Voiding position does not affect uroflowmetric parameters and post-void residual urine volume in healthy volunteers

To investigate the effect of voiding position using uroflowmetry and post-void residual (PVR) urine volume assessment in healthy men and women.

The study population comprised 72 healthy volunteers. The mean (range) ages of the male (n = 36) and female (n = 36) subjects were 30 (18-40) years and 32 (21-44) years, respectively. The uroflowmetric studies were repeated in the standing, sitting and crouching positions for men and in the sitting and crouching positions for women. At least three measurements were obtained for all voiding positions for each volunteer. PVR volumes were measured using trans-abdominal ultrasound after each voiding. Maximum flow rate (Qmax), average flow rate (Qave), voided volume (VV) and PVR values obtained in each voiding position were compared with those obtained in the other positions. Comparisons were done using one-way ANOVA.

The mean Qmax and Qave values obtained in the sitting, crouching and standing positions in men were 24.29 +/- 0.73 and 15.67 +/- 0.37, 23.28 +/- 0.64 and 15.56 +/- 0.33, and 23.58 +/- 0.63 and 15.81 +/- 0.34 ml/s, respectively. The mean VV and PVR values obtained in the sitting, crouching and standing positions in men were 297.5 +/- 12.71 and 13.52 +/- 1.02, 306.3 +/- 13.46 and 14.02 +/- 1.08, and 309.9 +/- 13.14 and 12.92 +/- 0.95 ml, respectively. In women, the mean Qmax and Qave values obtained in the sitting and crouching positions were 28.09 +/- 0.66 and 18.26 +/- 0.36, and 27.98 +/- 0.59 and 17.31 +/- 0.35 ml/s, respectively. The mean VV and PVR values obtained in the sitting and crouching positions in women were 331.8 +/- 13.28 and 11.82 +/- 0.99, and 326.9 +/- 12.87 and 12.79 +/- 1.07 ml, respectively. There were no significant differences in any of the parameters between voiding positions in either group.

Urinary flow rates and PVR urine volume do not seem to be affected by voiding position in healthy men and women.