[Effects of a 6F urethral catheter on uroflowmetry in men with benign prostatic hypertrophy].

OBJECTIVE

To determine whether the presence of a 6F catheter in the urethra modifies uroflowmetric parameters in a population of men with benign prostatic hyperplasia.

PATIENTS AND METHODS

260 patients, 45 to 86 years old, presenting with benign prostatic hyperplasia, underwent two uroflowmetries, one with the urethra free, the other with a 6F urethral catheter. Patients with a history of neurological disease, diabetes mellitus, prostatic cancer, lower urinary tract surgery or taking drugs likely to affect micturition, were excluded from the study. Maximum flow rate (Qmax) and voided volume were then compared during the 2 recordings, using Wilcoxon's non parametric test.

RESULTS

No significant difference was observed between voided volumes in the 2 groups (m: 207 ml versus m: 226 ml), but a very significant difference was observed for maximum flow rate measurements (m: 8.62 ml/s versus m: 6.97 ml/s p = 0.0001).

CONCLUSION

The presence of an urethral catheter, even small calibre (6F), modifies the flow rate by more than 1.5 ml/s. This element must be taken into account when performing and interpreting measurements of the pressure-flow relationship in men.