Prevalence and Distribution of Postvoid Residual Urine Volume in a Hospital-Based Sample of Men with Symptomatic Benign Prostatic Hyperplasia

Abstract

Background: Benign prostatic hyperplasia (BPH) is a known cause of bladder outlet obstruction (BOO) in aging men. Patients present with lower urinary tract symptoms (LUTS), elevated postvoid residual urine (PVR), and reduced peak flow rate of urine. Although urodynamic study is the gold standard for diagnosing and quantifying BOO, it is invasive and as such urologists in their routine practice frequently rely on less invasive methods like PVR estimation to objectively assess BOO. Aim: To study the prevalence and distribution of PVR in a hospital-based population of men with symptomatic BPH. Materials and Methods: Patients aged 40 years and above were enrolled for the study. History was taken from each of the 170 participants recruited, and physical examination was done including digital rectal examination. Every one of them completed the International Prostate Symptom Score (IPSS) questionnaire and also had ultrasonography assessment of PVR. Relevant laboratory investigations (PSA, renal function test, full blood count, urinalysis, and urine culture) and uroflowmetry to determine the peak flow rate of urine (Qmax) were done. Results: A total of 170 subjects who met the inclusion criteria were enrolled for this study. The mean age of the subjects was 63.70 ± 9.92 years with a range of 42–88 years. The subjects had a mean PSA of 2.68 ± 0.91 ng/ml and a mean prostate volume of 70.8 ± 39.5 ml. The prevalence of significant PVR was 57.06%. The distribution of PVR was skewed with values ranging from 4.0 ml to 382.9 ml, a median value of 60.5 ml (interquartile range, IQR, =25.0–100.76), and a mean value of 77.70 ± 69.30 ml. An IPSS range of 8 to 23 with a mean value of 13.64 ± 4.14 and a median value of 13 (interquartile range = 10.0-16.0) was observed. The Qmax range was from 5 ml/s to 50 ml/s with a mean value of 20.25 ± 9.70 ml/s, and a median value of 18.0 ml/s (interquartile range = 14.0–24.0). Conclusion: This study showed that the prevalence of significant PVR volume among men with symptomatic BPH in our environment is high. There was also a high variation in the distribution of PVR among the subjects. Therefore, it is essential to create more public awareness especially among men in their fourth decade of life and above to visit a urologist whenever they have BPH symptoms so as to avoid impairment in quality of life and renal function associated with neglected significant PVR.