Comparison of Intrathecal Fentanyl and Buprenorphine as an Adjuvant to 0.5% Hyperbaric Bupivacaine for Spinal Anesthesia

PURPOSE: This study was designed to evaluate and compare three groups, that is, (1) normal saline 0.5 mL with 15 mg of 0.5% hyperbaric bupivacaine normal (BN), (2) intrathecal fentanyl 25 μg (0.5 mL) as an adjuvant to 15 mg of 0.5% hyperbaric bupivacaine fentanyl (BF), and (3), 150 μg buprenorphine with 15 mg of 0.5% hyperbaric bupivacaine buprenorphine (BB) with respect to the onset and duration of sensory and motor spinal block, level of anesthesia, effects on hemodynamic parameters, requirement of postoperative analgesia, and side effects in patients aged 16–60 years undergoing surgical and orthopedic procedures requiring spinal anesthesia. METHODS: A prospective, observational study was performed at a single center with 90 consecutive patients enrolled as per the inclusion criteria. Patients were divided into three groups of 30 each based on drugs administered, BN, BF, and BB groups, and outcome measures were recorded. The three groups were compared with the analysis of variance test for the continuous variables, with P < 0.05 considered statistically significant. RESULTS: The groups were similarly matched with respect to age. The earliest onset of sensory block was in the BF group (2.87 min), P < 0.05. Similarly, the mean time to achieve the highest sensory level was least in the BF group (9.63 min), P < 0.05. The onset of motor blockade was earliest in the BB group (7.65 min), P < 0.05. The mean time for two segment regression was maximum in the BB group (126.03 min), P < 0.05. The mean time for regression to L1 was the longest in the BB group (200.83 min), P < 0.05. Maximum duration of analgesia after spinal drug administration was the highest in the BB group (412.17 min), P < 0.05. CONCLUSION: The addition of both buprenorphine 150 μg and fentanyl 25 μg to 0.5% hyperbaric bupivacaine 15 mg enhances the quality and duration of sensory block for spinal anesthesia providing better postoperative analgesia, while decreasing the incidence of complications associated with each drug alone.