Comparative evaluation of intrathecal preservative free isobaric 0.5% ropivacaine with isobaric 0.5% bupivacaine in patients undergoing lower abdominal surgeries

Abstract

Background: Spinal anaesthesia is the frequently used central block used in a surgical procedure. Different local anaesthetic drugs used in spinal anaesthesia differ in their analgesic property, lipid solubility, protein binding, pKa, and degree of spread, the baricity of solution being one of the primary determinants of spread of solutions. Aims: To compare and evaluate the anaesthetic profile of preservative free 0.5% isobaric ropivacaine and bupivacaine in patients undergoing lower abdominal surgeries. Materials and Methods: The clinical study enrolled 100 patients posted for lower abdominal surgeries under spinal anaesthesia. All the patients were then randomized and received either isobaric preservative free 3ml(15mg) of 0.5% bupivacaine (Group A, n=50) or 3ml(15mg) of 0.5% ropivacaine (Group B, n=50). Onset and duration of sensory and motor blocks, haemodynamic changes and any other side effects were noted.Results: Demographic variables between the two groups were not significant. Onset of sensory block was delayed in ropivacaine group B (4.80 ± 0.92 vs 4.35 ± 0.88 min, p <0.05) than group A, whereas duration was found to be significantly more in group A (170.29 ± 14.14 vs 155.77 ± 13.97min, p<0.05) than group B. Onset of motor block was also earlier in group A than group B with p value< 0.05, whereas duration was significantly shorter in group B (140.08 ± 16.58 vs 160.95 ± 15.74min). The two groups were comparable in maximum level of blockade reached and haemodynamic parameters. Incidence of hypotension and bradycardia was significantly less in ropivacaine group. Conclusion: This study establishes that ropivacaine produces good sensory block and is more stable hemodynamically with lesser side effects.