Jamieson W R, Turnbull K W, Larrieu A J, Dodds W A, Allison J C, Tyers G F
Can J Surg. 1982 Sep;25(5):538-43.
Serial measurement of mixed venous oxygen saturation is useful in the care of critically ill patients. It is an index of cardiac output and overall tissue perfusion. Previously, lack of refinement of the technology for continuous monitoring of mixed venous oxygen saturation deterred its clinical application. The authors evaluated the Oximetrix ShawTM catheter oximeter system between May 1980 and April 1981 in 84 high-risk and moderately high-risk patients. Fifty-four had undergone only myocardial revascularization while 30 had undergone valvular or combined procedures. In 20 patients with compromised left ventricular function (mean ejection fraction of less than 40%) continuous mixed venous oxygen saturation was compared to hemodynamic parameters in an intraoperative and early postoperative study. The results indicated that satisfactory mixed venous oxygen saturation (more than 65%) correlated with normal hemodynamic measurements including cardiac output and cardiac index. In general, a fall in mixed venous oxygen saturation of more than 10% was noted before the mean blood pressure, heart rate or pulmonary capillary wedge pressure changed. Cardiac output, cardiac index, systemic vascular resistance and left ventricular stroke work index were found to change in association with a change in mixed venous oxygen saturation. A fall (mixed venous oxygen saturation less than 65%) can be related to: (a) abnormal hemodynamic status--reduced cardiac output, hypotension, elevated systemic vascular resistance and arrhythmias, (b) abnormal oxygen demand--shivering, suctioning, positioning and pyrexia and (c) abnormal oxygen supply--anemia, airway obstruction and altered diffusion of oxygen at the alveolar capillary membrane. The Oximetrix system proved reliable. Mixed venous oxygen saturation is a nonspecific indicator of hemodynamic status. Continuous monitoring of the mixed venous oxygen saturation facilitates optimal patient management by immediately alerting intensive care personnel to the development of inadequate tissue perfusion.
连续测定混合静脉血氧饱和度对危重症患者的护理很有用。它是心输出量和整体组织灌注的一个指标。以前，用于连续监测混合静脉血氧饱和度的技术不够完善，阻碍了其临床应用。作者在1980年5月至1981年4月期间，对84例高危和中度高危患者评估了血氧测定法肖氏导管血氧测定系统。54例仅接受了心肌血运重建，30例接受了瓣膜手术或联合手术。在一项术中及术后早期研究中，对20例左心室功能受损（平均射血分数小于40%）的患者，将连续混合静脉血氧饱和度与血流动力学参数进行了比较。结果表明，满意的混合静脉血氧饱和度（超过65%）与包括心输出量和心脏指数在内的正常血流动力学测量值相关。一般来说，在平均血压、心率或肺毛细血管楔压改变之前，混合静脉血氧饱和度会下降超过10%。发现心输出量、心脏指数、全身血管阻力和左心室每搏功指数会随着混合静脉血氧饱和度的变化而改变。混合静脉血氧饱和度下降（小于65%）可能与以下因素有关：(a) 异常的血流动力学状态——心输出量减少、低血压、全身血管阻力升高和心律失常；(b) 异常的氧需求——寒战、吸痰、体位改变和发热；(c) 异常的氧供应——贫血、气道阻塞和肺泡毛细血管膜处氧弥散改变。血氧测定法系统被证明是可靠的。混合静脉血氧饱和度是血流动力学状态的一个非特异性指标。连续监测混合静脉血氧饱和度可通过立即提醒重症监护人员注意组织灌注不足的发生，促进对患者的最佳管理。
