Abraham E
Emerg Med Clin North Am. 1986 Nov;4(4):791-807.
Noninvasive methods for monitoring pH, pCO2 and pO2 have not achieved the original aim of providing a noninvasive, continuous assessment of arterial blood gases under all clinical conditions. Fingertip and ear oximeters provide measurement of oxygen saturation in arterial blood under most conditions, but accuracy is lost when intense peripheral vasoconstriction is present. Transcutaneous and conjunctival O2 and CO2 sensors also function as accurate trend monitors of PaO2 and PaCO2 in the hemodynamically stable patient. Measurement of pH by placement of a sensor into the subcutaneous tissue provides a continuous assessment of arterial pH in neonates with normal CO, but the use of these sensors in adult patients remains largely unproven. Noninvasive assessment of the adequacy of peripheral perfusion, cardiac function, and intravascular volume status can be performed using transcutaneous or conjunctival O2 and CO2 sensors. Early detection and correction of hypovolemia and diminished CO can be accomplished by monitoring tissue PO2 and PCO2. In the emergency department setting, in which the evaluation and initial treatment of critically ill patients often is performed by measurement of a limited set of physiologic parameters, the ability to evaluate tissue perfusion on a continuous basis is an important clinical advance.
用于监测pH、pCO₂和pO₂的非侵入性方法尚未实现其最初目标，即在所有临床情况下提供对动脉血气的非侵入性连续评估。指尖和耳部血氧计在大多数情况下可测量动脉血中的氧饱和度，但在出现强烈外周血管收缩时准确性会丧失。经皮和结膜O₂和CO₂传感器在血流动力学稳定的患者中也可作为PaO₂和PaCO₂的准确趋势监测器。将传感器置于皮下组织测量pH可对CO正常的新生儿的动脉pH进行连续评估，但这些传感器在成年患者中的应用在很大程度上仍未得到证实。使用经皮或结膜O₂和CO₂传感器可对周围灌注、心功能和血管内容量状态是否充足进行非侵入性评估。通过监测组织PO₂和PCO₂可早期发现并纠正低血容量和心输出量减少。在急诊科，危重病患者的评估和初始治疗通常通过测量一组有限的生理参数进行，能够持续评估组织灌注是一项重要的临床进展。
