Beilman G J, Groehler K E, Lazaron V, Ortner J P
North Trauma Institute, Robbinsdale, MN 55422-2900, USA.
Shock. 1999 Sep;12(3):196-200. doi: 10.1097/00024382-199909000-00005.
Adequate resuscitation of patients from shock states depends on restoration of oxygen delivery (DO2) to tissues. Direct measurement of systemic DO2 during shock states requires invasive techniques such as pulmonary artery catheterization. These experiments were performed to examine the ability of near-infrared spectroscopy (NIRS), to measure regional tissue oxygenation in a large-animal model of hemorrhagic shock, and to compare these measures to global measures of oxygen delivery. Splenectomized female pigs (n = 11) were anesthetized, instrumented, and monitored. NIRS probes were placed on the leg, in the stomach via nasogastric tube, and on the liver during laparotomy. Hemorrhagic shock was induced by phlebotomy of 28% of blood volume. After 1 hour, resuscitation was with shed blood and crystalloid until cardiac output plateaued. Measurements of physiologic parameters, blood gases, lactate, intramucosal pH, and NIRS values for regional tissue hemoglobin oxygen saturation (StO2), and cytochrome a,a3 redox state were recorded at intervals throughout the experiment. Tissue oxygenation as measured by oxyhemoglobin saturation and cytochrome a,a3 redox (NIRS) correlated with measures of systemic DO2 throughout the experiment. The liver probe demonstrated blunted changes in tissue oxygenation suggesting relatively protected circulation. Intramucosal pH did not correlate well with DO2. Regional tissue oxygenation as measured by NIRS shows excellent correlation with global oxygen delivery. NIRS may allow estimation of systemic oxygen delivery using rapid non-invasive techniques.
使处于休克状态的患者得到充分复苏取决于恢复向组织输送氧气（DO2）。在休克状态下直接测量全身DO2需要采用侵入性技术，如肺动脉插管术。进行这些实验是为了检验近红外光谱技术（NIRS）在大型失血性休克动物模型中测量局部组织氧合的能力，并将这些测量结果与全身氧输送的整体测量结果进行比较。对11只脾切除的雌性猪进行麻醉、仪器植入和监测。将NIRS探头置于腿部、通过鼻胃管置于胃部以及在剖腹手术期间置于肝脏上。通过抽取28%血容量进行放血诱导失血性休克。1小时后，用回输的血液和晶体液进行复苏，直至心输出量达到平稳状态。在整个实验过程中定期记录生理参数、血气、乳酸、黏膜内pH值以及局部组织血红蛋白氧饱和度（StO2）和细胞色素a,a3氧化还原状态的NIRS值。在整个实验过程中，通过氧合血红蛋白饱和度和细胞色素a,a3氧化还原（NIRS）测量的组织氧合与全身DO2的测量结果相关。肝脏探头显示组织氧合变化不明显，表明循环相对受保护。黏膜内pH值与DO2的相关性不佳。通过NIRS测量的局部组织氧合与整体氧输送显示出极好的相关性。NIRS可能允许使用快速非侵入性技术估计全身氧输送。
