婴幼儿深低温低流量的安全灌注流量及时间探讨

Safety Study of Low-flow Rate and Duration for Deep Hypothermia Cardiopulmonary Bypass in Infants

目的 探讨婴幼儿深低温低流量体外循环 (CPB)的安全灌注流量及时间。方法 回顾性总结 1994～ 2 0 0 2年采用深低温低流量CPB方法行法乐氏四联症 (TOF)根治术 ,低流量灌注时间超过 6 0min的婴幼儿。全组 2 7例 ,年龄 2～ 36 (14 .6 1± 11.30 )m ,体重 5～ 13(8.2 5± 2 .31)kg ,全身降温至鼻咽温 18～ 2 3(2 0 .0 9± 1.84 )℃ ,低流量 2 5～ 5 0 (37.5 6± 6 .82 )ml/ (kg .min) ,持续灌注 6 0～ 130 (81.35± 18.4 0 )min ,低流量期间红细胞压积 (Hct) 0 .16～ 0 .2 8(0 .2 2± 0 .0 5 ) ,静脉血氧饱和度 (SvO2 )维持高于 6 5 %。结果 2 7例婴幼儿 ,术后 1～ 5 (2 .39± 1.2 1)h清醒 ,未出现神经精神异常症状和体征。术后发生严重肺并发症 (灌注肺 ) 2例 ,2例因低心输出量综合征死亡。存活 2 5例 ,经治愈出院。结论 鼻咽温 2 0℃时 ,中度血液稀释Hct(0 .2 1～ 0 .2 4 ) ,婴幼儿低流量 4 0ml/ (kg .min)持续灌注 ,安全时间可达 90min甚至更长。

OBJECTIVE To study the safe low perfusion flow and duration for deep hypothermia cardiopulmonary bypass in infants.METHODS To summarize the experience of infants underwent cardiac operations for tetralogy of fallot from 1994 to 2002.RESULTS Operations were performed under deep hypothermia with low-flow perfusion and the low flow duration was more than 60 minutes. 27 cases, mean age was (14.61±11.3)months, mean weight was (8.25±2.31)kg.They were systemically cooled to nasopharyngeal temperature of 18～23(20.09±1.84)℃. Then they underwent low flow perfusion at 25～50(37.56±6.82) ml/(kg.min) for 60～130 (81.35±18.40) minutes. The hematocrit(Hct) was 0.16～0.28(0.22±0.05) during low flow perfusion . Results: 27 infants woke up at 1～5 (2.39±1.21) hours after operation without unusual signs of nervous system. 2 infants developed severe pulmonary complication and 2 cases died of low cardiac output postoperatively.CONCLUSION Low-flow rate of 40 ml/(kg.min) may be safety continued to more than 90 minutes when nasopharyngeal temperature is 20℃ with moderate hemodilution (Hct 0.21～0.24) in infants.