Comparison of Intrathecal Fentanyl and Butorphanol as an Adjuvant to Intrathecal Bupivacaine 0.5% in Infraumbilical Surgeries- A Randomised Double Blind Study

Abstract

Introduction: Neuraxial opioids are widely used as adjuvants to local anaesthetic as they improve quality and duration of block. Neuraxial opioids like Butorphanol and Fentanyl allow prolonged analgesia in the postoperative period and faster recovery from spinal anaesthesia. Aim: To compare the safety and efficacy of Butorphanol and Fentanyl combined with bupivacaine for spinal anaesthesia in infraumbilical surgeries. Materials and Methods: The present study was a randomised controlled trial in which 110, ASA I and II patients of either sex who underwent elective infraumbilical surgeries under spinal anaesthesia were selected. Patients were allocated randomly into two groups A (n=55) and B (n=55). Group A (F) received intrathecal 0.5% hyperbaric bupivacaine 12.5 mg (3 mL) with fentanyl 25 microgram (0.5 mL) to make it total 3.5 mL. Group B (B) received intrathecal 0.5% hyperbaric bupivacaine 12.5 mg (3 mL) with butorphanol 250 microgram (0.25 mL) and Normal Saline (NS) 0.25 mL to make it total 3.5 mL. Heart Rate (HR), Systolic and Diastolic Blood Pressure (SBP, DBP), two segment regression time of sensory block, motor block were assessed at preset intervals. Chi-square test or Fischer’s-exact test were used and a p-value ≤0.05 was considered as statistically significant. Results: Mean of two segment sensory regression time of Group A was 41.94±1.73 minutes and Group B was 50.56±4.43 minutes (p<0.0001). Time to onset of motor block in Group A was 5.28±.32 minutes and Group B was 5.27±.32 minutes (p=0.96). Mean duration of motor block in Group A was 81.23±4.87 minutes and Group B was 109.83±2.61 minutes (p<0.0001). Time to rescue analgesic was 289.27±7.37 minutes in Group A and 378.41±10.25 minutes in Group B (p<0.0001). HR, SBP and DBP were comparable among the groups. Conclusion: Intrathecal bupivacaine-butorphanol mixture was clinically better as it provided longer duration of analgesia with lesser incidences of pruritus and nausea/vomiting compared to intrathecal fentanyl-bupivacaine mixture.