In women with urinary incontinence how necessary is cystometry?

OBJECTIVES To evaluate the role of cystometry in the diagnostic evaluation of patients with symptoms of overactive bladder, by comparing the treatment outcome in those with and without urodynamically proven bladder instability. METHODS Prospective observational study performed at Urogynaecology Division, the Kidney Center Post-Graduate institute of nephro-urology, Karachi. Forty six patients with symptoms of overactive bladder, i.e., frequency (> or =8 voids/24 hours), nocturia, urgency with or without urge incontinence, were included. Patients were recruited solely on their symptoms of overactive bladder. All patients, irrespective of the results of cystometry were subsequently treated with oxybutynin 2.5 mg twice daily along with bladder training. Involuntary detrusor contraction over base line during filling are considered significant (AUA Update series). Following variables were compared in those with or without urodynamically proven bladder instability: the bladder volume and amplitude of detrusor contraction at first and maximum detrusor contractions, the treatment outcome and relapse rate The complications of the procedure were noted. RESULTS Total number of 46 women, aged between 21-74 years with symptoms of overactive bladder were subjected to cystometry. The audit of cystometry showed unstable bladder in 17 (36.9%), while rest of the patients 29 (63%) had normal stable bladder with normal emptying. The comparison of treatment outcome in the urodynamically stable and unstable bladder revealed out of 17 unstable bladder with symptoms of OAB in 09 (60%) and 05 (29.4%), a 100% cure rate was observed after 3 and 6 months of treatment respectively. Of the 29 patients with stable bladder and symptoms of OAB, 100% cure rate was achieved in 20 (68.9%) and 06 (20.6%) patients respectively. While in 3 patients in both groups, decrease of symptoms upto 75% after 6 months of treatment was observed. The median volume was less and amplitude of first and maximum detrusor contraction were more in unstable than stable bladder but it was not significant statistically. CONCLUSION Conventional Cystometry showed poor co-relation with Lower urinary tract symptoms (LUT). Both urodynamically proven unstable and stable bladder showed nearly equal improvement with treatment