近红外空间分辨光谱技术及其对新生猪脑缺氧缺血的检测

Detecting Cerebral Hypoxia-Ischemia of Newborn Piglets Using Spatially-Resolved Near-Infrared Spectroscopy

近红外光谱(NIRS)技术作为一种无创的组织氧检测手段,近年来在脑缺氧缺血的检测方面日益受到重视。文章介绍了自行研制的NIRS仪器(TSAH-100近红外组织血氧无损监测仪)的基本原理及用于新生猪脑氧检测时如何实现传感器与待测脑组织的最佳耦合。检测了28例新生猪在不同氧合状态下的脑组织氧饱和度(regional cerebral oxygen saturation,rSO2),在缺氧结束后进行了有创的动脉氧饱和度及生理参数的检测。结果表明,NIRS无创测得的脑rSO2与血气分析有创测得的动脉血氧饱和度(SaO2)有很好的相关性(p<0.001),并且脑rSO2与缺氧程度及缺氧后生理参数的变化一致。因此NIRS无创测得的脑rSO2能直接判断脑氧合状态,可在一定情况下替代有创血气分析,帮助临床无创、简便地诊断脑缺氧缺血。

As a non-invasive technique for measuring tissue oxygenation, near-infrared spectroscopy （NIRS） has increasing applications in detecting cerebral hypoxia-ischemia. The authors, introduced the basic principle of the NIRS oximeter developed independently by our group （TSAH-100）. The authors achieved the optimal coupling between the probe and the detected cerebral tissue. The present study investigated different regional oxygen saturations of brain （rSO2） measured non-invasively by NIRS, arterial blood oxygen saturation （SaO2） measured invasively by blood gas analysis and physiological parameters in newborn pigs with different hypoxia, in order to prove if the non-invasively cerebral rSO2 can indicate cerebral oxygenation status in clinical practice. Using this oximeter, cerebral rSO2 of 28 newborn piglets under different oxygenation status was detected. After mechanical ventilation and inhalation of 8%- 17 % oxygen for 30min in the newborn pigs, the pigs were grouped according to the inhalation of oxygen. With the inhalation of 13%-17% oxygen was mild hypoxia group, with 10%-13% was moderate hypoxia group, and with 8%-10% was severe hypoxia group. There were 4 animals in mild hypoxia group, 8 animals in moderate hypoxia group, 12 animals in severe hypoxia group and 4 animals were in the normal control group. The physiological parameters were monitored during the experiment. The SaO2 were invasively measured by blood gas analysis after the experiment. The results indicate that both rSO2 and SaO2 decreased after different degree of hypoxia and there was a good correlation between cerebral rSO2 non invasively measured by NIRS and SaO2 invasively measured by blood gas analysis （p〈0. 001）. Cerebral rSO2 was also consistent with the degree of hypoxia and the changes in physiological parameters after hypoxia. The arterial pH and the mean arterial pressure （MAP） in the severe hypoxia group was lower than that in the control group （p〈0. 05）. The blood lactic acid in the severe hypoxia group was higher than that in the control group （p〈0. 05）. Thus, the rSO2 can accurately and directly indicate cerebral oxygenation status and can also replace the SaO2 invasively measured by blood gas analysis. Cerebral hypoxia-ischemia can be non-invasively and conveniently diagnosed using NIRS.