A comparison of the effects of intrathecal ropivacaine and bupivacaine during cesarean section*

Aim: To compare the effects of intrathecal plain bupivacaine or ropivacaine with those of opioids on sensory and motor block characteristics during cesarean section (C/S). Materials and methods: Fifty-two ASA I or II women were randomly allocated into 2 groups to administer either 10 mg of 0.5% plain bupivacaine (Group B), or 15 mg of 0.75% plain ropivacaine (Group R) with 25 μg fentanyl and 100 μg morphine for spinal anesthesia. Characteristics of the sensory and motor block were recorded. Results: The time to achieve sensory block at T6 was significantly faster in Group B than in Group R (2.7 ± 1.8 min vs. 4.2 ± 2.5 min). The time to reach maximum sensory block was significantly faster in Group B than in Group R (8.1 ± 4.1 min vs. 11.6 ± 5.6 min). The times of sensory block regression to T10 and L1 dermatomes were signifi cantly shorter in Group B (118.2 ± 24.2 min and 145.5 ± 28.1 min, respectively) than in Group R (135 ± 32.1 min and 162.5 ± 32.5 min, respectively). Motor block duration was significantly longer in Group B than in Group R (165.8 ± 32.5 min vs. 135.2 ± 45.7 min). Conclusion: Intrathecal plain ropivacaine with opioids might be superior to bupivacaine in terms of a longer sensory block, and a shorter motor block duration for C/S.