A comparative study of spinal anesthesia with hyperbaric ropivacaine plus fentanyl and hyperbaric bupivacaine plus fentanyl in lower abdominal surgery and lower limb surgery

Abstract

Background: Ropivacaine 15 mg is found to be equivalent to 10 mg bupivacaine for knee surgery in terms of hemodynamic stability and degree of motor blockade under spinal anaesthesia. The efficacy of hyperbaric preparations of the similar doses, when mixed with an opioid was evaluated in this study. Methods: Sixty adult patients, of both sexes with American Society of Anaesthesiologists status I/II undergoing lower abdominal and lower limb surgery were enrolled in this prospective, randomized, double blind study. Patients were randomly assigned into two groups: group B (bupivacaine group) and group R (Ropivacaine group). Patients in group B (n = 30) received hyperbaric 0.5% bupivacaine (2 ml) with fentanyl 0.4 ml and normal saline (0.25 ml). Group R patients received ropivacaine 0.75% (2 ml) with fentany l 0.4 ml, 0.2 ml of 50% dextrose and normal saline (0.05 ml). The spinal block characteristics, hemodynamic parameters, and onset time to pass urine were recorded and statistically analyzed. Results: There were no differences between the two groups in the mean time to attain highest sensory block level (group R 9.10 ± 1.97 min; group B 9.17 ± 1.51min; P > 0.05) and median maximum extent (ropivacaine T6; bupivacaine T5; P > 0.05); but the mean duration of sensory block regression to S2 was significant (ropivacaine 157.44 ± 17.78 min; bupivacaine 180.60 ± 23.06 min; P < 0.001). The degree of motor block by 5 min was significantly different between the groups (ropivacaine 1.50 ± 0.82; bupivacaine 2.40 ± 0.49; P < 0.001). Patients receiving ropivacaine mobilized sooner (ropivacaine115.47 ± 17.07 min; bupivacaine 154.60 ± 20.37 min; P < 0.001) and passed urine sooner (ropivacaine 236.38 ± 90.44 min; bupivacaine 289.85 ± 73.21 min; P = 0.037). Three patients in group B required treatment for hypotension. Conclusion: Hyperbaric ropivacaine 15 mg with fentany l 20 μg was found to be a better alternative to bupivacaine (heavy) 10 mg with better block characteristics and hemodynamic stability.