[Postoperative analgesia after ligamentoplasty of the knee. Comparison of epidural morphine and intravenous nalbuphine].

Surgery of the anterior cruciate ligament causes severe postoperative pain. This study aimed to compare efficacy and side effects of two postoperative analgesia methods, during 24 hours. Twenty healthy patients were assigned to two groups (n = 10): the patients of the first group were given by an epidural catheter 3 mg of morphine hydrochloride, every twelve hours. The patients of the second group received 2 mg h-1 of intravenous nalbuphine. The degree of pain was studied with a visual analogue scale. After the third postoperative hour, it was significantly higher in the second group, but the nalbuphine dose was low. The incidence of respiratory depression, nausea, pruritus was not statistically different between the groups, but 7/10 patients in the first group suffered of urinary retention (the first micturition was obtained 10.5 hours after the end of surgery in the first group and 5.3 h in the second one). Two patients needed an uretral catheter. These results might tend to show a greater efficactly of epidural morphine, with a higher incidence of urinary side effects.