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.

OBJECTIVES

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.

MATERIAL AND

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.

INTERVENTION AND MEASUREMENTS: 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.

CONCLUSION

Air-charged catheters give lower readings for MUCP than microtip catheters with a good agreement between the two catheters.