Impact of intrathecal morphine on the tolerance of early feeding after cesarean section

Introduction. - Early feeding is well tolerated in patients undergoing caesarean section under general or regional anaesthesia. Intrathecal morphine is effective for postoperative analgesia but can induce nausea and vomiting which may hamper feeding. This study assessed prospectively the effects of intrathecal morphine on early feeding in patients undergoing caesarean section. Methodology. - After ethical committee approval, 66 consenting women scheduled for caesarean section were randomized to receive intrathecal morphine 0.1 mg (group M, n = 32) or not ("control group", group C, n = 34) at the time of intrathecal anaesthesia performed with a 3 ml mixture containing 8.6 mg bupivacaine, 64 mu g clonidine and 4.3 mu g sufentanil. Standard antiemetic prophylaxis (5 mg dexamethasone + 2 mg tropisetron) was administered intravenously in all patients after umbilical cord clamping. Standardized multimodal analgesia was initiated postoperatively with 1 g of paracetamol and 30 mg of ketorolac given every 6 hours. Analgesia was evaluated by a numeric rating scale (NRS) at 4 hours intervals and 10 mg of oral morphine was administered if the NRS score exceeded 3. All patients received a protein enriched solution, 8 hours after caesarean section and were allowed to eat solid food on postoperative day 1. Nausea and vomiting episodes, gas and/or stools emission, itching, NRS score and morphine consumption were recorded on the first, second and fourth postoperative hour and then every 4 hours during 48 hours. Results. Nausea was significantly more frequent and persisted longer in group M. Vomiting occurred equally in both groups and stopped after feeding. Gas and/or stools emission appeared within 48 hours postoperatively in 72 and 77 % of patients in group M and group C respectively. Oral morphine consumption was significantly lower in group M (1.9 +/- 4 vs 6.5 +/- 7.3 mg, p = 0.006). When compared to group C, NRS were also lower in group M from the second to the 20th postoperative hour. Itching was observed more frequently and persisted longer in group M. Discussion and conclusion. A small dose of intrathecal morphine provided adequate and prolonged pain relief after caesarean section but increased the incidence of nausea and vomiting despite antiemetic prophylaxis. Oral food intake was not hampered by intrathecal morphine. (C) 2009 Elsevier Masson SAS. All rights reserved.