Clinical validity of sonographically estimated postvoid residual volume in men with benign prostatic hyperplasia in Kano, North-West, Nigeria

Abstract

Background: Post-void residual urine (PVR) estimation is an important examination in patients with benign prostate hyperplasia. Urethral catheterization  has been the mainstay of post-void residual urine measurement however discomfort, risk of urinary tract infection and trauma were  incessantly recorded in patients. Thus, this study evaluated the accuracy of conventional ultrasound scan versus urethral catheterization for the  assessment of post-void residual volume in males with benign prostatic hyperplasia.

Materials and methods: A cross-sectional study which recruited ninety-five men with benign prostatic hyperplasia at the surgical out-patient clinic of  Aminu Kano Teaching Hospital, Kano Nigeria. Postvoid urine volume was determined serially by ultrasound scan and after bladder emptying with  urethral catheter. Data collected was analyzed using Statistical Package for Social Sciences version 20.0. The reliability of postvoid ultrasound was  determined using Cronbach’s reliability test while the validity was measured by calculating the test specificity, sensitivity and accuracy from a 2x2  contingency table.

Results: The age of the respondents ranged from 45 to 89 years with a mean age of 65 ± 11.4 years. Ultrasound scan was found to be  96.7% reliable in estimating residual volume with values of 141.45±89.54 ml by US and of 193.54±107.22 ml by urethral catheterization. The specificity,  sensitivity and accuracy of ultrasound scan for estimating residual volume was found to be 100%, 80% and 60% respectively.

Conclusion: Post-void  residual volume estimation by conventional ultrasound scan demonstrated reliable validity compared to urethral catheterization and can be used in a  clinical setting as a noninvasive measure technique of determining post-void residual volume.