A randomized comparison of microtip and air-charged catheter for the measurement of maximum urethral closure pressure.
BACKGROUND
Measurements of maximum urethral closure pressure (MUCP) are a part of urodynamic investigations preceding an incontinence surgery and a part of urethral function tests.


OBJECTIVE
The aim of the study was to compare maximum urethral closure pressure determined by a microtip catheter with those measured by an air-charged catheter.


METHODS
A prospective randomized study in a tertiary referral centre. 122 female patients with urodynamic stress incontinence were randomly assigned to have their urethral pressure profiles measured at rest by both microtip and air-charged catheters.


METHODS
Each patient had three measurements taken by each catheter type. Means of the measurements were compared with regard to correlation and repeatability. For statistical analysis, an approach proposed by Bland-Altman was applied to assess the agreement between the two techniques.


RESULTS
Correlation coefficient between MUCP by the air-charged and the microtip catheter was r=0.8507 (95% CI 0.7928 - 0.8934; p<0.0001). MUCP by the air-charged catheter was significantly lower than MUCP measured by the microtip catheter. The two-tailed p value was <0.0001, considered extremely significant. (95% CI of the differences; mean difference = -3.033; mean of paired differences -3.730 to -2.335). Discrepancies between measurements of the microtip and the air-charged catheters suggest good agreement between the two catheters since the mean difference was 2.8 cmH2O and the 95% CI of agreement were narrow with -0.03319 to 0.3151.


CONCLUSIONS
Air-charged catheters give lower readings for MUCP than microtip catheters with a good agreement between the two catheters.
Departments of Obstetrics and Gynaecology, University Hospital and University of Bern, Switzerland. martin.mueller@insel.ch
Martin M
MM
Mueller
Marc U
MU
Baumann
Michael D
MD
Mueller
Annette
A
Kuhn
D000328:Adult; D000368:Aged; D002404:Catheterization / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013557:Switzerland; D014160:Transducers, Pressure; D014546:Urinary Catheterization / Q000295:instrumentation*; D014550:Urinary Incontinence, Stress / Q000175:diagnosis* / Q000503:physiopathology*; D014563:Urodynamics / Q000502:physiology*