EFFECT OF NARCOTIC ANESTHESIA AND SKELETAL-MUSCLE PARALYSIS ON PASSIVE AND DYNAMIC URETHRAL FUNCTION OF STRESS CONTINENT AND INCONTINENT WOMEN

The aim of this study was to assess the importance of conscious skeletal muscle activity on the resting and stressed urethral sphincteric mechanism in stress continent and stress incontinent women. We evaluated the effects of loss of consciousness induced by a narcotic-based general anesthetic technique, with and without concurrent skeletal muscle paralysis, urethral sphincteric function. Nine premenopausal women who underwent vaginal hysterectomy without continence surgery had passive and dynamic urethral pressure profilometry performed within 24 hours before surgery, while asleep and totally paralyzed following endotracheal intubation before the start of surgery, while asleep and totally nonparalyzed at the end of surgery, and at the time of discharge from the hospital on the second or third postoperative day. Five subjects were stress incontinent and four had mild genuine stress incontinence but did not desire continence surgery with their hysterectomy. Measurements analyzed included urethral maximum closure pressure (MUCP) and functional length (FUL) from the passive profiles and bladder to urethra pressure transmission ratios (PTR) for each quarter of the urethra from the dynamic profiles. We found significant attenuation of urethral sphincteric function with stress due to muscle paralysis and loss of consciousness independent of muscle paralysis. Passive urethral function was more significantly depressed by paralysis than by loss of consciousness. These changes were statistically significant only in stress continent subjects and not in the stress incontinent subjects, an observation that supports other evidence suggesting that there are important neuromuscular components in the pathogenesis of stress incontinence.