剖宫产术中预防性输注去甲肾上腺素对腰麻下母婴的影响

Effects of Prophylactic Infusion of Norepinephrine on Parturients and Fetus Under Spinal Anesthesia for Cesarean Section

关键词:  去甲肾上腺素  去氧肾上腺素  腰麻  剖宫产术

Key words:  norepinephrine  phenylephrine  spinal anesthesia  cesarean section

摘要:

目的 探讨剖宫产术中预防性输注去甲肾上腺素对腰麻下产妇及胎儿的影响。方法 选择择期行剖宫产术的美国麻醉医师协会分级标准Ⅰ~Ⅱ级、单胎、足月初产妇160例，随机分为2组（n=80）：去甲肾上腺素组和去氧肾上腺素组。当鞘内注射局麻药时2组分别静脉持续输注0.05 μg·kg^-1·min^-1去甲肾上腺素或0.5 μg·kg^-1·min^-1去氧肾上腺素，当收缩压（systolic blood pressure，SBP）>140 mmHg时停药。连续监测SBP、舒张压（diastolic blood pressure，DBP）、心率（heart rate，HR）、心输出量（cardiac output，CO）及外周血管阻力（systemic vascular resistance，SVR）及胎心情况。胎儿娩出后采集脐动脉血样行血气分析及新生儿Apger评分。记录产妇和胎儿不良反应的发生情况（低血压、窦性心动过缓、恶心呕吐及胎儿窘迫等）。结果 切皮（t₂）和胎儿娩出后即刻（t₃）时间去甲肾上腺素组SBP，HR及CO均高于去氧肾上腺素组，但SVR低于去氧肾上腺素组（P<0.05）；其他时间点2组间SBP、DBP、HR、CO及SVR比较差异无统计学意义。去甲肾上腺素组心动过缓发生率降低，但2组产妇低血压、恶心和呕吐发生率比较差异无统计学意义。2组胎儿脐动脉血pH值差异无统计学意义。结论 与去氧肾上腺素比较，预防性静脉输注去甲肾上腺素能够能更好地维持腰麻下产妇血压和CO，降低产妇心动过缓的发生率，但不能降低低血压、恶心和呕吐的发生率。

Abstract:

OBJECTIVE To investigate the effects of prophylactic infusion of norepinephrine on parturients and fetus under spinal anesthesia for caesarean section. METHODS One hundred and sixty full-term parturients with American Society of Anesthestists classification I-Ⅱand singletonu ndergoing elective cesarean delivery under spinal anesthesia were randomly divided into two groups(n=80):norepinephrine group and phenylephrine group. The parturients received prophylactic infusion of either 0.5 μg·kg^-1·min^-1 phenylephfine or 0.05 μg·kg^-1·min^-1 norepinephrine when starting intrathecal injection. The vasopressor infusion was stopped when the systolic blood pressure(SBP) >140 mmHg. The SBP, diastolic blood pressure(DBP), heart rate(HR), cardiac output(CO) and systemic vascular resistance(SVR) were carried out. The fetal heart rate was monitored. The umbilical artery blood was collected to analysis after baby delivery and Apgar scores were assessed. The adverse reactions(such as hypotension, sinus bradycardia, nausea and vomiting, fetal distress, etc.) of parturients and fetus were recorded also. RESULTS Compared with the phenylephrine group, SBP, HR, and CO were increased, SVR were lower at skin incision(t₂) and delivery of baby(t₃), but there were no significant differences in SBP, DBP, HR, CO and SVR at other time points. The incidence of maternal bradycardia was lower in the epinephrine group, but there was no significant difference in the incidence of hypotension, nausea and vomiting between the two groups. There were no significant difference in pH of umbilical artery between the 2 groups. CONCLUSION Compared with phenylephrine, prophylactic infusion of norepinephrine can increase blood pressure and CO, decrease the incidence of bradycardia during cesarean section under spinal anesthesia, but can't reduce the incidence of hypotension, nausea and vomiting.