Linkoping University, Department of Biomedical Engineering, Division of Biomedical Instrumentation, Linkoping, 58185 Sweden.
J Biomed Opt. 2010 Mar-Apr;15(2):027009. doi: 10.1117/1.3374050.
Intramyocardial oxygen transport was assessed during open-chest surgery in calves by diffuse reflectance spectroscopy using a small intramuscular fiber-optic probe. The sum of hemo- and myoglobin tissue fraction and oxygen saturation, the tissue fraction and oxidation of cytochrome aa3, and the tissue fraction of methemoglobin were estimated using a calibrated empirical light transport model. Increasing the oxygen content in the inhaled gas, 21%-50%-100%, in five calves (group A) gave an increasing oxygen saturation of 19+/-4%, 24+/-5%, and 28+/-8% (p<0.001, ANOVA repeated measures design) and mean tissue fractions of 1.6% (cytochrome aa3) and 1.1% (hemo- and myoglobin). Cardiac arrest in two calves gave an oxygen saturation lower than 5%. In two calves (group B), a left ventricular assistive device (LVAD pump) was implanted. Oxygen saturation in group B animals increased with LVAD pump speed (p<0.001, ANOVA) and with oxygen content in inhaled gas (p<0.001, ANOVA). The cytochrome aa3 oxidation level was above 96% in both group A and group B calves, including the two cases involving cardiac arrest. In conclusion, the estimated tissue fractions and oxygenation/oxidation levels of the myocardial chromophores during respiratory and hemodynamic provocations were in agreement with previously presented results, demonstrating the potential of the method.
在小牛开胸手术中，通过使用小型肌内光纤探头的漫反射光谱法评估心肌内氧传输。使用经过校准的经验光传输模型估计血红蛋白和肌红蛋白组织分数和氧饱和度、细胞色素 aa3 的组织分数和氧化、以及高铁血红蛋白的组织分数。在五头小牛（A 组）中，将吸入气体中的氧含量增加到 21%-50%-100%，分别得到 19+/-4%、24+/-5%和 28+/-8%的氧饱和度增加（p<0.001，ANOVA 重复测量设计）和 1.6%（细胞色素 aa3）和 1.1%（血红蛋白和肌红蛋白）的平均组织分数。在两头小牛中发生心脏骤停，导致氧饱和度低于 5%。在两头小牛（B 组）中植入了左心室辅助装置（LVAD 泵）。B 组动物的氧饱和度随 LVAD 泵速度增加（p<0.001，ANOVA）和吸入气体中的氧含量增加（p<0.001，ANOVA）而增加。在 A 组和 B 组的小牛中，细胞色素 aa3 的氧化水平均高于 96%，包括涉及心脏骤停的两个病例。总之，在呼吸和血液动力学激发期间估计的心肌色素的组织分数和氧合/氧化水平与之前呈现的结果一致，证明了该方法的潜力。
