Brashear R E, Oei T O, Rhodes M L, Futty D E, Hostetler M L
Arch Intern Med. 1979 Apr;139(4):440-2.
We determined the clinical efficacy of using the venous CO2 value, as obtained with routine "electrolytes", in acid-base management. Venipuncture samples for venous CO2 content and chloride concentrations were obtained in 336 patients with arterial blood pH, PaO2, PaCO2, and oxygen saturation determinations. The linear correlation between actual calculated arterial HCO3- and the measured venous CO2 was significant (P less than .001). Using venous CO2, chloride, and arterial pH values, we present various prediction equations for estimating arterial HCO3-. We determined the effects of time delay, exposure to air, and acute changes in arterial blood pH and PaCO2 on venous CO2 levels. Venous CO2 determinations should not be substituted for the arterial HCO3 value in the Henderson-Hasselbalch equation to calculate arterial blood pH or PaCO2. Clinically, the venous CO2 value has little direct use, but when venous CO2 content is abnormal, it should alert the clinician to the need for obtaining arterial blood gas and pH values.
我们确定了在酸碱管理中使用通过常规“电解质”检测获得的静脉血二氧化碳值的临床疗效。对336例患者进行了静脉穿刺，测定静脉血二氧化碳含量、氯化物浓度，并同时测定动脉血pH值、动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）和血氧饱和度。实际计算的动脉血碳酸氢根（HCO3-）与测得的静脉血二氧化碳之间存在显著的线性相关性（P<0.001）。利用静脉血二氧化碳、氯化物和动脉血pH值，我们给出了各种估算动脉血HCO3-的预测方程。我们还确定了时间延迟、暴露于空气中以及动脉血pH值和PaCO2的急性变化对静脉血二氧化碳水平的影响。在亨德森-哈塞尔巴尔赫方程中，不应使用静脉血二氧化碳值替代动脉血HCO3值来计算动脉血pH值或PaCO2。临床上，静脉血二氧化碳值几乎没有直接用途，但当静脉血二氧化碳含量异常时，应提醒临床医生需要获取动脉血气和pH值。
