McKinley B A, Marvin R G, Cocanour C S, Moore F A
University of Texas-Houston Medical School, 77030, USA.
J Trauma. 2000 Apr;48(4):637-42. doi: 10.1097/00005373-200004000-00009.
Near infrared (NIR) spectrometry offers a noninvasive monitor of tissue hemoglobin O2 saturation and has been developed to report a quantitative clinical variable, StO2 [= HbO2/(HbO2 + Hb)]. In this study, a prototype NIR oximeter was used to investigate the hypothesis that changes in systemic O2 delivery index (D(O2)I) would be reflected by changes in StO2 in skeletal muscle, subcutaneous tissue, or both, as reperfusion occurs during shock resuscitation. StO2 was also compared with other indices of severity of shock or adequacy of resuscitation, including arterial base deficit, lactate, gastric mucosal P(CO2) (PgCO2), and mixed venous hemoglobin O2 saturation (S(VO2)).
Skeletal muscle and subcutaneous tissue StO2 were monitored simultaneously in eight severely injured trauma patients (88% blunt mechanism; age, 42 +/- 6 years; Injury Severity Score, 27 +/- 3) during standardized shock resuscitation in the intensive care unit with the primary goal of D(O2)I > or = 600 mL O2/min/m2 for 24 hours, and for an additional 12 hours during transition from resuscitation to standard intensive care unit care.
Skeletal muscle StO2 increased significantly from 15 +/- 2% (mean +/- SEM) at the start of resuscitation to 49 +/- 14% at 24 hours, and to approximately 55% from 25 to 36 hours. Subcutaneous tissue StO2 approximately 82% and was significantly greater than skeletal muscle StO2 throughout. D(O2)I increased significantly from 372 +/- 54 to 718 +/- 47 mL O2/min/m2 during resuscitation. Over 36 hours, mean D(O2)I and skeletal muscle StO2 were highly correlated (r = 0.95). Neither D(O2)I-PgCO2 nor D(O2)I-S(VO2) were significantly correlated; neither S(VO2) nor subcutaneous tissue StO2 changed significantly.
Hemoglobin O2 saturation was monitored noninvasively and simultaneously in skeletal muscle and subcutaneous tissues as StO2 (%) by using a prototype NIR oximeter. Skeletal muscle StO2 tracked systemic O2 delivery during and after resuscitation. As a rapidly deployable, noninvasive monitor of peripheral tissue oxygenation and O2 delivery, skeletal muscle StO2 obtained using NIR spectrometry would be useful to guide resuscitation in the intensive care unit, to monitor resuscitation status in the operating room, and, potentially, in combination with indicators such as base deficit and lactate, to detect shock during initial assessment of the severe trauma patient in the emergency department.
近红外（NIR）光谱法可对组织血红蛋白氧饱和度进行无创监测，并已开发用于报告定量临床变量StO2[=HbO2/（HbO2 + Hb）]。在本研究中，使用一种原型近红外血氧饱和度测定仪来研究以下假设：在休克复苏期间发生再灌注时，全身氧输送指数（D（O2）I）的变化将通过骨骼肌、皮下组织或两者的StO2变化反映出来。还将StO2与休克严重程度或复苏充分性的其他指标进行了比较，包括动脉碱缺失、乳酸、胃黏膜P（CO2）（PgCO2）和混合静脉血红蛋白氧饱和度（S（VO2））。
在重症监护病房对8名严重受伤的创伤患者（88%为钝性机制；年龄42±6岁；损伤严重度评分27±3）进行标准化休克复苏期间，同时监测骨骼肌和皮下组织的StO2，主要目标是使D（O2）I≥600 mL O2/min/m2达24小时，并在从复苏过渡到标准重症监护病房护理的另外12小时内保持该目标。
骨骼肌StO2在复苏开始时为15±2%（平均值±标准误），在24小时时显著增加至49±14%，在25至36小时时增至约55%。皮下组织StO2约为82%，且在整个过程中显著高于骨骼肌StO2。复苏期间D（O2）I从372±54显著增加至718±47 mL O2/min/m2。在36小时内，平均D（O2）I与骨骼肌StO2高度相关（r = 0.95）。D（O2）I与PgCO2或D（O2）I与S（VO2）均无显著相关性；S（VO2）和皮下组织StO2均未发生显著变化。
使用原型近红外血氧饱和度测定仪以StO2（%）的形式对骨骼肌和皮下组织中的血红蛋白氧饱和度进行了无创同时监测。骨骼肌StO2在复苏期间及复苏后跟踪全身氧输送情况。作为一种可快速部署的外周组织氧合和氧输送的无创监测方法，使用近红外光谱法获得的骨骼肌StO2对于指导重症监护病房的复苏、监测手术室的复苏状态以及潜在地与碱缺失和乳酸等指标结合，以在急诊科对严重创伤患者进行初始评估时检测休克将是有用的。
