Department of Acute General Medicine, The John Radcliffe Hospital Kadoorie Centre for Critical Care Research and Education, The John Radcliffe Hospital, Oxford, UK.
Diabet Med. 2012 Jan;29(1):32-5. doi: 10.1111/j.1464-5491.2011.03390.x.
To assess the comparability of venous and arterial samples for pH, bicarbonate and potassium measurements in critically ill patients.
Simultaneous arterial and venous samples from 206 critically ill patients were analysed in duplicate. Coefficients of variation and 95% limits of agreement were calculated for arterial and venous samples. Bland-Altman plots were constructed to assess agreement between sampling sites.
The median (range) of arterial pH, bicarbonate concentrations, potassium concentrations and glucose concentrations were 7.40 (7.01-7.56), 25 (9-41) mmol/l, 4.2 (3.1-6.8) mmol/l and 7.4 (3.0-13.5) mmol/l, respectively. Coefficients of variation for arterial and venous pH were both 0.1%, with bias (95% limits of agreement) of -0.01 (-0.03 to 0.01) for arterial and -0.01 (-0.02 to 0.01) for venous samples. The bias (95% limits of agreement) between arterial and venous samples was 0.03 (-0.02 to 0.08). Coefficients of variation for arterial and venous bicarbonate results were 0.8 and 0.7%, respectively, with bias (95% limits of agreement) of 0 (-0.5 to 0.5) mmol/l for both sample types. The bias (95% limits of agreement) between venous and arterial samples was 0 (-1.3 to 1.3) mmol/l. Coefficients of variation for arterial and venous potassium samples were 0.8 and 1.1%, respectively, with bias (95% limits of agreement) of 0 (-0.1 to 0.1) for both sample types. The bias (95% limits of agreement) between venous and arterial samples was 0.1 (-0.4 to 0.6) mmol/l.
A venous blood sample, analysed on a blood gas machine, is sufficiently reliable to assess pH, bicarbonate and potassium concentrations in critically ill patients, suggesting that venous sampling alone is appropriate in the management of diabetic ketoacidosis.
评估危重病患者动脉和静脉样本在 pH 值、碳酸氢盐和钾测量方面的可比性。
对 206 例危重病患者的动脉和静脉样本进行了重复分析。计算了动脉和静脉样本的变异系数和 95%一致性界限。绘制 Bland-Altman 图以评估采样部位之间的一致性。
动脉 pH 值、碳酸氢盐浓度、钾浓度和葡萄糖浓度的中位数（范围）分别为 7.40（7.01-7.56）、25（9-41）mmol/L、4.2（3.1-6.8）mmol/L 和 7.4（3.0-13.5）mmol/L。动脉和静脉 pH 值的变异系数均为 0.1%，动脉样本的偏倚（95%一致性界限）为-0.01（-0.03 至 0.01），静脉样本为-0.01（-0.02 至 0.01）。动脉和静脉样本之间的偏差（95%一致性界限）为 0.03（-0.02 至 0.08）。动脉和静脉碳酸氢盐结果的变异系数分别为 0.8%和 0.7%，两种样本类型的偏倚（95%一致性界限）均为 0（-0.5 至 0.5）mmol/L。静脉和动脉样本之间的偏差为 0（-1.3 至 1.3）mmol/L。动脉和静脉钾样本的变异系数分别为 0.8%和 1.1%，两种样本类型的偏倚（95%一致性界限）均为 0（-0.1 至 0.1）mmol/L。静脉和动脉样本之间的偏差为 0.1（-0.4 至 0.6）mmol/L。
血气机能分析静脉血样足以可靠地评估危重病患者的 pH 值、碳酸氢盐和钾浓度，表明在糖尿病酮症酸中毒的治疗中，单独静脉采样是合适的。
