近红外分光仪在婴幼儿体外循环脑功能监测中的应用

Monitoring of cerebral oxygenation by near-infrared spectroscopy during cardiopulmonary bypass in infants

目的 在不同体外循环 (CPB)模式下 ,探讨近红外分光仪 (NIRS)在脑氧合功能监测方面的价值。 方法 室间隔缺损 (VSD)合并肺动脉高压 (PH)行心内直视手术患者 2 4例 ,用随机数字表法分为 3组 ,中度低温体外循环(MHCPB)组 (n=6 ) ,深低温低流量体外循环 (DHL F)组 (n=6 )和深低温停循环 (DHCA)组 (n=12 ) ,应用 NIRS测定脑组织氧合血红蛋白 (Hb O2 )、还原血红蛋白 (Hb D)、细胞色素 aa3(Cyt Ox)和氧合血红蛋白最低点持续时间 (Hb O2 - NT) ,CPB后 2分钟、降温末、复温末和术后 6小时分别抽颈静脉球血测定乳酸值 (L act)和特异性神经源性烯醇化酶 (NSE) ,术前、术后测定脑电图各 1次 ,并对它们之间的关系进行相关分析。 结果 MHCPB组和 DHL F组 NIRS测定的指标与生化指标和脑电图之间无显著相关关系 ;而 DHCA组 Hb O2 、Cyt Ox的最小值和 Hb O2 - NT与复温末 L act和 NSE值显著相关 ,Hb O2 - NT小于 35分钟的患者均无脑功能损伤表现。 结论 DHCA组 NIRS测定指标中的 Hb O2 、Cyt Ox最小值和 Hb O2 - NT与反映脑损伤的其它指标显著相关 ,Hb O2 - NT是预测停循环安全时限的有效指标。

Objective To assess the value of near-infrared spectroscopy (NIRS) on monitoring cerebral oxygenation during different cardiopulmonary bypass(CPB). Methods Twenty-four patients with ventricular septal defect combined with pulmonary hypertension undergoing open heart operation were randomly assigned to 3 groups: moderate hypothermia cardiopulmonary bypass(MHCPB) group(n=6), deep hypothermia low flow(DHLF) group (n=6)and deep hypothermia circulatory arrest(DHCA) group (n=12). NIRS data including cerebral oxygenated hemoglobin (HbO 2) , deoxygenated hemoglobin(HbD), oxidized cytochrome aa 3(CytOx) and oxygenated hemoglobin signal nadir time(HbO 2-NT) were tested, lactate (Lact) and neuron-specific enolase (NSE), electroencephalography(EEG) were measured, and correlation analysis of all these data were undertaken. Results NIRS data showed no correlation with biochemical data and EEG in MHCPB group and DHLF group; the minimum value of HbO 2 , CytOx and HbO 2-NT were closely correlated with increase in Lact and NSE. All patients in which HbO 2-NT less than 35 minutes were free of behavioral evidence of brain injury. Conclusions NIRS data including the minimum value of HbO 2, CytOx and HbO 2-NT showed strong correlation with other cerebral function assessment during DHCA, HbO 2-NT determined by NIRS monitoring is a useful predictor of safe duration of circulatory arrest.