脑血红蛋白浓度指数在体外循环中的应用

Non-invasive detecting cerebral hemoglobin concentration index used in cardiopulmonary bypass

目的基于稳态的近红外光谱技术,可无创、实时监测脑组织血红蛋白浓度指数,以反映人体脑组织中血红蛋白总浓度变化的百分比,从而有利于评价脑血流动力学及脑氧合。方法基于稳态近红外光在人体脑组织中的传播规律研发了近红外组织血氧检测仪,并用其无创、实时监测了8例经受体外循环手术的先天性心脏病婴儿的脑组织血红蛋白浓度指数及脑组织氧饱和度。结果在体外循环末期的改良超滤阶段,所有婴儿的脑组织血红蛋白浓度指数均显著上升,上升速率为(0.0304±0.0136)mM/(cm·min),P<0.001。改良超滤结束与起始时相比,脑血红蛋白浓度指数增加了(18.8±7.5)%,这是由于改良超滤提高了血液的红细胞容积比。此过程中脑组织氧饱和度平均增加了(5.3±4.1)个百分点(P<0.05),但不如脑血红蛋白浓度指数的上升趋势明显。结论在体外循环手术的改良超滤过程中,脑组织血红蛋白浓度指数可有效反映脑组织血流动力学与氧合的变化。

Objective Using continuous-wave near infrared spectroscopy (NIRS ),human cerebral tissue hemoglobin concentration index (tHI)is detected non-invasively and in real time,so that the change percentage of cerebral total hemoglobin concentration can be indicated and cerebral hemodynamics as well as oxygenation can be evaluated.Methods Based on the propagation of near-infrared light in human brain,the near-infrared oximeter was developed,and the cerebral tHI as well as cerebral oxygen saturation of 8 infants suffered from congenital heart disease were monitored non-invasively and in real time under cardiopulmonary bypass.Results During modified ultrapurification in the end of cardiopulmonary bypass,the cerebral tHI of all the infants increased significantly at the average speed of (0.0304 ±0.01 36)mM/(cm?min),P<0.001 . Comparing the end to the beginning of modified ultrapurification,the cerebral tHI increased for (18.8 ±7.5)%,because the hematocrit was increased by filtering out the redundant water in the blood.The cerebral oxygen <br> saturation increased for (5.3 ±4.1 )% (P <0.05 ), which was not so obvious as the increase trend of cerebral tHI.Conclusions During modified ultrapurification in the end of cardiopulmonary bypass,the changes of cerebral hemodynamics and oxygenation may be indicated effectively by cerebral tHI.