Dexmedetomidine versus fentanyl added to bupivacaine for epidural analgesia in combination with general anesthesia for elective lumbar disc operations: A prospective, randomized double-blinded study

BACKGROUND: The literature on drugs used for combined general anesthesia and epidural analgesia (CGE) in lumbar operations is scarce. The purpose of the study was to compare the addition of either dexmedetomidine or fentanyl to bupivacaine for epidural analgesia in combination with general anesthesia with regard to efficacy and adverse events in such operations. MATERIALS AND METHODS: This prospective, randomized, double-blinded study was conducted on 80 patients who were scheduled for an elective lumbar disc operation, age 20–65 years, of either sex and American Society of Anesthesiologists physical status I or II. They were randomly allocated into one of the two groups – group bupivacaine-dexmedetomidine (BD) (n = 40): patients who received CGE with 15 mL of bupivacaine 0.20% plus 50 μg of dexmedetomidine and group bupivacaine-fentanyl (BF) (n = 40): patients who received CGE with 15 mL of bupivacaine 0.20% plus 50 μg fentanyl. The primary outcome was time to first analgesic requirement, whereas the secondary outcomes were the total opioid consumption and pain scores during the first 24 h. The incidence of adverse postoperative (PO) effects related to the study drugs, such as sedation, nausea and vomiting, pruritus, shivering, and respiratory depression, was also documented. RESULTS: Patients in the BD group experienced a significantly prolonged pain-free period, lower total opioid consumption, and lower pain scores than patients in the BF group (P < 0.001). Patients in the BD group showed a significantly lower intraoperative heart rate and mean blood pressure (P < 0.001). Regarding adverse events, there were greater PO sedation scores (P < 0.001) and less frequent episodes of PO nausea and vomiting in the BD group. In addition, patients in the BD group showed less pruritis and shivering. There were no reported cases of respiratory depression in either group. CONCLUSION: CGE with bupivacaine plus dexmedetomidine provided better PO pain control than bupivacaine plus fentanyl, with fewer adverse events overall.