A provocative maneuver to elicit cystometric instability: Measuring instability at maximum infusion

Purpose: We identify a provocative maneuver to enhance the sensitivity of c ystometry in detecting detrusor instability when urge incontinence is suspe cted based on clinical history. Materials and Methods: A total of 134 consecutive women with clinical urge incontinence underwent carbon dioxide cystometry between August 1995 and Oc tober 1996. The bladder was filled to maximal capacity with the patient sup ine. Six provocative maneuvers were performed consecutively to evoke detrus or instability, including lying supine, rising to a seated position, walkin g toward the bathroom, handwashing, coughing and sitting on the toilet with instructions not to void. Subjects were divided into 2 groups depending on the order of maneuvers. Sitting on the toilet was the last maneuver for gr oup I (80 patients) and was in the middle of the sequence for group 2 (54). Results: Sitting on the toilet evoked detrusor instability in 37.5% of grou p 1 and 53.8% of group 2. This maneuver with instructions not to void was t he most provocative stimulus in eliciting detrusor instability with a detec tion rate of 68.4% for all subjects. Conclusions: Sitting on the toilet with the bladder at maximal capacity is the most provocative maneuver for detecting detrusor instability. The incid ence of suspected detrusor instability is enhanced by using this test durin g routine cystometry.