Usefulness of 0.5% Hyperbaric Bupivacaine with Dexmedetomidine on Spinal Anaesthesia in Lower Limb Orthopaedic Patients

Background: The present study was conducted to assess the usefulness of 0.5% hyperbaric bupivacaine with dexmedetomidine on spinal anesthesia in lower limb orthopedic patients. Subjects and Methods: This study involved 50 patients with ASA Grade I and II of both genders. Patients were randomly allocated into group I (n=25) Patients received Dexmedetomidine 0.5 µ g/kg over 15 minutes using an infusion pump 20 minutes prior to SAB and group II (n=25) Intraoperatively HR, BP and SpO2 were measured and noted. Results: The mean heart rate at baseline was 80.00 8.49 in group I and 81.80 8.74 in group II. The mean heart rate at 5 minutes was 73.80 13.38 in group I which was significantly higher (p=0.02) compared to 65.63 12.45 in group II. The mean arterial pressure at baseline was 97.64  5.24 in group I and 97.73  6.96 in  group II suggesting MAP in both groups was comparable. The MAP at 5 minutes was 90.73 14.65 in group I which was significantly higher (p=0.01) compared to 81.22 11.64 in group II, suggesting a greater fall from the baseline in group II compared to group I. The MAP in both groups was found to be comparable at 15, 30, 45, 60, 75, 90, 105, 120 minutes (p>0.05). The oxygen saturation in both groups was found to be comparable at all time intervals. The duration of onset of sensory blockade (Time is taken to reach T10 level) in 53.33% of patients in Group I is between 1 to 2 minutes (60 to 120 seconds) and less than 1 minute (60 seconds) in 46.67% of patients. The average mean time and standard deviation of onset of sensory blockade in Group I is 66 44.14 seconds. Conclusion: Authors found that dexmedetomidine was given intravenously as premedication before spinal anaesthesia using injection bupivacaine results in a quicker onset of analgesia, prolonged duration of sensory, motor block and well balanced hemodynamic parameters.