婴幼儿体外循环中乳酸的管理

目的 观察和评估体外循环中乳酸的变化情况,探讨体外循环对乳酸水平变化的影响.方法 选取21例15 kg以下先心病患儿,在体外循环（CPB）下进行先心病纠治术,术中行平衡超滤（BUF）,CPB结束后行改良超滤（MUF）.分别在手术开始、主动脉阻断时、主动脉开放、CPB结束时、MUF后、术后2、20预h 7个时间点抽取血液样品来检测其乳酸（LAC）值.结果 手术开始时,乳酸值处于正常范围之内,随着体外循环开始至主动脉阻断,乳酸值便开始升高（P〈0.01）,在主动脉阻断期间趋于平稳,主动脉开放至停体外循环乳酸值进一步上升（P〈0.01）,MUF后乳酸值有明显的下降（P〈0.01）,LAC水平在术后逐渐降低,术后20并h已经趋于正常.结论 体外循环会使乳酸值升高,改良预充液及BUF和MUF的联合运用,有助于控制和降低乳酸水平,有利患儿术后恢复.

Management of Lactic Acid during Cardiopulmonary Bypass in Infants

Objective To observe and assess the changes in lactic acid （LAC） levels during car- diopulmonary bypass（CPB）, and to investigate the influence of CPB on LAC levels. Methods Twenty-one children （weighing 〈15 kg） underwent repair operation for congenital heart disease under CPB. Balanced utrafitration（gUF） was performed during CPB and modified ultrafiltration （MUF） was performed after CPB. The blood samples were collected to detect LAC levels at the beginning of operation, during aortic clamping（P〈0.01）, at aortic declamping, at the end of CPB, after MUF（P〈0.01） ,and at 2 and 20 hours after operation. Results Lactic acid values were nor- mal at the beginning of operation,began to increase from CPB start to aortic clamping（P〈0.01）, stabilized during aortic clamping, further increased from aortic declamping to CPB end（P〈0.01）, significantly decreased after MUF（P〈0.01）, gradually reduced after operation,and returned to normal at 20 hours after operation. Conclusion LAC values increase during CPB. The combined use of improved pre-filled liquid, BUF and MUF can help to control and reduce LAC levels and contribute to postoperative recovery in infants.