Urology>>>>>Benign Prostatic Hyperplasia (BPH) and Lower Urinary Tract Symptoms (LUTS)
Question 11#

An 82-year-old man with mixed storage and voiding LUTS is referred for urodynamics. His Qmax is 15 mL/s and a pdet at Qmax of 85 cm H20. What is the bladder outlet obstruction index for this man?

A. 45
B. 50
C. 55
D. 70
E. 103

Correct Answer is C


Answer C

When performing urodynamics the diagnosis of bladder outlet obstruction is made by plotting the maximum flow rate (Qmax) against detrusor pressure at Qmax (pdetQmax) into the International Continence Society Nomogram. The degree of obstruction is calculated using the Bladder Outlet Obstruction Index (BOOI) equation: BOOI = pdet@Qmax – 2Qmax.

If the BOOI is >40 then the patient is obstructed, if it is below 20 then the patient is unlikely to be obstructed and between 20–40 the findings are equivocal.