Comparison of Three Doses of Isobaric Ropivacaine Mixed with Fentanyl during Spinal Anesthesia for Cesarean Section

Abstract

BACKGROUND: We evaluated the appropriate dose of spinal isobaric 0.75% ropivacaine with fentanyl for cesarean section. METHODS: Forty-five healthy term parturients scheduled for an elective cesarean section randomly received 14, 16, 18 mg of 0.75% isobaric ropivacaine intrathecally, which was mixed with fentanyl 20microgram. Sensory blockade variables such as time to L1 block, max. block height, time to max block height, and time to recovery to L1 were assessed. Motor blockade variables such as time to Bromage scale 3, motor recovery time (Bromage scale 3 to 1) and muscle relaxation were assessed. We also checked side effects, and hemodynamic variables. RESULTS: Anesthesia was successful in 57%, 80%, and 93.3% of groups I (14 mg), II (16 mg), and III (18 mg) respectively and there was no significant difference between the three groups. The time to max. sensory and motor block and level of maximum sensory block were not significantly different between the three groups. All groups showed complete motor block, and muscle relaxation was equally excellent in the three groups. Sensory and motor recovery time were not significantly different. The incidence of hypotension was more frequent in group 3 compared with group 1. The incidence of nausea was more frequent in group 3 compared with group 1, and 2. CONCLUSIONS: An intrathecal injection of 16 mg of isobaric 0.75% ropivacaine with fentanyl 20microgram during spinal anesthesia is suitable for an elective cesarean section.