Document Detail

Urodynamic patterns of normal male micturition: influence of water consumption on urine production and detrusor function.
MedLine Citation:
PMID:  12352417     Owner:  NLM     Status:  MEDLINE    
PURPOSE: Urodynamic characterization of normal male micturition can be a useful standard in the analysis of data on patients complaining of voiding dysfunction. The validity of such a standard is based on the need to obtain baseline parameters of pressure flow values, an important consideration when evaluating prostatic obstruction and its treatment. While current numerical pressure flow values provide a useful summary of the voiding sequence, a more complete analysis of the pattern of normal voiding may reveal more functionally useful information concerning micturition. We establish basic experimental conditions that simulate normal voiding of physiologically produced urine by the kidneys measured at intervals representing real stages of bladder filling. We report the results of an investigation designed to study consecutive micturitions at bladder volumes determined by water consumption and endogenous circadian rhythm. Our particular focus is to examine critically the urodynamic pattern of pressure flow and obtain evidence to support the hypothesis that fluid consumption has an important role in detrusor function. MATERIALS AND METHODS: Urodynamic studies were conducted on 39 asymptomatic male volunteers with a mean age of 25.8 years (range 21 to 31) and mean weight of 75.5 kg. (range 63 to 95). Volunteers were divided into 2 groups according to water consumption regimen of 30 ml./kg. daily (17 patients, group 1) and 60 ml./kg. daily (12, group 2). Bladder pressure was monitored via a suprapubic catheter and abdominal pressure was measured via a rectal balloon using an ambulatory system. Average duration of each monitoring period was 20.5 hours. Detrusor pressure and flow rate records from each subject were identified, and consecutive filling and voiding phases were averaged during the entire monitoring period using the onset of micturition as a time marker. The average pattern of pressure, flow rate, cumulative volume and contractility curves for each subject, as well each for group, was computed and graphically presented. For each group the average parameters of urethral opening pressure, maximum detrusor pressure, detrusor pressure at maximum flow rate, bladder capacity and bladder contraction strength were calculated and compared statistically. Numerical values are mean +/- SE. RESULTS: Water consumption and urine production rate influenced the pattern and many of the urodynamic parameters of micturition. In both groups there was a detrusor pressure increase before voiding and numerically maximum detrusor pressure consistently occurred before micturition started. Micturition pattern showed an asymptotic relationship between pressure and flow. Doubling of water consumption increased urethral opening pressure from 51.2 +/- 3.2 to 61.5 +/- 5.1 (p <0.05), maximum detrusor pressure from 58.9 +/- 4.5 to 70.0 +/- 6.2 cm. H(2)O (p <0.01) and contractility from 15.4 +/- 1.4 to 17.7 +/- 1.4 w/m(2). There were no significant differences due to water consumption in maximum flow rate (24.4 +/- 1.4 to 25.2 +/- 1.8 ml. per second) or bladder capacity (286 +/- 20 to 329 +/- 15 ml.) but a significant increase in the number of micturitions from 5.8 +/- 0.5 to 9.8 +/- 0.5 per day (p <0.001) proportional to water consumption. CONCLUSIONS: The configuration of the observed pressure flow characteristics of the normal male is suggestive of the "Starlings law" relationship and the pattern of the urodynamic parameters were markedly different from those reported in the current standardization literature, suggesting the need to revise the current concept of normal male micturition. Voiding pressure and contractility increased in accordance with water consumption and urine production.
Frank Schmidt; Peter Shin; Troels Munch Jorgensen; Jens C Djurhuus; Chritos E Constantinou
Related Documents :
17701987 - The nature of high-pressure voiding in small boys and its relation with the influence o...
556717 - The action of neuropharmacologic agents on the bladder and urethra during experimental ...
8386967 - Role of adrenoceptors in the proximal urethral function of female and male rabbits usin...
4049577 - Rotational differences in urethral pressure in incontinent women.
11212977 - Glomerular hypertension and hyperfiltration in adrenocorticotrophin-induced hypertensio...
12775577 - Genetic loci contribute to the progression of vascular and cardiac hypertrophy in salt-...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of urology     Volume:  168     ISSN:  0022-5347     ISO Abbreviation:  J. Urol.     Publication Date:  2002 Oct 
Date Detail:
Created Date:  2002-09-27     Completed Date:  2002-10-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0376374     Medline TA:  J Urol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1458-63     Citation Subset:  AIM; IM    
Institute of Experimental Clinical Research, Aarhus, Denmark.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Drinking / physiology*
Hydrostatic Pressure
Reference Values
Urethra / physiology*
Urinary Bladder / physiology*
Urination / physiology*
Urodynamics / physiology*
Comment In:
J Urol. 2002 Oct;168(4 Pt 1):1464   [PMID:  12352418 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Normal values and determinants of circadian urine production in older men: a population based study.
Next Document:  Transurethral holmium laser enucleation versus transvesical open enucleation for prostate adenoma gr...