探讨基于体重的格拉司琼剂量，对于改善腰麻剖宫产术中低血压的作用及其最低有效剂量确定。

选择2018年1月1日至2018年12月31日，于四川大学华西第二医院进行择期剖宫产术分娩的146例产妇为研究对象。采用随机数字表法，将受试者随机分为3组，A组(n＝49，静脉缓慢注射格拉司琼40 μg/kg)，B组(n＝49，静脉缓慢注射格拉司琼20 μg/kg)和C组(n＝48，静脉缓慢注射生理盐水作为空白对照)。3组受试者分别于腰麻开始前5 min，根据组别按照上述措施进行处理。采用单因素方差分析、Kruskal-Wallis H秩和检验及χ²检验，对3组产妇一般临床资料、手术相关参数及新生儿Apgar评分进行统计学比较；采用重复测量资料的方差分析，对3组受试者腰麻后不同时间点平均动脉压(MABP)和心率变化进行统计学比较；并观察药物不良反应及母婴结局等。本研究符合2013年修订的《世界医学协会赫尔辛基宣言》要求，并取得受试者知情同意。

①3组产妇年龄、身高及体重等一般临床资料，感觉平面达T6时间、手术时间、低血压发生率与发生次数、去氧肾上腺素及阿托品使用总量等手术相关参数，以及新生儿1、5 min Apgar评分比较，差异均无统计学意义(P>0.05)。②产妇腰麻后不同时间点(0、3、6、9、12、15、18、21、24、27、30、33、36、39、42、45 min)的MABP及心率分别比较，差异均有统计学意义(F_时间＝15.606，P<0.001；F_时间＝4.297，P<0.001)。3组产妇腰麻后的MABP及心率分别比较，差异均无统计学意义(F_处理＝1.103，P＝0.335；F_处理＝0.706，P＝0.496)。③本研究产妇术中，均无QT间期延长，无恶性心血管事件发生；娩出新生儿均未发生心动过缓、低体温及中枢神经系统病变等药物相关不良反应及不良结局。

择期剖宫产术分娩产妇腰麻前，经静脉缓慢注射20 μg/kg或40 μg/kg格拉司琼，均不能有效改善腰麻所致的剖宫产术分娩中的产妇低血压。

To explore the minimum effect dose of granisetron required based on the puerperants′ weight to improve hypotension following spinal anesthesia for cesarean section.

A total of 146 puerperants who underwent elective cesarean section from January 1 to December 31 in 2018 in West China Second University Hospital, Sichuan University, were included in this study. They were randomly allocated into three groups by random digits table method to receive either granisetron 40 μg/kg (group A, n=49) or granisetron 20 μg/kg (group B, n=49) or normal saline (group C, n=48, as blank) intravenous injection slowly 5 min before induction of spinal anesthesia. The general clinical data, operation related data and the newborn Apgar scores were compared among three groups by using one-way analysis of variance, Kruskal-Wallis H rank sum test and chi-square test. Changes of mean arterial blood pressure (MABP) and heart rates at different time points after spinal anesthesia were compared statistically among three groups by using analysis of variance of repeated measurement data. The adverse drug reaction and outcomes of maternal and newborns were also evaluated. This study was in line with World Medical Association Declaration of Helsinki revised in 2013, and written consents from all patients were obtained.

①There were no significant differences among three groups of puerperants in general clinical data including age, body height and weight, and operation related data including time of sensory block to T6, operating time, incidence rates and times of hypotension, the phenylephrine and atropine requirements, and 1 and 5 min Apgar scores of newborns (P>0.05). ②There were significant differences in MABP and heart rates of puerperants at different time points including 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45 min after spinal anesthesia, respectively (F_time=15.606, P<0.001; F_time=4.297, P<0.001). There were no significant differences among three groups of puerperants in MABP and heart rates, respectively (F_intervention=1.103, P=0.335; F_intervention=0.706, P=0.496). ③There were no reports of drug-related adverse reactions and adverse outcomes including QT prolongation or serious cardiovascular events in puerperants, and bradycardia or hypothermia or central nervous system lesion in newborns in among three groups.

Granisetron 20 μg/kg or 40 μg/kg administered by intravenous injection slowly before spinal anesthesia could not effectively improve the puerperants′ hypotension in elective cesarean section.