Purpose: To investigate whether postvoiding residual bladder volume (PVR) and uroflowmetry parameters associate with bladder sensation in male patients with bladder outlet obstruction (BOO) and to find out the reliable time of these examinations.
Materials and Methods: Sixty men with bladder outlet obstruction underwent transabdominal ultrasound in order to measure postvoiding residual volume and uroflowmetry. At the first day, PVR was measured while the patients had mild bladder sensation. Patients emptied their bladder during uroflowmetry. The next day, same patients underwent a second uroflowmetry and PVR measurement while the patients had severe bladder sensation. The first and next day PVR and uroflowmetry parameters were compared and their correlation with lower urinary tract symptoms (LUTS) were analysed.
Results: The mean age of the subjects was 69.7 ± 8.6 years. PVR measured at the first day while patients had mild bladder sensation was significantly found lower than the next day PVR (mean ± SD: 80.79 ± 72.18 vs 158 ± 115.82, p<0.001) and correlated with LUTS (rs =0.38, p=0.012). In contrary, uroflowmetry parameters at severe sensation of bladder (mean ± SD: Qmax:13.53 ± 6.32; Qave:5.32 ± 2.31) showed correlation with LUTS (rs = -0.492, p= 0.001).
Conclusions: PVR measurement at mild bladder sensation correlates with LUTS and should be performed in the evaluation of male patients with BOO. However, uroflowmetry is advised to be performed when the patient has severe bladder sensation.