The Correlation between Symptom Score and Urodynamic Parameters in Diagnosing Benign Prostatic Hyperplasia / 대한비뇨기과학회지

ABSTRACT

PURPOSE: Although symptom score, peak flow rate(Qmax), postvoid residuals(PVR) and prostate volume are measured in the diagnosis of bladder outlet obstruction(BOO) caused by benign prostatic hyperplasia, pressure flow study is the most objective parameter in diagnosing BOO. To predict the degree of bladder outlet obstruction or detrusor contractility, correlations between clinical and urodynamic parameters such as linear passive urethral resistance relation(L-PURR) nomogram were estimated and also determined whether it is possible to predict the presence of BOO by non-invasive clinical variables in patients with lower urinary tract symptoms(LUTS). MATERIALS AND METHODS: The study was composed of 56 male patients referred for urodynamic study due to LUTS. Patients with disease that might directly or indirectly affect detrusor function and those undergone operation may affect bladder mechanics were excluded from the study. BPH was diagnosed by symptom score(IPSS), uroflowmetry, transrectal ultrasound and urodynamic study. Correlations between L-PURR nomogram grade and other clinical variables(symptom score, Qmax, PVR and prostate volume) were obtained. Predictive value of peak flow rate and prostate volume in diagnosing bladder outlet obstruction were also determined. Comparison of clinical and urodynamic parameters between obstructive(LPURR>3) and nonobstructive as well as those between normal and low contractility groups were performed. RESULTS: Grade of obstruction in urodynamic study correlated with symptom score(r=0.34, p<0.05) and peak flow rate(r=-0.36, p<0.01) but not with PVR and prostate volume. Contractility grade didn`t correlate well with other clinical parameters. Obstruction grade correlated with voiding symptom(question 1, 6) and bother score(r=0.34, p<0.05, r=0.42, p<0.01, r=0.49, p<0.01, respectively). Voiding symptoms(question 1, 5), bother and total symptom score were significantly greater in obstructive group than in nonobstructive one. Qmax was significantly lower in obstructive than in nonobstructive group(8.9+/-0.9 vs 14.0+/-1.0ml/sec, p<0.01). Detrusor pressure at peak flow was significantly greater in obstructive than in nonobstructive group (76.6+/-16.7 vs 42.2+/-3.1cmH2O, p<0.01). Positive predictive values of BOO were 86.2% if Qmax is less than 10ml/sec but 15.4% if Qmax is more than 15ml/sec(x2=16.6, p<0.01). CONCLUSIONS: Obstruction grade of L-PURR correlated well with obstructive symptom and negatively with peak flow rate. Obstructive symptoms in the obstructive group were significantly higher compared to those in the nonobstructive group. Peak flow rate combined with L-PURR seems to be effective parameters in predicting obstruction. Conclusively, L-PURR nomogram was thought to be a good parameter in predicting the presence and degree of bladder outlet obstruction caused by BPH.