剖宫产时缩宫素对产妇Tp-e和QTc间期的影响

目的 观察和评价脊麻剖宫产时缩宫素对健康产妇Tp-e和QTc间期的影响.方法 ASA分级Ⅰ级择期剖宫产产妇40例,按随机数字表法分为缩宫素静脉推注组(静推组)和缩宫素静脉微泵组(微泵组),每组20例.在胎儿娩出后静推组55～60s静脉单次推注5%葡萄糖5ml+5 U缩宫素,微泵组10 min内静脉匀速泵注完5%葡萄糖20 ml+5 U缩宫素.记录并比较术前与脊麻后1、3、5 min,应用缩宫素后1、3、5、10min的QTc间期、Tp-e间期、平均动脉压(MAP)和心率.结果 静推组在应用缩宫素后1 min较术前心率明显增快[(89±13)次/min比(73±12)次/min],MAP显著降低[(69±12)mm Hg(1 mm Hg=0.133 kPa)比(82±13)mm Hg]和QTc间期明显延长[(426±21)ms比(405±18)ms](P＜0.01);而在应用缩宫素后1、3、5min时Tp-e间期均较术前延长(P＜0.01或＜0.05).结论 单次较大剂量(5 U)缩宫素静脉快速推注可延长健康产妇的QTc和Tp-e间期;而Tp-e间期的延长可能更准确预测室性心律失常的发生.在处理QT间期延长综合征产妇脊麻剖宫产时,缩宫素的使用方式应慎重考虑.

Abstract：

Objective To evaluate the effect of oxytocin on Tp-e and QTc interval during caesarean section under spinal anesthesia in healthy puerperas. Methods Forty ASA Ⅰ puerperas were selected and allocated to receive oxytocin intravenous bolus group (group-IB) or oxytocin continuous infusion group (group-CI) with 20 puerperas in each by random digits table. An intravenous bolus of 5% glucose 5 ml and 5 U oxytocin was administered after delivery a 55-60 s period. A continuous infusion of 5% glucose 5 ml and 5U oxytocin was administered after delivery a 10 min period. Measured the QTc interval,Tp-e interval,mean arterial pressure (MAP) and beart rate ( HR ) pre-operatively, then 1,3 and 5 ain after spinal anesthesia, and at least 1,3,5 and 10 min after oxytocin injection. Results In group-IB:HR was fast 1 min after oxytocin injection compared with pre-operatively [(89 ± 13) beats/min vs. (73 ± 12) beats/min] ,MAP was decreased [(69 ± 12 ) mm Hg ( 1 mm Hg= 0. 133 kPa ) vs. ( 82 ± 13 ) mm Hg] and QTc interval was prolonged [(426 ±21 ) ms vs. (405 ± 18 ) ms] (P ＜ 0.01 ); but Tp-e interval was prolonged 1,3,5 min after oxytocin injection compared with pre-operatively (P ＜ 0.01 or ＜ 0.05 ). Conclusions Single large dose of oxytocin intravenous bolus (5 U) can prolong QTc interval and Tp-e interval in healthy puerperas, and Tp-e interval can exact predict the occurrence of ventricular arrhythmias. The risk-benefit balance of oxytocin bolus during caesarean delivery should be discussed with women with a history of long QT syndrome.

Effect of oxytocin on Tp-e and QTc interval during caesarean section

Objective To evaluate the effect of oxytocin on Tp-e and QTc interval during caesarean section under spinal anesthesia in healthy puerperas. Methods Forty ASA Ⅰ puerperas were selected and allocated to receive oxytocin intravenous bolus group (group-IB) or oxytocin continuous infusion group (group-CI) with 20 puerperas in each by random digits table. An intravenous bolus of 5% glucose 5 ml and 5 U oxytocin was administered after delivery a 55-60 s period. A continuous infusion of 5% glucose 5 ml and 5U oxytocin was administered after delivery a 10 min period. Measured the QTc interval,Tp-e interval,mean arterial pressure (MAP) and beart rate ( HR ) pre-operatively, then 1,3 and 5 ain after spinal anesthesia, and at least 1,3,5 and 10 min after oxytocin injection. Results In group-IB:HR was fast 1 min after oxytocin injection compared with pre-operatively [(89 ± 13) beats/min vs. (73 ± 12) beats/min] ,MAP was decreased [(69 ± 12 ) mm Hg ( 1 mm Hg= 0. 133 kPa ) vs. ( 82 ± 13 ) mm Hg] and QTc interval was prolonged [(426 ±21 ) ms vs. (405 ± 18 ) ms] (P ＜ 0.01 ); but Tp-e interval was prolonged 1,3,5 min after oxytocin injection compared with pre-operatively (P ＜ 0.01 or ＜ 0.05 ). Conclusions Single large dose of oxytocin intravenous bolus (5 U) can prolong QTc interval and Tp-e interval in healthy puerperas, and Tp-e interval can exact predict the occurrence of ventricular arrhythmias. The risk-benefit balance of oxytocin bolus during caesarean delivery should be discussed with women with a history of long QT syndrome.