptomatic malignant ascites.

Radiologically placed tunneled peritoneal catheter in palliation of malignant ascites

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Akinci, Devrim; Erol, Bekir; Ciftci, Tuerkmen T. [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey); Akhan, Okan, E-mail: akhano@tr.net [Hacettepe University, Faculty of Medicine, Department of Radiology, 06100 Ankara (Turkey)

2011-11-15

The purpose of this study was to evaluate retrospectively the safety and effectiveness of radiologically placed tunneled peritoneal catheter in palliation of malignant ascites. Between July 2005 and June 2009, 41 tunneled peritoneal catheters were placed under ultrasonographic and fluoroscopic guidance in 40 patients (mean age, 55 years; 22 women) who had symptomatic malignant ascites. No procedure related mortality was observed. Major complication occurred in one patient (2.5%) in the form of serious bacterial peritonitis that necessitated catheter removal. Minor complications such as minor bacterial peritonitis, catheter dislodgement, tunnel infection, and catheter blockage occurred in 11 patients (27.5%). The mean duration of survival after catheter placement was 11.8 weeks. All patients expired of their primary malignancies in the follow-up. Radiologically placed tunneled peritoneal catheter is safe and effective in palliation of symptomatic malignant ascites.

Where does the pulmonary artery catheter float: Transesophageal echocardiography evaluation

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Deepak K Tempe

2015-01-01

Full Text Available Background: Pulmonary artery (PA catheter provides a variety of cardiac and hemodynamic parameters. In majority of the patients, the catheter tends to float in the right pulmonary artery (RPA than the left pulmonary artery (LPA. We evaluated the location of PA catheter with the help of transesophageal echocardiography (TEE to know the incidence of its localization. Three views were utilized for this purpose; midesophageal ascending aorta (AA short-axis view, modified mid esophageal aortic valve long-axis view, and modified bicaval view. Methods: We enrolled 135 patients undergoing elective cardiac surgery where both the PA catheter and TEE were to be used; for this prospective observational study. PA catheter was visualized by TEE in the above mentioned views and the degree of clarity of visualization by three views was also noted. Position of the PA catheter was further confirmed by a postoperative chest radiograph. Results: One patient was excluded from the data analysis. PA catheter was visualized in RPA in 129 patients (96% and in LPA in 4 patients (3%. In 1 patient, the catheter was visualized in main PA in the chest radiograph. The midesophageal AA short-axis, modified aortic valve long-axis, and modified bicaval view provided good visualization in 51.45%, 57.4%, and 62.3% patients respectively. Taken together, PA catheter visualization was good in 128 (95.5% patients. Conclusion: We conclude that the PA catheter has a high probability of entering the RPA as compared to LPA (96% vs. 3% and TEE provides good visualization of the catheter in RPA.

Spatio Temporal EEG Source Imaging with the Hierarchical Bayesian Elastic Net and Elitist Lasso Models.

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Paz-Linares, Deirel; Vega-Hernández, Mayrim; Rojas-López, Pedro A; Valdés-Hernández, Pedro A; Martínez-Montes, Eduardo; Valdés-Sosa, Pedro A

2017-01-01

The estimation of EEG generating sources constitutes an Inverse Problem (IP) in Neuroscience. This is an ill-posed problem due to the non-uniqueness of the solution and regularization or prior information is needed to undertake Electrophysiology Source Imaging. Structured Sparsity priors can be attained through combinations of (L1 norm-based) and (L2 norm-based) constraints such as the Elastic Net (ENET) and Elitist Lasso (ELASSO) models. The former model is used to find solutions with a small number of smooth nonzero patches, while the latter imposes different degrees of sparsity simultaneously along different dimensions of the spatio-temporal matrix solutions. Both models have been addressed within the penalized regression approach, where the regularization parameters are selected heuristically, leading usually to non-optimal and computationally expensive solutions. The existing Bayesian formulation of ENET allows hyperparameter learning, but using the computationally intensive Monte Carlo/Expectation Maximization methods, which makes impractical its application to the EEG IP. While the ELASSO have not been considered before into the Bayesian context. In this work, we attempt to solve the EEG IP using a Bayesian framework for ENET and ELASSO models. We propose a Structured Sparse Bayesian Learning algorithm based on combining the Empirical Bayes and the iterative coordinate descent procedures to estimate both the parameters and hyperparameters. Using realistic simulations and avoiding the inverse crime we illustrate that our methods are able to recover complicated source setups more accurately and with a more robust estimation of the hyperparameters and behavior under different sparsity scenarios than classical LORETA, ENET and LASSO Fusion solutions. We also solve the EEG IP using data from a visual attention experiment, finding more interpretable neurophysiological patterns with our methods. The Matlab codes used in this work, including Simulations, Methods

Implantation port-catheter permanent indwelling of pulmonary artery in treating lung metastasis from HCC

International Nuclear Information System (INIS)

Cheng Jiemin; Wang Jianhua; Yan Zhiping; Wang Xiaolin; Gong Gaoquan; Liu Qingxin

2000-01-01

Objective: To observe the efficacy of a percutaneous implantation port-catheter permanent indwelling pulmonary artery for regional chemotherapy of the metastatic lung cancer from HCC. Methods: Between 1995 and 1999, 62 patients (42 males, 20 females; mean age 46 years) suffering from the metastatic lung cancer from HCC underwent percutaneous implantation of port-catheter permanent indwelling pulmonary artery using the right subclavian vein. In 19 patients with metastatic tumor located on one side of the lung, an indwelling catheter was placed into the ipsilateral side pulmonary artery. With metastasis of both sides, the catheter was inserted into the main trunk of pulmonary artery. The regimens of the chemotherapy were 5-FU + CDDP + MMC(FDM) or 5-FU + CDDP + MMC(FDA). Results: The interventional procedure was successfully completed in all 62 cases (100%). The complications occurred in 8% cases, including infections (3.2%), unhealed wound (1.6%) and pneumothorax (3.2%). The treatment effects of 3-months after the procedure were as follows: the obvious decrease of lung tumor size was 35.5%; stable disease (SD) 32.3% and progressive disease (PD) 32.3%. 6 months follow-up: 12 patients were dead (12/62) and the others are still doing well. The response rates were 22.6%, partial response (PR) 32.3%; stable disease (SD) 25.8% and progressive disease (PD) 32.3%. Conclusions: The percutaneous implantation techniques of pulmonary arterial port-catheter could be a good method in the treatment of metastatic lung cancer from HCC because of it is simple, with few complications and positive effect

Central venous catheters: the role of radiology

International Nuclear Information System (INIS)

Tan, P.L.; Gibson, M.

2006-01-01

The insertion and management of long-term venous catheters have long been the province of anaesthetists, intensive care physicians and surgeons. Radiologists are taking an increasing role in the insertion of central venous catheters (CVCs) because of their familiarity with the imaging equipment and their ability to manipulate catheters and guide-wires. The radiological management of the complications of CVCs has also expanded as a result. This article reviews the role of radiology in central venous access, covering the detection and management of their complications

Magnetic catheter manipulation in the interventional MR imaging environment.

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Wilson, Mark W; Martin, Alastair B; Lillaney, Prasheel; Losey, Aaron D; Yee, Erin J; Bernhardt, Anthony; Malba, Vincent; Evans, Lee; Sincic, Ryan; Saeed, Maythem; Arenson, Ronald L; Hetts, Steven W

2013-06-01

To evaluate deflection capability of a prototype endovascular catheter, which is remotely magnetically steerable, for use in the interventional magnetic resonance (MR) imaging environment. Copper coils were mounted on the tips of commercially available 2.3-3.0-F microcatheters. The coils were fabricated in a novel manner by plasma vapor deposition of a copper layer followed by laser lithography of the layer into coils. Orthogonal helical (ie, solenoid) and saddle-shaped (ie, Helmholtz) coils were mounted on a single catheter tip. Microcatheters were tested in water bath phantoms in a 1.5-T clinical MR scanner, with variable simultaneous currents applied to the coils. Catheter tip deflection was imaged in the axial plane by using a "real-time" steady-state free precession MR imaging sequence. Degree of deflection and catheter tip orientation were measured for each current application. The catheter tip was clearly visible in the longitudinal and axial planes. Magnetic field artifacts were visible when the orthogonal coils at the catheter tip were energized. Variable amounts of current applied to a single coil demonstrated consistent catheter deflection in all water bath experiments. Changing current polarity reversed the observed direction of deflection, whereas current applied to two different coils resulted in deflection represented by the composite vector of individual coil activations. Microcatheter navigation through the vascular phantom was successful through control of applied current to one or more coils. Controlled catheter deflection is possible with laser lithographed multiaxis coil-tipped catheters in the MR imaging environment. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

Positioning of nasobiliary tube using magnet-loaded catheters.

Science.gov (United States)

Watanabe, Seitaro; Sato, Takamitsu; Kato, Shingo; Hosono, Kunihiro; Kobayashi, Noritoshi; Nakajima, Atsushi; Kubota, Kensuke

2013-10-01

In endoscopic nasobiliary drainage (ENBD), repositioning the catheter from the mouth to the nose is complicated. We devised a method using catheters with magnets and verified its utility and safety. We prospectively enrolled 20 patients undergoing ENBD at Yokohama City University Hospital. The procedures were successful in all 20 cases and no case required a change of operators to a senior doctor. The mean time for the procedure was 36.6 seconds. The emetic reflex was induced 0.5 times on average using the magnet method. The mean X-ray exposure time was 29.6 seconds. No complications occurred. The magnet-loaded catheter method for positioning the ENBD catheter before finally leading it through the nose took little time and was performed successfully and safely. Therefore, the magnet method could become the first choice among techniques for ENBD catheter placement. © Georg Thieme Verlag KG Stuttgart · New York.

Hyperacute stroke patients and catheter thrombolysis therapy. Correlation between computed tomography perfusion maps and final infarction

International Nuclear Information System (INIS)

Naito, Yukari; Tanaka, Shigeko; Inoue, Yuichi; Ota, Shinsuke; Sakaki, Saburo; Kitagaki, Hajime

2008-01-01

We investigated the correlation between abnormal perfusion areas by computed tomography perfusion (CTP) study of hyperacute stroke patients and the final infarction areas after intraarterial catheter thrombolysis. CTP study using the box-modulation transfer function (box-MTF) method based on the deconvolution analysis method was performed in 22 hyperacute stroke patients. Ischemic lesions were immediately treated with catheter thrombolysis after CTP study. Among them, nine patients with middle cerebral artery (MCA) occlusion were investigated regarding correlations of the size of the prolonged mean transit time (MTT) area, the decreased cerebral blood volume (CBV) area, and the final infarction area. Using the box-MTF method, the prolonged MTT area was almost identical to the final infarction area in the case of catheter thrombolysis failure. The decreased CBV areas resulted in infarction or hemorrhage, irrespective of the outcome of recanalization after catheter thrombolysis. The prolonged MTT areas, detected by the box-MTF method of CTP in hyperacute stroke patients, included the area of true prolonged MTT and the tracer delay. The prolonged MTT area was almost identical to the final infarction area when recanalization failed. We believe that a tracer delay area also indicates infarction in cases of thrombolysis failure. (author)

Intravascular catheter related infections in children admitted on the ...

African Journals Online (AJOL)

peripheral venous intravascular catheters uncoated with no antibiotic or antiseptic, was done. Social demographic characteristics, anthropometry, clinical examination including the catheter site were determined at enrollment. The children had their blood, catheter tip and hub samples taken off for culture and sensitivity as ...

Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies

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Robinson, Eric; Oldham, Melissa; Cuckson, Imogen; Brunstrom, Jeffrey M.; Rogers, Peter J.; Hardman, Charlotte A.

2016-01-01

Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study ...

Treatment of infected bulla with alcohol sclerosis combined with percutaneous catheter drainage: a preliminary report

International Nuclear Information System (INIS)

Han, Young Min; Lee, Jeong Min; Kim, Chong Soo; Chung, Gyung Ho; Rhee, Yang Keen; Lee, Yong Chul; Sohn, Myung Hee; Choi, Ki Chul

1995-01-01

To evaluate effectiveness of alcohol sclerosis combined with percutaneous catheter drainage (PCD) for treatment of infected bulla. Infected bulla in four consecutive patients were treated. In all patients, percutaneous catheter drainage of the bulla was performed. Instillation of sterile alcohol (99% ethanol) was carried out into the cavity of the bulla. Alcohol was left in the cavity for approximately 30 minutes in each session. Alcohol instillation was repeated according to the size of bulla. Patients were subsequently followed up with serial chest radiographs and CT scans. All patients showed significant improvement both clinically and radiologically. Disappearance of the bulla and reexpansion of surrounding lung parenchyma was observed in two patients and partial resolution (80% reduction in size) was seen in another two patients. Complications included mild chest pain during instillation of alcohol in all patients and delayed radiating shoulder pain in one patient. We provisionally conclude that intracavitary alcohol instillation combined with PCD is effective in the treatment of the infected bulla

Hemodialysis catheter insertion: is increased PO2 a sign of arterial cannulation? A case report.

Science.gov (United States)

Chirinos, Julio C; Neyra, Javier A; Patel, Jiten; Rodan, Aylin R

2014-07-29

Ultrasound-guided Central Venous Catheterization (CVC) for temporary vascular access, preferably using the right internal jugular vein, is widely accepted by nephrologists. However CVC is associated with numerous potential complications, including death. We describe the finding of a rare left-sided partial anomalous pulmonary vein connection during central venous catheterization for continuous renal replacement therapy (CRRT). Ultrasound-guided cannulation of a large bore temporary dual-lumen Quinton-Mahurkar catheter into the left internal jugular vein was performed for CRRT initiation in a 66 year old African-American with sepsis-related oliguric acute kidney injury. The post-procedure chest X-ray suggested inadvertent left carotid artery cannulation. Blood gases obtained from the catheter showed high partial pressure of oxygen (PO2) of 140 mmHg and low partial pressure of carbon dioxide (PCO2) of 22 mmHg, suggestive of arterial cannulation. However, the pressure-transduced wave forms appeared venous and Computed Tomography Angiography located the catheter in the left internal jugular vein, but demonstrated that the tip of the catheter was lying over a left pulmonary vein which was abnormally draining into the left brachiocephalic (innominate) vein rather than into the left atrium. Although several mechanical complications of dialysis catheters have been described, ours is one of the few cases of malposition into an anomalous pulmonary vein, and highlights a sequential approach to properly identify the catheter location in this uncommon clinical scenario.

The importance of effective catheter securement.

Science.gov (United States)

Fisher, Jayne

This article examines the importance of securing/fixing indwelling urinary catheters. The Oxford English dictionary interlinks the two words-'secure' and 'fix'-as having the same meaning. To secure the catheter should not be confused with 'support', whereby the weight of the urine drainage bag is supported with the use of velcro straps or a sleeve. The author introduces the need for the concept of this practice to be at the forefront of nurses' minds in all settings, and this is demonstrated through the use of case studies. Current guidance in this area is reviewed, as well as the problems that can arise when catheters are not secured properly and the available products for health professionals to use.

Efficacy of a one-catheter concept for transradial coronary angiography.

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Christoph Langer

Full Text Available Transradial coronary angiography (TRC can be performed with a one-catheter approach for the right and left coronary ostium (R/LCO. We investigated the performance of a special diagnostic catheter widely used for the one-catheter-approach, the Tiger (Tiger II, TerumoTM.In a dual center registry we analyzed 1412 TRC-procedures exclusively performed by experienced TRC-operators. We compared the performance of the Tiger with Judkins catheters by retrospectively judging ostial catheter stability during contrast injection, and by measuring contrast use, fluoroscopy time (FT and complication rate.Poor or failed ostial engagement was found in 40.5% in the Tiger group, compared to 46.6% with the use of Judkins catheters (p<0.183. Ostial instability of the Tiger was found more often during engagement of the LCO than the RCO (34.4% vs. 10.8%, p<0.001, whereas it was similar in the LCO and RCO for Judkins catheters (27.4% vs. 26.7%, p = 0.840. TRC-procedures performed with Tiger catheters were associated with less contrast volume (63.48 ± 29.83mL vs. 82.51 ± 56.58mL, p<0.004 and shorter FT than with Judkins catheters. (198.27 ± 194.8sec vs. 326.85 ± 329.70sec. Forearm hematomas occurred less often with the Tiger (1.2% vs. 6.6%, p< 0.02.The Tiger employed as a single catheter in TRC is an effective tool to achieve lower contrast volume and fluoroscopy time at a low complication rate. Unstable engagement affects predominantly the left coronary artery, but its overall frequency is similar for both, the Tiger and Judkins catheters.

An intervention to improve the catheter associated urinary tract infection rate in a medical intensive care unit: Direct observation of catheter insertion procedure.

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Galiczewski, Janet M; Shurpin, Kathleen M

2017-06-01

Healthcare associated infections from indwelling urinary catheters lead to increased patient morbidity and mortality. The purpose of this study was to determine if direct observation of the urinary catheter insertion procedure, as compared to the standard process, decreased catheter utilization and urinary tract infection rates. This case control study was conducted in a medical intensive care unit. During phase I, a retrospective data review was conducted on utilsiation and urinary catheter infection rates when practitioners followed the institution's standard insertion algorithm. During phase II, an intervention of direct observation was added to the standard insertion procedure. The results demonstrated no change in utilization rates, however, CAUTI rates decreased from 2.24 to 0 per 1000 catheter days. The findings from this study may promote changes in clinical practice guidelines leading to a reduction in urinary catheter utilization and infection rates and improved patient outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Femoral venous catheters: a safe alternative for delivering parenteral alimentation.

Science.gov (United States)

Friedman, B; Kanter, G; Titus, D

1994-04-01

Femoral vein catheterization is an alternative method of obtaining central venous access. Placement of femoral venous catheters (FVCs) is possible in the majority of patients, suitable for most indications, and associated with a low complication rate during insertion. We wished to determine the incidence of infections or other complications resulting when parenteral nutrition was delivered through FVCs. Fifty-two patients were followed from a hospital-wide population including patients in the critical care units. Triple-lumen catheters were placed by using the sterile Seldinger technique, and sites were examined daily for inflammation. Bacteriologic surveillance was accomplished by submitting the catheter tip for semiquantitative cultures. If catheter line sepsis was suspected, blood samples for cultures were drawn through the catheter and peripherally. The rate of occurrence of colonized catheters was 9.6% (five of 52), and catheter sepsis was found in one case (1.9%). Other than inflammation at six (11.5%) of 52 catheter sites, noninfectious complications of FVCs were not found. On the basis of these findings, we consider FVC-delivered parenteral alimentation a safe and effective alternative to other forms of central venous access.

Totally implantable venous catheters for chemotherapy: experience in 500 patients

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Nelson Wolosker

Full Text Available CONTEXT: Totally implantable devices are increasingly being utilized for chemotherapy treatment of oncological patients, although few studies have been done in our environment to analyze the results obtained from the implantation and utilization of such catheters. OBJECTIVE: To study the results obtained from the implantation of totally implantable catheters in patients submitted to chemotherapy. TYPE OF STUDY: Prospective. SETTING: Hospital do Câncer A.C. Camargo, São Paulo, Brazil. METHODS: 519 totally implantable catheters were placed in 500 patients submitted to chemotherapy, with preference for the use of the right external jugular vein. Evaluations were made of the early and late-stage complications and patient evolution until removal of the device, death or the end of the treatment. RESULTS: The prospective analysis showed an average duration of 353 days for the catheters. There were 427 (82.2% catheters with no complications. Among the early complications observed, there were 15 pathway hematomas, 8 cases of thrombophlebitis of the distal stump of the external jugular vein and one case of pocket infection. Among the late-stage complications observed, there were 43 infectious complications (0.23/1000 days of catheter use, 11 obstructions (0.06/1000 days of catheter use and 14 cases of deep vein thrombosis (0.07/1000 days of catheter use. Removal of 101 catheters was performed: 35 due to complications and 66 upon terminating the treatment. A total of 240 patients died while the catheter was functioning and 178 patients are still making use of the catheter. CONCLUSION: The low rate of complications obtained in this study confirms the safety and convenience of the use of totally implantable accesses in patients undergoing prolonged chemotherapy regimes.

Monorail Piccolino catheter: a new rapid exchange/ultralow profile coronary angioplasty system.

Science.gov (United States)

Mooney, M R; Douglas, J S; Mooney, J F; Madison, J D; Brandenburg, R O; Fernald, R; Van Tassel, R A

1990-06-01

The Monorail Piccolino coronary angioplasty balloon catheter (MBC) was evaluated on 118 patients at two centers. Technical success was achieved in 110 patients (93%). Time for catheter exchange and total fluoroscopy time were significantly lower for the Monorail catheter than with standard equipment (exchange time 97 vs. 170 seconds P less than .05 and fluoroscopy time 17 vs. 88 seconds P less than .001). The advantages of rapid exchange and the ability of utilize 2 Monorail balloon catheters through one 9F guiding catheter for simultaneous inflations allowed for maximal flexibility in treating patients with bifurcation lesions. The double wire approach utilizing one Monorail balloon catheter with a 7F guiding catheter was also technically successful. The Monorail Piccolino balloon catheter has unique features that allow for greater ease of operator use, rapid catheter exchange, and optimal angiographic visualization. It is felt that this catheter design provides distinct advantages over standard angioplasty equipment.

Radiographic signs of non-venous placement of intended central venous catheters in children

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Taylor, Erin C. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Taylor, George A. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Harvard Medical School, Department of Radiology, Boston, MA (United States)

2016-02-15

Central venous catheters (CVCs) are commonly used in children, and inadvertent arterial or extravascular cannulation is rare but has potentially serious complications. To identify the radiographic signs of arterial placement of CVCs. We retrospectively reviewed seven cases of arterially malpositioned CVCs on chest radiograph. These cases were identified through departmental quality-assurance mechanisms and external consultation. Comparison of arterial cases was made with 127 age-matched chest radiographs with CVCs in normal, expected venous location. On each anteroposterior (AP) radiograph we measured the distance of the catheter tip from the right lateral border of the thoracic spine, and the angle of the vertical portion of the catheter relative to the midline. On each lateral radiograph we measured the angle of the vertical portion of each catheter relative to the anterior border of the thoracic spine. When bilateral subclavian catheters were present, the catheter tips were described as crossed, overlapping or uncrossed. On AP radiographs, arterially placed CVCs were more curved to the left, with catheter tip positions located farther to the left of midline than normal venous CVCs. When bilateral, properly placed venous catheters were present, all catheters crossed at the level of the superior vena cava (SVC). When one of the bilateral catheters was in arterial position, neither of the catheters crossed or the inter-catheter crossover distance was exaggerated. On lateral radiographs, there was a marked anterior angulation of the vertical portion of the catheter (mean angle 37 ± 15 standard deviation [SD] in arterial catheters versus 5.9 ± 8.3 SD in normally placed venous catheters). Useful radiographic signs suggestive of unintentional arterial misplacement of vascular catheters include leftward curvature of the vertical portion of the catheter, left-side catheter tip position, lack of catheter crossover on the frontal radiograph, as well as exaggerated

Catheter-Related Sepsis Due to Rhodotorula glutinis

Science.gov (United States)

Hsueh, Po-Ren; Teng, Lee-Jene; Ho, Shen-Wu; Luh, Kwen-Tay

2003-01-01

We describe a central venous catheter-related (Port-A-Cath; Smiths Industries Medical Systems [SIMS] Deltec, Inc., St. Paul, Minn.) infection caused by Rhodotorula glutinis in a 51-year-old man with nasopharyngeal carcinoma. He was treated with fluconazole for 8 weeks and had the catheter removed. Two isolates of R. glutinis recovered from blood specimens (one obtained via peripheral veins and one via the catheter) before administration of fluconazole and one recovered from the removed catheter 17 days after initiation of fluconazole therapy exhibited high-level resistance to fluconazole (MICs, >256 μg/ml). These three isolates were found to belong to a single clone on the basis of identical antibiotypes determined by the E test (PDM Epsilometer; AB Biodisk, Solna, Sweden) and biotypes determined by API ID32 C (bioMerieux, Marcy I'Etoile, France) and their identical random amplified polymorphic DNA patterns. PMID:12574300

Use of asymmetric bidirectional catheters with different curvature radius for catheter ablation of cardiac arrhythmias.

Science.gov (United States)

Mantziari, Lilian; Suman-Horduna, Irina; Gujic, Marko; Jones, David G; Wong, Tom; Markides, Vias; Foran, John P; Ernst, Sabine

2013-06-01

The impact of recently introduced asymmetric bidirectional ablation catheters on procedural parameters and acute success rates of ablation procedures is unknown. We retrospectively analyzed data regarding ablations using a novel bidirectional catheter in a tertiary cardiac center and compared these in 1:5 ratio with a control group of procedures matched for age, gender, operator, and ablation type. A total of 50 cases and 250 controls of median age 60 (50-68) years were studied. Structural heart disease was equally prevalent in both groups (39%) while history of previous ablations was more common in the study arm (54% vs 30%, P = 0.001). Most of the ablation cases were for atrial fibrillation (46%), followed by atrial tachycardia (28%), supraventricular tachycardia (12%), and ventricular tachycardia (14%). Median procedure duration was 128 (52-147) minutes with the bidirectional, versus 143 (105-200) minutes with the conventional catheter (P = 0.232), and median fluoroscopy time was 17 (10-34) minutes versus 23 (12-39) minutes, respectively (P = 0.988). There was a trend toward a lower procedure duration for the atrial tachycardia ablations, 89 (52-147) minutes versus 130 (100-210) minutes, P = 0.064. The procedure was successfully completed in 96% of the bidirectional versus 84% of the control cases (P = 0.151). A negative correlation was observed between the relative fluoroscopy duration and the case number (r = -0.312, P = 0.028), reflecting the learning curve for the bidirectional catheter. The introduction of the bidirectional catheter resulted in no prolongation of procedure parameters and similar success rates, while there was a trend toward a lower procedure duration for atrial tachycardia ablations. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Evaluation of digital soil mapping approaches with large sets of environmental covariates

Science.gov (United States)

Nussbaum, Madlene; Spiess, Kay; Baltensweiler, Andri; Grob, Urs; Keller, Armin; Greiner, Lucie; Schaepman, Michael E.; Papritz, Andreas

2018-01-01

The spatial assessment of soil functions requires maps of basic soil properties. Unfortunately, these are either missing for many regions or are not available at the desired spatial resolution or down to the required soil depth. The field-based generation of large soil datasets and conventional soil maps remains costly. Meanwhile, legacy soil data and comprehensive sets of spatial environmental data are available for many regions. Digital soil mapping (DSM) approaches relating soil data (responses) to environmental data (covariates) face the challenge of building statistical models from large sets of covariates originating, for example, from airborne imaging spectroscopy or multi-scale terrain analysis. We evaluated six approaches for DSM in three study regions in Switzerland (Berne, Greifensee, ZH forest) by mapping the effective soil depth available to plants (SD), pH, soil organic matter (SOM), effective cation exchange capacity (ECEC), clay, silt, gravel content and fine fraction bulk density for four soil depths (totalling 48 responses). Models were built from 300-500 environmental covariates by selecting linear models through (1) grouped lasso and (2) an ad hoc stepwise procedure for robust external-drift kriging (georob). For (3) geoadditive models we selected penalized smoothing spline terms by component-wise gradient boosting (geoGAM). We further used two tree-based methods: (4) boosted regression trees (BRTs) and (5) random forest (RF). Lastly, we computed (6) weighted model averages (MAs) from the predictions obtained from methods 1-5. Lasso, georob and geoGAM successfully selected strongly reduced sets of covariates (subsets of 3-6 % of all covariates). Differences in predictive performance, tested on independent validation data, were mostly small and did not reveal a single best method for 48 responses. Nevertheless, RF was often the best among methods 1-5 (28 of 48 responses), but was outcompeted by MA for 14 of these 28 responses. RF tended to over

Number and location of drainage catheter side holes: in vitro evaluation.

Science.gov (United States)

Ballard, D H; Alexander, J S; Weisman, J A; Orchard, M A; Williams, J T; D'Agostino, H B

2015-09-01

To evaluate the influence of number and location of catheter shaft side holes regarding drainage efficiency in an in vitro model. Three different drainage catheter models were constructed: open-ended model with no side holes (one catheter), unilateral side hole model (six catheters with one to six unilateral side holes), and bilateral side hole model (six catheters with one to six bilateral side holes). Catheters were inserted into a drainage output-measuring device with a constant-pressure reservoir of water. The volume of water evacuated by each of the catheters at 10-second intervals was measured. A total of five trials were performed for each catheter. Data were analysed using one-way analysis of variance. The open-ended catheter had a mean drainage volume comparable to the unilateral model catheters with three, four, and five side holes. Unilateral model catheters had significant drainage volume increases up to three side holes; unilateral model catheters with more than three side holes had no significant improvement in drainage volume. All bilateral model catheters had significantly higher mean drainage volumes than their unilateral counterparts. There was no significant difference between the mean drainage volume with one, two, or three pairs of bilateral side holes. Further, there was no drainage improvement by adding additional bilateral side holes. The present in vitro study suggests that beyond a critical side hole number threshold, adding more distal side holes does not improve catheter drainage efficiency. These results may be used to enhance catheter design towards improving their drainage efficiency. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Virtual 5-French intra-aortic pumping using a Glidesheath Slender and 6-French intra-aortic balloon catheter

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Akihiko, E-mail: a-takahashi@wine.ocn.ne.jp; Taniguchi, Norimasa; Mizuguchi, Yukio; Yamada, Takeshi; Nakajima, Shunsuke; Hashimoto, Sho; Hata, Tetsuya

2015-07-15

Objectives: The aim of this study was to evaluate the feasibility and safety of the 6-Fr Glidesheath Slender, which has equivalent outer size to the conventional 5-Fr sheath, for use with the 6-Fr intra-aortic balloon pump (IABP) catheter. Methods: Between May 2014 and March 2015, 24 patients with acute coronary syndrome underwent percutaneous coronary intervention using a 6-Fr IABP catheter through a 6-Fr Glidesheath Slender for support. The adverse events, including access site complications, kinking of the sheath during the procedure, and any evidence of balloon pump failure, were retrospectively investigated. Results: Insertion of the IABP catheter through either the femoral or brachial artery was successful in all patients. The mean support time was 32.4 ± 22.0 h. No major hemorrhagic event or severe limb ischemia was observed. Kinking of the shaft occurred during insertion in one patient; however, the subsequent balloon pumping was well maintained and did not require exchange of the sheath or IABP catheter. No kind of IABP failure was observed. Conclusion: Although this sheath was originally designed to allow radial access, our results suggest that the use of the Glidesheath Slender is feasible for insertion of the 6-Fr IABP catheter through the brachial and femoral arteries, and may reduce vascular complications in patients who undergo percutaneous coronary intervention.

Suprapubic catheter care

Science.gov (United States)

... going back into your bladder. Try not to disconnect the catheter more than you need to. Keeping ... Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for EHRs For Developers U.S. National Library of ...

Three-Catheter Technique for Ablation of Left-Sided Accessory Pathways in Wolff-Parkinson-White is Less Expensive and Equally Successful When Compared to a Five-Catheter Technique.

Science.gov (United States)

Capone, Christine A; Ceresnak, Scott R; Nappo, Lynn; Gates, Gregory J; Schechter, Clyde B; Pass, Robert H

2015-12-01

To compare the efficacy, safety, and cost-effectiveness of a three-catheter approach with a conventional five-catheter approach for the mapping and ablation of supraventricular tachycardia in pediatric patients with Wolff-Parkinson-White Syndrome (WPW) and concealed accessory pathways (APs). A retrospective review from 2008 to 2012 of patients less than 21 years with WPW who underwent a three-catheter radiofrequency (RF) ablation of a left-sided AP (ablation, right ventricular [RV] apical, and coronary sinus [CS] decapolar catheters) was performed. The three-catheter group was compared to a control group who underwent a standard five-catheter (ablation, RV apical, CS decapolar, His catheter, and right atrial catheter) ablation for the treatment of left-sided WPW or concealed AP. Demographics, ablation outcomes, and costs were compared between groups. Twenty-eight patients met inclusion criteria with 28 control patients. The groups did not differ in gender, age, weight, or body surface area. Locations of the AP on the mitral annulus were similar between the groups. All patients were ablated via transseptal approach. Note that 28 of 28 in the three-catheter group (100%) and 27 of 28 (96%) controls were acutely successfully ablated (P = 0.31). No complications were encountered. There was no difference in procedural time, time to loss of AP conduction, or number of RF applications. Use of the three-catheter technique resulted in a total savings of $2,465/case, which includes the $680 savings from using fewer catheters as well as the savings from a shortened procedure time. Ablation in patients with WPW and a left-sided AP can be performed using three catheters with similar efficacy and safety while offering significant cost savings compared to a conventional five-catheter approach. © 2015 Wiley Periodicals, Inc.

Reliable pipeline repair system for very large pipe size

Energy Technology Data Exchange (ETDEWEB)

Charalambides, John N.; Sousa, Alexandre Barreto de [Oceaneering International, Inc., Houston, TX (United States)

2004-07-01

The oil and gas industry worldwide has been mainly depending on the long-term reliability of rigid pipelines to ensure the transportation of hydrocarbons, crude oil, gas, fuel, etc. Many other methods are also utilized onshore and offshore (e.g. flexible lines, FPSO's, etc.), but when it comes to the underwater transportation of very high volumes of oil and gas, the industry commonly uses large size rigid pipelines (i.e. steel pipes). Oil and gas operators learned to depend on the long-lasting integrity of these very large pipelines and many times they forget or disregard that even steel pipelines degrade over time and more often that that, they are also susceptible to various forms of damage (minor or major, environmental or external, etc.). Over the recent years the industry had recognized the need of implementing an 'emergency repair plan' to account for such unforeseen events and the oil and gas operators have become 'smarter' by being 'pro-active' in order to ensure 'flow assurance'. When we consider very large diameter steel pipelines such as 42' and 48' nominal pipe size (NPS), the industry worldwide does not provide 'ready-made', 'off-the-shelf' repair hardware that can be easily shipped to the offshore location and effect a major repair within acceptable time frames and avoid substantial profit losses due to 'down-time' in production. The typical time required to establish a solid repair system for large pipe diameters could be as long as six or more months (depending on the availability of raw materials). This paper will present in detail the Emergency Pipeline Repair Systems (EPRS) that Oceaneering successfully designed, manufactured, tested and provided to two major oil and gas operators, located in two different continents (Gulf of Mexico, U.S.A. and Arabian Gulf, U.A.E.), for two different very large pipe sizes (42'' and 48'' Nominal Pipe Sizes

Catheter-associated UTI

Science.gov (United States)

... UTI; Health care-associated UTI; Catheter-associated bacteriuria; Hospital acquired-UTI Images Bladder catheterization, female Bladder catheterization, male References Calfee DP. Prevention and control of health care-associated infections. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

Outcome of tunneled infusion catheters inserted via the right internal jugular vein

International Nuclear Information System (INIS)

Shin, Sung Wook; Do, Young Soo; Choo, Sung Wook; Yoo, Wi Kang; Choo, In Wook; Kim, Jae Hyung

2003-01-01

To assess the outcome of tunneled central venous catheter placement via the right internal jugular vein. Between June 2001 and May 2002, 670 consecutive Hickman catheters were placed in 654 patients via the right internal jugular vein. The procedural complications arising and follow-up data obtained from May to July 2002 were evaluated. The technical success rate for catheter placement was 99.9% (669/670). Procedural complications were limited to eight cases (1.2%), including three pneumothoraces, one early migration of the catheter, one clinically unimportant air embolism, one catheter injury, one catheter kinking and one primary malpositioning in the azygos vein. Catheter dwelling time ranged from 1 to 407 (mean 107.1) days. During the follow-up period, 416 catheter were removed for various reasons: treatment had ended (n=334), patients declined treatment or their drug regimen was changed (n=16), late complications arose (n=53), or other circumstances intervened (n=13). Late complications included 44 cases of catheter-related infection (6.6%), five of catheter migration (0.7%), two of catheter occlusion (0.3%), one of thrombophlebitis (0.15%), and one of catheter-related right atrial thrombosis (0.15%). Only one instance of symptomatic venous thrombosis or stenosis was noted, namely the one case of thrombophlebitis. Because the incidence of subsequent symptomatic venous thrombosis or stenosis is lower, the preferred route for tunneled central venous catheter placement is the right internal jugular vein

A computational fluid dynamics simulation framework for ventricular catheter design optimization.

Science.gov (United States)

Weisenberg, Sofy H; TerMaath, Stephanie C; Barbier, Charlotte N; Hill, Judith C; Killeffer, James A

2017-11-10

OBJECTIVE Cerebrospinal fluid (CSF) shunts are the primary treatment for patients suffering from hydrocephalus. While proven effective in symptom relief, these shunt systems are plagued by high failure rates and often require repeated revision surgeries to replace malfunctioning components. One of the leading causes of CSF shunt failure is obstruction of the ventricular catheter by aggregations of cells, proteins, blood clots, or fronds of choroid plexus that occlude the catheter's small inlet holes or even the full internal catheter lumen. Such obstructions can disrupt CSF diversion out of the ventricular system or impede it entirely. Previous studies have suggested that altering the catheter's fluid dynamics may help to reduce the likelihood of complete ventricular catheter failure caused by obstruction. However, systematic correlation between a ventricular catheter's design parameters and its performance, specifically its likelihood to become occluded, still remains unknown. Therefore, an automated, open-source computational fluid dynamics (CFD) simulation framework was developed for use in the medical community to determine optimized ventricular catheter designs and to rapidly explore parameter influence for a given flow objective. METHODS The computational framework was developed by coupling a 3D CFD solver and an iterative optimization algorithm and was implemented in a high-performance computing environment. The capabilities of the framework were demonstrated by computing an optimized ventricular catheter design that provides uniform flow rates through the catheter's inlet holes, a common design objective in the literature. The baseline computational model was validated using 3D nuclear imaging to provide flow velocities at the inlet holes and through the catheter. RESULTS The optimized catheter design achieved through use of the automated simulation framework improved significantly on previous attempts to reach a uniform inlet flow rate distribution using

[Recording of ventricular pressure by conventional catheter manometer systems. Efficiency of several combinations of conventional catheters, modern transducers and catheter-flush systems (author's transl)].

Science.gov (United States)

Hellige, G

1976-01-01

The experimentally in vitro determined dynamic response characteristics of 38 catheter manometer systems were uniform in the worst case to 5 c.p.s. and optimally to 26 c.p.s. Accordingly, some systems are only satisfactory for ordinary pressure recording in cardiac rest, while better systems record dp/dt correct up to moderate inotropic stimulation of the heart. In the frequency range of uniform response (amplitude error less +/- 5%) the phase distortion is also negligible. In clinical application the investigator is often restricted to special type of cardiac catheter. In this case a low compliant transducer yields superior results. In all examined systems the combination with MSD 10 transducers is best, whereas the combination with P 23 Db transducers leads to minimal results. An inadequate system for recording ventricular pressure pulses leads in most cases to overestimations of dp/dtmax. The use of low frequency pass filters to attenuate higher frequency artefacts is, under clinical conditions, not suitable for extending the range of uniform frequency response. The dynamic response of 14 catheter manometer systems with two types of continuous self flush units was determined. The use of the P 37 flush unit in combination with small internal diameter catheters leads to serious error in ordinary pressure recording, due to amplitude distortion of the lower harmonics. The frequency response characteristics of the combination of an Intraflow flush system and MSD 10 transducer was similar to the non-flushing P 23 Db transducer feature.

Compatibility of electrolytically produced sodium hypochlorite solutions on long- term implanted dialysis catheters.

Science.gov (United States)

Mishkin, G J

2007-01-01

More than 20% of the world's population use a catheter for dialysis, despite guidelines limiting their use. Although the structure and design of the catheters differ by manufacturer, the material used in central venous catheters and peritoneal dialysis catheters are the same across manufacturers. Given the long-term use of these catheters in the dialysis population, the good compatibility of the antiseptics and disinfectants used on the catheters is imperative to prevent failure and cracking of the catheter material. Tensile strengths of commercially available catheters were measured after exposure to commonly used disinfectants. The tensile strength was then compared between the catheters by analyzing the displacement vs. force (N) curves produced during the evaluation. A total of 44 catheter lumens were evaluated. The electrolytically produced sodium hypochlorite solution, Alcavis 50/ExSept Plus, was the only solution shown to be compatible with all three catheter materials resulting in a deviation of less than 10% for each of the different catheter types. Electrolytically produced sodium hypochlorite solutions were the only solutions in this study that did not alter the physical properties of any of the catheters after long-term exposure.

Percutaneous untying of a knot in a retained Swan-Ganz catheter

International Nuclear Information System (INIS)

Bhatti, Waqar A.; Sinha, Sankar; Rowlands, Peter

2000-01-01

A patient was referred to us with a tightly knotted Swan-Ganz catheter. The catheter could not be removed by conventional simple methods. We describe a minimally invasive means of removal of the catheter using an Amplatz gooseneck snare and an angioplasty balloon. This allowed the Catheter to be removed without trauma.

Dialysis catheter-related septicaemia--focus on Staphylococcus aureus septicaemia

DEFF Research Database (Denmark)

Nielsen, J; Ladefoged, S D; Kolmos, H J

1998-01-01

BACKGROUND: Dialysis catheters are a common cause of nosocomial septicaemia in haemodialysis units usually due to staphylococci, of which Staphylococcus aureus is the most pathogenic. In this study, the epidemiology and pathogenesis of dialysis catheter-related infections were studied, and methods...... to infection were measured. After catheter insertion, all patients were screened for nasal carriage of S. aureus, and a culture was taken from the skin overlying the catheter insertion site. Once a week, cultures were taken from the insertion site and from the hub, and aerobic and anaerobic blood cultures were...... drawn from the catheter. If clinical signs of septicaemia occurred, peripheral blood cultures were also performed, when it was possible. RESULTS: The incidence of septicaemia was 49% (21/43) in patients, and 56% of all cases were caused by S. aureus. The mortality was 14% (3/21) and the incidence...

Radiological Tenckhoff catheter insertion for peritoneal dialysis: A cost-effective approach.

Science.gov (United States)

Lee, James; Mott, Nigel; Mahmood, Usman; Clouston, John; Summers, Kara; Nicholas, Pauline; Gois, Pedro Henrique França; Ranganathan, Dwarakanathan

2018-04-01

Radiological insertion of Tenckhoff catheters can be an alternative option for peritoneal dialysis access creation, as compared to surgical catheter insertion. This study will review the outcomes and complications of radiological Tenckhoff catheter insertion in a metropolitan renal service and compare costs between surgical and radiological insertion. Data were collected prospectively for all patients who had a Tenckhoff catheter insertion for peritoneal dialysis (PD) under radiological guidance at our hospital from May 2014 to November 2016. The type of catheter used and complications, including peri-catheter leak, exit site infection and peritonitis were reviewed. Follow-up data were also collected at points 3, 6 and 12 months from catheter insertion. Costing data were obtained from Queensland Health Electronic Reporting System (QHERS) data, average staff salaries and consumable contract price lists. In the 30-month evaluation period, 70 catheters were inserted. Two patients had an unsuccessful procedure due to the presence of abdominal adhesions. Seven patients had an episode of peri-catheter leak, and four patients had an exit site infection following catheter insertion. Peritonitis was observed in nine patients during the study period. The majority of patients (90%) remained on peritoneal dialysis at 3-month follow-up. The average costs of surgical and radiological insertion were noted to be AUD$7788.34 and AUD$1597.35, respectively. Radiological Tenckhoff catheter insertion for peritoneal dialysis appears to be an attractive and cost-effective option given less waiting periods for the procedure, the relatively low cost of insertion and comparable rates of complications. © 2017 The Royal Australian and New Zealand College of Radiologists.

Comparison of air-charged and water-filled urodynamic pressure measurement catheters.

Science.gov (United States)

Cooper, M A; Fletter, P C; Zaszczurynski, P J; Damaser, M S

2011-03-01

Catheter systems are utilized to measure pressure for diagnosis of voiding dysfunction. In a clinical setting, patient movement and urodynamic pumps introduce hydrostatic and motion artifacts into measurements. Therefore, complete characterization of a catheter system includes its response to artifacts as well its frequency response. The objective of this study was to compare the response of two disposable clinical catheter systems: water-filled and air-charged, to controlled pressure signals to assess their similarities and differences in pressure transduction. We characterized frequency response using a transient step test, which exposed the catheters to a sudden change in pressure; and a sinusoidal frequency sweep test, which exposed the catheters to a sinusoidal pressure wave from 1 to 30 Hz. The response of the catheters to motion artifacts was tested using a vortex and the response to hydrostatic pressure changes was tested by moving the catheter tips to calibrated heights. Water-filled catheters acted as an underdamped system, resonating at 10.13 ± 1.03 Hz and attenuating signals at frequencies higher than 19 Hz. They demonstrated significant motion and hydrostatic artifacts. Air-charged catheters acted as an overdamped system and attenuated signals at frequencies higher than 3.02 ± 0.13 Hz. They demonstrated significantly less motion and hydrostatic artifacts than water-filled catheters. The transient step and frequency sweep tests gave comparable results. Air-charged and water-filled catheters respond to pressure changes in dramatically different ways. Knowledge of the characteristics of the pressure-measuring system is essential to finding the best match for a specific application. Copyright © 2011 Wiley-Liss, Inc.

Devices and dressings to secure peripheral venous catheters to prevent complications.

Science.gov (United States)

Marsh, Nicole; Webster, Joan; Mihala, Gabor; Rickard, Claire M

2015-06-12

methodological procedures expected by Cochrane. We included six RCTs (1539 participants) in this review. Trial sizes ranged from 50 to 703 participants. These six trials made four comparisons, namely: transparent dressings versus gauze; bordered transparent dressings versus a securement device; bordered transparent dressings versus tape; and transparent dressing versus sticking plaster. There is very low quality evidence of fewer catheter dislodgements or accidental removals with transparent dressings compared with gauze (two studies, 278 participants, RR 0.40; 95% CI 0.17 to 0.92, P = 0.03%). The relative effects of transparent dressings and gauze on phlebitis (RR 0.89; 95% CI 0.47 to 1.68) and infiltration (RR 0.80; 95% CI 0.48 to 1.33) are unclear. The relative effects on PVC failure of a bordered transparent dressing and a securement device have been assessed in only one small study and these were unclear. There was very low quality evidence from the same single study of less frequent dislodgement or accidental catheter removal with bordered transparent dressings than securement devices (RR 0.14, 95% CI 0.03 to 0.63) but more phlebitis with bordered dressings (RR 8.11, 95% CI 1.03 to 64.02) (very low quality evidence). A small single study compared bordered transparent dressings with tape and found very low quality evidence of more PVC failure with the bordered dressing (RR 1.84, 95% CI 1.08 to 3.11) but the relative effects on dislodgement were not clear (very low quality evidence). The relative effects of transparent dressings and a sticking plaster have only been compared in one small study and are unclear. More high quality RCTs are required to determine the relative effects of alternative PVC dressings and securement devices. It is not clear if any one dressing or securement device is better than any other in securing peripheral venous catheters. There is a need for further, independent high quality trials to evaluate the many traditional as well as the newer, high use

Reducing unnecessary urinary catheter use and other strategies to prevent catheter-associated urinary tract infection: an integrative review

Science.gov (United States)

Meddings, Jennifer; Rogers, Mary A M; Krein, Sarah L; Fakih, Mohamad G; Olmsted, Russell N; Saint, Sanjay

2014-01-01

Background Catheter-associated urinary tract infections (CAUTI) are costly, common and often preventable by reducing unnecessary urinary catheter (UC) use. Methods To summarise interventions to reduce UC use and CAUTIs, we updated a prior systematic review (through October 2012), and a meta-analysis regarding interventions prompting UC removal by reminders or stop orders. A narrative review summarises other CAUTI prevention strategies including aseptic insertion, catheter maintenance, antimicrobial UCs, and bladder bundle implementation. Results 30 studies were identified and summarised with interventions to prompt removal of UCs, with potential for inclusion in the meta-analyses. By meta-analysis (11 studies), the rate of CAUTI (episodes per 1000 catheter-days) was reduced by 53% (rate ratio 0.47; 95% CI 0.30 to 0.64, p<0.001) using a reminder or stop order, with five studies also including interventions to decrease initial UC placement. The pooled (nine studies) standardised mean difference (SMD) in catheterisation duration (days) was −1.06 overall (p=0.065) including a statistically significant decrease in stop-order studies (SMD −0.37; p<0.001) but not in reminder studies (SMD, −1.54; p=0.071). No significant harm from catheter removal strategies is supported. Limited research is available regarding the impact of UC insertion and maintenance technique. A recent randomised controlled trial indicates antimicrobial catheters provide no significant benefit in preventing symptomatic CAUTIs. Conclusions UC reminders and stop orders appear to reduce CAUTI rates and should be used to improve patient safety. Several evidence-based guidelines have evaluated CAUTI preventive strategies as well as emerging evidence regarding intervention bundles. Implementation strategies are important because reducing UC use involves changing well-established habits. PMID:24077850

Breast cancer tumor classification using LASSO method selection approach

International Nuclear Information System (INIS)

Celaya P, J. M.; Ortiz M, J. A.; Martinez B, M. R.; Solis S, L. O.; Castaneda M, R.; Garza V, I.; Martinez F, M.; Ortiz R, J. M.

2016-10-01

Breast cancer is one of the leading causes of deaths worldwide among women. Early tumor detection is key in reducing breast cancer deaths and screening mammography is the widest available method for early detection. Mammography is the most common and effective breast cancer screening test. However, the rate of positive findings is very low, making the radiologic interpretation monotonous and biased toward errors. In an attempt to alleviate radiological workload, this work presents a computer-aided diagnosis (CAD x) method aimed to automatically classify tumor lesions into malign or benign as a means to a second opinion. The CAD x methos, extracts image features, and classifies the screening mammogram abnormality into one of two categories: subject at risk of having malignant tumor (malign), and healthy subject (benign). In this study, 143 abnormal segmentation s (57 malign and 86 benign) from the Breast Cancer Digital Repository (BCD R) public database were used to train and evaluate the CAD x system. Percentile-rank (p-rank) was used to standardize the data. Using the LASSO feature selection methodology, the model achieved a Leave-one-out-cross-validation area under the receiver operating characteristic curve (Auc) of 0.950. The proposed method has the potential to rank abnormal lesions with high probability of malignant findings aiding in the detection of potential malign cases as a second opinion to the radiologist. (Author)

Breast cancer tumor classification using LASSO method selection approach

Energy Technology Data Exchange (ETDEWEB)

Celaya P, J. M.; Ortiz M, J. A.; Martinez B, M. R.; Solis S, L. O.; Castaneda M, R.; Garza V, I.; Martinez F, M.; Ortiz R, J. M., E-mail: morvymm@yahoo.com.mx [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico)

2016-10-15

Breast cancer is one of the leading causes of deaths worldwide among women. Early tumor detection is key in reducing breast cancer deaths and screening mammography is the widest available method for early detection. Mammography is the most common and effective breast cancer screening test. However, the rate of positive findings is very low, making the radiologic interpretation monotonous and biased toward errors. In an attempt to alleviate radiological workload, this work presents a computer-aided diagnosis (CAD x) method aimed to automatically classify tumor lesions into malign or benign as a means to a second opinion. The CAD x methos, extracts image features, and classifies the screening mammogram abnormality into one of two categories: subject at risk of having malignant tumor (malign), and healthy subject (benign). In this study, 143 abnormal segmentation s (57 malign and 86 benign) from the Breast Cancer Digital Repository (BCD R) public database were used to train and evaluate the CAD x system. Percentile-rank (p-rank) was used to standardize the data. Using the LASSO feature selection methodology, the model achieved a Leave-one-out-cross-validation area under the receiver operating characteristic curve (Auc) of 0.950. The proposed method has the potential to rank abnormal lesions with high probability of malignant findings aiding in the detection of potential malign cases as a second opinion to the radiologist. (Author)

Higher albedos and size distribution of large transneptunian objects

Science.gov (United States)

Lykawka, Patryk Sofia; Mukai, Tadashi

2005-11-01

Transneptunian objects (TNOs) orbit beyond Neptune and do offer important clues about the formation of our solar system. Although observations have been increasing the number of discovered TNOs and improving their orbital elements, very little is known about elementary physical properties such as sizes, albedos and compositions. Due to TNOs large distances (>40 AU) and observational limitations, reliable physical information can be obtained only from brighter objects (supposedly larger bodies). According to size and albedo measurements available, it is evident the traditionally assumed albedo p=0.04 cannot hold for all TNOs, especially those with approximately absolute magnitudes H⩽5.5. That is, the largest TNOs possess higher albedos (generally >0.04) that strongly appear to increase as a function of size. Using a compilation of published data, we derived empirical relations which can provide estimations of diameters and albedos as a function of absolute magnitude. Calculations result in more accurate size/albedo estimations for TNOs with H⩽5.5 than just assuming p=0.04. Nevertheless, considering low statistics, the value p=0.04 sounds still convenient for H>5.5 non-binary TNOs as a group. We also discuss about physical processes (e.g., collisions, intrinsic activity and the presence of tenuous atmospheres) responsible for the increase of albedo among large bodies. Currently, all big TNOs (>700 km) would be capable to sustain thin atmospheres or icy frosts composed of CH 4, CO or N 2 even for body bulk densities as low as 0.5 g cm -3. A size-dependent albedo has important consequences for the TNOs size distribution, cumulative luminosity function and total mass estimations. According to our analysis, the latter can be reduced up to 50% if higher albedos are common among large bodies. Lastly, by analyzing orbital properties of classical TNOs ( 42AUbodies. For both populations, distinct absolute magnitude distributions are maximized for an inclination threshold

Randomized clinical trial of pigtail catheter versus chest tube in injured patients with uncomplicated traumatic pneumothorax.

Science.gov (United States)

Kulvatunyou, N; Erickson, L; Vijayasekaran, A; Gries, L; Joseph, B; Friese, R F; O'Keeffe, T; Tang, A L; Wynne, J L; Rhee, P

2014-01-01

Small pigtail catheters appear to work as well as the traditional large-bore chest tubes in patients with traumatic pneumothorax, but it is not known whether the smaller pigtail catheters are associated with less tube-site pain. This study was conducted to compare tube-site pain following pigtail catheter or chest tube insertion in patients with uncomplicated traumatic pneumothorax. This prospective randomized trial compared 14-Fr pigtail catheters and 28-Fr chest tubes in patients with traumatic pneumothorax presenting to a level I trauma centre from July 2010 to February 2012. Patients who required emergency tube placement, those who refused and those who could not respond to pain assessment were excluded. Primary outcomes were tube-site pain, as assessed by a numerical rating scale, and total pain medication use. Secondary outcomes included the success rate of pneumothorax resolution and insertion-related complications. Forty patients were enrolled. Baseline characteristics of 20 patients in the pigtail catheter group were similar to those of 20 patients in the chest tube group. No patient had a flail chest or haemothorax. Pain scores related to chest wall trauma were similar in the two groups. Patients with a pigtail catheter had significantly lower mean(s.d.) tube-site pain scores than those with a chest tube, at baseline after tube insertion (3.2(0.6) versus 7.7(0.6); P pneumothorax, use of a 14-Fr pigtail catheter is associated with reduced pain at the site of insertion, with no other clinically important differences noted compared with chest tubes. NCT01537289 (http://clinicaltrials.gov). © 2013 BJS Society Ltd. Published by John Wiley & Sons Ltd.

Embolization of brain arteriovenous malformations using tracker catheter

International Nuclear Information System (INIS)

Kim, Sun Yong; Son, Mi Young; Jang, Jae Chun; Hwang, Mi Soo; Park, Bok Hwan

1990-01-01

With the recent advance in micro catheters, steerable guide wires, balloons, embolic materials and digital subtraction angiography (DSA), as well as technical refinements in endovascular surgery, there has been a revolution in therapeutic strategies for cerebral arteriovenous malformations (AVMs). We have performed super selective angiography and embolization with Tracker micro catheter about 12 cases of brain AVMs for therapeutic and preoperative aims. This micro catheter and guide wire provided high selectivity of feeding artery, greater maneuverability and useful for deliver various embolus materials

Spin-torque oscillation in large size nano-magnet with perpendicular magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Luo, Linqiang, E-mail: LL6UK@virginia.edu [Department of Physics, University of Virginia, Charlottesville, VA 22904 (United States); Kabir, Mehdi [Department of Electrical & Computer Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Dao, Nam; Kittiwatanakul, Salinporn [Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Cyberey, Michael [Department of Electrical Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Wolf, Stuart A. [Department of Physics, University of Virginia, Charlottesville, VA 22904 (United States); Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Institute of Defense Analyses, Alexandria, VA 22311 (United States); Stan, Mircea [Department of Electrical & Computer Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Lu, Jiwei [Department of Materials Science & Engineering, University of Virginia, Charlottesville, VA 22904 (United States)

2017-06-15

Highlights: • 500 nm size nano-pillar device was fabricated by photolithography techniques. • A magnetic hybrid structure was achieved with perpendicular magnetic fields. • Spin torque switching and oscillation was demonstrated in the large sized device. • Micromagnetic simulations accurately reproduced the experimental results. • Simulations demonstrated the synchronization of magnetic inhomogeneities. - Abstract: DC current induced magnetization reversal and magnetization oscillation was observed in 500 nm large size Co{sub 90}Fe{sub 10}/Cu/Ni{sub 80}Fe{sub 20} pillars. A perpendicular external field enhanced the coercive field separation between the reference layer (Co{sub 90}Fe{sub 10}) and free layer (Ni{sub 80}Fe{sub 20}) in the pseudo spin valve, allowing a large window of external magnetic field for exploring the free-layer reversal. A magnetic hybrid structure was achieved for the study of spin torque oscillation by applying a perpendicular field >3 kOe. The magnetization precession was manifested in terms of the multiple peaks on the differential resistance curves. Depending on the bias current and applied field, the regions of magnetic switching and magnetization precession on a dynamical stability diagram has been discussed in details. Micromagnetic simulations are shown to be in good agreement with experimental results and provide insight for synchronization of inhomogeneities in large sized device. The ability to manipulate spin-dynamics on large size devices could be proved useful for increasing the output power of the spin-transfer nano-oscillators (STNOs).

Adverse effects associated with ethanol catheter lock solutions: a systematic review.

Science.gov (United States)

Mermel, Leonard A; Alang, Neha

2014-10-01

Antimicrobial lock therapy has been widely utilized internationally for the prevention and management of intravascular catheter-related bloodstream infections. One of the agents commonly utilized for lock therapy is ethanol. However, a systematic review of adverse events associated with ethanol locks has not been published. PubMed was searched to collect articles published from May 2003 through March 2014. The bibliographies of relevant articles were also reviewed. In vitro studies of the mechanical properties of catheters after ethanol immersion have revealed changes predominantly in polyurethane catheters and to a lesser extent in silicone and Carbothane catheters. An elution of polymers from polyurethane and Carbothane catheters has been observed at the ethanol concentrations used in ethanol lock therapy. Ethanol above a concentration of 28% leads to plasma protein precipitation. Ethanol locks were associated with catheter occlusion in 11 studies and independently increased the risk of thrombosis compared with heparin lock in a randomized trial. Six studies noted abnormalities in catheter integrity, including one case leading to catheter embolization. Of note, five of these studies involved silicone catheters. Ethanol lock use was associated with systemic side effects in 10 studies and possible side effects in one additional study. Four studies noted liver function test abnormalities, predominantly transaminase elevation, related to ethanol lock use. However, a prospective study did not find any difference in the risk of doubling the transaminase level above the normal range during use of ethanol locks compared with not using an ethanol lock. The use of ethanol locks has been associated with structural changes in catheters, as well as the elution of molecules from the catheter polymers. Clinical studies have revealed systemic toxicity, increased catheter occlusion and breaches in catheter integrity. © The Author 2014. Published by Oxford University Press on

Potential In Vivo UVC Disinfection of Catheter Lumens: Estimation of the Doses Received by the Blood Flow Outside the Catheter Tip Hole

DEFF Research Database (Denmark)

Bak, Jimmy; Jørgensen, Thomas Martini; Helfmann, Jurgen

2011-01-01

hole for administration of drugs, bloods or nutrients into the bloodstream. Even if the UVC light is strongly attenuated during its propagation through the catheter tube a fraction of the UVC launched into the catheter will escape through the exit hole and irradiate the blood. We demonstrate......We have demonstrated that it is possible to launch UVC LED light into bacterial contaminated polymer tubes/catheters and disinfect the intraluminal space of these tubes. This can be achieved by UVC treatment of the catheters on a regular basis. Catheters are in the distal end equipped with an exit...... by calculations that very small effective doses are exposed to the blood (ca 10(-4) J m(-2) ). This dosage level is very low compared with UVC doses reported from other therapeutic applications. The very short residence time of the blood constituents in the irradiated volume in front of the exit hole is the main...

The effect of elastic modulus on ablation catheter contact area.

Science.gov (United States)

Camp, Jon J; Linte, Cristian A; Rettmann, Maryam E; Sun, Deyu; Packer, Douglas L; Robb, Richard A; Holmes, David R

2015-02-21

Cardiac ablation consists of navigating a catheter into the heart and delivering RF energy to electrically isolate tissue regions that generate or propagate arrhythmia. Besides the challenges of accurate and precise targeting of the arrhythmic sites within the beating heart, limited information is currently available to the cardiologist regarding intricate electrode-tissue contact, which directly impacts the quality of produced lesions. Recent advances in ablation catheter design provide intra-procedural estimates of tissue-catheter contact force, but the most direct indicator of lesion quality for any particular energy level and duration is the tissue-catheter contact area, and that is a function of not only force, but catheter pose and material elasticity as well. In this experiment, we have employed real-time ultrasound (US) imaging to determine the complete interaction between the ablation electrode and tissue to accurately estimate contact, which will help to better understand the effect of catheter pose and position relative to the tissue. By simultaneously recording tracked position, force reading and US image of the ablation catheter, the differing material properties of polyvinyl alcohol cryogel [1] phantoms are shown to produce varying amounts of tissue depression and contact area (implying varying lesion quality) for equivalent force readings. We have shown that the elastic modulus significantly affects the surface-contact area between the catheter and tissue at any level of contact force. Thus we provide evidence that a prescribed level of catheter force may not always provide sufficient contact area to produce an effective ablation lesion in the prescribed ablation time.

SU-F-T-20: Novel Catheter Lumen Recognition Algorithm for Rapid Digitization

Energy Technology Data Exchange (ETDEWEB)

Dise, J; McDonald, D; Ashenafi, M; Peng, J; Mart, C; Koch, N; Vanek, K [Medical University of South Carolina, Charleston, SC (United States)

2016-06-15

Purpose: Manual catheter recognition remains a time-consuming aspect of high-dose-rate brachytherapy (HDR) treatment planning. In this work, a novel catheter lumen recognition algorithm was created for accurate and rapid digitization. Methods: MatLab v8.5 was used to create the catheter recognition algorithm. Initially, the algorithm searches the patient CT dataset using an intensity based k-means filter designed to locate catheters. Once the catheters have been located, seed points are manually selected to initialize digitization of each catheter. From each seed point, the algorithm searches locally in order to automatically digitize the remaining catheter. This digitization is accomplished by finding pixels with similar image curvature and divergence parameters compared to the seed pixel. Newly digitized pixels are treated as new seed positions, and hessian image analysis is used to direct the algorithm toward neighboring catheter pixels, and to make the algorithm insensitive to adjacent catheters that are unresolvable on CT, air pockets, and high Z artifacts. The algorithm was tested using 11 HDR treatment plans, including the Syed template, tandem and ovoid applicator, and multi-catheter lung brachytherapy. Digitization error was calculated by comparing manually determined catheter positions to those determined by the algorithm. Results: he digitization error was 0.23 mm ± 0.14 mm axially and 0.62 mm ± 0.13 mm longitudinally at the tip. The time of digitization, following initial seed placement was less than 1 second per catheter. The maximum total time required to digitize all tested applicators was 4 minutes (Syed template with 15 needles). Conclusion: This algorithm successfully digitizes HDR catheters for a variety of applicators with or without CT markers. The minimal axial error demonstrates the accuracy of the algorithm, and its insensitivity to image artifacts and challenging catheter positioning. Future work to automatically place initial seed

SU-F-T-20: Novel Catheter Lumen Recognition Algorithm for Rapid Digitization

International Nuclear Information System (INIS)

Dise, J; McDonald, D; Ashenafi, M; Peng, J; Mart, C; Koch, N; Vanek, K

2016-01-01

Purpose: Manual catheter recognition remains a time-consuming aspect of high-dose-rate brachytherapy (HDR) treatment planning. In this work, a novel catheter lumen recognition algorithm was created for accurate and rapid digitization. Methods: MatLab v8.5 was used to create the catheter recognition algorithm. Initially, the algorithm searches the patient CT dataset using an intensity based k-means filter designed to locate catheters. Once the catheters have been located, seed points are manually selected to initialize digitization of each catheter. From each seed point, the algorithm searches locally in order to automatically digitize the remaining catheter. This digitization is accomplished by finding pixels with similar image curvature and divergence parameters compared to the seed pixel. Newly digitized pixels are treated as new seed positions, and hessian image analysis is used to direct the algorithm toward neighboring catheter pixels, and to make the algorithm insensitive to adjacent catheters that are unresolvable on CT, air pockets, and high Z artifacts. The algorithm was tested using 11 HDR treatment plans, including the Syed template, tandem and ovoid applicator, and multi-catheter lung brachytherapy. Digitization error was calculated by comparing manually determined catheter positions to those determined by the algorithm. Results: he digitization error was 0.23 mm ± 0.14 mm axially and 0.62 mm ± 0.13 mm longitudinally at the tip. The time of digitization, following initial seed placement was less than 1 second per catheter. The maximum total time required to digitize all tested applicators was 4 minutes (Syed template with 15 needles). Conclusion: This algorithm successfully digitizes HDR catheters for a variety of applicators with or without CT markers. The minimal axial error demonstrates the accuracy of the algorithm, and its insensitivity to image artifacts and challenging catheter positioning. Future work to automatically place initial seed

Percutaneous Management of Postoperative Duodenal Stump Leakage with Foley Catheter

International Nuclear Information System (INIS)

Oh, Jung Suk; Lee, Hae Giu; Chun, Ho Jong; Choi, Byung Gil; Lee, Sang Hoon; Hahn, Seong Tai; Ohm, Joon Young

2013-01-01

Purpose: This study was designed to evaluate retrospectively the safety and efficacy of the percutaneous management of duodenal stump leakage with a Foley catheter after subtotal gastrectomy. Methods: Ten consecutive patients (M:F = 9:1, median age: 64 years) were included in this retrospective study. The duodenal stump leakages were diagnosed in all the patients within a median of 10 days (range, 6–20). At first, the patients underwent percutaneous drainage on the day of or the day after confirmation of the presence of duodenal stump leakage, and then the Foley catheters were replaced at a median of 9 days (range, 6–38) after the percutaneous drainage. Results: Foley catheters were placed successfully in the duodenal lumen of all the patients under a fluoroscopic guide. No complication was observed during and after the procedures in all the patients. All of the patients started a regular diet 1 day after the Foley catheter placement. The patients were discharged at a median of 7 days (range, 5–14) after the Foley catheter placement. The catheters were removed in an outpatient clinic 10–58 days (median, 28) after the Foley catheter placement. Conclusions: Fluoroscopy-guided percutaneous Foley catheter placement may be a safe and effective treatment option for postoperative duodenal stump leakage and may allow for shorter hospital stays, earlier oral intake, and more effective control of leakage sites

Hemodialysis Access Usage Patterns in the Incident Dialysis Year and Associated Catheter-Related Complications

Science.gov (United States)

Xue, Hui; Ix, Joachim H.; Wang, Weiling; Brunelli, Steven M.; Lazarus, Michael; Hakim, Raymond; Lacson, Eduardo

2012-01-01

Background Hemodialysis(HD) access is considered a critical and actionable determinant of morbidity, with a growing literature suggesting that initial HD access type is an important marker of long term outcomes. Accordingly, we examined HD access during the incident dialysis period, focusing on infection risk and successful fistula creation over the first dialysis year. Study Design Longitudinal cohort Setting & Participants All United States adults admitted to Fresenius Medical Care North America facilities within 15 days of first maintenance dialysis session between January 1 and December 31, 2007. Predictor Vascular access type at HD initiation Outcomes Vascular access type at 90 days and at the end of the first year on HD, bloodstream infection within the first year by access type, and catheter complication rate. Results Amongst the 25,003 incident dialysis patients studied, 19,622(78.5%) initiated dialysis with a catheter, 4,151(16.6%) with a fistula, and 1,230(4.9%) with a graft. At 90 days, 14,105(69.7%) had a catheter, 4432(21.9%) patients had a fistula, and 1705(8.4%) had a graft. Functioning fistulas and grafts at dialysis initiation had first year failure rates of 10% and 15%, respectively. Grafts were seldom replaced by fistulas (3%), while 7,064 (47.6%) of all patients who initiated with a catheter alone still had only a catheter at 1 year. Overall, 3,327 (13.3%) patients had at least one positive blood culture during follow-up, with the risk being similar between fistula and graft groups, but approximately 3-fold higher in patients with a catheter (p<0.001 for either comparison). Nearly one in three catheters (32.5%) will require TPA use by median time of 41 days, with 59% requiring more than one TPA administration. Limitations Potential underestimation of bacteremia because follow-up blood culture results did not include samples sent to local laboratories. Conclusions Among a large and representative population of incident US dialysis patients

Intravascular catheter-related infection – current concepts

African Journals Online (AJOL)

2006-08-28

Aug 28, 2006 ... prevented. ... blood from both the catheter and a peripheral site, may ... Given the important role of cutaneous microflora in the ... valvular heart disease (especially prosthetic valves) and ... be explained by high arterial flow around the catheter, ... vena cava or right atrium via the cephalic and basilar veins of ...

The influence of chest tube size and position in primary spontaneous pneumothorax

DEFF Research Database (Denmark)

Riber, Sara S.; Riber, Lars P S; Olesen, Winnie H.

2017-01-01

Background: Optimal chest tube position in the pleural cavity is largely unexplored for the treatment of primary spontaneous pneumothorax (PSP). We investigated whether type, size and position of chest tubes influenced duration of treatment for PSP. Methods: A retrospective follow-up study of all...... patients admitted with PSP over a 5-year period. Traumatic, iatrogenic and secondary pneumothoraxes were excluded. Gender, age, smoking habits, type and size of chest tube used (pigtail catheter or surgical chest tube) were recorded from the patients' charts. All chest X-rays upon admittance...... and immediately following chest tube placement were retrieved and re-evaluated for size of pneumothorax (categorized into five groups) and location of the chest tube tip (categorized as upper, middle or lower third of the pleural cavity). All data were analysed in a Cox proportional hazards regression model...

Tunnel unroofing effectiveness in chronic peritoneal catheter infection

Directory of Open Access Journals (Sweden)

Lorena Carranza

2017-04-01

Full Text Available Introduction: Chronic catheter infection usually involves external Dacron cuff colonization, without its removal, antibiotic treatment proved ineffective. Catheter unroofing technique has been described as an alternative to peritoneal catheter removal. Material and methods: We analyzed the data from 13 patients retrospectively. Evolution after unroofing was evaluated, considering as treatment failure the appearance of new infection in the hole, tunnel or peritonitis associated to the same germ. Results: Between 1997-2014 years, unroofing was performed on 13 patients. Mean age-rate: 46.2 (IC 95%: 35.9 years – 56.5 years male sex 9, 69.23%. Germs: staphylococcus 7, pseudomona 2, polymicrobial 1, negative culture 3. Nine patiens healed: 69.2%; there was no statistical association among sex, age, microbiological result, previous hemodialysis use, type of catheter, surgical technique or with the surgeon who performed the procedure (p≥ 0.05. Discussion: Catheter removal implies transient transference to hemodialysis and new replacement surgery, although there is few experience with this technique, it could be an acceptable alternative, enabling a group of patients to continue with PD treatment. Conclusion: Unroofing technique proved to be beneficial in 69.2% of the cases (9 patients independently of the type of germ present, representing an acceptable treatment which avoids catheter removal, enabling the procedure to continue, and decreasing the need to employ more aggressive therapies.

Innovating urinary catheter design: An introduction to the engineering challenge.

Science.gov (United States)

Murphy, Cathy

2018-05-01

Every day, people around the world rely on intermittent and indwelling urinary catheters to manage bladder dysfunction, but the potential or actual harm caused by these devices is well-recognised. Current catheter designs can cause urinary tract infection and septicaemia, bladder and urethral trauma and indwelling devices frequently become blocked. Furthermore, the devices can severely disrupt users' lives, limiting their daily activities and can be costly to manage for healthcare providers. Despite this, little significant design innovation has taken place in the last 80 years. In this article current catheter designs and their limitations are reviewed, common catheter-associated problems are outlined and areas of design ripe for improvement proposed. The potential to relieve the individual and economic burden of catheter use is high.

The dialysis catheter and infectious peritonitis in intermittent peritoneal dialysis

DEFF Research Database (Denmark)

Kolmos, Hans Jørn; Hemmeløff Andersen, Karl Erik; Hansen, Lise

1984-01-01

118 episodes of infectious peritonitis registered among 156 patients treated with intermittent peritoneal dialysis over a 5-yr period were analysed with special reference to potential routes of infection associated with the dialysis catheter. Peritonitis was randomly distributed among the patients......, and the change of keeping free of peritonitis declined exponentially with time. The main factor determining the individual number of episodes was the total space of time, in which a patient had been wearing a dialysis catheter, whereas the number of catheter disconnections played no significant role. A relative...... preponderance of cases due to Enterobacteriaceae was noted within the first week after catheter implantation. In contrast with this, peritonitis with skin microorganisms was not associated with the implantation of catheters....

Catheter fracture of intravenous ports and its management.

Science.gov (United States)

Wu, Ching-Yang; Fu, Jui-Ying; Feng, Po-Hao; Kao, Tsung-Chi; Yu, Sheng-Yueh; Li, Hao-Jui; Ko, Po-Jen; Hsieh, Hung-Chang

2011-11-01

Intravenous ports are widely used for oncology patients. However, catheter fractures may lead to the need for re-intervention. We aimed to identify the risk factors associated with catheter fractures. Between January 1 and December 31, 2006, we retrospectively reviewed the clinical data and plain chest films of 1,505 patients implanted with an intravenous port at Chang Gung Memorial Hospital. Different vascular sites were compared using the chi-square or Fisher's exact test for categorical variables, and the t test was used for continuous variables with normal distribution; P port type Arrow French (Fr.) 8.1 (P port and catheter removal is recommended. Female gender, intravenous port implantation via the subclavian route, and the Arrow Fr. 8.1 port were found to be risk factors. Patients with these risk factors should be monitored closely to avoid catheter fractures.

Two years experience with tunneled dialysis catheters in patients requiring haemodialysis

International Nuclear Information System (INIS)

Raheem, A.; Rana, A. I.; Ramzan, M.; Shah, R. A.; Mehmood, S. N.; Naseem, S.

2014-01-01

Objective: To look for survival rate and major reasons behind the failure of tunnelled dialysis catheters in patients on haemodialysis. Methods: The retrospective study was conducted at the Department of Interventional Radiology, Shifa International Hospital, Islamabad, and comprised records of 100 consecutive subjects from a list of patients in whom tunnelled cuffed catheters were placed from February 2009 to January 2011 and were followed up for two years. Data was collected on a proforma from the hospital database and medical records of patients. SPSS 19 was used for statistical analysis. Results: Of the total 122 catheters placed in 100 patients, 49(40.16%) were lost to follow-up. Of the remaining 73(59.83%) catheters, 38(52%) had achieved their desired function, while 35(48%) failed to achieve the target duration. Among the reasons of catheter failure, infection was the commonest at 13(37.14%) with infection rate of 0.24 per 1000 catheter days. According to Kaplan Meier analysis, catheter survival rates at 60, 90 and 180 days were 89%, 77% and 64% respectively. Mean effective duration of catheter was 129+-117 days. Conclusion: Tunnelled dialysis catheters can be safely used as vascular access till the maturation of fistula and may be an alternative to Arterio-Venous Fistula or graft for long-term vascular access if indicated. (author)

An experimental study about efficacy of the drain catheters

Energy Technology Data Exchange (ETDEWEB)

Ahn, Bum Gyu; Nho, Joon Young; Woo, Hyo Cheol; Hwang, Woo Cheol; Park, Choong Ki; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

1993-09-15

Although percutaneous abscess drainage has become and accepted alternative from of therapy for selected patients with abscess, it is well known that there are several factors in the failure of adequate drainage such as pre- and post-procedural management, technique itself, various features of abscess, and selection and application of catheters. Among these factors, we made an experiment about drainage efficacy of commonly used various catheters with different viscosities of water-glycerin solution under the two different pressure gradients. The experimental values of flow rate were very lower than the calculated values. An efficacy of experimental value was 4-14%. Because the inner diameter of fittings and stopcocks was usually smaller than the inner diameter of catheters, these factors also affected the drain efficacy. Finally, we thought that it will be very helpful to the treatment of patient as well as to study about the catheter drainage, if the drain efficacy of individual catheters has been notified.

Vessel bifurcation localization based on intraoperative three-dimensional ultrasound and catheter path for image-guided catheter intervention of oral cancers.

Science.gov (United States)

Luan, Kuan; Ohya, Takashi; Liao, Hongen; Kobayashi, Etsuko; Sakuma, Ichiro

2013-03-01

We present a method to localize intraoperative target vessel bifurcations under bones for ultrasound (US) image-guided catheter interventions. A catheter path is recorded to acquire skeletons for the target vessel bifurcations that cannot be imaged by intraoperative US. The catheter path is combined with the centerlines of the three-dimensional (3D) US image to construct a preliminary skeleton. Based on the preliminary skeleton, the orientations of target vessels are determined by registration with the preoperative image and the bifurcations were localized by computing the vessel length. An accurate intraoperative vessel skeleton is obtained for correcting the preoperative image to compensate for vessel deformation. A reality check of the proposed method was performed in a phantom experiment. Reasonable results were obtained. The in vivo experiment verified the clinical workflow of the proposed method in an in vivo environment. The accuracy of the centerline length of the vessel for localizing the target artery bifurcation was 2.4mm. These results suggest that the proposed method can allow the catheter tip to stop at the target artery bifurcations and enter into the target arteries. This method can be applied for virtual reality-enhanced image-guided catheter intervention of oral cancers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Percutaneous transfermoral embolization of intracerebral arteriovenous malformation by using conventional catheter

International Nuclear Information System (INIS)

Choo, In Wook; Park, Soo Sung; Yoon, Jung Sup; Lim, Hyo Keun; Lee, Kyu Ho; Eoh, Whan

1988-01-01

Non-surgical transfermoral embolization of centrally located huge intracerebral arteriovenous malformation (AVM) was successfully performed by using conventional 6.5F DAVIS II Catheter in the department of Radiology, Kangdong Sacred Heart Hospital, May 17, 1988. The large A.V.M. was located in left basal ganglia and thalamus on brain C.T. and was supplied by multiple dilated lateral lenticulostriate arteries from left middle cerebral artery and posterior thalamoperforating artery, posterior choroidal artery from left posterior cerebral artery angiographically. The AVM was partially obliterated after embolization of lateral lenticulostriate arteries and thalamoperforating artery with P.V.A. (Polyvinyl Alcohol, ivalon) using conventional 6.5F DAVIS II angiographic catheter. There was no complication which was related to those embolization procedures except transient drowsy consciousness after embolization but it is completely recovered to the level of preembolization state after 10 hours.

Fecal containment in bedridden patients: economic impact of 2 commercial bowel catheter systems.

Science.gov (United States)

Kowal-Vem, Areta; Poulakidas, Stathis; Barnett, Barbara; Conway, Deborah; Culver, Daniel; Ferrari, Michelle; Potenza, Bruce; Koenig, Michael; Mah, John; Majewski, Mary; Morris, Linda; Powers, Jan; Stokes, Elizabeth; Tan, Michael; Salstrom, Sara-Jane; Zaletel, Cindy; Ambutas, Shirley; Casey, Kathleen; Stein, Jayne; DeSane, Mary; Berry, Kathy; Konz, Elizabeth C; Riemer, Michael R; Cullum, Malford E

2009-05-01

Fecal contamination is a major challenge in patients in acute/critical care settings that is associated with increased cost of care and supplies and with development of pressure ulcers, incontinence dermatitis, skin and soft tissue infections, and urinary tract infections. To assess the economic impact of fecal containment in bedridden patients using 2 different indwelling bowel catheters and to compare infection rates between groups. A multicenter, observational study was done at 12 US sites (7 that use catheter A, 5 that use catheter B). Patients were followed from insertion of an indwelling bowel catheter system until the patient left the acute/critical care unit or until 29 days after enrollment, whichever came first. Demographic data, frequency of bedding/dressing changes, incidence of infection, and Braden scores (risk of pressure ulcers) were recorded. The study included 146 bedridden patients (76 with catheter A, 70 with catheter B) who had similar Braden scores at enrollment. The rate of bedding/dressing changes per day differed significantly between groups (1.20 for catheter A vs 1.71 for catheter B; P = .004). According to a formula that accounted for personnel resources and laundry cycle costs, catheter A cost $13.94 less per patient per day to use than did catheter B. Catheter A was less likely than was catheter B to be removed during the observational period (P = .03). Observed infection rates were low. Catheter A may be more cost-effective than catheter B because it requires fewer unscheduled linen changes per patient day.

Implementation of the updated 2015 Commission for Hospital Hygiene and Infection Prevention (KRINKO) recommendations "Prevention and control of catheter-associated urinary tract infections" in the hospitals in Frankfurt/Main, Germany.

Science.gov (United States)

Heudorf, Ursel; Grünewald, Miriam; Otto, Ulla

2016-01-01

The Commission for Hospital Hygiene and Infection Prevention (KRINKO) updated the recommendations for the prevention of catheter-associated urinary tract infections in 2015. This article will describe the implementation of these recommendations in Frankfurt's hospitals in autumn, 2015. In two non-ICU wards of each of Frankfurt's 17 hospitals, inspections were performed using a checklist based on the new KRINKO recommendations. In one large hospital, a total of 5 wards were inspected. The inspections covered the structure and process quality (operating instructions, training, indication, the placement and maintenance of catheters) and the demonstration of the preparation for insertion of a catheter using an empty bed and an imaginary patient, or insertion in a model. Operating instructions were available in all hospital wards; approximately half of the wards regularly performed training sessions. The indications were largely in line with the recommendations of the KRINKO. Alternatives to urinary tract catheters were available and were used more often than the urinary tract catheters themselves (15.9% vs. 13.5%). In accordance with the recommendations, catheters were placed without antibiotic prophylaxis or the instillation of antiseptic or antimicrobial substances or catheter flushing solutions. The demonstration of catheter placement was conscientiously performed. Need for improvement was seen in the daily documentation and the regular verification of continuing indication for a urinary catheter, as well as the omission of regular catheter change. Overall, the recommendations of the KRINKO on the prevention of catheter-associated urinary tract infections were adequately implemented. However, it cannot be ruled out that in situations with time pressure and staff shortage, the handling of urinary tract catheters may be of lower quality than that observed during the inspections, when catheter insertion was done by two nurses. Against this background, a sufficient

Safety and efficacy of percutaneous cecostomy/colostomy for treatment of large bowel obstruction in adults with cancer.

Science.gov (United States)

Tewari, Sanjit O; Getrajdman, George I; Petre, Elena N; Sofocleous, Constantinos T; Siegelbaum, Robert H; Erinjeri, Joseph P; Weiser, Martin R; Thornton, Raymond H

2015-02-01

To assess the safety and efficacy of image-guided percutaneous cecostomy/colostomy (PC) in the management of colonic obstruction in patients with cancer. Twenty-seven consecutive patients underwent image-guided PC to relieve large bowel obstruction at a single institution between 2000 and 2012. Colonic obstruction was the common indication. Patient demographics, diagnosis, procedural details, and outcomes including maximum colonic distension (MCD; ie, greatest transverse measurement of the colon on radiograph or scout computed tomography image) were recorded and retrospectively analyzed. Following PC, no patient experienced colonic perforation; pain was relieved in 24 of 27 patients (89%). Catheters with tip position in luminal gas rather than mixed stool/gas or stool were associated with greater decrease in MCD (-40%, -12%, and -16%, respectively), with the difference reaching statistical significance (P = .002 and P = .013, respectively). Catheter size was not associated with change in MCD (P = .978). Catheters were successfully removed from six of nine patients (67%) with functional obstructions and two of 18 patients (11%) with mechanical obstructions. One patient underwent endoscopic stent placement after catheter removal. Three patients required diverting colostomy after PC, and their catheters were removed at the time of surgery. One major complication (3.7%; subcutaneous emphysema, pneumomediastinum, and sepsis) occurred 8 days after PC and was successfully treated with cecostomy exchange, soft-tissue drainage, and intravenous antibiotic therapy. Image-guided PC is safe and effective for management of functional and mechanical bowel obstruction in patients with cancer. For optimal efficacy, catheters should terminate within luminal gas. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

Percutaneous catheter drainage of intrapulmonary fluid collection

International Nuclear Information System (INIS)

Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H.

1994-01-01

With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment

Percutaneous catheter drainage of intrapulmonary fluid collection

Energy Technology Data Exchange (ETDEWEB)

Park, E. D.; Kim, H. J.; Choi, P. Y.; Jung, S. H. [Gyeongsang National University Hospital, Chinju (Korea, Republic of)

1994-01-15

With the success of percutaneous abdominal abscess drainage, attention is now being focused on the use of similar techniques in the thorax. We studied to evaluate the effect of percutaneous drainage in parenchymal fluid collections in the lungs. We performed percutaneous drainage of abscesses and other parenchymal fluid collections of the lungs in 15 patients. All of the procedures were performed under the fluoroscopic guidance with an 18-gauge Seldinger needle and coaxial technique with a 8-10F drainage catheter. Among 10 patients with lung abscess, 8 patients improved by percutaneous catheter drainage. In one patient, drainage was failed by the accidental withdrawal of the catheter before complete drainage. One patient died of sepsis 5 hours after the procedure. Among three patients with complicated bulla, successful drainage was done in two patients, but in the remaining patient, the procedure was failed. In one patient with intrapulmonary bronchogenic cyst, the drainage was not successful due to the thick internal contents. In one patient with traumatic hematoma, after the drainage of old blood clots, the signs of infection disappeared. Overally, of 14 patients excluding one who died, 11 patients improved with percutaneous catheter drainage and three patients did not. There were no major complications during and after the procedure. We conclude that percutaneous catheter drainage is effective and safe procedure for the treatment of parenchymal fluid collections of the lung in patients unresponsive to the medical treatment.

Integrative Sparse K-Means With Overlapping Group Lasso in Genomic Applications for Disease Subtype Discovery.

Science.gov (United States)

Huo, Zhiguang; Tseng, George

2017-06-01

Cancer subtypes discovery is the first step to deliver personalized medicine to cancer patients. With the accumulation of massive multi-level omics datasets and established biological knowledge databases, omics data integration with incorporation of rich existing biological knowledge is essential for deciphering a biological mechanism behind the complex diseases. In this manuscript, we propose an integrative sparse K -means (is- K means) approach to discover disease subtypes with the guidance of prior biological knowledge via sparse overlapping group lasso. An algorithm using an alternating direction method of multiplier (ADMM) will be applied for fast optimization. Simulation and three real applications in breast cancer and leukemia will be used to compare is- K means with existing methods and demonstrate its superior clustering accuracy, feature selection, functional annotation of detected molecular features and computing efficiency.

Large-scale ocean connectivity and planktonic body size

KAUST Repository

Villarino, Ernesto; Watson, James R.; Jö nsson, Bror; Gasol, Josep M.; Salazar, Guillem; Acinas, Silvia G.; Estrada, Marta; Massana, Ramó n; Logares, Ramiro; Giner, Caterina R.; Pernice, Massimo C.; Olivar, M. Pilar; Citores, Leire; Corell, Jon; Rodrí guez-Ezpeleta, Naiara; Acuñ a, José Luis; Molina-Ramí rez, Axayacatl; Gonzá lez-Gordillo, J. Ignacio; Có zar, André s; Martí , Elisa; Cuesta, José A.; Agusti, Susana; Fraile-Nuez, Eugenio; Duarte, Carlos M.; Irigoien, Xabier; Chust, Guillem

2018-01-01

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

Large-scale ocean connectivity and planktonic body size

KAUST Repository

Villarino, Ernesto

2018-01-04

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

Dialysis catheter-related superior vena cava syndrome with patent vena cava: Long term efficacy of unilateral viatorr stent-graft avoiding catheter manipulation

Energy Technology Data Exchange (ETDEWEB)

Quaretti, Pietro; Galli, Franco; Maramarco, Lorenzo Paplo; Corti, Riccardo; Leati, Giovanni; Fiorina, Ilaria; Maestri, Marcello [IRCCS Policlinico San Matteo Foundation, Pavia (Italy)

2014-06-15

Central venous catheters are the most frequent causes of benign central vein stenosis. We report the case of a 79-year-old woman on hemodialysis through a twin catheter in the right internal jugular vein, presenting with superior vena cava (SVC) syndrome with patent SVC. The clinically driven endovascular therapy was conducted to treat the venous syndrome with a unilateral left brachiocephalic stent-graft without manipulation of the well-functioning catheter. The follow-up was uneventful until death 94 months later.

Dialysis catheter-related superior vena cava syndrome with patent vena cava: Long term efficacy of unilateral viatorr stent-graft avoiding catheter manipulation

International Nuclear Information System (INIS)

Quaretti, Pietro; Galli, Franco; Maramarco, Lorenzo Paplo; Corti, Riccardo; Leati, Giovanni; Fiorina, Ilaria; Maestri, Marcello

2014-01-01

Central venous catheters are the most frequent causes of benign central vein stenosis. We report the case of a 79-year-old woman on hemodialysis through a twin catheter in the right internal jugular vein, presenting with superior vena cava (SVC) syndrome with patent SVC. The clinically driven endovascular therapy was conducted to treat the venous syndrome with a unilateral left brachiocephalic stent-graft without manipulation of the well-functioning catheter. The follow-up was uneventful until death 94 months later.

Multiple Coaxial Catheter System for Reliable Access in Interventional Stroke Therapy

International Nuclear Information System (INIS)

Kulcsar, Zsolt; Yilmaz, Hasan; Bonvin, Christophe; Lovblad, Karl O.; Ruefenacht, Daniel A.

2010-01-01

In some patients with acute cerebral vessel occlusion, navigating mechanical thrombectomy systems is difficult due to tortuous anatomy of the aortic arch, carotid arteries, or vertebral arteries. Our purpose was to describe a multiple coaxial catheter system used for mechanical revascularization that helps navigation and manipulations in tortuous vessels. A triple or quadruple coaxial catheter system was built in 28 consecutive cases presenting with acute ischemic stroke. All cases were treated by mechanical thrombectomy with the Penumbra System. In cases of unsuccessful thrombo-aspiration, additional thrombolysis or angioplasty with stent placement was used for improving recanalization. The catheter system consisted of an outermost 8-Fr and an intermediate 6-Fr guiding catheter, containing the inner Penumbra reperfusion catheters. The largest, 4.1-Fr, reperfusion catheter was navigated over a Prowler Select Plus microcatheter. The catheter system provided access to reach the cerebral lesions and provided stability for the mechanically demanding manipulations of thromboaspiration and stent navigation in all cases. Apart from their mechanical role, the specific parts of the system could also provide access to different types of interventions, like carotid stenting through the 8-Fr guiding catheter and intracranial stenting and thrombolysis through the Prowler Select Plus microcatheter. In this series, there were no complications related to the catheter system. In conclusion, building up a triple or quadruple coaxial system proved to be safe and efficient in our experience for the mechanical thrombectomy treatment of acute ischemic stroke.

Septic Thrombophlebitis of the Cephalic Vein Caused by a Peripherally Inserted Venous Catheter

Directory of Open Access Journals (Sweden)

M Mirmohammadsadeghi

2005-07-01

Full Text Available Septic thrombophlebitis of a vein is a rare but life-threatening complication of an intravascular (IV catheter placed percutaneously in the veins. Most published clinical experiences with IV catheters, mainly in the outpatient settings, have reported very low rates of catheter-related bloodstream infection compared to rates with central venous catheters placed in a subclavian or internal jugular vein. Most of the complications reported with IV catheters have been non-infectious, particularly sterile phlebitis or thrombosis. We report a case of cephalic vein suppurative thrombophlebitis from an intravascular catheter and offer guidelines for diagnosis and management of this complication. Key words: Septic thrombophlebitis, Intravascular catheter, Suppurative thrombophlebitis

Radiologic interventional retrieval of retained central venous catheter fragment in prematurity: case report

International Nuclear Information System (INIS)

Park, Jee Won; Jo, Jung Hyun; Park, Byeong Ho

2007-01-01

The fracture of a central venous catheter is a rare but potentially serious complication. Moreover, removal of the broken catheter pieces is considerably challenging, especially for premature infants. We report 3 case studies of the percutaneous transcatheter retrieval of broken catheter parts in 3 premature infants. We confirmed the location of the catheter fragments via a DSA venogram with diluted contrast media. Using the minimum amount of contrast, and extreme caution, we made certain no contrast-induced nephrotoxicity of air embolism occurred during catheter manipulation. In addition, when the broken fragment was curled or attached to the cardiac wall, we used a hook-shaped catheter to facilitate the capturing of the catheter with a loopsnare. This report demonstrates the feasibility of removing a retained catheter fragment in a premature infant using a percutaneous transcatheter approach

Estimated spatial requirements of the medium- to large-sized ...

African Journals Online (AJOL)

Conservation planning in the Cape Floristic Region (CFR) of South Africa, a recognised world plant diversity hotspot, required information on the estimated spatial requirements of selected medium- to large-sized mammals within each of 102 Broad Habitat Units (BHUs) delineated according to key biophysical parameters.

Foley Catheter versus Vaginal Misoprostol for Labour Induction

Directory of Open Access Journals (Sweden)

Nasreen Noor

2015-01-01

Full Text Available Objectives. To compare the efficacy and safety of intravaginal misoprostol with transcervical Foley catheter for labour induction. Material and Methods. One hundred and four women with term gestation, with Bishop score < 4, and with various indications for labour induction were randomly divided into two groups. In Group I, 25 μg of misoprostol tablet was placed intravaginally, 4 hourly up to maximum 6 doses. In Group II, Foley catheter 16F was placed through the internal os of the cervix under aseptic condition and then inflated with 50 cc of sterile saline. Statistical analysis was done using SPSS software. Results. The induction to delivery interval was 14.03 ± 7.61 hours versus 18.40 ± 8.02 hours (p<0.01. The rate of vaginal delivery was 76.7% versus 56.8% in misoprostol and transcervical Foley catheter group, respectively. Uterine hyperstimulation was more common with misoprostol. Neonatal outcome was similar in both the groups. Conclusion. Intravaginal misoprostol is associated with a shorter induction to delivery interval as compared to Foley’s catheter and it increases the rate of vaginal delivery in cases of unripe cervix at term. Transcervical Foley catheter is associated with a lower incidence of uterine hyperstimulation during labour.

Evaluation of a respiratory assist catheter that uses an impeller within a hollow fiber membrane bundle.

Science.gov (United States)

Mihelc, Kevin M; Frankowski, Brian J; Lieber, Samuel C; Moore, Nathan D; Hattler, Brack G; Federspiel, William J

2009-01-01

Respiratory assist using an intravenous catheter may be a potential treatment for patients suffering from acute or acute-on-chronic lung failure. The objective of this study was to evaluate a novel respiratory catheter that uses an impeller within the fiber bundle to enhance gas exchange efficiency, thus requiring a smaller fiber bundle and insertional size (25 Fr) and permitting simple percutaneous insertion. Bench testing of gas exchange in deionized water was used to evaluate eight impeller designs. The three best performing impeller designs were evaluated in acute studies in four calves (122 + or - 10 kg). Gas exchange increased significantly with increasing impeller rotation rate. The degree of enhancement varied with impeller geometry. The maximum gas exchange efficiency (exchange per unit surface area) for the catheter with the best performing impeller was 529 + or - 20 ml CO(2)/min/m(2) and 513 + or - 21 ml CO(2)/min/m(2) for bench and animal studies, respectively, at a rotation rate of 20,000 rpm. Absolute CO(2) exchange was 37 and 36 ml CO(2)/min, respectively. Active mixing by rotating impellers produced 70% higher gas exchange efficiency than pulsating balloon catheters. The sensitivity of gas exchange to impeller design suggests that further improvements can be made by computational fluid dynamics-based optimization of the impeller.

A Novel SCCA Approach via Truncated ℓ1-norm and Truncated Group Lasso for Brain Imaging Genetics.

Science.gov (United States)

Du, Lei; Liu, Kefei; Zhang, Tuo; Yao, Xiaohui; Yan, Jingwen; Risacher, Shannon L; Han, Junwei; Guo, Lei; Saykin, Andrew J; Shen, Li

2017-09-18

Brain imaging genetics, which studies the linkage between genetic variations and structural or functional measures of the human brain, has become increasingly important in recent years. Discovering the bi-multivariate relationship between genetic markers such as single-nucleotide polymorphisms (SNPs) and neuroimaging quantitative traits (QTs) is one major task in imaging genetics. Sparse Canonical Correlation Analysis (SCCA) has been a popular technique in this area for its powerful capability in identifying bi-multivariate relationships coupled with feature selection. The existing SCCA methods impose either the ℓ 1 -norm or its variants to induce sparsity. The ℓ 0 -norm penalty is a perfect sparsity-inducing tool which, however, is an NP-hard problem. In this paper, we propose the truncated ℓ 1 -norm penalized SCCA to improve the performance and effectiveness of the ℓ 1 -norm based SCCA methods. Besides, we propose an efficient optimization algorithms to solve this novel SCCA problem. The proposed method is an adaptive shrinkage method via tuning τ . It can avoid the time intensive parameter tuning if given a reasonable small τ . Furthermore, we extend it to the truncated group-lasso (TGL), and propose TGL-SCCA model to improve the group-lasso-based SCCA methods. The experimental results, compared with four benchmark methods, show that our SCCA methods identify better or similar correlation coefficients, and better canonical loading profiles than the competing methods. This demonstrates the effectiveness and efficiency of our methods in discovering interesting imaging genetic associations. The Matlab code and sample data are freely available at http://www.iu.edu/∼shenlab/tools/tlpscca/ . © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Implementation of the updated 2015 Commission for Hospital Hygiene and Infection Prevention (KRINKO recommendations “Prevention and control of catheter-associated urinary tract infections” in the hospitals in Frankfurt/Main, Germany

Directory of Open Access Journals (Sweden)

Heudorf, Ursel

2016-06-01

Full Text Available Aim: The Commission for Hospital Hygiene and Infection Prevention (KRINKO updated the recommendations for the prevention of catheter-associated urinary tract infections in 2015. This article will describe the implementation of these recommendations in Frankfurt’s hospitals in autumn, 2015.Material and methods: In two non-ICU wards of each of Frankfurt’s , inspections were performed using a checklist based on the new KRINKO recommendations. In one large hospital, a total of were inspected. The inspections covered the structure and process quality (operating instructions, training, indication, the placement and maintenance of catheters and the demonstration of the preparation for insertion of a catheter using an empty bed and an imaginary patient, or insertion in a model.Results: Operating instructions were available in all hospital wards; approximately half of the wards regularly performed training sessions. The indications were largely in line with the recommendations of the KRINKO. Alternatives to urinary tract catheters were available and were used more often than the urinary tract catheters themselves (15.9% vs. 13.5%. In accordance with the recommendations, catheters were placed without antibiotic prophylaxis or the instillation of antiseptic or antimicrobial substances or catheter flushing solutions. The demonstration of catheter placement was conscientiously performed. Need for improvement was seen in the daily documentation and the regular verification of continuing indication for a urinary catheter, as well as the omission of regular catheter change.Conclusion: Overall, the recommendations of the KRINKO on the prevention of catheter-associated urinary tract infections were adequately implemented. However, it cannot be ruled out that in situations with time pressure and staff shortage, the handling of urinary tract catheters may be of lower quality than that observed during the inspections, when catheter insertion was done by two

Comparison of complications between pediatric peripherally inserted central catheter placement techniques

International Nuclear Information System (INIS)

Dasgupta, Niloy; Lungren, Matthew P.; Patel, Manish N.; Racadio, John M.; Johnson, Neil D.

2016-01-01

Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique. To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center. We retrospectively reviewed all PICC placements at a single institution over a 4-year period. We reviewed patient records for demographic data, PICC placement technique, catheter size and number of lumens, and the incidence of complications (i.e. multiple attempted puncture sites, phlebitis and vessel thrombosis). We analyzed complication rates between two placement techniques using a chi-square test. We identified 8,816 successful PICC placements, 4,749 (53.9%) in males and 4,067 (46.1%) in females. The average age of the patients for which a line was placed was 5.6 years (range 1 day to 45 years). A direct sheathed needle puncture technique was used in 8,362 (94.9%) placements and a modified Seldinger technique was used in 454 (5.1%). Complications occurred in 312 (3.7%) of direct sheathed needle puncture placements versus 17 (3.7%) of modified Seldinger placements (P = 0.99). Multiple puncture sites were required in 175 (2.1%) attempted direct sheathed needle puncture placements compared with 8 (1.7%) attempted modified Seldinger placements (P = 0.63). Phlebitis occurred in 94 (1.1%) direct sheathed needle puncture lines versus 5 (1.1%) modified Seldinger placed lines (P = 0.96). Vessel thrombosis occurred in 43 (0.5%) direct sheathed needle puncture lines versus 4 (0.9%) modified Seldinger placed lines (P = 0.30). The direct peel-away sheathed needle vessel puncture technique and the modified Seldinger technique used to place PICC lines in children have similar complication rates. (orig.)

Comparison of complications between pediatric peripherally inserted central catheter placement techniques

Energy Technology Data Exchange (ETDEWEB)

Dasgupta, Niloy; Lungren, Matthew P. [Lucile Packard Children' s Hospital Stanford, Department of Radiology, Palo Alto, CA (United States); Patel, Manish N.; Racadio, John M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

2016-09-15

Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique. To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center. We retrospectively reviewed all PICC placements at a single institution over a 4-year period. We reviewed patient records for demographic data, PICC placement technique, catheter size and number of lumens, and the incidence of complications (i.e. multiple attempted puncture sites, phlebitis and vessel thrombosis). We analyzed complication rates between two placement techniques using a chi-square test. We identified 8,816 successful PICC placements, 4,749 (53.9%) in males and 4,067 (46.1%) in females. The average age of the patients for which a line was placed was 5.6 years (range 1 day to 45 years). A direct sheathed needle puncture technique was used in 8,362 (94.9%) placements and a modified Seldinger technique was used in 454 (5.1%). Complications occurred in 312 (3.7%) of direct sheathed needle puncture placements versus 17 (3.7%) of modified Seldinger placements (P = 0.99). Multiple puncture sites were required in 175 (2.1%) attempted direct sheathed needle puncture placements compared with 8 (1.7%) attempted modified Seldinger placements (P = 0.63). Phlebitis occurred in 94 (1.1%) direct sheathed needle puncture lines versus 5 (1.1%) modified Seldinger placed lines (P = 0.96). Vessel thrombosis occurred in 43 (0.5%) direct sheathed needle puncture lines versus 4 (0.9%) modified Seldinger placed lines (P = 0.30). The direct peel-away sheathed needle vessel puncture technique and the modified Seldinger technique used to place PICC lines in children have similar complication rates. (orig.)

The use of peridural catheter in the treatment of chronic malignant pain in the abdomen: Case report (peridural catheter in the treatment chronic pain

Directory of Open Access Journals (Sweden)

Palibrk Ivan

2017-01-01

Full Text Available Introduction: Chronic pain in the abdomen occurs as a consequence of malignancy in these parts of the body, surgical, of radiological and chemotherapy treatments. It may also be as a result of relapse of the basic process. Non-invasive therapy of oral and transdermal analgesic was successful for some time, where necessary applies and epidural catheter. Case Report: The patient had a diagnosis of chronic postoperative pain malignant etiology. He is already used transdermal fentanyl and Nonsteroidal Anti-Inflammatory Drugs, but without success (VAS score 8-10. We increased doses of analgesics, but without success. In order of pain therapy, peridural catheter placed in the level L3 - L4. 5 ml of a solution of 8 ml of 0.25% bupivacaine, 2 ml (100 micrograms of fentanyl and 10 ml of saline was administered every 6 hours through epidural catheter. The former chronic non-invasive treatment of pain did not stop. The first three to five days of pain relief was quite satisfactory in this way. Then the pain intensified but the peridural catheter had to be removed due to local infection. New peridural catheter was placed in the level L2 -L3. Then, 5 ml of the solution: of 8 ml 0,25% bupivacaine, 2 ml (100 micrograms of fentanyl and 10 ml of saline is administered through peridural catheter. Peridural catheter was total used for 45 days. We had a need for more and more frequently administering analgesics through a catheter during use. The patient was using transdermal fentanyl and Nonsteroidal Anti-Inflammatory Drugs, all the time. The patient soon died due to progression of the underlying disease. Conclusion: After long-term administration of opioids, it is necessary to change the type and route of administration of the drug to achieve the success of the therapy. In this case it was the use of analgesics and local anesthetics through the peridural catheter.

DESIGN AND DEVELOPMENT OF A LARGE SIZE NON-TRACKING SOLAR COOKER

Directory of Open Access Journals (Sweden)

N. M. NAHAR

2009-09-01

Full Text Available A large size novel non-tracking solar cooker has been designed, developed and tested. The cooker has been designed in such a way that the width to length ratio for reflector and glass window is about 4 so that maximum radiation falls on the glass window. This has helped in eliminating azimuthal tracking that is required in simple hot box solar cooker towards the Sun every hour because the width to length ratio of reflector is 1. It has been found that stagnation temperatures were 118.5oC and 108oC in large size non-tracking solar cooker and hot box solar cooker respectively. It takes about 2 h for soft food and 3 h for hard food. The cooker is capable of cooking 4.0 kg of food at a time. The efficiency of the large size non-tracking solar cooker has been found to be 27.5%. The cooker saves 5175 MJ of energy per year. The cost of the cooker is Rs. 10000.00 (1.0 US$ = Rs. 50.50. The payback period has been calculated by considering 10% annual interest, 5% maintenance cost and 5% inflation in fuel prices and maintenance cost. The payback period is least, i.e. 1.58 yr., with respect to electricity and maximum, i.e. 4.89 yr., with respect to kerosene. The payback periods are in increasing order with respect to fuel: electricity, coal, firewood, liquid petroleum gas, and kerosene. The shorter payback periods suggests that the use of large size non-tracking solar cooker is economical.

Hemodialysis Catheter Heat Transfer for Biofilm Prevention and Treatment.

Science.gov (United States)

Richardson, Ian P; Sturtevant, Rachael; Heung, Michael; Solomon, Michael J; Younger, John G; VanEpps, J Scott

2016-01-01

Central line-associated bloodstream infections (CLABSIs) are not easily treated, and many catheters (e.g., hemodialysis catheters) are not easily replaced. Biofilms (the source of infection) on catheter surfaces are notoriously difficult to eradicate. We have recently demonstrated that modest elevations of temperature lead to increased staphylococcal susceptibility to vancomycin and significantly soften the biofilm matrix. In this study, using a combination of microbiological, computational, and experimental studies, we demonstrate the efficacy, feasibility, and safety of using heat as an adjuvant treatment for infected hemodialysis catheters. Specifically, we show that treating with heat in the presence of antibiotics led to additive killing of Staphylococcus epidermidis with similar trends seen for Staphylococcus aureus and Klebsiella pneumoniae. The magnitude of temperature elevation required is relatively modest (45-50°C) and similar to that used as an adjuvant to traditional cancer therapy. Using a custom-designed benchtop model of a hemodialysis catheter, positioned with tip in the human vena cava as well as computational fluid dynamic simulations, we demonstrate that these temperature elevations are likely achievable in situ with minimal increased in overall blood temperature.

Infection and natural history of emergency department-placed central venous catheters.

Science.gov (United States)

LeMaster, Christopher H; Schuur, Jeremiah D; Pandya, Darshan; Pallin, Daniel J; Silvia, Jennifer; Yokoe, Deborah; Agrawal, Ashish; Hou, Peter C

2010-11-01

Central line-associated bloodstream infection (CLABSI, hereafter referred to in this paper as "bloodstream infection") is a leading cause of hospital-acquired infection. To our knowledge, there are no previously published studies designed to determine the rate of bloodstream infection among central venous catheters placed in the emergency department (ED). We design a retrospective chart review methodology to determine bloodstream infection and duration of catheterization for central venous catheters placed in the ED. Using hospital infection control, administrative, and ED billing databases, we identified patients with central venous catheters placed in the ED between January 1, 2007, and December 31, 2008, at one academic, urban ED with an annual census of 57,000. We performed a structured, explicit chart review to determine duration of catheterization and confirm bloodstream infection. We screened 4,251 charts and identified 656 patients with central venous catheters inserted in the ED, 3,622 catheter-days, and 7 bloodstream infections. The rate of bloodstream infection associated with central venous catheters placed in the ED was 1.93 per 1,000 catheter-days (95% confidence interval 0.50 to 3.36). The mean duration of catheterization was 5.5 days (median 4; range 1 to 29 days). Among infected central venous catheters, the mean duration of catheterization was 8.6 days (median 7; range 2 to 19 days). A total of 667 central venous catheters were placed in the internal jugular (392; 59%), subclavian (145; 22%), and femoral (130; 19%) veins. The sensitivity of using ED procedural billing code for identifying ED-placed central venous catheters among patients subsequently admitted to any ICU was 74.9% (95% confidence interval 71.4% to 78.3%). The rate of ED bloodstream infection at our institution is similar to current rates in ICUs. Central venous catheters placed in the ED remain in admitted patients for a substantial period. Copyright © 2010 American College of

Detection of electrophysiology catheters in noisy fluoroscopy images

NARCIS (Netherlands)

Franken, E.M.; Rongen, P.M.J.; Almsick, van M.A.; Haar Romenij, ter B.M.

2006-01-01

Cardiac catheter ablation is a minimally invasive medical procedure to treat patients with heart rhythm disorders. It is useful to know the positions of the catheters and electrodes during the intervention, e.g. for the automatization of cardiac mapping. Our goal is therefore to develop a robust

Association of thrombophilia and catheter-associated thrombosis in children: a systematic review and meta-analysis.

Science.gov (United States)

Neshat-Vahid, S; Pierce, R; Hersey, D; Raffini, L J; Faustino, E V S

2016-09-01

Essentials It is unclear if thrombophilia increases the risk of catheter-associated thrombosis in children. We conducted a meta-analysis on thrombophilia and pediatric catheter-associated thrombosis. Presence of ≥1 trait confers additional risk of venous thrombosis in children with catheters. Limitations of included studies preclude us from recommending routine thrombophilia testing. Background The association between thrombophilia and deep vein thrombosis (DVT) associated with central venous catheter (CVC) use, the most important pediatric risk factor for thrombosis, is unclear in children. Pediatric studies with small sample sizes have reported conflicting results. We sought to evaluate whether, among children with CVCs, thrombophilia increases the risk of CVC-associated DVT (CADVT). Materials and methods We systematically searched MEDLINE, EMBASE, the Web of Science, the Cochrane Central Register for Controlled Trials, PubMed and reference lists for controlled studies published from the inception of the database until September 2015. Included were studies of children aged levels and the FV Leiden mutation had an increased prevalence of CADVT. The association with thrombophilia seemed to be stronger for symptomatic CADVT (pOR 6.71; 95% CI 1.93-23.37) than for asymptomatic CADVT (pOR 2.14; 95% CI 1.10-4.18). Conclusions On the basis of the low prevalence of specific traits, the relatively weak association with CADVT, and the limitations of the included studies, we cannot recommend routine testing of thrombophilias in children with CADVT. © 2016 International Society on Thrombosis and Haemostasis.

Development of a force-reflecting robotic platform for cardiac catheter navigation.

Science.gov (United States)

Park, Jun Woo; Choi, Jaesoon; Pak, Hui-Nam; Song, Seung Joon; Lee, Jung Chan; Park, Yongdoo; Shin, Seung Min; Sun, Kyung

2010-11-01

Electrophysiological catheters are used for both diagnostics and clinical intervention. To facilitate more accurate and precise catheter navigation, robotic cardiac catheter navigation systems have been developed and commercialized. The authors have developed a novel force-reflecting robotic catheter navigation system. The system is a network-based master-slave configuration having a 3-degree of freedom robotic manipulator for operation with a conventional cardiac ablation catheter. The master manipulator implements a haptic user interface device with force feedback using a force or torque signal either measured with a sensor or estimated from the motor current signal in the slave manipulator. The slave manipulator is a robotic motion control platform on which the cardiac ablation catheter is mounted. The catheter motions-forward and backward movements, rolling, and catheter tip bending-are controlled by electromechanical actuators located in the slave manipulator. The control software runs on a real-time operating system-based workstation and implements the master/slave motion synchronization control of the robot system. The master/slave motion synchronization response was assessed with step, sinusoidal, and arbitrarily varying motion commands, and showed satisfactory performance with insignificant steady-state motion error. The current system successfully implemented the motion control function and will undergo safety and performance evaluation by means of animal experiments. Further studies on the force feedback control algorithm and on an active motion catheter with an embedded actuation mechanism are underway. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Relative incidence of phlebitis associated with peripheral intravenous catheters in the lower versus upper extremities.

Science.gov (United States)

Benaya, A; Schwartz, Y; Kory, R; Yinnon, A M; Ben-Chetrit, E

2015-05-01

Peripheral venous access in elderly, hospitalized patients is often challenging. The usual alternative is insertion of a central venous catheter, with associated risk for complications. The purpose of this investigation was to determine the relative incidence of phlebitis secondary to lower as compared to upper extremity intravenous catheters (IVCs) and associated risk factors. A non-randomized, observational, cohort-controlled study was carried out. Consecutive patients receiving a lower extremity IVC were enrolled and compared with patients receiving an upper extremity IVC. Patients were followed from insertion until removal of the IVC. The major endpoint was phlebitis. The incidence of phlebitis secondary to upper extremity IVCs was 3/50 (6 %) compared to 5/53 (9.4 %) in lower extremity IVCs (χ(2) Yates = 0.08, p = 0.776). Age, gender, obesity, diabetes mellitus, site (arm versus leg, left versus right), and size of needle were not found to be risk factors for phlebitis according to univariate analysis. None of the patients developed bloodstream infection. In elderly patients with poor venous access, lower extremity IVCs are a reasonable and low-risk alternative to central venous catheters.

Intravascular (catheter) MR imaging

International Nuclear Information System (INIS)

Cohen, A.M.; Hurst, G.C.; Katz, D.E.; Dverk, J.L.; Wiesen, E.J.; Czerski, L.W.; Malaya, R.; Bellon, E.M.

1989-01-01

Intravascular MR probes allow excellent spatial resolution and have the potential to detect arterial wall microstructure. Ultrasonic intravascular probes suggest that detailed morphologic information can assist clinical decision making. Catheter MR probes of 2--7 mm outside diameter (OD) were built of copper wire, Teflon, and parts from standard commercial catheters. The probes were connected to the surface coil receiver input of our Picker VISTA 2055HP 1.5-T imaging system. The extant (linear) body coil was used for transmit. Phantoms were constructed of coaxial glass MR tubes, filled with doped water. Watanabe rabbit aorta and human autopsy iliac artery specimens were examined within 4 hours of excision or stored by freezing. In vivo iliac arteries in dogs under general anesthesia were imaged, with percutaneous placement of the probe. Results are presented

Performance evaluation of a robot-assisted catheter operating system with haptic feedback.

Science.gov (United States)

Song, Yu; Guo, Shuxiang; Yin, Xuanchun; Zhang, Linshuai; Hirata, Hideyuki; Ishihara, Hidenori; Tamiya, Takashi

2018-06-20

In this paper, a novel robot-assisted catheter operating system (RCOS) has been proposed as a method to reduce physical stress and X-ray exposure time to physicians during endovascular procedures. The unique design of this system allows the physician to apply conventional bedside catheterization skills (advance, retreat and rotate) to an input catheter, which is placed at the master side to control another patient catheter placed at the slave side. For this purpose, a magnetorheological (MR) fluids-based master haptic interface has been developed to measure the axial and radial motions of an input catheter, as well as to provide the haptic feedback to the physician during the operation. In order to achieve a quick response of the haptic force in the master haptic interface, a hall sensor-based closed-loop control strategy is employed. In slave side, a catheter manipulator is presented to deliver the patient catheter, according to position commands received from the master haptic interface. The contact forces between the patient catheter and blood vessel system can be measured by designed force sensor unit of catheter manipulator. Four levels of haptic force are provided to make the operator aware of the resistance encountered by the patient catheter during the insertion procedure. The catheter manipulator was evaluated for precision positioning. The time lag from the sensed motion to replicated motion is tested. To verify the efficacy of the proposed haptic feedback method, the evaluation experiments in vitro are carried out. The results demonstrate that the proposed system has the ability to enable decreasing the contact forces between the catheter and vasculature.

Catheter Removal versus Retention in the Management of Catheter-Associated Enterococcal Bloodstream Infections

Directory of Open Access Journals (Sweden)

Jonas Marschall

2013-01-01

Full Text Available BACKGROUND: Enterococci are an important cause of central venous catheter (CVC-associated bloodstream infections (CA-BSI. It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI.

Cost-effectiveness of a central venous catheter care bundle.

Directory of Open Access Journals (Sweden)

Kate A Halton

Full Text Available BACKGROUND: A bundled approach to central venous catheter care is currently being promoted as an effective way of preventing catheter-related bloodstream infection (CR-BSI. Consumables used in the bundled approach are relatively inexpensive which may lead to the conclusion that the bundle is cost-effective. However, this fails to consider the nontrivial costs of the monitoring and education activities required to implement the bundle, or that alternative strategies are available to prevent CR-BSI. We evaluated the cost-effectiveness of a bundle to prevent CR-BSI in Australian intensive care patients. METHODS AND FINDINGS: A Markov decision model was used to evaluate the cost-effectiveness of the bundle relative to remaining with current practice (a non-bundled approach to catheter care and uncoated catheters, or use of antimicrobial catheters. We assumed the bundle reduced relative risk of CR-BSI to 0.34. Given uncertainty about the cost of the bundle, threshold analyses were used to determine the maximum cost at which the bundle remained cost-effective relative to the other approaches to infection control. Sensitivity analyses explored how this threshold alters under different assumptions about the economic value placed on bed-days and health benefits gained by preventing infection. If clinicians are prepared to use antimicrobial catheters, the bundle is cost-effective if national 18-month implementation costs are below $1.1 million. If antimicrobial catheters are not an option the bundle must cost less than $4.3 million. If decision makers are only interested in obtaining cash-savings for the unit, and place no economic value on either the bed-days or the health benefits gained through preventing infection, these cost thresholds are reduced by two-thirds. CONCLUSIONS: A catheter care bundle has the potential to be cost-effective in the Australian intensive care setting. Rather than anticipating cash-savings from this intervention, decision

More than just a urinary catheter — Haemorrhage control by using a Foley catheter in a penetrating aortic root injury

Directory of Open Access Journals (Sweden)

Adel Elmoghrabi

2016-08-01

Full Text Available The prevalence of great vessel injuries in thoracic trauma is reported at 0.3–10%, predominantly due to a penetrating mechanism. Thoracic aortic injuries, more specifically those within proximity of the aortic root are challenging to manage and unceasing bleeding hampers adequate visualisation for performing repair. We report a case of a 31-year-old male that presented to the emergency department 1 h after sustaining a stab wound injury within proximity of the left upper sternal border. Vital signs were stable on presentation. Physical examination revealed a 1.5 cm laceration in the 3rd intercostal space. Chest X-ray revealed a small left pneumothorax, FAST scan was negative, and CT of the chest revealed left sided haemopneumothorax and haemopericardium. The patient was emergently transferred to the operating room where median thoracotomy was performed. A significant amount of bleeding was observed originating from a 1 cm laceration of the aortic root. Bleeding was controlled using a Foley catheter after unsuccessful attempts of digital compression, and the laceration was repaired using pledgeted sutures. Postoperative echocardiography and CT scan of the chest revealed normal cardiac functions with resolution of haemopericardium and haemopneumothorax, and the patient was discharged in a stable condition. High index of suspicion should be maintained for injury to the great vessels in patients with penetrating chest injuries, despite apparent haemodynamic stability. In this case, balloon tamponade using a Foley catheter served as a quick and simple technique that resulted in an almost bloodless field, facilitating adequate visualisation for definitive repair. Although the use of this technique has been previously described, this report serves as a reminder that a Foley catheter can be successfully used for balloon catheter tamponade in injuries to the aortic root. Keywords: Aortic root, Injury, Foley's catheter, Balloon catheter, Aorta

Needle catheter duodenostomy: a technique for duodenal alimentation of birds.

Science.gov (United States)

Goring, R L; Goldman, A; Kaufman, K J; Roberts, C; Quesenberry, K E; Kollias, G V

1986-11-01

A technique for duodenal alimentation (needle catheter duodenostomy) of birds was developed, using the domestic pigeon (Columba livia) as the experimental model. A needle catheter was inserted into the descending duodenum of 5 pigeons and was secured to the body wall and dorsum of each bird. A liquid diet was administered daily (in equal amounts of 0, 4, 8, 12, and 16 hours) for 14 days without adverse effects. On day 15, the catheters were removed, and the birds immediately resumed normal consumption of a pigeon ration and water diet. Although 4 of the 5 birds had minor weight loss, dietary alterations probably could be used on an individual basis to alleviate this problem. After oral alimentation was resumed, the 5 birds exceeded their initial body weight within 7 days. Four weeks after catheter removal, positive-contrast radiographic evaluations indicated that the duodenum of each pigeon appeared normal. Needle catheter duodenostomy was a viable method of alimentation in the domestic pigeon. This technique should be applicable for other avian species requiring bypass of the upper gastrointestinal tract proximal to the region of catheter insertion in the duodenum.

A novel suture method to place and adjust peripheral nerve catheters

DEFF Research Database (Denmark)

Rothe, C.; Steen-Hansen, C.; Madsen, M. H.

2015-01-01

We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in-plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial...

Total parenteral alimentation via indwelling umbilical catheters in the newborn period.

Science.gov (United States)

Hall, R T; Rhodes, P G

1976-01-01

Total parenteral alimentation (TPA) was delivered to 80 infants via indwelling umbilical artery and to 9 via indwelling umbilical venous catheters. The primary indication for catheter placement and maintenance was monitoring of arterial blood gases (umbilical venous catheter tip in left atrium) in a group of sick neonates requiring increased inspired oxygen or assisted ventilation. Results were compared with those from 23 infants who had tunnelled jugular catheters for a variety of chronic medical and surgical problems preventing gastric or intestinal feeding. A mean weight gain was achieved in both groups. Mortality and morbidity rates were similar in both groups. The most common complications were infection and thrombotic phenomena. Metabolic complications were few. It is concluded that infusing TPA solutions via indwelling umbilical catheters presents no greater risk than infusion via tunnelled jugular catheters, and provides a method for supplying adequate caloric intake for growth during the acute stage of illness. PMID:827978

Using an indwelling catheter for the domiciliary management of malignant effusions

Directory of Open Access Journals (Sweden)

Ramkumar P

2003-01-01

Full Text Available Background: Many patients with malignant pleural effusions and ascites require repeated hospital visits for paracentesis. Materials and Methods: Patients and caregivers were taught to drain malignant effusions at home, using an indwelling catheter inserted into the pleural/ peritoneal cavity. The catheter, (ARROW 14 wire gauge with three additional side holes made to prevent blockage was inserted using the Seldenger technique for central venous cannulation and secured with a stitch. A three way stopcock was used to regulate fluid drainage. The caregiver was taught to do biweekly dressings with antiseptic ointment. Results: The catheter has been used in 200 patients over a period of five years. Two patients developed infections in the pleural cavity, which were managed with antibiotics. Two patients needed catheter change because of blockage. Other patients retained the catheter till last follow up or death. The procedure can be carried out as a day case. This article describes practical guidelines for inserting and maintaining the catheter.

Interlayer catalytic exfoliation realizing scalable production of large-size pristine few-layer graphene

OpenAIRE

Geng, Xiumei; Guo, Yufen; Li, Dongfang; Li, Weiwei; Zhu, Chao; Wei, Xiangfei; Chen, Mingliang; Gao, Song; Qiu, Shengqiang; Gong, Youpin; Wu, Liqiong; Long, Mingsheng; Sun, Mengtao; Pan, Gebo; Liu, Liwei

2013-01-01

Mass production of reduced graphene oxide and graphene nanoplatelets has recently been achieved. However, a great challenge still remains in realizing large-quantity and high-quality production of large-size thin few-layer graphene (FLG). Here, we create a novel route to solve the issue by employing one-time-only interlayer catalytic exfoliation (ICE) of salt-intercalated graphite. The typical FLG with a large lateral size of tens of microns and a thickness less than 2?nm have been obtained b...

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

International Nuclear Information System (INIS)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark

1997-01-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis

Correction of malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Ryong; Baek, Kyong Hee; Jung, Gyoo Sik; Huh, Jin Do; Joh, Young Duk; Rim, Hark [Kosin Medical College, Pusan (Korea, Republic of)

1997-11-01

To determine the efficacy of correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance. Between November 1994 and March 1997, we performed 15 manipulations in 12 patients in whom a dual-cuff, straight Tenckhoff peritoneal dialysis catheter had been implanted due to chronic renal failure. The causes of catheter malfunctioning were inadequate drainage of the dialysate(n=14) and painful dialysis(n=1). Under fluoroscopic guidance, adhesiolysis and repositioning of the malfunctioning catheter were performed with an Amplatz Super Stiff guidewire and the stiffener from a biliary drainage catheter. The results of procedures were categorized as either immediate or durable success, this latter being defined as adequate catheter function for at least one month after the procedure. Immediate success was achieved in 14 of 15 procedures (93%), and durable success in 7 of 15(47%). The mean duration of catheter function was 157 (range, 30 to 578) days. After manipulation, abdominal pain developed in eight patients and peritonitis in two, but with conservative treatment, these symptoms improved. The correction of a malfunctioning peritoneal dialysis catheter with guidewire and stiffener under fluoroscopic guidance is an effective means of restoring catheter function and may be an effective alternative to surgical reimplantation of the catheter, or hemodialysis.

The left atrial catheter: its uses and complications.

Science.gov (United States)

Leitman, B S; Naidich, D P; McGuinness, G; McCauley, D I

1992-11-01

The authors describe the radiographic appearance of the left atrial catheter, a widely used postsurgical intracardiac device. Recognition of the characteristic appearance of this catheter should be of value in detection of potential complications, including line fracture with resultant retention and/or embolization, infection, prosthetic valve dysfunction, and even cardiac tamponade.

A prototype catheter designed for ultraviolet C disinfection

DEFF Research Database (Denmark)

Bak, Jimmy; Begovic, Tanja

2013-01-01

UVC light exposure, sampling and plate counting. Findings Two minutes of UVC exposure was sufficient to obtain 4 log10 disinfection for the full-length prototype catheter. This exposure corresponds to ∼40 mJ/cm2 at the catheter tip and indicates that even shorter exposure times can be achieved...

Early catheter removal after radical retropubic prostatectomy: long-term followup.

Science.gov (United States)

Koch, Michael O; Nayee, Anish H; Sloan, James; Gardner, Thomas; Wahle, Greg R; Bihrle, Richard; Foster, Richard S

2003-06-01

We examine the complication and continence rates with early catheter removal (day 3 or 4) after radical retropubic prostatectomy. A total of 365 patients with localized prostate cancer underwent radical retropubic prostatectomy at Indiana University Hospital with planned urethral catheter removal before discharge home. Low pressure cystograms were performed on postoperative day 3 or 4 to determine if catheter removal was possible. A subset of patients were analyzed using a validated prostate cancer specific questionnaire (University of California, Los Angeles Prostate Cancer Symptom Index) to determine quality of life outcomes. The catheter was removed on postoperative day 3 or 4 in 263 patients (72%). The reasons for leaving the catheter indwelling were significant leak on cystogram or excessive suprapubic drainage (21%), extensive bladder neck reconstruction (1%) and prolonged hospitalization because of an ileus or other complicating factor (6%). Thirteen patients (3.6%) were either unable to void after catheter removal or presented with retention (not associated with hematuria or clots) after hospital discharge, requiring reinsertion of the Foley catheter. A total of 41 patients (11%) had either an early or late complication (excluding incontinence). There were 3 complications (0.8%) that were considered major because they were potentially life threatening or required a return to the operating room. A pelvic abscess developed in 2 patients and a lymphocele in 1, which required percutaneous drainage. After at least 6 months (mean 20.9 months) 140 patients (89.2%) and 14 (8.9%) reported excellent and good continence, respectively. The patient questionnaire demonstrated bother scores to be minimal to no bother for 95% to 98% of patients at 6 and 12 months. This study confirms that it is safe to remove catheters in most patients 3 to 4 days after prostatectomy if a cystogram demonstrates no extravasation. Complication rates and continence rates with this approach

Large- and small-size advantages in sneaking behaviour in the dusky frillgoby Bathygobius fuscus

Science.gov (United States)

Takegaki, Takeshi; Kaneko, Takashi; Matsumoto, Yukio

2012-04-01

Sneaking tactic, a male alternative reproductive tactic involving sperm competition, is generally adopted by small individuals because of its inconspicuousness. However, large size has an advantage when competition occurs between sneakers for fertilization of eggs. Here, we suggest that both large- and small-size advantages of sneaker males are present within the same species. Large sneaker males of the dusky frillgoby Bathygobius fuscus showed a high success rate in intruding into spawning nests because of their advantage in competition among sneaker males in keeping a suitable position to sneak, whereas small sneakers had few chances to sneak. However, small sneaker males were able to stay in the nests longer than large sneaker males when they succeeded in sneak intrusion. This suggests the possibility of an increase in their paternity. The findings of these size-specific behavioural advantages may be important in considering the evolution of size-related reproductive traits.

Culture-dependent and -independent investigations of microbial diversity on urinary catheters

DEFF Research Database (Denmark)

Xu, Yijuan; Moser, Claus Ernst; Abu Al-Soud, Waleed

2012-01-01

Catheter-associated urinary tract infection is caused by bacteria, which ascend the catheter along its external or internal surface to the bladder and subsequently develop into biofilms on the catheter and uroepithelium. Antibiotic-treated bacteria and bacteria residing in biofilm can be difficult...... to culture. In this study we used culture-based and 16S rRNA gene-based culture-independent methods (fingerprinting, cloning, and pyrosequencing) to determine the microbial diversity of biofilms on 24 urinary catheters. Most of the patients were catheterized for...

Micrococcus-associated central venous catheter infection in patients with pulmonary arterial hypertension.

Science.gov (United States)

Oudiz, Ronald J; Widlitz, Allison; Beckmann, X Joy; Camanga, Daisy; Alfie, Jose; Brundage, Bruce H; Barst, Robyn J

2004-07-01

To determine the incidence of catheter-related infection in patients with pulmonary arterial hypertension (PAH) receiving epoprostenol (EPO), and to note an etiologic role for Micrococcus spp, which is rarely reported as a pathogen in the medical literature. Observational study. Two PAH specialty treatment centers, Harbor-UCLA Medical Center (Torrance, CA), and the College of Physicians and Surgeons, Columbia University (New York, NY). A total of 192 patients with PAH receiving continuous therapy with IV EPO. From 1987 to 2000, 192 patients with PAH received infusions of EPO via central venous catheter. Catheter care included regular dressing changes with dry gauze using a sterile procedure, without the use of flushes. Patients were asked to report on known infections and treatments, and symptoms. All infections were verified by a telephone call to the patient, care provider, and microbiology laboratory whenever possible. There were 335,285 catheter days (mean +/- SD, 1,325 +/- 974 catheter days). There were 88 clinical catheter infections with 51 blood culture-positive infections, necessitating catheter removal in 38 instances. The following pathogens were isolated: Staphylococcus aureus (25); Micrococcus spp (14); mixed flora (3); coagulase-negative Staphylococcus spp (2); Corynebacterium spp (2); Serratia marcessens (1); Enterobacter spp (1); Pseudomonas aeruginosa (1); enterococci (1); and unidentified Gram-positive cocci (1). The catheter infection rate was 0.26 per 1,000 catheter days. The use of long-term therapy with continuous EPO appears to be associated with a low incidence of catheter-related infections. Micrococcus spp were the second most common etiologic agent. Caregivers managing patients with PAH must be aware of the risk of catheter infection, as it may contribute to the morbidity and mortality associated with the use of EPO. When isolated, Micrococcus spp should not be viewed as a contaminant, but rather as a true pathogen that may require

Urinary catheterization diary – A useful tool in tracking causes of non-deflating Foley catheter

Directory of Open Access Journals (Sweden)

C.O. Okorie

2015-06-01

Conclusions: Most urinary catheters marketed in developing countries are unidentifiable after unpacking. A catheterization diary is a useful tool for solving catheter-related problems, and its application in health-care facilities should be encouraged. Companies marketing Foley catheters should print the catheter name on both the catheter packaging and on the catheter itself.

Microbiocidal effects of various taurolidine containing catheter lock solutions

NARCIS (Netherlands)

Olthof, E.D.; Nijland, R van; Gulich, A.F.; Wanten, G.J.A.

2015-01-01

BACKGROUND & AIMS: We have recently shown that a catheter lock solution containing taurolidine dramatically decreases catheter-related bloodstream infections (CRBSI) in patients on home parenteral nutrition (HPN) when compared to heparin. Since several taurolidine formulations are commercially

Empyema and Effusion: Outcome of Image-Guided Small-Bore Catheter Drainage

International Nuclear Information System (INIS)

Keeling, A. N.; Leong, S.; Logan, P. M.; Lee, M. J.

2008-01-01

Empyema and complicated pleural effusion represent common medical problems. Current treatment options are multiple. The purpose of this study was to access the outcome of image-guided, small-bore catheter drainage of empyema and effusion. We evaluated 93 small-bore catheters in 82 patients with pleural effusion (n = 30) or empyema (n = 52), over a 2-year period. Image guidance was with ultrasound (US; n = 56) and CT (n = 37). All patients were followed clinically, with catheter dwell times, catheter outcome, pleural fluid outcome, reinsertion rates, and need for urokinase or surgery recorded. Ninety-three small-bore chest drains (mean=10.2 Fr; range, 8.2-12.2 Fr) were inserted, with an average dwell time of 7.81 days for empyemas and 7.14 days for effusions (p > 0.05). Elective removal rates (73% empyema vs 86% effusions) and dislodgement rates (12% empyema vs 13% effusions) were similar for both groups. Eight percent of catheters became blocked and 17% necessitated reinsertion in empyemas, with no catheters blocked or requiring reinsertion in effusions (p < 0.05). Thirty-two patients (51%) required urokinase in the empyema group, versus 2 patients (6%) in the effusion group (p < 0.05). All treatment failures, requiring surgery, occurred in the empyema group (19%; n = 12; p < 0.05). In conclusion, noninfected pleural collections are adequately treated with small-bore catheters, however, empyemas have a failure rate of 19%. The threshold for using urokinase and larger-bore catheters should be low in empyema

Hematologic patients' clinical and psychosocial experiences with implanted long-term central venous catheter

DEFF Research Database (Denmark)

Møller, Tom; Adamsen, Lis

2010-01-01

A significant decrease in catheter-related infections was demonstrated in our earlier randomized controlled trial of central venous catheter (CVC) care in hematologic patients.......A significant decrease in catheter-related infections was demonstrated in our earlier randomized controlled trial of central venous catheter (CVC) care in hematologic patients....

Classification of large-sized hyperspectral imagery using fast machine learning algorithms

Science.gov (United States)

Xia, Junshi; Yokoya, Naoto; Iwasaki, Akira

2017-07-01

We present a framework of fast machine learning algorithms in the context of large-sized hyperspectral images classification from the theoretical to a practical viewpoint. In particular, we assess the performance of random forest (RF), rotation forest (RoF), and extreme learning machine (ELM) and the ensembles of RF and ELM. These classifiers are applied to two large-sized hyperspectral images and compared to the support vector machines. To give the quantitative analysis, we pay attention to comparing these methods when working with high input dimensions and a limited/sufficient training set. Moreover, other important issues such as the computational cost and robustness against the noise are also discussed.

Phased array inspection of large size forged steel parts

Science.gov (United States)

Dupont-Marillia, Frederic; Jahazi, Mohammad; Belanger, Pierre

2018-04-01

High strength forged steel requires uncompromising quality to warrant advance performance for numerous critical applications. Ultrasonic inspection is commonly used in nondestructive testing to detect cracks and other defects. In steel blocks of relatively small dimensions (at least two directions not exceeding a few centimetres), phased array inspection is a trusted method to generate images of the inside of the blocks and therefore identify and size defects. However, casting of large size forged ingots introduces changes of mechanical parameters such as grain size, the Young's modulus, the Poisson's ratio, and the chemical composition. These heterogeneities affect the wave propagation, and consequently, the reliability of ultrasonic inspection and the imaging capabilities for these blocks. In this context, a custom phased array transducer designed for a 40-ton bainitic forged ingot was investigated. Following a previous study that provided local mechanical parameters for a similar block, two-dimensional simulations were made to compute the optimal transducer parameters including the pitch, width and number of elements. It appeared that depending on the number of elements, backwall reconstruction can generate high amplitude artefacts. Indeed, the large dimensions of the simulated block introduce numerous constructive interferences from backwall reflections which may lead to important artefacts. To increase image quality, the reconstruction algorithm was adapted and promising results were observed and compared with the scattering cone filter method available in the CIVA software.

Minimizing Hemodialysis Catheter Dysfunction: An Ounce of Prevention

Directory of Open Access Journals (Sweden)

Timmy Lee

2012-01-01

Full Text Available The maintenance of tunneled catheter (TC patency is critical for the provision of adequate hemodialysis in patients who are TC-dependent. TC dysfunction results in the need for costly and inconvenient interventions, and reduced quality of life. Since the introduction of TCs in the late 1980s, heparin catheter lock has been the standard prophylactic regimen for the prevention of TC dysfunction. More recently, alternative catheter locking agents have emerged, and in some cases have shown to be superior to heparin lock with respect to improving TC patency and reducing TC-associated infections. These include citrate, tissue plasminogen activator, and a novel agent containing sodium citrate, methylene blue, methylparaben, and propylparaben. In addition, prophylaxis using oral anticoagulants/antiplatelet agents, including warfarin, aspirin, ticlodipine, as well as the use of modified heparin-coated catheters have also been studied for the prevention of TC dysfunction with variable results. The use of oral anticoagulants and/or antiplatelet agents as primary or secondary prevention of TC dysfunction must be weighed against their potential adverse effects, and should be individualized for each patient.

Clinical study of the Erlanger silver catheter--data management and biometry.

Science.gov (United States)

Martus, P; Geis, C; Lugauer, S; Böswald, M; Guggenbichler, J P

1999-01-01

The clinical evaluation of venous catheters for catheter-induced infections must conform to a strict biometric methodology. The statistical planning of the study (target population, design, degree of blinding), data management (database design, definition of variables, coding), quality assurance (data inspection at several levels) and the biometric evaluation of the Erlanger silver catheter project are described. The three-step data flow included: 1) primary data from the hospital, 2) relational database, 3) files accessible for statistical evaluation. Two different statistical models were compared: analyzing the first catheter only of a patient in the analysis (independent data) and analyzing several catheters from the same patient (dependent data) by means of the generalized estimating equations (GEE) method. The main result of the study was based on the comparison of both statistical models.

Predicting success of catheter drainage in infected necrotizing pancreatitis

NARCIS (Netherlands)

Hollemans, Robbert A.; Bollen, Thomas L.; Van Brunschot, Sandra; Bakker, Olaf J.; Ali, Usama Ahmed; Van Goor, Harry; Boermeester, Marja A.; Gooszen, Hein G.; Besselink, Marc G.; Van Santvoort, Hjalmar C.

2016-01-01

Introduction: At least 30% of patients with infected necrotizing pancreatitis are successfully treated with catheter drainage alone. It is currently not possible to predict which patients also need necrosectomy. We evaluated predictive factors for successful catheter drainage. Methods: This was a

Predicting Success of Catheter Drainage in Infected Necrotizing Pancreatitis

NARCIS (Netherlands)

Hollemans, R.A.; Bollen, T.L.; Brunschot, S. van; Bakker, O.J.; Ali, U. Ahmed; Goor, H. van; Boermeester, M.A.; Gooszen, H.G.; Besselink, M.G.; Santvoort, H.C. van

2016-01-01

INTRODUCTION: At least 30% of patients with infected necrotizing pancreatitis are successfully treated with catheter drainage alone. It is currently not possible to predict which patients also need necrosectomy. We evaluated predictive factors for successful catheter drainage. METHODS: This was a

Qureshi-5 Catheter for Complex Supra- and Abdominal-Aortic Catheterization.

Science.gov (United States)

Qureshi, Adnan I; Xiao, WeiGang; Liu, HongLiang

2015-10-01

The use of previously described catheter technique was expanded to complex supra- and abdominal- aortic catheterizations. A new (Qureshi 5) catheter with curved shape at the distal end that has two lumens was used. One of lumens can accommodate a 0.035-inch guide wire and the second lumen can accommodate a 0.018-inch guide wire and terminates at the beginning of the distal curve of the first lumen. The manipulation and engagement of the curved distal end catheter was facilitated by rotation and movement of the J-shaped 0.018-inch guide wire extended coaxial and beyond the distal end of catheter. Subsequently, either contrast was injected or a 0.035-inch guide wire advanced into the target artery. The catheters were used in one patient to perform diagnostic cerebral and abdominal angiography through a 6F introducer sheath placed in the right common femoral artery. The catheterization was complex because of severe tortuosity of arch and descending aorta secondary to kyphosis. The left and right internal carotid arteries and left and right vertebral arteries, left renal artery, and superior mesenteric artery were catheterized in patient (fluoroscopy time 19:46 min). No complications were observed in the patient. The Qureshi-5 catheter was successful in complex supra- and abdominal-aortic catheterizations.

Catheter design optimization for practical intravascular photoacoustic imaging (IVPA) of vulnerable plaques

Science.gov (United States)

Iskander-Rizk, Sophinese; Wu, Min; Springeling, Geert; Mastik, Frits; Beurskens, Robert H. S. H.; van der Steen, Antonius F. W.; van Soest, Gijs

2018-02-01

Intravascular photoacoustic/ultrasound imaging (IVPA/US) can image the structure and composition of atherosclerotic lesions identifying lipid-rich plaques ex vivo and in vivo. In the literature, multiple IVPA/US catheter designs were presented and validated both in ex-vivo models and preclinical in-vivo situations. Since the catheter is a critical component of the imaging system, we discuss here a catheter design oriented to imaging plaque in a realistic and translatable setting. We present a catheter optimized for light delivery, manageable flush parameters and robustness with reduced mechanical damage risks at the laser/catheter joint interface. We also show capability of imaging within sheath and in water medium.

Peripherally inserted central catheters. Guidewire versus nonguidewire use: a comparative study.

Science.gov (United States)

Loughran, S C; Edwards, S; McClure, S

1992-01-01

To date, no research articles have been published that explore the practice of using guidewires for placement of peripherally inserted central catheters. The literature contains speculations regarding the pros and cons of guidewire use. However, no studies to date have compared patient outcomes when peripherally inserted central catheter lines are inserted with and without guidewires. To examine the use of guidewires for peripherally inserted central lines, a comparative study was conducted at two acute care facilities, one using guidewires for insertion and one inserting peripherally inserted central catheter lines without guidewires. 109 catheters were studied between January 1, 1990 and January 1, 1991. The primary focus of this study was to examine whether guidewire use places patients at higher risk for catheter-related complications, particularly phlebitis. No significant differences in phlebitis rates between the two study sites were found. Other catheter-related and noncatheter-related complications were similar between the two facilities. The results of this study do not support the belief that guidewire use increases complication rates.

Successful Use of Modified Suprapubic Catheter to Rescue Prostatorectal Fistula

Directory of Open Access Journals (Sweden)

Yi-Chun Chiu

2008-06-01

Full Text Available Prostatorectal fistula is a complication following radiotherapy. It remains a clinical challenge to treat because most patients experience a poor quality of life. This case report discusses a modified suprapubic catheter for use in a patient with a prostatorectal fistula that developed after radiotherapy for localized prostate cancer. It is an inexpensive, easily available, and more patient-tolerable catheter that improves quality of life. Herein, we describe the development of this catheter.

Longer Duration of Urinary Catheterization Increases Catheter-Associated Urinary Tract Infection in PICU.

Science.gov (United States)

Fukuoka, Kahoru; Furuichi, Mihoko; Ito, Kenta; Morikawa, Yoshihiko; Watanabe, Ichiro; Shimizu, Naoki; Horikoshi, Yuho

2018-06-13

Catheter-associated urinary tract infections account for 30% of healthcare-associated infections. To date, few studies have addressed pediatric catheter-associated urinary tract infection in PICUs. The aim of our study was to assess the risk of catheter-associated urinary tract infection in relation to the duration of catheterization in the PICU. Retrospective cohort study. PICU at a tertiary children's hospital. Our study was conducted between April 2012 and June 2015 at Tokyo Metropolitan Children's Medical Center in Japan. Children in the PICU with an urethral catheter were included. Catheter-associated urinary tract infection cases were defined according to the National Healthcare Safety Network criteria. The patients' demographic data and isolated organisms were reviewed. Duration of catheterization and the catheter-associated urinary tract infection occurrence rate were analyzed. None. Among 1,890 catheterizations, 23 catheter-associated urinary tract infection cases were identified. The overall occurrence rate was 2.35/1,000 catheter-days. Among the patients with catheter-associated urinary tract infection, 13 were boys. The median age was 11 months (interquartile range, 7-35 mo), and the median duration of catheterization was 7 days (interquartile range, 5-12 d). The isolated bacteria were Escherichia coli (26.5%), Enterococcus faecalis (17.6%), and Klebsiella pneumoniae (11.8%). Two species were isolated in each of 11 cases (47.8%). Each additional day of catheterization increased the risk of catheter-associated urinary tract infection (odds ratio, 1.06; 95% CI, 1.02-1.10, and odds ratio adjusted for contact precaution status and surgical procedures was 1.05; 95% CI, 1.01-1.09). Longer duration of catheterization increased the risk of catheter-associated urinary tract infection by 5% each day at the PICU. Prompt removal of the urethral catheter is strongly recommended whenever feasible.

Catheter-free Period Over 2 Days Is Associated with Better Outcome in Catheter-related Bloodstream Infection due to Candida

OpenAIRE

Matsuo, Takahiro; Mori, Nobuyoshi; Hoshino, Eri; Sakurai, Aki; Furukawa, Keiichi

2017-01-01

Abstract Background Regardless of active antifungal drugs, mortality of candidemia remains high. Although it is well-known that central venous catheter (CVC) is one of the most important risk factors of candidemia and should be removed immediately, little is known about optimal timing of CVC replacement after removal. Here, we analyzed contributing risk factors associated with 30-day mortality for catheter-related bloodstream infection (CRBSI) due to candida and optimal timing of CVC replacem...

Initial experience with the Europass: a new ultra-low profile monorail balloon catheter.

Science.gov (United States)

Zimarino, M; Corcos, T; Favereau, X; Tamburino, C; Toussaint, M; Spaulding, C; Guérin, Y

1994-09-01

One of the causes for percutaneous transluminal coronary angioplasty (PTCA) failure is the inability to cross the lesion with the balloon catheter after guidewire positioning. The Europass coronary angioplasty catheter is a monorail Duralyn balloon catheter developed to enhance lesion crossability and to overcome this limitation. This system was evaluated in 50 patients in which target lesions were chronic total coronary occlusions (12 cases) or stenoses that could not be reached or crossed by other new monorail balloon catheters. Overall procedural success was obtained in 49/50 patients (98%), using a single Europass balloon catheter in 46/50 patients (92%), with no in-hospital complications. Its low profile, small distal shaft, and excellent trackability allowed successful angioplasty in cases where other catheters failed. This balloon catheter represents a significant advance in angioplasty technology and can be considered as a first-choice device for a safe and expeditious single-operator procedure.

Risk Factors for Catheter Associated Urinary Tract Infections in a Pediatric Institution.

Science.gov (United States)

Lee, Nora G; Marchalik, Daniel; Lipsky, Andrew; Rushton, H Gil; Pohl, Hans G; Song, Xiaoyan

2016-04-01

Catheter associated urinary tract infections are an essential measure for health care quality improvement that affects reimbursement through hospital acquired condition reduction programs in adult patients. With the mounting importance of preventing such infections we evaluated risk factors for acquiring catheter associated urinary tract infections in pediatric patients. All catheter associated urinary tract infections were identified at 1 pediatric institution from September 2010 to August 2014 from a prospective database maintained by the infection control office. To identify risk factors patients with a catheter associated urinary tract infection were individually matched to control patients with a urinary catheter but without infection by age, gender, date and the hospital location of the infection in 1:2 fashion. A total of 50 patients with catheter associated urinary tract infection were identified and matched to 100 control patients. Compared to controls the patients with infection were more likely to have a catheter in place for longer (2.9 days, OR 1.08, 95% CI 1.01, 1.15, p = 0.02). They were also more likely to be on contact precautions (OR 4.00, 95% CI 1.73, 9.26, p = 0.001), and have concurrent infections (OR 3.04, 95% CI 1.39, 6.28, p = 0.005) and a history of catheterization (OR 3.24, 95% CI 1.55, 6.77, p = 0.002). Using a conditional multivariate regression model the 3 most predictive variables were duration of catheter drainage, contact isolation status and history of catheterization. Longer duration of urinary catheter drainage, positive contact precautions status and a history of catheterization appear to be associated with a higher risk of catheter associated urinary tract infection in hospitalized pediatric patients. Physicians should attempt to decrease the duration of catheterization, especially in patients who meet these criteria, to minimize the risk of catheter associated urinary tract infection. Copyright © 2016 American Urological

Efficient Selection of Multiple Objects on a Large Scale

DEFF Research Database (Denmark)

Stenholt, Rasmus

2012-01-01

The task of multiple object selection (MOS) in immersive virtual environments is important and still largely unexplored. The diffi- culty of efficient MOS increases with the number of objects to be selected. E.g. in small-scale MOS, only a few objects need to be simultaneously selected. This may...... consuming. Instead, we have implemented and tested two of the existing approaches to 3-D MOS, a brush and a lasso, as well as a new technique, a magic wand, which automati- cally selects objects based on local proximity to other objects. In a formal user evaluation, we have studied how the performance...

Urinary catheter related nosocomial infections in paediatric intensive care unit.

Directory of Open Access Journals (Sweden)

Tullu M

1998-04-01

Full Text Available The present prospective study was carried out in the Paediatric Intensive Care Unit (PICU of a tertiary care teaching hospital in Mumbai. The objective was to determine the incidence, risk factors, mortality and organisms responsible for urinary catheter related infections (UCRI. Colonization and/or bacteriuria was labelled as urinary catheter related infection (UCRI. Forty-four patients with 51 urinary catheters were studied. Incidence of UCRI was 47.06%. Age, female sex and immunocompromised status did not increase the risk of UCRI. Duration of catheter in-situ and duration of stay in the PICU were associated with higher risk of UCRI. The mortality was not increased by UCRI. Commonest organism isolated in UCRI was E. coli, which had maximum susceptibility to nitrofurantoin and amikacin.

Pleural fluid drainage: Percutaneous catheter drainage versus surgical chest tube drainage

International Nuclear Information System (INIS)

Illescas, F.F.; Reinhold, C.; Atri, M.; Bret, P.M.

1987-01-01

Over the past 4 years, 55 cases (one transudate, 28 exudates, and 26 empymas) were drained. Surgical chest tubes alone were used in 35 drainages, percutaneous catheters alone in five drainages, and both types in 15 drainages. Percutaneous catheter drainage was successful in 12 of 20 drainages (60%). Surgical tube drainage was successful in 18 of 50 drainages (36%). The success rate for the nonempyema group was 45% with both types of drainage. For the empyema group, the success rate for percutaneous catheter drainage was 66% vs 23% for surgical tube drainage. Seven major complications occurred with surgical tube drainage, but only one major complication occurred with percutaneous catheter drainage. Radiologically guided percutaneous catheter drainage should be the procedure of choice for pleural fluid drainage. It has a higher success rate for empyemas and is associated with less complications

Laparoscopic Placement of Peritoneal Dialysis Catheters in CAPD Patients: Complications and Survival

Directory of Open Access Journals (Sweden)

A Roueentan

2008-06-01

Full Text Available Background: Laparoscopic techniques for the placement of peritoneal dialysis catheters are becoming increasingly popular. Recently, with the improvements in laparoscopic surgery, various methods for the insertion of peritoneal dialysis catheters have been reported, indicating that the laparoscopic insertion is preferred over the open and percutaneous techniques. The aim of this study was to introduce and assess a simplified laparoscopic method for the insertion of peritoneal dialysis catheters in continuous ambulatory peritoneal dialysis (CAPD patients.Methods: We enrolled 79 consecutive end-stage renal patients (46 men and 33 women with a mean age of 50 years (range: 19-83 years in this study. During the surgery, a 5-mm trocar was placed in the left upper quadrant for the optics and another 5-mm trocar was placed to the left of the umbilicus. Using the second trocar, a tunnel was formed 2 cm left of the umbilical plane for the insertion of a Tenckhoff catheter. Under direct vision, the catheter was advanced into the abdomen. The catheter was tested for patency. Catheters of all subjects were capped for two weeks before dialysis initiation.Results: The mean duration of the operation was 15 minutes. Ten patients died during the follow-up period, all due to other medical problems, and six patients underwent renal transplantation; however, no deaths or complications were observed during surgery. Early onset complications were seen in 12 patients (15.1%. The most frequent late-onset medical and mechanical complications were peritonitis (6.3% and hernia (3.7%. During a follow-up period of four years, removal of the catheter was required in two patients as a result of peritonitis.Conclusion: We obtained a low complication rate and a high catheter survival rate with this laparoscopic insertion of the Tenckhoff catheter. We believe future experience will encourage the use of this safe, simple and quick procedure.

Large- and small-size advantages in sneaking behaviour in the dusky frillgoby Bathygobius fuscus

OpenAIRE

Takegaki, Takeshi; Kaneko, Takashi; Matsumoto, Yukio

2012-01-01

Sneaking tactic, a male alternative reproductive tactic involving sperm competition, is generally adopted by small individuals because of its inconspicuousness. However, large size has an advantage when competition occurs between sneakers for fertilization of eggs. Here, we suggest that both large- and small-size advantages of sneaker males are present within the same species. Large sneaker males of the dusky frillgoby Bathygobius fuscus showed a high success rate in intruding into spawning n...

Predicting Success of Catheter Drainage in Infected Necrotizing Pancreatitis

NARCIS (Netherlands)

Hollemans, Robbert A.; Bollen, Thomas L.; van Brunschot, Sandra; Bakker, Olaf J.; Ahmed Ali, Usama; van Goor, Harry; Boermeester, Marja A.; Gooszen, Hein G.; Besselink, Marc G.; van Santvoort, Hjalmar C.

2016-01-01

At least 30% of patients with infected necrotizing pancreatitis are successfully treated with catheter drainage alone. It is currently not possible to predict which patients also need necrosectomy. We evaluated predictive factors for successful catheter drainage. This was a post hoc analysis of 130

Frequency of puncture holes in peritoneal dialysis catheters related to the beta cap adapter.

Science.gov (United States)

Ohashi, Yasushi; Kansal, Sheru; Schreiber, Martin

2012-01-01

Between November 2009 and September 2011, 12 patients (6 women, 6 men) undergoing continuous peritoneal dialysis (PD) or automated PD developed puncture-like holes in the PD catheter near the interface of the adapter with the superior aspect of the Silastic PD catheter The adapter is used to connect the PD catheter to the PD transfer set. Over the course of 23 months, the 12 patients presented to the PD unit with 19 separate instances of catheter holes, for an event rate of 0.23 holes per patient-year Data including socio-demographic information, PD modality, need for antibiotic treatment, event recurrence, infectious complications, and time from catheter placement were collected from patients whose catheters did and did not develop holes. We observed no differences between patients whose catheters developed holes and those whose catheters did not. The location of the individual holes suggested a relationship between the adapter and the catheter holes. The holes, which led to increased patient morbidity and costs, may be related to structural changes made in 2006 to the adapter.

Percutaneous pigtail catheter in the treatment of pneumothorax in major burns: the best alternative? Case report and review of literature.

Science.gov (United States)

Sebastian, Raul; Ghanem, Omar; Diroma, Frank; Milner, Stephen M; Gerold, Kevin B; Price, Leigh A

2015-05-01

Multiple factors place burn patients at a high risk of pneumothorax development. Currently, no specific recommendations for the management of pneumothorax in large total body surface area (TBSA) burn patients exist. We present a case of a major burn patient who developed pneumothorax after central line insertion. After the traditional large bore (24 Fr) chest tube failed to resolve the pneumothorax, the pneumothorax was ultimately managed by a percutaneous placed pigtail catheter thoracostomy placement and resulted in its complete resolution. We will review the current recommendations of pneumothorax treatment and will highlight on the use of pigtail catheters in pneumothorax management in burn patients. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

The welfare implications of large litter size in the domestic pig I

DEFF Research Database (Denmark)

Rutherford, K.M.D; Baxter, E.M.; D'Eath, R.B.

2013-01-01

Increasing litter size has long been a goal of pig breeders and producers, and may have implications for pig (Sus scrofa domesticus) welfare. This paper reviews the scientific evidence on biological factors affecting sow and piglet welfare in relation to large litter size. It is concluded that, i...

Computational scalability of large size image dissemination

Science.gov (United States)

Kooper, Rob; Bajcsy, Peter

2011-01-01

We have investigated the computational scalability of image pyramid building needed for dissemination of very large image data. The sources of large images include high resolution microscopes and telescopes, remote sensing and airborne imaging, and high resolution scanners. The term 'large' is understood from a user perspective which means either larger than a display size or larger than a memory/disk to hold the image data. The application drivers for our work are digitization projects such as the Lincoln Papers project (each image scan is about 100-150MB or about 5000x8000 pixels with the total number to be around 200,000) and the UIUC library scanning project for historical maps from 17th and 18th century (smaller number but larger images). The goal of our work is understand computational scalability of the web-based dissemination using image pyramids for these large image scans, as well as the preservation aspects of the data. We report our computational benchmarks for (a) building image pyramids to be disseminated using the Microsoft Seadragon library, (b) a computation execution approach using hyper-threading to generate image pyramids and to utilize the underlying hardware, and (c) an image pyramid preservation approach using various hard drive configurations of Redundant Array of Independent Disks (RAID) drives for input/output operations. The benchmarks are obtained with a map (334.61 MB, JPEG format, 17591x15014 pixels). The discussion combines the speed and preservation objectives.

Scale-space for empty catheter segmentation in PCI fluoroscopic images.

Science.gov (United States)

Bacchuwar, Ketan; Cousty, Jean; Vaillant, Régis; Najman, Laurent

2017-07-01

In this article, we present a method for empty guiding catheter segmentation in fluoroscopic X-ray images. The guiding catheter, being a commonly visible landmark, its segmentation is an important and a difficult brick for Percutaneous Coronary Intervention (PCI) procedure modeling. In number of clinical situations, the catheter is empty and appears as a low contrasted structure with two parallel and partially disconnected edges. To segment it, we work on the level-set scale-space of image, the min tree, to extract curve blobs. We then propose a novel structural scale-space, a hierarchy built on these curve blobs. The deep connected component, i.e. the cluster of curve blobs on this hierarchy, that maximizes the likelihood to be an empty catheter is retained as final segmentation. We evaluate the performance of the algorithm on a database of 1250 fluoroscopic images from 6 patients. As a result, we obtain very good qualitative and quantitative segmentation performance, with mean precision and recall of 80.48 and 63.04% respectively. We develop a novel structural scale-space to segment a structured object, the empty catheter, in challenging situations where the information content is very sparse in the images. Fully-automatic empty catheter segmentation in X-ray fluoroscopic images is an important and preliminary step in PCI procedure modeling, as it aids in tagging the arrival and removal location of other interventional tools.

Damage threshold from large retinal spot size repetitive-pulse laser exposures.

Science.gov (United States)

Lund, Brian J; Lund, David J; Edsall, Peter R

2014-10-01

The retinal damage thresholds for large spot size, multiple-pulse exposures to a Q-switched, frequency doubled Nd:YAG laser (532 nm wavelength, 7 ns pulses) have been measured for 100 μm and 500 μm retinal irradiance diameters. The ED50, expressed as energy per pulse, varies only weakly with the number of pulses, n, for these extended spot sizes. The previously reported threshold for a multiple-pulse exposure for a 900 μm retinal spot size also shows the same weak dependence on the number of pulses. The multiple-pulse ED50 for an extended spot-size exposure does not follow the n dependence exhibited by small spot size exposures produced by a collimated beam. Curves derived by using probability-summation models provide a better fit to the data.

Folding and unfolding of large-size shell construction for application in Earth orbit

Science.gov (United States)

Kondyurin, Alexey; Pestrenina, Irena; Pestrenin, Valery; Rusakov, Sergey

2016-07-01

A future exploration of space requires a technology of large module for biological, technological, logistic and other applications in Earth orbits [1-3]. This report describes the possibility of using large-sized shell structures deployable in space. Structure is delivered to the orbit in the spaceship container. The shell is folded for the transportation. The shell material is either rigid plastic or multilayer prepreg comprising rigid reinforcements (such as reinforcing fibers). The unfolding process (bringing a construction to the unfolded state by loading the internal pressure) needs be considered at the presence of both stretching and bending deformations. An analysis of the deployment conditions (the minimum internal pressure bringing a construction from the folded state to the unfolded state) of large laminated CFRP shell structures is formulated in this report. Solution of this mechanics of deformable solids (MDS) problem of the shell structure is based on the following assumptions: the shell is made of components whose median surface has a reamer; in the separate structural element relaxed state (not stressed and not deformed) its median surface coincides with its reamer (this assumption allows choose the relaxed state of the structure correctly); structural elements are joined (sewn together) by a seam that does not resist rotation around the tangent to the seam line. The ways of large shell structures folding, whose median surface has a reamer, are suggested. Unfolding of cylindrical, conical (full and truncated cones), and large-size composite shells (cylinder-cones, cones-cones) is considered. These results show that the unfolding pressure of such large-size structures (0.01-0.2 atm.) is comparable to the deploying pressure of pneumatic parts (0.001-0.1 atm.) [3]. It would be possible to extend this approach to investigate the unfolding process of large-sized shells with ruled median surface or for non-developable surfaces. This research was

Risk factors for peritoneal dialysis catheter failure in children ...

African Journals Online (AJOL)

Background Peritoneal dialysis catheter (PDC) failure still remains a common clinical problem in pediatric patients despite advancements in catheter placement and dialysis techniques. Our aim was to determine the risk factors that may lead to PDC failure, especially those factors that could be potentially modified to ...

Encrusted and incarcerated urinary bladder catheter: what are the ...

African Journals Online (AJOL)

Urinary bladder catheter encrustations are known complications of long-term urinary catheterisation, which is commonly seen in clinical practice. These encrustations can impede deflation of the balloon and therefore cause problems in the removal of the catheter. The options in managing an encrusted and incarcerated ...

Encrusted and incarcerated urinary bladder catheter: what are the ...

African Journals Online (AJOL)

2010-11-25

Nov 25, 2010 ... cases of extraluminal encrusted urethral catheters. Extracorporeal shock wave lithotripsy (ESWL) has been utilised in the treatment of the bladder stones. Borrowing this principle, Kunzman et al. (12) has even used ESWL to fragment the stone-like encrustation over the retained Foley catheter balloon.

Accuracy of the photogrametric measuring system for large size elements

Directory of Open Access Journals (Sweden)

M. Grzelka

2011-04-01

Full Text Available The aim of this paper is to present methods of estimating and guidelines for verifying the accuracy of optical photogrammetric measuringsystems, using for measurement of large size elements. Measuring systems applied to measure workpieces of a large size which oftenreach more than 10000mm require use of appropriate standards. Those standards provided by the manufacturer of photogrammetricsystems are certified and are inspected annually. To make sure that these systems work properly there was developed a special standardVDI / VDE 2634, "Optical 3D measuring systems. Imaging systems with point - by - point probing. " According to recommendationsdescribed in this standard research on accuracy of photogrametric measuring system was conducted using K class gauge blocks dedicatedto calibrate and test accuracy of classic CMMs. The paper presents results of research of estimation the actual error of indication for sizemeasurement MPEE for photogrammetric coordinate measuring system TRITOP.

Percutaneous placement of peritoneal port-catheter in oncologic patients

International Nuclear Information System (INIS)

Orsi, Franco; Vigna, Paolo Della; Bonomo, Guido; Penco, Silvia; Lovati, Elena; Bellomi, Massimo

2004-01-01

The aim of this paper is to describe the technique of percutaneous ultrasound (US)-guided placement of a peritoneal port-catheter in an interventional radiological setting. Nineteen patients with peritoneal carcinomatosis were selected for intraperitoneal port-catheter placement in order to perform intracavitary receptor-immuno- or radio-immunotherapy with Ytrium-90. All the procedures were performed percutaneously under US and fluoro guidance; the insertion site for catheters was chosen according to abdominal conditions and US findings: all devices were implanted at the lower abdominal quadrants. All patients were followed up with CT and US according to the therapy protocol. The procedure was successfully completed in 15/19 patients, in 4 being contraindicated by peritoneal adhesions. No procedure-related complications and device occlusions during therapy were observed; one catheter displaced 7 months later the placement. In our experience, this procedure was feasible, reliable and easy to perform, allowing the correct administration of the planned intracavitary therapy. Peritoneal adhesions are the main limitation of peritoneal port placement. (orig.)

Effective flow performances and dialysis doses delivered with permanent catheters: a 24-month comparative study of permanent catheters versus arterio-venous vascular accesses.

Science.gov (United States)

Canaud, Bernard; Leray-Moragues, Hélène; Kerkeni, Nadia; Bosc, Jean-Yves; Martin, Katja

2002-07-01

Permanent venous catheters have emerged as a long-term vascular access option for renal replacement therapy in end-stage renal disease patients. The design and venous location of catheter devices bear intrinsic flow limitations that may negatively affect the adequacy of dialysis and the patient outcome. There is limited data comparing the long-term dialysis adequacy delivered with permanent catheters vs arterio-venous vascular accesses (AVA). To explore this problem, we conducted a prospective 24-month trial comparing the flow performances and dialysis dose (Kt/Vdp) deliveries of both access options in a group of 42 haemodialysis patients during two study phases. During the first 12 months the patients completed a treatment period by means of permanent dual silicone catheters (DualKT). Then they were transferred to an AVA (40 native arterio-venous fistulas and two PTFE grafts) and monitored for an additional 12-month period. Assessments of flow adequacy and dialysis quantification were performed monthly. Dialysis adequacy was achieved in all cases. No patient had to be transferred prematurely to the AVA because of catheter failure. Three catheters had to be replaced due to bacteraemia in three patients. The mean effective blood flow rates achieved were 316+/-3.5 ml/min and 340+/-3.3 ml/min with DualKT and AVA, respectively, for a pre-set machine blood flow of 348+/-2.2 ml/min. Recirculation rates evaluated with the 'slow blood flow' method were 8.6+/-0.6 and 12.1+/-0.8% for DualKT and AVA using mean values of the solute markers urea and creatinine. Due to the possibility of a comparison veno-venous vs arterio-venous blood circulation, a corrected arterio-venous access recirculation could be derived from the difference between the two, which was around 3%. The blood flow resistance of the DualKT was slightly higher than with AVA as indicated by venous pressure differences. Kt/Vdp delivered was 1.37+/-0.02 and 1.45+/-0.02 with DualKT and AVA access respectively. The

Bi-layer sandwich film for antibacterial catheters.

Science.gov (United States)

Franz, Gerhard; Schamberger, Florian; Zare, Hamideh Heidari; Bröskamp, Sara Felicitas; Jocham, Dieter

2017-01-01

Background: Approximately one quarter of all nosocomial infections can be attributed to the urinary tract. The infections are supposed to be mainly caused by implantations of urethral catheters and stents. A new catheter design is introduced with the aim to lower the high number of nosocomial urethral infections. In order to avoid limitations to use, the design is first applied to conventional commercially available balloon catheters. Results: The main feature of the design is a sandwich layer on both sides of the catheter wall, which is composed of a fragmented base layer of silver capped by a thin film of poly( p -xylylene). This top layer is mainly designed to release a controlled amount of Ag + ions, which is bactericidal, but not toxic to humans. Simultaneously, the lifetime is prolonged to at least one year. The base layer is electrolessly deposited applying Tollens' reagens, the cap layer is deposited by using chemical vapor deposition. Conclusion: The three main problems of this process, electroless deposition of a fragmented silver film on the surface of an electrically insulating organic polymer, irreproducible evaporation during heating of the precursor, and exponential decrease of the layer thickness along the capillary, have been solved trough the application of a simple electrochemical reaction and two standard principles of physics: Papin's pot and the principle of Le Chatelier.

Bi-layer sandwich film for antibacterial catheters

Directory of Open Access Journals (Sweden)

Gerhard Franz

2017-09-01

Full Text Available Background: Approximately one quarter of all nosocomial infections can be attributed to the urinary tract. The infections are supposed to be mainly caused by implantations of urethral catheters and stents. A new catheter design is introduced with the aim to lower the high number of nosocomial urethral infections. In order to avoid limitations to use, the design is first applied to conventional commercially available balloon catheters.Results: The main feature of the design is a sandwich layer on both sides of the catheter wall, which is composed of a fragmented base layer of silver capped by a thin film of poly(p-xylylene. This top layer is mainly designed to release a controlled amount of Ag+ ions, which is bactericidal, but not toxic to humans. Simultaneously, the lifetime is prolonged to at least one year. The base layer is electrolessly deposited applying Tollens’ reagens, the cap layer is deposited by using chemical vapor deposition.Conclusion: The three main problems of this process, electroless deposition of a fragmented silver film on the surface of an electrically insulating organic polymer, irreproducible evaporation during heating of the precursor, and exponential decrease of the layer thickness along the capillary, have been solved trough the application of a simple electrochemical reaction and two standard principles of physics: Papin’s pot and the principle of Le Chatelier.

Accelerating Deep Learning with Shrinkage and Recall

OpenAIRE

Zheng, Shuai; Vishnu, Abhinav; Ding, Chris

2016-01-01

Deep Learning is a very powerful machine learning model. Deep Learning trains a large number of parameters for multiple layers and is very slow when data is in large scale and the architecture size is large. Inspired from the shrinking technique used in accelerating computation of Support Vector Machines (SVM) algorithm and screening technique used in LASSO, we propose a shrinking Deep Learning with recall (sDLr) approach to speed up deep learning computation. We experiment shrinking Deep Lea...

Efficacy and safety of transradial percutaneous coronary intervention using sheathless guide catheter technique

Directory of Open Access Journals (Sweden)

Mohamed Aboel-Kassem F. Abdelmegid

2014-03-01

Conclusions: TR PCI via standard and sheathless hydrophilic-coated GC techniques are effective and safe with high rate of procedural success and low rate of asymptomatic radial artery occlusion. Moreover, TR PCI using sheathless GC technique has the advantage of performing complex intervention requiring large bore catheters that can not be performed via standard TR PCI using 6F GC.

[Catheter-associated bloodstream infections: implementation of a new consensus protocol].

Science.gov (United States)

Urrea Ayala, M; Rozas Quesada, L

2009-07-01

Catheter-associated bloodstream infection is highly prevalent and often associated with fatal complications. Some studies have shown that applying preventive interventions could help to reduce and control this type of infection. To determine whether a new consensus protocol for the manipulation and maintenance of central venous catheters would decrease catheter-associated bloodstream infections (CA-BSIs) in paediatric patients. To evaluate its compliance in intensive care units. Prospective study in the paediatric (PICU) and neonatal (NICU) intensive cares units, haematology, oncology and hospital wards in a Maternal and Paediatric reference Hospital in Barcelona. The study period is divided into two periods: before (first semester) and after the start of the new protocol (second semester) in 2007. The most important changes have been the insertion of the hermetic connection in the proximal and distal site (between the line and the syringe) of the central venous catheter (CVC), the labelling of the medication line and the CVC with the date of placement. A check-list to evaluate compliance was introduced in both intensive care units (paediatrics and neonatal) during the second study period. The rates of bloodstream infection per 1000 catheter-days were assessed. The rate of bloodstream infections per 1000 catheter-days before and after the start of the new protocol was 5.7 and 4.9 in PICU; 24.6 and 18.0 in NICU; 7.6 and 4.6 in haematology-oncology, and 11.9 and 10.3 in hospital wards. As regards compliance to the protocol, we found that proximal sealed connectors were used in more than 95% of the cases and up to 85% of the central venous catheter were labelled with the insertion date in both intensive care units. A consensus protocol for the use and maintenance of central venous catheters and healthcare worker training helped to control the rate of CA-BSIs. We reaffirm the importance of epidemiological surveillance as a measure for controlling nosocomial infections.

Vaginal extrusion of a ventriculo-peritoneal shunt catheter in an adult

Directory of Open Access Journals (Sweden)

Christopher M Bonfield

2015-01-01

Full Text Available Ventriculo-peritoneal shunts (VPS are commonly used in the treatment of various neurosurgical conditions, including hydrocephalus and pseudotumor cerebri. We report only the second case of vaginal extrusion of a VPS catheter in an adult, and the first case with a modern VPS silastic peritoneal catheter. A 45-year-old female with a history of VPS for pseudotumor cerebri, Behcet′s syndrome, and hysterectomy presented to our institution with the chief complaint of tubing protruding from her vagina after urination. On gynecologic examination, the patient was found to have approximately 15 cm of VPS catheter protruding from her vaginal apex. A computed tomography scan of the abdomen and shunt X-ray series demonstrated no breaks in the tubing, but also confirmed the finding of the VPS catheter extruding through the vaginal cuff into the vagina. The patient had the VPS removed and an external ventricular drain was placed for temporary cerebrospinal fluid diversion. Ventricular catheter cultures were positive for diphtheroids. After an appropriate course of antibiotics, a contralateral ventriculo-pleural shunt was placed one week later. Although vary rare, vaginal extrusion can occur in adults, even with modern VPS catheters.