Intrathecal Buprenorphine versus Intrathecal Fentanyl as Adjuvants to Hyperbaric Bupivacaine in Spinal Anaesthesia for Lower Segment Caesarean Sections: A Randomised Clinical Study

Introduction: Spinal anaesthesia is the choice technique for Lower Segment Caesarean Section (LSCS). When using subarachnoid block (spinal analgesia), opioids are employed as the main adjuvants along with local anaesthetics to achieve intra/postoperative analgesia. These opioids have desirable properties such as reducing the dose of local anaesthetics, minimising side-effects, providing analgesia, and prolonging the duration of anaesthesia.<br />Aim: To evaluate and compare the efficacy between intrathecal Buprenorphine and Fentanyl as adjuvants to hyperbaric bupivacaine (0.5%) in women undergoing LSCS under spinal anaesthesia.<br />Materials and Methods: A randomised double-blinded clinical trial was conducted at Bharati Vidyapeeth Hospital and Research Centre in Pune, Maharashtra, India between July 2021 and February 2022. A total of 80 parturients with American Society of Anaesthesilogists (ASA) grade II, aged 18 and older, scheduled for elective LSCS, were randomly divided into two groups of 40 each. Group B received 1.8 mL of 0.5% Bupivacaine with 60 mu g Buprenorphine, while Group F received 1.8 mL of 0.5% Bupivacaine with 25 mu g Fentanyl. The onset/duration of motor block and sensory block, intraoperative haemodynamics, side-effects, postoperative pain, and demand for the first rescue analgesia were assessed using Chi-square test, Fisher's-exact probability test, or independent sample t-test.<br />Results: Demographic data such as age, weight, Body Mass Index (BMI), and ASA grade were similar in both groups. The mean duration of surgery in Group B and Group F was 48.12 +/- 6.86 min and 48.25 +/- 6.56 min, respectively. The mean duration of sensory blockade in Group B was 264.38 +/- 37.16 min, and in Group F it was 193.50 +/- 34.27 min. The total duration of motor block was 231.00 +/- 43.74 minutes in Group B and 171.00 +/- 36.87 min in Group F. The total duration of sensory and motor block in Group B was significantly longer (p-value <0.05). The mean time to first rescue analgesia in Group B and Group F was 304.63 min and 228.63 min, respectively (p-value <0.05).<br />Conclusion: The present study concluded that both drugs are safe and suitable as adjuvants with local anaesthetics in spinal anaesthesia for LSCS. The addition of intrathecal buprenorphine to bupivacaine provides a more promising postoperative analgesic effect compared to intrathecal fentanyl, without causing any significant maternal or neonatal side-effects.