Efficacy of epidural dexamethasone versus fentanyl on postoperative analgesia.

Purpose: Dexamethasone has analgesic, anti-inflammatory, and antiemetic effects. This prospective, randomized, double-blind, controlled study was designed to evaluate the efficacy of adding dexamethasone versus fentanyl to epidural bupivacaine on postoperative analgesia.

Methods: Ninety patients ASA I-II scheduled for lower abdominal surgeries were randomly allocated into three groups to receive a total of 10 mL epidural plain bupivacaine 0.25% in the control group (group B), with either 50 microg fentanyl in group BF or 4 mg dexamethasone in group BD. Patients then received general anesthesia. Sedation, satisfaction, and visual analogue pain scores (VAS) were measured postoperatively. Meperidine was administered when VAS > or =4. Intraoperative fentanyl dose, postoperative meperidine consumption, and the time to first analgesic requirement were recorded.

Results: Intraoperative fentanyl requirements were comparable among groups. Time to first analgesic requirement was significantly prolonged (5.2 times) in the BF group and (4.8 times) in the BD group compared with group B (p < 0.01). There was significant reduction in postoperative meperidine consumption during the first 24 h in the BF and BD groups (65, 62.5% respectively) in comparison with group B (p < 0.01). VAS scores were significantly lower and patient satisfaction score was significantly higher in the BF and BD groups compared with group B (p < 0.01). Postoperative nausea was significantly lower in the BD group versus the B and BF groups (p < 0.05).

Conclusions: This study revealed that epidural bupivacaine-dexamethasone admixture had almost the same analgesic potency as bupivacaine-fentanyl with opioid-sparing and antiemetic effects. Further studies are required to evaluate the optimum dose of epidural dexamethasone for postoperative analgesia.