Duration of postoperative catheterization: A randomized,doubleblind trial comparing two catheter management protocols and the effect of bethanechol chloride

A randomized trial of two postoperative suprapubic catheter clamping protocols was undertaken to compare their effect on the duration of both postoperative indwelling catheter time and hospital stay. In addition, patients were given either bethanechol chloride or placebo in a double-blind fashion to test the proposal that the use of bethanechol chloride would enhance return of bladder function and shorten postoperative catheter time. Forty-nine patients who underwent an anterior repair, Burch colposuspension or Marshall-Marchetti-Krantz (MMK) procedure were preoperatively randomized to one of two catheter clamping protocols. Protocol I involved a continuous clamping regimen with residuals measured with each void. Protocol II involved an intermittent clamping (bladder training) regimen with residuals measured at specified intervals while the catheter was in place. Each patient received either bethanechol chloride or placebo in identical capsules. Protocol I significantly shortened the duration of postoperative catheterization (P<0.01). The use of bethanechol chloride prolonged the duration of catheterization in Protocol I patients and made no difference in Protocol II patients. We would recommend our simplified catheter protocol and the avoidance of bethanechol chloride in the management of indwelling catheters after surgery for urinary incontinence.     

The use of anxiolytic and parasympathomimetic agents in the treatment of postoperative urinary retention following anorectal surgery

Approximately 30 percent of patients undergoing anorectal surgery will develop acute urinary retention. The cause of this complication is poorly understood. Anxiety, anal distention, bladder distention as a result of vigorous hydration during surgery, and reflex inhibition of the urinary bladder detrusor muscle secondary to pain have been postulated as contributing factors. A four-armed prospective, double-blind, randomized trial was carried out to determine whether an anxiolytic agent (midazolam, 5 mg intramuscularly) and/or a parasympathomimetic agent (bethanechol, 10 mg subcutaneously) reduce the incidence of postoperative urinary retention following anorectal surgery. One hundred thirty-two patients (ages, 18 to 50 years), in acute urinary retention 6 to 12 hours following anorectal surgery, were enrolled. Sixty-nine percent of patients responded to bethanechol. Side effects were minimal. Midazolam alone had no effect on retention. Bethanechol and midazolam in combination resulted in less retention than midazolam and a placebo (P<0.05). Bethanechol alone was better than a placebo (P<0.002). Mean intraoperative intravenous fluid volume for the entire study group was 900 cc. Initial postoperative urinary volumes of patients who failed the treatment protocol were significantly higher than in those responding to bethanechol (mean of 527 ccvs. 241 cc,P<0.001). The use of an anxiolytic agent was not effective in the treatment of postoperative urinary retention. Bladder distention may increase the incidence of urinary retention. Behanechol, in a dose of 10 mg subcutaneously, significantly lowered the incidence of postoperative urinary catheterization and should be considered as initial treatment of postoperative urinary retention following anorectal surgery. Poster presentation at the meeting of the American Society of Colon and Rectal Surgeons, Anaheim, California, June 12 to 17, 1988.     

Effect of intragastric and intraperitoneal water and saline loads on the pharmacologic induction of drinking in rats

Water intake, induced by subcutaneous (SC) administration of angiotensin II (AII, 200 micrograms/kg), isoproterenol (25 micrograms/kg), 5-hydroxytryptophan (25 mg/kg), and bethanechol (8 mg/kg), was reduced completely to control level by administration of either an intragastric (IG) or intraperitoneal (IP) load of distilled water (3% of body weight) prior to administration of the dipsogen. A similar load of isotonic saline given by both the IG and IP routes was either ineffective or only partially effective in reducing the dipsogenic response. The similar effectiveness of IP and IG loads of water in inhibiting the responsiveness to administration of dipsogenic agents argues against a gastrointestinal mechanism as an integral part of the feedback process limiting water intake in the rat. In addition, the lack of a significant effect of similar IP and IG loads of saline suggests that stretch of either the gastrointestinal or intraperitoneal spaces is not an important factor in the inhibition observed. A possibility exists that osmotic dilution, as a result of the water load, may play a role in the feedback inhibition of the drinking responses to the dipsogenic agents used in these studies, even though the responses were mediated via the AII receptor pathway rather than the osmoreceptor pathway.