Intrathecal 0.75% Isobaric Ropivacaine Versus 0.5% Heavy Bupivacaine for Elective Cesarean Delivery: A Randomized Controlled Trial

摘要

OBJECTIVE: Ropivacaine, a local anesthetic with duration of action of 2-3 hours, has shown greater selectivity for sensory blockade along with lower systemic toxicity as compared to bupivacaine when used for spinal anesthesia. This study was aimed to compare the intrathecal efficacy and safety of 0.75% isobaric ropivacaine for cesarean delivery with 0.5% heavy bupivacaine in parturients. MATERIALS AND METHODS: We enrolled 46 parturients of ASA (American Society of Anesthesiologists) grade I-II scheduled for elective cesarean delivery under spinal anesthesia for this prospective randomized control trial. The patients were randomized to receive either 12.5 mg of 0.5% hyperbaric bupivacaine or 24 mg of 0.75% isobaric ropivacaine intrathecally. Intraoperative hemodynamic parameters, characteristics of sensory and motor nerve block, neonatal outcome and maternal adverse effect (such as hypotension, bradycardia, nausea, vomiting, shivering or pruritis) were evaluated. RESULTS: Baseline demographic variables were similar in the 2 groups (p-value>0.05). Neonatal outcomes were also similar in both the groups. The time to achieve sensory block to T10 (3.2 ± 1.5 vs 2.5 ± 1.3 minutes) or to the maximal level (9.8 ± 3.1 vs 7.9 ± 2.3 minutes) was longer in the ropivacaine group (p-value 0.048) but the median maximal level of sensory block was similar between the two groups (p-value>0.05). Duration of sensory block was shorter in the ropivacaine group (160.5± 22.2 vs 182.3± 30.5 minutes) (p-value 0.03). Duration of motor block was also significantly shorter than bupivacaine group (112.5 ± 45 vs 165.3 ± 26) (p-value 0.004). CONCLUSION: Spinal anesthesia for elective cesarean delivery with intrathecal 24 mg of 0.75% isobaric ropivacaine provided clinically effective surgical anesthesia of shorter duration without compromising neonatal outcome and can be used as an effective and safe alternative to bupivacaine.