Postcesarean delivery epidural patient-controlled analgesia. Fentanyl or sufentanil?

The highly lipid-soluble opioids, fentanyl and sufentanil, frequently are used in combination with local anesthetic agents and/or epinephrine to provide postoperative epidural analgesia. The authors compared the incidence of side effects and patient satisfaction during prolonged epidural patient-controlled analgesia (PCA) infusions of these opioids in combination with bupivacaine and epinephrine.

Using a double-blind study design, 250 patients scheduled for elective cesarean delivery were, on arrival in the postanesthesia care unit, randomized into two epidural PCA infusion groups: group I (n = 125) received fentanyl 2 micrograms/ml with bupivacaine 0.01% and epinephrine 0.5 micrograms/ml and group II (n = 125) received sufentanil 0.8 micrograms/ml with bupivacaine 0.01% and epinephrine 0.5 microgram/ml. The initial infusion rate was 16 ml/h with self-administered 3-ml boluses every 15 min by PCA as desired. At intervals after discontinuation of the infusion, plasma samples were obtained to determine opioid concentrations.

The median overall satisfaction scores were 9.0 for group I and 10.0 for group II (difference not significant). Pain relief was satisfactory and comparable in both groups, and all patients could ambulate easily. The total number of times PCA requests were made was greater (P < 0.05, by Wilcoxon rank-sum test) for group I than for group II (106.7 +/- 312 vs. 70.8 +/- 138). There were no differences between the groups with respect to incidence of pruritus, sedation, and nausea; however, vomiting occurred more frequently with sufentanil than with fentanyl (12% vs. 4.8%, respectively; P < 0.05). At approximately 1-2 h after discontinuation of the infusion, 1 patient receiving fentanyl and 42 patients receiving sufentanil complained of lightheadedness and dizziness (P < 0.0001).

Epidural PCA in both groups had no serious side effects and achieved a high level of patient satisfaction. Those receiving sufentanil made fewer PCA requests but had a significantly greater incidence of vomiting during the infusion and dizziness after the termination of the infusion. Epidural sufentanil offered no advantages over epidural fentanyl.