小儿体外循环采用中度低温低流量灌注技术的临床研究

The Moderate Hypothermia with Low Flow Rate Cardiopulmonary Bypass in Congenital Heart Disease Surgery

目的研究先天性心脏病患儿体外循环手术中采用中度低温合并低流量灌注技术的可行性。方法３０例手术患儿体外循环降温至肛温２５．６±０．８４℃，食管温度２４．１±１．３２℃，鼓膜温度２３．８±１．４１℃，维持流量１．２３±０．０９Ｌ／ｍｉｎｍ２，转流时间９５．４±３４．６分钟，主动脉阻断时间５１．４±２０．２分钟，低流量维持时间４５．７±２２．４分钟。结果低流量灌注时静脉血氧饱和度均在８０％以上，除１例外，其余均无缺氧酸中毒的血气表现，血乳酸值也未升高，术后恢复良好。结论中度低温体外循环选用低流量灌注可满足机体代谢的需要，有利于减少长时间高流量灌注的不良反应。

Objectivc The feasibility of using moderate hypothermia with low flow rate in cardiopulmonary bypass(CPB) for congenital heart disease repair was studied. Methods 30 cases were selected to this trial.During CPB,the temperature were cooled down to 25.6±0.84℃ for rectum,24.1±1.32℃ for esophagus and 23 8±1.41℃ for tympanum.Maintainance flow was 1.23±0.09L/min·m 2.The total CPB,cross clamping and low flow rate perfusion times were 95.4±34.6min,51.4±20.2 min and 45.7±22.4 min respectively. Results Among 30 cases only one showed metabolic acidosis during CPB and received an extra 12 mEq sodium bicarbonate.After 27 to 99 min low flow rate perfusion,the venous oxygen saturation was still greater than 80% for each patient and lactate concentration did not increase.All the patients recoverd smoothly. Conclusion Low flow rate perfusion may safely be used in moderate hypothermic CPB as long as we monitor the oxygen saturation of returned venous blood,keeping it above 80%