近红外光谱法监测脑氧合预测CPB心脏瓣膜置换术病人缺血性脑损伤的评价

目的 评估应用近红外光谱法监测脑氧合预测CPB心脏瓣膜置换术病人缺血性脑损伤的准确性.方法 选择CPB心脏瓣膜置换术病人17例,术中使用NIRO-200型近红外含氧量监视仪监测双侧额叶脑氧饱和度(rScO2)、组织血红蛋白指数(THI)、氧合血红蛋白浓度变化(△O2Hb)、还原血红蛋白浓度变化(△HHb)和总血红蛋白浓度变化(△cHb).于入室时、气管插管后即刻、主动脉插管即刻、上下腔静脉插管后即刻、CPB开始即刻、CPB中最低温、复温至36.5 ℃、停机即刻和1 h时记录上述指标和rScO2最低值≤50%的发生情况;于麻醉诱导前即刻、复温前、复温至36.5℃、停机1、5、20 h时采集右颈内静脉血样,测定血浆S100蛋白与神经元特异性烯醇化酶(NSE)的浓度.于术前1 d和术后8 d时评估认知功能,记录术后认知功能障碍的发生情况.结果 9例rScO2最低值≤50%的病人中7例出现术后认知功能障碍.rScO2最低值≤50%的病人停机1 h和5 h时血浆NSE和S100蛋白的浓度高于rScO2＞50%的病人(P＜0.05).结论 近红外光谱法监测脑氧合可较准确地预测CPB心脏瓣膜置换术病人缺血性脑损伤.

Evaluation of cerebral oxygenation measured by near-infrared spectroscopy in predicting cerebral ischemic injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass

Objective To assess the accuracy of cerebral oxygenation measured by near-infrared spectroscopy (NIRS) in predicting ischemic cerebral injury in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB). Methods Seventeen patients undergoing cardiac valve replacement under CPB were enrolled in this study. During operation, NIRS was used to measure regional oxygen saturation (rScO2),tissue hemoglobin index ( THI ), changes in concentrations of oxyhemoglobin (△ O2 Hb ), deoxyhemoglobin (△ HHb) and total hemoglobin (△ cHb) of the frontal lobes. The parameters mentioned above and patients whose minimal rScO2 decreased to less than 50% were recorded after entering the operation room, immediately after tracheal intubation, aortic cannulation and superior and inferior vena cava cannula, at the beginning of CPB, at the lowest temperature during CPB, after rewarming to 36.5 ℃, immediately after termination of CPB, and at 1 h after termination of CPB. Blood samples were taken from right internal jugular vein immediately before anesthesia induction, before rewarming, after rewarming to 36.5 C, and at 1, 5 and 20 h after termination of CPB to detect plasma concentrations of S100 protein and neuron-specific enolase (NSE) by ELISA. The cognitive function of patients was assessed 1 day before surgery and 8 days after surgery, and postoperative cognitive dysfunction (POCD) was recorded. Results Nine patients presented with minimal rScO2 less than 50%. Among them,7 patients developed POCD. The plasma concentrations of S100 protein and NSE were significantly higher at 1 and 5 h after termination of CPB in patients whose minimal rScO2 decreased to ≤ 50% than in those whose rScO2 ＞50% .Conclusion Cerebral oxygenation measured by NIRS can accurately predict cerebral ischemic injury in patients undergoing cardiac valve replacement under CPB.