A Comparative Study between Hyperbaric Bupivacaine with Fentanyl and Hyperbaric Bupivacaine with Dexmedetomidine in Spinal Anesthesia for Lower Limb Orthopedic Surgery

Abstract

Introduction: Lower limbs surgery is a wide known phenomenon in the field of medical science, research and technology and spinal block is a common procedure for lower limbs surgery. Fentanyl is a synthetic opioid with central action, which is used widely for pain control. Intrathecal fentanyl is usually added to other local anesthetics to increase anesthesia and analgesia. It has improved spinal anesthesia and reduced the anesthetic drug related side effects including pruritus nausea and vomiting’ and dexmedetomidine is a potent and highly selective a-2 adrenoceptor agonist with analgesic potency have been used in spinal anesthesia to prolong intraoperative and postoperative analgesia. However, here the researcher purposively, wanted to explore a double blind clinical trial between hyperbaric bupivacaine with fentanyl and hyperbaric bupivacaine with dexmedetomidine in spinal anesthesia for lower limb orthopedic surgery. The aim of this study was to observe and compare the onset & duration of motor & sensory block, hemodynamic effect, postoperative analgesia & adverse effect of each group. Material & Methods: This was a randomized double blinded clinical trial. A total of 60 patients of both genders aged 18 to 50 years, American Society of Anaesthesiologist (ASA) physical status I and II who underwent lower limb orthopedic surgery were enrolled into the present study. Considering the sample size of 30 patients were selected for each group in our study. The patients received 15mg hyperbaric bupivacaine 0.5% plus 10 micrograms dexmedetomidine (Detomax) (BD group) & 25 micrograms fentanyl (Opifen) (BF group) respectively. Time to reach the highest sensory level, the complete motor block, regression from block, analgesic request and duration of the drug effect, hemodynamic changes and side effects were compared between the groups. Simple statistical tools were used to analyze the collected data and calculation. This present study was conducted in the Department of Anesthesiology at Kurmitola General Hospital, Dhaka, Bangladesh, during 1st July 2019 to 31stJanuary 2020. Results: A total of 60 patients had selected during the study period.(Table I) shows the characteristics of the studied participants were comprising the primary analysis study population both groups had each 30 participants. Majority (56.67%) of cases was female and (43.33%) were male in the group BF and (36.67%) were male and (63.67%) were female in group BD. The age distribution of the studied
participants majority (60%) were aged 18-40 years and 41-50 were (40.00%) in group BF. In group BD majority (66.67%) were 18-40 years and 41-50 were (33.33%). Sixty patients were randomly allocated to two groups of 30 patients. There was no significant difference between the groups in baseline findings. Time to reach the highest sensory level was shorter in BD group than BF group (6.33±1.69 vs 7.15±1.35, p=0.042). Time to reach complete motor block, there was no significant difference (p=0.171). Time to regress two sensory level(67.22±6.69 vs 87.98±11,98 min, p<0.001) and to regress S1(242.10±21.99 vs 330.10±43.98,p<0.001) between BF & BD Group. Group BD has longer duration to regress to Bromage 0 (P<0.001), to analgesic request (222.10±21.99 vs 295.98±45.10 min, p<0.001), and nonsignificant lower mean of NRS after six hours of operation (6.32±1.16 vs 6.17±1.43.p<0.657). There was no significant hemodynamic change between two groups and side effects were comparable. In two groups highest sensory block occurred in T6 dermatome (Table III). T5 dermatome was the second highest in BD group and T7 dermatome was second highest in BF group. We did not observe respiratory depression in any of the patient from either group. Conclusion: Hyperbaric bupivacaine with Dexmedetomidine is a superior anaesthesia technique alternate to hyperbaric bupivacaine with fentanyl in spinal anaesthesia for lower limb orthopaedic surgery.