Zhang Jian Bo, Lin Ji, Zhao Xiao Dong
Emergency Department, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, China.
Institute of Basic Medicine, Chinese PLA General Hospital, Beijing 100853, China.
PLoS One. 2015 Apr 7;10(4):e0122383. doi: 10.1371/journal.pone.0122383. eCollection 2015.
The emergency departments (EDs) of Chinese hospitals are gradually being equipped with blood gas machines. These machines, along with the measurement of biochemical markers by the hospital laboratory, facilitate the care of patients with severe conditions who present to the ED. However, discrepancies have been noted between the Arterial Blood Gas (ABG) analyzers in the ED and the hospital laboratory autoanalyzer in relation to electrolyte and hemoglobin measurements. The present study was performed to determine whether the ABG and laboratory measurements of potassium, sodium, and hemoglobin levels are equivalent, and whether ABG analyzer results can be used to guide clinical care before the laboratory results become available.
Study power analyses revealed that 200 consecutive patients who presented to our ED would allow this prospective single-center cohort study to detect significant differences between ABG- and laboratory-measured potassium, sodium, and hemoglobin levels. Paired arterial and venous blood samples were collected within 30 minutes. Arterial blood samples were measured in the ED by an ABL 90 FLEX blood gas analyzer. The biochemistry and blood cell counts of the venous samples were measured in the hospital laboratory. The potassium, sodium, and hemoglobin concentrations obtained by both methods were compared by using paired Student's t-test, Spearman's correlation, Bland-Altman plots, and Deming regression.
The mean ABG and laboratory potassium values were 3.77±0.44 and 4.2±0.55, respectively (P<0.0001). The mean ABG and laboratory sodium values were 137.89±5.44 and 140.93±5.50, respectively (P<0.0001). The mean ABG and laboratory Hemoglobin values were 12.28±2.62 and 12.35±2.60, respectively (P = 0.24).
Although there are the statistical difference and acceptable biases between ABG- and laboratory-measured potassium and sodium, the biases do not exceed USCLIA-determined limits. In parallel, there are no statistical differences and biases beyond USCLIA-determined limits between ABG- and laboratory-measured hemoglobin. Therefore, all three variables measured by ABG were reliable.
中国医院的急诊科正逐渐配备血气分析仪。这些仪器与医院检验科对生化指标的检测一起，有助于对到急诊科就诊的重症患者进行护理。然而，已注意到急诊科的动脉血气（ABG）分析仪与医院检验科自动分析仪在电解质和血红蛋白测量方面存在差异。本研究旨在确定ABG测量与检验科测量的钾、钠和血红蛋白水平是否等效，以及在检验科结果出来之前，ABG分析仪的结果是否可用于指导临床护理。
研究功效分析表明，连续200例到我院急诊科就诊的患者将使这项前瞻性单中心队列研究能够检测出ABG测量与检验科测量的钾、钠和血红蛋白水平之间的显著差异。在30分钟内采集配对的动脉血和静脉血样本。动脉血样本在急诊科用ABL 90 FLEX血气分析仪进行测量。静脉样本的生化指标和血细胞计数在医院检验科进行检测。通过配对t检验、Spearman相关性分析、Bland-Altman图和Deming回归比较两种方法测得的钾、钠和血红蛋白浓度。
ABG测量与检验科测量的钾均值分别为3.77±0.44和4.2±0.55（P<0.0001）。ABG测量与检验科测量的钠均值分别为137.89±5.44和140.93±5.50（P<0.0001）。ABG测量与检验科测量的血红蛋白均值分别为12.28±2.62和12.35±2.60（P = 0.24）。
尽管ABG测量与检验科测量的钾和钠之间存在统计学差异和可接受的偏差，但偏差未超过美国临床实验室改进修正案（USCLIA）规定的限值。同时，ABG测量与检验科测量的血红蛋白之间不存在统计学差异，且偏差未超过USCLIA规定的限值。因此，ABG测量的所有三个变量都是可靠的。
