Xiao Fei, Xu Wen-Ping, Yao Han-Qing, Fan Jia-Ming, Chen Xin-Zhong
Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Department of Anesthesia, Jiaxing University Affiliated Women and Children Hospital, Jiaxing, China.
Front Pharmacol. 2021 May 12;12:608198. doi: 10.3389/fphar.2021.608198. eCollection 2021.
Prophylactic infusion of a vasopressor is preferred as a rational choice in clinical practice in Cesarean delivery. Metaraminol is one of most common vasopressors used in obstetric clinical practice. However, the dose-response of metaraminol has not been fully determined and the optimal infusion dose is unknown. Therefore, this study aimed to determine the median effective dose (ED50) and 90% effective dose (ED90) of weight-based fixed-rate metaraminol infusions for preventing spinal-anesthesia-induced hypotension in patients having combined spinal-epidural anesthesia for elective Caesarean delivery. One hundred and seventeen patients with singleton pregnancies were enrolled and randomly allocated into one of five groups in this study. Patients received prophylactic metaraminol infusion at a fixed rate of 0, 0.25, 1.0, 1.75 or 2.5 μg/kg/min in each group immediately after induction with intrathecal 10 mg of hyperbaric bupivacaine mixed with 5 μg of sufentanil. An effective prophylactic dose was defined as no occurrence of hypotension during the period of spinal introduction and neonatal delivery. Values for ED50 and ED90 of prophylactic infusion of metaraminol were calculated using probit regression. Characteristics of spinal anesthesia and side effects were recorded. The ED50 and ED90 values of weight-based fixed rate of metaraminol infusion were 0.64 (95% CI, 0.04-1.00) μg/kg/min and 2.00 (95% CI, 1.58-2.95) μg/kg/min respectively. The incidence of hypotension decreased with an increased infusion rate of metaraminol in the five groups (test for trend, < 0.001). The incidence of hypotension was similar between group 0 and 0.25, but significant higher than other groups; the incidence of hypotension was also similar between group 1.0 and 1.75, but higher than group 2.5. The incidence of reactive hypertension was significantly higher in group 2.5 compared to the other groups. Physician interventions were more frequent in group 0, 0.25 and 2.5 than in group 1.0 and 1.75 (adjusted < 0.001). No difference was found in neonatal outcomes, including Apgar score and pH value of the umbilical artery. In summary, we have compared four different prophylactic weight-based infusion doses of metaraminol for preventing post-spinal hypotension in Cesarean delivery. The ED and ED values of metaraminol infusion for preventing spinal anesthesia-induced hypotension were 0.64 μg/kg/min and 2.00 μg/kg/min, respectively. This finding may be helpful for guiding clinical practice and further research.
在剖宫产临床实践中，预防性输注血管升压药是一种合理的选择。间羟胺是产科临床实践中最常用的血管升压药之一。然而，间羟胺的剂量反应尚未完全确定，最佳输注剂量也未知。因此，本研究旨在确定基于体重的固定速率间羟胺输注用于预防择期剖宫产联合腰麻-硬膜外麻醉患者脊髓麻醉诱导低血压的半数有效剂量（ED50）和90%有效剂量（ED90）。本研究纳入了117名单胎妊娠患者，并将其随机分为五组。每组患者在鞘内注射10mg重比重布比卡因与5μg舒芬太尼诱导后，立即以0、0.25、1.0、1.75或2.5μg/kg/min的固定速率接受预防性间羟胺输注。有效预防剂量定义为在脊髓穿刺和新生儿分娩期间未发生低血压。使用概率回归计算间羟胺预防性输注的ED50和ED90值。记录脊髓麻醉的特征和副作用。基于体重的间羟胺固定速率输注的ED50和ED90值分别为0.64（95%CI，0.04 - 1.00）μg/kg/min和2.00（95%CI，1.58 - 2.95）μg/kg/min。五组中间羟胺输注速率增加时，低血压发生率降低（趋势检验，<0.001）。0组和0.25组间低血压发生率相似，但显著高于其他组；1.0组和1.75组间低血压发生率也相似，但高于2.5组。2.5组的反应性高血压发生率显著高于其他组。0组、0.25组和2.5组的医生干预比1.0组和1.75组更频繁（校正后<0.001）。在新生儿结局方面，包括阿氏评分和脐动脉pH值，未发现差异。总之，我们比较了四种不同的基于体重的预防性间羟胺输注剂量用于预防剖宫产术后脊髓低血压。间羟胺输注预防脊髓麻醉诱导低血压的ED50和ED90值分别为0.64μg/kg/min和2.00μg/kg/min。这一发现可能有助于指导临床实践和进一步研究。
