Patient-controlled analgesia with morphine and droperidol following caesarean section under spinal anaesthesia

Abstract

Background: The addition of droperidol to morphine for patient-controlled analgesia reduces the incidence of nausea and vomiting, but may result in unwanted side effects.

Method: We studied 40 women randomised to receive morphine sulphate with or without added droperidol (10mg droperidol/60 mg morphine) by patient-controlled analgesia following elective caesarean section under spinal anaesthesia.

Results: Median morphine demand in the 20 h after surgery was 74 mg with morphine alone, and 53 mg with added droperidol, the median consumption of which was 8.8 mg. The incidence of nausea was reduced from 80% to 38.8% (P < 0.01), and that of emesis from 55% to 16.7% (P < 0.05) by the addition of droperidol. Psychomotor function was significantly impaired to a similar degree in both groups and there was no significant difference in sedation scores or pain scores. Subjective drowsiness which resulted in withdrawal from the study occurred in two patients, both of whom were receiving droperidol, and though all patients who completed the study were satisfied with their analgesia overall, significantly more of those receiving unsupplemented morphine (11/19 compared with 4/18, P < 0.05) described it as excellent.

Conclusion: The addition of droperidol 10 mg to morphine 60 mg for PCA following caesarean section under spinal anaesthesia reduces the incidence of nausea and emesis, but may result in drowsiness, limiting the usefulness of the technique.