Background: Earlier studies demonstrated that the intrathecal ropivacaine could be used to provide quality anesthesia with advantages of lesser hypotension and quicker recovery compared to bupivacaine for cesarean delivery. However, the optimal dose of spinal ropivacaine in obstetric patients varies greatly in different reports. Here we designed a randomized double-blind study to determine the optimal dose of spinal ropivacaine for elective cesarean delivery in China.
Methods: A total of 500 healthy primiparas who underwent elective cesarean delivery were randomly divided into five groups, 100 primiparas in each group. Participants received hyperbaric ropivacaine in the subarachnoid with 10, 12, 14, 16 or 18 mg at 0.2 mL/second as groups R10, R12, R14, R16, and R18 respectively. The speed of onset, duration of sensory and motor block, the satisfaction of the mother and surgeon, incidences of hypotension, bradycardia, nausea and vomiting, supplement of intravenous analgesics, use of vasoactive drugs and neonatal Apgar score were all recorded. A dose was considered effective if an upper sensory level to the pinprick of T6 or above was achieved and no intravenous supplements were required. The median effective dose (ED50) and ED95 were determined by a logistic regression model.
Results: Totally, 492 patients completed the study. All the participants in the study were comparable with respect to age, weight, and height. The average duration of the surgery was 40 minutes. The mean time to achieve T6 sensory block was significantly shorter in Group R18 compared to R10 (2 ± 0.8 min vs. 3.05 ± 1.2 min, P < 0.05). Accordingly, the duration of sensory block (regression to T12) was markedly longer in Group R18 than R10 (151.3 ± 30.7 min vs. 92.3 ± 30.5 min, P < 0.05). Importantly, the perfect patients’ satisfaction was much higher in Group R18 than R10 (100% vs. 66%, P < 0.05), same as surgeons’ satisfaction (100% vs. 49%, P < 0.05). The incidence of hypotension in Group R16 was higher than R10 (P < 0.05). Moreover, the incidence of hypotension in Group R18 was higher than R10, R12 and R14 (P < 0.05). The incidences of nausea in Groups R16 and R18 were higher than R10 and R12 (P < 0.05). The incidence of vomiting in Group R18 was higher than Groups R10 and R12 (P < 0.05). The ED50 was 9.7 mg (95% confidence interval [CI], 8.9 to 10.3) and ED95 was 14.3 (95% CI, 13.7 to 15.3) mg.
Conclusion: The dose of 14 mg of hyperbaric ropivacaine for spinal anesthesia can provide a satisfying anesthetic effect, with fewer occurrences of intraoperative adverse events during a cesarean delivery for Chinese women. (Funded by the Department of Anesthesiology, Obstetrics and Gynecology Hospital to Nanjing Medical University, Nanjing, China.)
Author & Article info
Hyperbaric Spinal Ropivacaine for Cesarean Delivery: The Optimal Dose in Chinese Women
Yunhe Zhu*, Susu Zhang*, Caijuan Li, Yao Zhang, Shiqin Xu, and Xiaofeng Shen
From the Department of Anesthesiology, Obstetrics and Gynecology Hospital to Nanjing Medical University, Nanjing, China.
*Contributed equally to this work.
Correspondence to Dr. Xiaofeng Shen at email@example.com.
Citation: Yunhe Zhu, Susu Zhang, Caijuan Li, Yao Zhang, Shiqin Xu, Xiaofeng Shen. Hyperbaric Spinal Ropivacaine for Cesarean Delivery: The Optimal Dose in Chinese Women. J Anesth Perioper Med 2019; 6 : 23- 27.