Increased postvoid residual volume after measuring the isovolumetric bladder pressure using the noninvasive condom catheter method.

OBJECTIVE

To test, in an ongoing noninvasive longitudinal study in healthy men, whether the condom catheter method (a noninvasive urodynamic test to assess bladder function and bladder outlet obstruction) inhibits bladder function and whether this affects the reliability of the measured isovolumetric bladder pressure (P(ves.iso)).

SUBJECTS AND

METHODS

Subjects (754, aged 40-79 years) voided three times, i.e. one free void and two condom measurements. The postvoid residual volume (PVR) was measured after each void using transabdominal ultrasonography. The statistical significance of differences was tested using Wilcoxon rank test and the Mann-Whitney U-test.

RESULTS

After free voiding the median (interquartile range) PVR was 18 (37) mL, and independent of the amount of fluid intake. In a subgroup of volunteers, when the free void was done last, the PVR was no different (P = 0.25), suggesting that the bladder did not become exhausted during the protocol. The PVR after two subsequent condom measurements was significantly higher than after free voiding, at 45 (78) and 57 (88) (both P < 0.05), independent of the number of interruptions in voiding. After supplementary fluid intake before the condom measurements, the PVR was double that with a normal fluid intake (P = 0.03). The median P(ves.iso) was 3 cmH(2)O higher in the second condom measurement than in the first (P < 0.05), although this small difference was not clinically relevant.

CONCLUSIONS

The condom measurement is associated with a significantly higher PVR, partly caused by supplementary fluid intake. This effect was only temporary and did not affect the measured P(ves.iso).