去氧肾上腺素在剖宫产脊髓麻醉期间抗低血压治疗中的安全性。

Safety of Phenylephrine in Antihypotensive Treatment during Spinal Anesthesia for Cesarean Section.

作者信息

Anusorntanawat Ratikorn, Uerpairojkit Ketchada, Thongthaweeporn Nutnicha, Charuluxananan Somrat

出版信息

J Med Assoc Thai. 2016 Feb;99(2):188-96.

Abstract

OBJECTIVE

In Thailand, hypotension after spinal anesthesia for cesarean section is routinely treated by ephedrine. As incidence of fetal acidosis reportedly increases resulting from placental transfer of ephedrine, phenylephrine, an alpha-1 agonist with less lipid solubility, becomes an alternative. However, the potential development of serious bradycardia after phenylephrine is a concern. The objectives of this study were to investigate the incidence of serious bradycardia and identify risk factors associated with phenylephrine-induced serious bradycardia and other side effects of phenylephrine.

MATERIAL AND METHOD

This descriptive cross-sectional study was conducted between July 1, 2014 and March 15, 2015 on 509 parturients undergoing cesarean section under spinal anesthesia. Predelivery hypotension was treated by intravenous phenylephrine 100 mcg and pretherapeutic heart rate (pHR) was recorded. If serious bradycardia (HR < 60 bpm and hypotension or HR <45 bpm) developed, atropine 0.6 mg was administered intravenously. Data were analyzed using multivariable logistic regression and AuROC.

RESULTS

Incidence of serious bradycardia was 11% (95% CI: 8.0-14.0). A one bpm increment increase in pHR reduced this incidence by 4% (adjusted OR: 0.96; 95% CI: 0.94-0.98, p < 0.001; AuROC: 0.76). As compared to apHR greater than 80 bpm, apHR of 61 to 80 bpm and a pHR of 60 bpm or lower increased the risk of serious bradycardia by 3.55 times and 12.81 times, respectively. Other risk factors were height (adjusted OR: 0.94; 95% CI: 0.89-0.98, p = 0.015), baseline DBP (adjusted OR: 0.97; 95% CI: 0.94-0.99,p = 0.03), and anesthetic level at first minute (adjusted OR: 1.13; 95% CI: 1.02-1.23, p = 0.02). Benign and temporary abnormal ECG readings were noted.

CONCLUSION

Phenylephrine for antihypotensive treatment in spinal anesthesia induces bradycardia. Findings indicate an association between slower HR at time phenylephrine is administered and serious bradycardia. Close ECG monitoring and prompt treatment are required.

摘要

目的

在泰国，剖宫产脊髓麻醉后低血压通常用麻黄碱治疗。据报道，由于麻黄碱经胎盘转运导致胎儿酸中毒的发生率增加，苯肾上腺素这种脂溶性较低的α-1激动剂成为了一种替代药物。然而，使用苯肾上腺素后可能发生严重心动过缓令人担忧。本研究的目的是调查严重心动过缓的发生率，并确定与苯肾上腺素诱发的严重心动过缓及苯肾上腺素其他副作用相关的危险因素。

材料与方法

这项描述性横断面研究于2014年7月1日至2015年3月15日对509例行脊髓麻醉下剖宫产的产妇进行。分娩前低血压通过静脉注射100微克苯肾上腺素治疗，并记录治疗前心率（pHR）。如果发生严重心动过缓（心率<60次/分钟且伴有低血压或心率<45次/分钟），则静脉注射0.6毫克阿托品。使用多变量逻辑回归和受试者工作特征曲线下面积（AuROC）进行数据分析。

结果

严重心动过缓的发生率为11%（95%置信区间：8.0 - 14.0）。pHR每增加1次/分钟，该发生率降低4%（校正比值比：0.96；95%置信区间：0.94 - 0.98，p < 0.001；AuROC：0.76）。与pHR大于80次/分钟相比，pHR为61至80次/分钟和pHR为60次/分钟或更低分别使严重心动过缓的风险增加3.55倍和12.81倍。其他危险因素包括身高（校正比值比：0.94；95%置信区间：0.89 - 0.98，p = 0.015）、基线舒张压（校正比值比：0.97；95%置信区间：0.94 - 0.99，p = 0.03）以及第一分钟时的麻醉平面（校正比值比：1.13；95%置信区间：1.02 - 1.23，p = 0.02）。观察到良性和暂时性异常心电图读数。