Epidural morphine and neostigmine for postoperative analgesia after orthopedic surgery

In this study, we examined the side effects and analgesia of the combination of epidural neostigmine and morphine in patients undergoing orthopedic surgery. Sixty patients undergoing knee surgery were divided into four groups. The intrathecal anesthetic was 15 mg of bupivacaine. The epidural test drug was diluted in saline to a final volume of 10 mL. The control group received saline as the epidural test drug. The morphine group received 0.6 mg of epidural morphine. The neostigmine group (NG) received 60 micro g of epidural neostigmine. The morphine/neostigmine group received 0.6 mg of epidural morphine combined with 60 micro g of epidural neostigmine. The groups were demographically the same and did not differ in intraoperative characteristics. The visual analog scale score at first rescue analgesic and the incidence of adverse effects were similar among groups (P > 0.05). One patient from the NG complained of intraoperative nausea, closely related to spinal hypotension. Postoperatively, two patients from the NG had vomited once. The time (min) to first rescue analgesic was longer in the morphine/neostigmine group ( approximately 11 h) compared with the other groups (P < 0.05). The analgesic consumption (number of analgesic administrations in 24 h) was larger in the control group compared with the other groups (P < 0.05). IMPLICATIONS: The combination of epidural morphine and epidural neostigmine resulted in postoperative analgesia (11 h) devoid of side effects, being an alternative analgesic technique in the population studied.