Comparative Study of Hyperbaric Bupivacaine and Isobaric Ropivacaine for Lower Limb Surgery under Spinal Anesthesia
Introduction: Subarachnoid block is commonly employed technique for lower abdominal and lower limb procedures. Bupivacaine and ropivacaine are commonly used local anesthetics for subarachnoid block. The aim of this study is to compare the efficacy and safety of isobaric Ropivacaine over hyperbaric Bupivacaine.
Methods: This was a prospective comparative study for a duration of six months. 60 ASA grade I-II adult patients between 16-60 years undergoing lower limb surgery under spinal anesthesia were randomized into two groups. Group I including patients who received 15 mg of hyperbaric bupivacaine 0.5% and group II including patients who received 22.5 mg of isobaric ropivacaine 0.75%. The onset and duration of sensory and motor block and hemodynamics including heart rate (HR), non invasive mean arterial blood pressure (MAP) and respiratory depression were recorded. Data were entered in Microsoft excel and statistical analysis was done by chi square test and T test using SPSS (version 23.0).
Results: Both the groups were demographically statistically insignificant. Successful block was attained in all patients in both groups. The sensory onset and motor onset were significantly delayed in the Ropivacaine Group compared to the Bupivacaine Group P<0.001. There was no significant difference in the hemodynamics (heart rate and mean arterial pressure ).
Conclusions: Though isobaric ropivacaine provided lesser degree of sensory and motor block with delayed onset compared to hyperbaric bupivacaine, it can effectively and safely used in subarachnoid block in lower limb surgeries without any major hemodynamic changes and adverse effects.