Droperidol and the side effects of epidural morphine after cesarean section.

UNLABELLED

Epidural morphine produces analgesia with a high incidence of side effects that include pruritus, nausea, and vomiting. This study investigated whether epidural or i.v. droperidol could alleviate these symptoms. In a prospective, double-blind, randomized, controlled trial, 97 pregnant women undergoing cesarean section were randomly assigned to three groups. All received standard continuous epidural anesthesia. After delivery, each received 5 mg of epidural morphine with either no droperidol injection, 2.5 mg of epidural droperidol, or 2.5 mg of i.v. droperidol. The incidence, onset, duration, and severity of pruritus; the onset and severity of pain; and satisfaction were similar for each group, but the incidence and severity of nausea and vomiting was lower in the group that received i.v. droperidol (P < 0.01). Sedation was minimal throughout the study. Thus, epidural droperidol failed to alleviate the side effects caused by epidural morphine, but i.v.droperidol reduced both the incidence and severity of nausea and vomiting. These results suggest that droperidol acts systemically to counter the effects of epidural morphine but that it is not entirely effective.

IMPLICATIONS

A single dose of epidural morphine provides long-lasting pain relief for women who have undergone cesarean section, but it has some troublesome side effects (itching, nausea, vomiting). We performed a prospective, randomized, controlled trial in 97 such women to study whether droperidol could reduce these side effects. We found that i.v. droperidol reduced nausea and vomiting but did not prevent itching, and that epidural droperidol failed to prevent all side effects.