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Abdominal Pressure (abdominal + pressure)
Selected AbstractsOesophageal adenocarcinoma: A paradigm of mechanical carcinogenesis?INTERNATIONAL JOURNAL OF CANCER, Issue 3 2002Carlo La Vecchia Abstract Incidence of adenocarcinoma of the oesophagus and gastric cardia is increasing in most developed countries and strongly associated with obesity and male gender. An underlying increase in the prevalence of gastro-oesophageal reflux has generally been postulated. We suggest that the increase in frequency of reflux and the 2 associated forms of cancer can be explained by growing abdominal pressure brought about by increasing central obesity, most common among men, and sedentary lifestyle, including car use. Abdominal pressure is further accentuated mainly in men by the shift in Western male dressing towards the general use of belts. © 2002 Wiley-Liss, Inc. [source] Long pediatric colonoscope versus intermediate length adult colonoscope for colonoscopyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7pt2 2008Yu-Hsi Hsieh Abstract Background:, Controversy exists on how the length and diameter of colonoscopes affect the quality of colonoscopy. The aim of this study was to compare a long pediatric colonoscope with an intermediate length adult colonoscope with regards to completion rate and cecal intubation time. Whether either scope may be more efficient in any subgroups was also investigated. Methods:, Asymptomatic patients admitted to the physical check-up department of Buddhist Dalin Tzu Chi General Hospital were included. A single endoscopist performed all of the colonoscopic examinations under sedation. Consecutive patients were randomized to undergo colonoscopy with either intermediate length adult colonoscope (CF-240I) or long pediatric colonoscope (PCF-240L). The success rate and time required to reach cecum were compared between the two groups. Results:, Between April 2005 and February 2006, a total of 918 patients were enrolled. Incomplete colonoscopy occurred in 21 (2.3%) cases (14 in the CF-240I group and seven in the PCF-240L group, P > 0.1). The overall cecal mean insertion time was 6.00 ± 3.66 min. There was no significant difference between the CF-240I and PCF 240L groups with regard to the cecal intubation rate (96.9% vs 98.5%, P = 0.18), the need for abdominal pressure (71.7% vs 73.4%, P = 0.55) and change of position (13.5% vs 11.5%, P = 0.37). However, the cecal intubation time was shorter in the CF-240I group (5.75 ± 3.18 vs 6.26 ± 3.30 min, P = 0.02). Subgroup analysis by sex, age, and body mass index showed comparable outcomes between the two groups except that the cecal intubation times were significantly shorter in the CF-240I group when only men (4.78 ± 2.57 vs 5.50 ± 2.93 min, P < 0.01) or those younger than 50 years (5.50 ± 2.90 vs 6.25 ± 3.68 min, P = 0.02) were considered. Conclusion:, Cecal intubation time is shorter in patients examined with an intermediate length adult colonoscope, mainly in the subgroups of men and those younger than 50 years of age. [source] Renal failure and abdominal hypertension after liver transplantation: Determination of critical intra-abdominal pressureLIVER TRANSPLANTATION, Issue 12 2002Gianni Biancofiore MD There is growing interest in measuring intra-abdominal pressure (IAP) in postsurgical and critically ill patients because increased pressure can impair various organs and functions. The aim of this study was to evaluate the effect of different IAP levels on the postoperative renal function of subjects undergoing orthotopic liver transplantation. IAP was measured every 8 hours with the urinary bladder pressure method for at least 72 hours after surgery. At the end of the study, the patients were classified on the basis of their IAP values: , 18 mm Hg (group A), 19 to 24 mm Hg (group B), , 25 mm Hg (group C). The three groups were compared in terms of the incidence of acute renal failure (defined as blood creatinine > 1.5 mg/dL or an increase in the same of > 1.1 mg/dL within 72 hours of surgery), hourly diuresis, blood creatinine, the filtration gradient, hemodynamic variations, and outcome. The incidence of renal failure was higher among the subjects in group C (P < .05 versus group A and < .01 versus group B), who also had higher creatinine levels (P < .01), a greater need for diuretics (P < .01) and a worse outcome (P < .05). Receiver Operator Characteristic curve analysis showed that an abdominal pressure of 25 mm Hg had the best sensitivity/specificity ratio for renal failure. An intra-abdominal pressure of , 25 mm Hg is an important risk factor for renal failure in subjects undergoing liver transplant. [source] External anal sphincter contraction during cough: Not a simple spinal reflex,NEUROUROLOGY AND URODYNAMICS, Issue 7 2006Xavier Deffieux Abstract Aims: To assess whether the anal contraction during voluntary coughing is a simple spinal reflex-mediated activity or not. To address this question we studied the external intercostal (EIC) muscle activity and external anal sphincter (EAS) response to cough. Materials and Methods: Electromyographic recordings were made from pre-gelled disposable surface electrodes. EAS electromyographic recordings were made from the EAS of the pelvic floor in 15 continent women all suffering from urgency and/or frequency without urge or stress urinary incontinence, and referred for urodynamic investigation. Electromyographic signal was immediately integrated (EMGi). The abdominal pressure was recorded with bladder and rectal pressure. EAS EMGi was recorded during successive voluntary cough. In three women, we have also recorded EIC EMGi activity since it is synchronous with diaphragmatic EMG activity during cough initiation. Results: In all subjects, EAS EMGi activity precedes the onset of the abdominal pressure increase. The mean latency of EAS EMGi was 615 msec (±278). In the three subjects whose EMGi activity was recorded both on EAS and EIC, the onset of EAS EMGi activity occurred before the EIC EMGi activity (latency ranging from 40 to 780 msec) and before the increase in the abdominal pressure. Conclusions: The present study suggests that during coughing, EAS EMG activity increases before external intercostal muscle EMGi activity. The contraction of the EAS preceding the activation of muscles involved in coughing indicates that this response is not a result of a simple spinal reflex, but more likely the result of a more intricate reflex involving complex integrative centers. Neurourol. Urodynam. 25:782,787, 2006. © 2006 Wiley-Liss, Inc. [source] Theoretical analysis of the effects of viscous losses and abdominal straining on urinary outlet function,NEUROUROLOGY AND URODYNAMICS, Issue 1 2004Srboljub M. Mijailovich Abstract Aims The aim of this study was to theoretically explore the relationship between the tube law (TL) of the urethra and the pressure,flow (p,Q) relationship during micturition. The understanding of this relation is important for the evaluation of outlet obstruction by urodynamic interpretation of p,Q plots. Methods We simulated the outlet function by a lumped theoretical model, and suggested how the TL can be used to quantitatively predict the p,Q relationship of the system. Our analysis considered the relation between the TL and the steady state p,Q plot for various TLs including the hysteresis of the pressure,area relationship. Results and Conclusions The inclusion of pressure losses distal to the flow controlling zone and experimentally measured p,A relations of the urethra in the model lead to the predictions that flow in the flow controlling zone is not always critical but is often in the sub-critical range, that an increase in abdominal pressure can increase the flow under certain conditions, and that hysteresis in the pressure,area relation is correlated to the hysteresis in the p,Q plot. Neurourol. Urodynam. 23:76,85, 2004. Published 2003 Wiley-Liss, Inc. [source] Compliance of the bladder neck supporting structures: Importance of activity pattern of levator ani muscle and content of elastic fibers of endopelvic fasciaNEUROUROLOGY AND URODYNAMICS, Issue 4 2003Matija Barbi Abstract Aims Firm bladder neck support during cough, suggested to be needed for effective abdominal pressure transmission to the urethra, might depend on activity of the levator ani muscle and elasticity of endopelvic fascia. Methods The study group of 32 patients with stress urinary incontinence and hypermobile bladder neck, but without genitourinary prolapse, were compared with the control group of 28 continent women with stable bladder neck. The height of the bladder neck (HBN) and compliance of the bladder neck support (C) were assessed, the latter by the quotient of the bladder neck mobility during cough and the change in abdominal pressure. By using wire electrodes, the integrated full-wave rectified electromyographic (EMGave) signal of the levator ani muscle was recorded simultaneously with urethral and bladder pressures. The pressure transmission ratio (PTR), time interval between the onset of muscle activation and bladder pressure increment (,T), and area under the EMGave curve during cough (EMGcough) were calculated. From bioptic samples of endopelvic fascia connecting the vaginal wall and levator ani muscle, elastic fiber content was assessed by point counting method. Mann-Whitney test was used to compare all the variables. Correlations between the parameters were evaluated by using the Spearman correlation coefficient. Results In the study group, HBN was significantly lower (P,<,0.001), C was significantly greater (P,<,0.001), and PTR was significantly lower (P,<,0.001). In the study group, the muscular activation started later (median, ,Tl, ,0.147 second; ,Tr, ,0.150 second), and in the control group, it preceded (,Tl, 0.025 second; P,<,0.001; ,Tr, 0.050 second; P,<,0.001) the bladder pressure increment. EMGcough on the left side was significantly greater in the study group (P,<,0.046). Elastic fiber content showed no difference between the groups. The analysis of all patients revealed negative correlations between C and PTR (r,=,,0.546; P,<,0.001) and between C and ,Tl (r,=,,0.316; P,<,0.018). Conclusions Firm bladder neck support enables effective pressure transmission. Timely activation of the levator ani seems to be an important feature. Neurourol. Urodynam. 22:269,276, 2003. © 2003 Wiley-Liss, Inc. [source] Baseline abdominal pressure and valsalva leak point pressures-correlation with clinical and urodynamic dataNEUROUROLOGY AND URODYNAMICS, Issue 1 2003Shahar Madjar Abstract Aims: To characterize the factors contributing to changes in baseline abdominal pressure (Pabd) and the correlation between ,VLPP, VLPPtot, and other clinical and urodynamic variables. Methods: Two hundred sixty-four female patients who had undergone an anti-incontinence procedure between February 1994 and October 1999 were retrospectively reviewed. The urodynamics performed for each patient included abdominal and vesical pressures measured in a standardized manner with the patient sitting upright and the pressure sensors maintained at the level of the symphysis pubis. VLPP was determined at bladder volumes of 200 mL during a gradually increasing Valsalva maneuver. Results: Baseline Pabd varied between 10 and 55 cm H2O (mean, 32.7,±,8.8) and were significantly correlated with patient weight (P<0.001) and with patient body mass index (P<0.001). Baseline Pabd was not found to be correlated with patient age, Baden and Walker Classification of the grading of pelvic floor prolapse, degree of incontinence (determined by the number of pads used per day), or prior surgical procedures for stress incontinence. Higher baseline Pabd were significantly correlated with the peak abdominal pressure reached during the Valsalva maneuver (P<0.0001) and with VLPPtot (P<0.0001) but not with ,VLPP. Higher VLPPtot significantly correlated with decreased age (P=0.004), less severe incontinence (P=0.004), higher peak Valsalva pressure (P<0.0001), and the ability to increase abdominal pressure for a longer period of time (time to peak Pabd during Valsalva). VLPPtot and ,VLPP had similar statistical correlation with all the clinical variables examined and neither could predict the outcome of any anti-incontinence surgery. By using a VLPP of 60 cm H2O as a cutoff to differentiate severe ISD from GSUI, 211 (67.4%) of the patients would be categorized as having ISD according to their ,VLPP compared with only 106 (40.1%) by using the VLPPtot. Conclusions: Baseline Pabd varies considerably among patients, is correlated with patient weight and habitus. In addition, it varies with both the ability to be increased for longer periods of time and with VLPPtot. Looking at VLPPtot and ,VLPP will result in a different categorization of the type of incontinence in at least 25% of patients and, thus, affect the physician's selection of an anti-incontinence procedure for an individual patient. Neurourol. Urodynam. 22:2,6, 2003. © 2003 Wiley-Liss, Inc. [source] Baroreflex Sensitivity: Measurement and Clinical ImplicationsANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2008Maria Teresa La Rovere M.D. Alterations of the baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) contribute to the reciprocal reduction of parasympathetic activity and increase of sympathetic activity that accompany the development and progression of cardiovascular diseases. Therefore, the measurement of the baroreflex is a source of valuable information in the clinical management of cardiac disease patients, particularly in risk stratification. This article briefly recalls the pathophysiological background of baroreflex control, and reviews the most relevant methods that have been developed so far for the measurement of BRS. They include three "classic" methods: (i) the use of vasoactive drugs, particularly the ,-adrenoreceptor agonist phenylephrine, (ii) the Valsalva maneuver, which produces a natural challenge for the baroreceptors by voluntarily increasing intrathoracic and abdominal pressure through straining, and (iii) the neck chamber technique, which allows a selective activation/deactivation of carotid baroreceptors by application of a negative/positive pressure to the neck region. Two more recent methods based on the analysis of spontaneous oscillations of systolic arterial pressure and RR interval are also reviewed: (i) the sequence method, which analyzes the relationship between increasing/decreasing ramps of blood pressure and related increasing/decreasing changes in RR interval through linear regression, and (ii) spectral methods, which assess the relationship (in terms of gain) between specific oscillatory components of the two signals. The limitations of the coherence criterion for the computation of spectral BRS are discussed, and recent proposals for overcoming them are presented. Most relevant clinical applications of BRS measurement are finally reviewed with particular reference to patients with myocardial infarction and heart failure. [source] Quality control in urodynamics: a review of urodynamic traces from one centreBJU INTERNATIONAL, Issue 3 2003J. Sullivan OBJECTIVE To investigate quality control in our unit and to enable other units to compare their results, as experience from central reviews of urodynamic traces for multicentre trials has suggested that poor quality control is common. PATIENTS AND METHODS All consecutive male urodynamic tests conducted over 1 year were reviewed. A list of criteria to assess the quality of the records was devised, based upon International Continence Society guidelines on ,good urodynamic practice', and on other sources. Eligible traces were analysed for aspects of quality control, e.g. baseline pressures and coughs to test pressure transmission. The data were analysed to establish how often quality criteria were met, and identify areas for improvement. RESULTS In 100 eligible traces, the baseline detrusor pressure was 0,10 cmH2O in 86, and , 5 to +10 cmH2O in 94%. Baseline intravesical and abdominal pressure were 30,50 cmH2O in 68% and 73% of cases, respectively. Coughs were present before filling in 94%, during filling in 95%, before voiding in 72% and after voiding in 87% of cases. The cough-test frequency was sufficient in 30% of traces. In 11 the intravesical pressure line fell out during voiding. CONCLUSION Most of the traces assessed met the quality criteria defined, but significant defects were not uncommon. Some of the problems identified suggest areas of urodynamic technique which should be studied in more detail. We intend to modify our quality control practices, and hope to show an improvement on re-audit. We hope that other urodynamic departments will be encouraged to review their practice, and we aim to improve our results. [source] Effects of vaginal distension on urethral anatomy and functionBJU INTERNATIONAL, Issue 4 2002T.W. Cannon Objective ,To determine the effect of repeated and prolonged vaginal distension on the leak-point pressure (LPP) and urethral anatomy in the female rat, as prolonged vaginal distension has been clinically correlated with signs of stress urinary incontinence (SUI). Materials and methods ,Sixty female rats were placed into one of five groups; four groups underwent one of four vaginal distension protocols using a modified 10 F Foley catheter, i.e. prolonged (1 h), brief (0.5 h), intermittent (cycling inflated/deflated for 0.5 h) or sham distension. All animals had a suprapubic bladder catheter implanted 2 days after and were assessed urodynamically 4 days after vaginal distension. The fifth group of rats acted as controls and did not undergo vaginal distension, but did have a suprapubic bladder catheter placed and urodynamics assessed. To measure LPP the rats were anaesthetized with urethane, placed supine and the bladder filled with saline (5 mL/h) while bladder pressure was measured via the bladder catheter. LPPs were measured three times in each animal by manually increasing the abdominal pressure until leakage at the urethral meatus, when the external abdominal pressure was rapidly released. Peak bladder pressure was taken as the LPP and a mean value calculated for each animal. Immediately after measuring LPP the urethra was removed and processed routinely for histology (5 µm sections, stained with haematoxylin/eosin and trichrome). The means ( sem ) were compared using a Kruskal,Wallis one-way anova on ranks, followed by a Dunn's test, with P < 0.05 indicating a significant difference. Results ,Both LPP and the external increase in abdominal pressure were significantly lower after prolonged distension, at 31.4 (1.7) and 19.8 (1.2) cmH 2 O, than in the sham group, at 41.1 (3.2) and 32.0 (4.7) cmH 2 O, respectively. There were no significant differences in LPP or in the increase in abdominal pressure between the brief, intermittent and sham groups. Qualitative histology showed that prolonged distension resulted in extensive disruption and marked thinning of urethral skeletal muscle fibres. Brief and intermittent distension showed mild and focal disruptions, respectively. Conclusions ,As observed clinically, prolonged vaginal distension results in a lower LPP, greater anatomical injury and increased severity of SUI. These results suggest that ischaemia is important in the development of SUI after prolonged vaginal distension. [source] | ||||||||||