Postoperative urinary retention in general surgical patients.

A prospective study has been performed to measure the incidence of postoperative urinary retention in 280 general surgical patients. Eighteen patients (6 per cent) were catheterized after a range of operations under general anaesthesia. There was no statistical difference in the retention rate between men and women. Increasing age did not predispose to retention of urine. Of 72 patients who had either herniorrhaphy, haemorrhoidectomy or testicular operations, only 1 was catheterized, whereas 16 (23 per cent) of 70 patients undergoing laparotomy were catheterized. Most of these laparotomy patients had upper abdominal procedures carried out. Those having lower abdominal operations were usually catheterized pre-operatively and were excluded from the study. There was a significantly higher incidence of retention among patients who had long anaesthetics (greater than 60 min). There was also a significantly higher incidence of retention among those who were ventilated, relaxed and reversed by atropine and neostigmine. Of those 193 patients who had opiate analgesia, 15 (8 per cent) developed retention of urine, compared with 3 (3 per cent) of the 87 patients who had non-opiate analgesia. There was a significantly higher retention rate among the patients who had opiate analgesia by intravenous infusion compared with those who had opiates by intramuscular bolus injection; 7 patients had painful and 11 had painless retention. This study suggests that postoperative retention of urine is a result more commonly of diminished awareness of bladder sensation, than of factors such as anxiety or local pain.