Comparison of Intrathecal 0.5% Hyperbaric Bupivacaine with 0.5% Hyperbaric Ropivacaine in Infraumbilical Surgeries

Introduction: A 0.5% hyperbaric bupivacaine has been extensively used for spinal anaesthesia. It provides an intense motor block, of longer duration which is usually not needed for perineal and lower limb surgeries. Ropivacaine is a relatively new amino-amide local anaesthetic that appears to be less potent and gives less intense motor block of shorter duration as compared to bupivacaine. Ropivacaine also has less cardiovascular and central nervous system toxicity than bupivacaine. It is well established that addition of dextrose to local anaesthetic increases the specific gravity there by providing more reliable block as compared to isobaric solutions. This improves their anaesthetic profile by giving higher cephalad spread and good muscle relaxation. Hyperbaric solutions give more predictable block with greater spread in the direction of gravity. Methods: The present study was conducted in a Tertiary health centre for 18 months amongst 150 patients posted for infra umbilical surgeries. The study population was divided into two groups of 75 each, Group B and Group R. Group B: Group of 75 patients received 3 ml of 0.5% hyperbaric bupivacaine. Group R: Group of 75 patients received 3ml of 0.5% hyperbaric Ropivacaine. Assessment of sensory and motor blockade was done using pin prick and Bromage scale respectively. Results: The demographic parameters like age, sex, weight, ASA grading and duration of surgery were comparable. The onset time of sensory blockade to T10 dermatome was significantly earlier in group B than group R. The mean time for onset of Peak sensory blockade T6 dermatome in group B (6.05±1.05min) than in group R (10.05±2.06min) and difference between them was statistically significant. The mean time for onset of maximum motor blockade T6 dermatome in group B (10±0.15min) than in group R (10.75±1.30min) and difference between them was statistically significant. The total duration of motor block in group B was 150 ± 35.09 min and in group R was 120 ± 30.09 min. Maximum motor blockade was achieved significantly earlier in group B than group R. The total duration of sensory blockade in group B was significantly prolonged in group B than in group R. Conclusion: Finally, we conclude that freshly prepared hyperbaric 0.5% Ropivacaine is a better alternative to hyperbaric 0.5% Bupivacaine for undergoing infraumbilical surgeries with faster onset of motor block, better haemodynamic stability, lower incidence of adverse effects and early recovery of sensory and motor block.