Rees S E, Toftegaard M, Andreassen S
Center for Model-based Medical Decision Support, Aalborg University, Niels Jernes Vej 144-313, DK-9220 Aalborg East, Aalborg, Denmark.
Comput Methods Programs Biomed. 2006 Jan;81(1):18-25. doi: 10.1016/j.cmpb.2005.10.003. Epub 2005 Nov 21.
In non-emergency medical departments such as internal medicine sampling of arterial blood and analysis for acid-base status is not routinely performed. Peripheral venous blood is routinely taken but interpretation of its acid-base status is difficult. This paper presents a method for calculation of arterial acid-base and blood gas status from measurements in peripheral venous blood combined with a pulse oximeter measurement of arterial saturation. The use of the method has been illustrated using the data of three patients with different acid-base, haemodynamic, and metabolic conditions. The sensitivity of the method has been tested for measurement errors including venous blood acid-base and blood gas status and pulse oximetry; errors due to physiological assumptions including the values of RQ and strong acid production at the tissues; and errors due to air bubbles in the blood. Errors due to these effects are relatively insignificant except for errors in calculated arterial PO(2), particularly when SpO(2) is greater than 97%; and errors when the change in base excess across the sampling site due to strong acid production is greater that 1.3 mmol/l.
在内科等非急诊医疗科室，动脉血采样及酸碱状态分析并非常规操作。外周静脉血采样是常规进行的，但对其酸碱状态的解读较为困难。本文介绍了一种通过外周静脉血测量结合动脉血氧饱和度脉搏血氧仪测量来计算动脉酸碱和血气状态的方法。已利用三名患有不同酸碱、血流动力学和代谢状况患者的数据说明了该方法的应用。已针对测量误差对该方法的敏感性进行了测试，这些误差包括静脉血酸碱和血气状态以及脉搏血氧测定；因生理假设导致的误差，包括呼吸商（RQ）值和组织强酸生成量；以及血液中气泡导致的误差。除了计算出的动脉血氧分压（PO₂）存在误差（尤其是当血氧饱和度（SpO₂）大于97%时），以及由于强酸生成导致采样部位碱剩余变化大于1.3 mmol/L时出现的误差外，这些影响导致的误差相对较小。
