Assessing the Efficacy of Intrathecal Ultra-Low Dose Buprenorphine with Hyperbaric Bupivacaine in Infraumbilical Surgeries: A Randomised Control Study

Abstract

Introduction: Pain management is one of the defining roles of an anesthesiologist. Across the world, infraumbilical surgeries are carried out under subarachnoid blocks. However, one of the major limiting factors of spinal anesthesia is limited block duration. The addition of opioids and other adjuvants prolongs the block duration but a high dose of intrathecal opioids is associated with adverse events. This study was carried out in an attempt to evaluate ultra-low dose buprenorphine administered intrathecally and its effect on bupivacaine spinal anesthesia.

Material and Methods: The present prospective doubleblind study was undertaken on ninety American Society of Anaesthesiologists I and II patients between 18 and 60 years of age undergoing subarachnoid block for lower limb surgery. Group 1 (n = 45) patients were administered 3 mL of injection bupivacaine heavy 0.5% with 30 mcg of buprenorphine while group 2 (n = 45) was administered 3 mL of injection bupivacaine heavy 0.5%. The following parameters were observed: Onset times and duration of sensory and motor block, time for a 2-segment dermatomal recession, hemodynamic parameters and side effects if any. Data were analyzed by appropriate statistical tests and p < 0.05 were considered significant.

Results: The two groups were comparable in terms of the demographic profile, and onset of sensory blockade mean time taken to achieve the highest level of sensory blockade. Most patients in both groups achieved a maximum sensory level of T4 (n = 29 vs n = 26). However, 2-segment regression time and time for complete sensory recovery was significantly higher in patients who received intrathecal buprenorphine (145.36 ± 7.34 vs 78.956 ± 7.845; p < 0.0001) and (327.31 ± 11.151 vs 160.31 ± 16.258; p < 0.0001). Both groups were comparable in terms of grade III motor block onset and duration (12.620 + 0.79 vs 12.827 + 0.77; p = 0.2215) and duration of motor block (122.58 + 9.117 vs 119 + 16.396; p = 0.2039). There was no significant difference in terms of side effects between the two groups.

Conclusion: Intrathecal buprenorphine is a viable alternative for prolonging sensory block in spinal anesthesia without affecting motor blockade and no significant adverse events.