Schulich School of Dentistry and Medicine, Victoria Hospital, London Health Sciences Centre, Western University, 800 Commissioners Rd E, London, ON, N6A 5W9, Canada.
Critical Care Western, Department of Medicine, Schulich School of Dentistry and Medicine, Western University, London, ON, Canada.
Can J Anaesth. 2017 Nov;64(11):1138-1143. doi: 10.1007/s12630-017-0951-8. Epub 2017 Aug 23.
To determine whether the use of venous blood gases can be a suitable alternative to arterial sampling to evaluate acid-base status.
The database of the clinical laboratory in a large academic hospital was searched for records of venous blood gas analysis and an arterial sample taken within ten minutes from the same patient. Bland-Altman analyses of pH, pCO, and lactate were performed for samples obtained from patients separately from within and outside the intensive care unit (ICU).
In 2,296 paired arterial-venous samples from 351 ICU patients, the bias was 0.044, -6.2 mmHg, and -0.07 mEq·L for pH, pCO, and lactate, respectively. The range of agreement centred on this bias (upper minus lower level of agreement) was 0.134, 16.7 mmHg, and 1.35 mEq·L for pH, pCO, and lactate, respectively. Intraclass correlation coefficients (ICCs) were 0.79, 0.76, and 0.99 for pH, pCO, and lactate, respectively, indicating excellent agreement. Multiple samples obtained from the same patient had a median standard deviation of 0.02, 2.77 mmHg, and 0.18 mEq·L for pH, pCO, and lactate, respectively. Similar agreement was observed in samples from patients outside the ICU, although the ICC was only 0.53 for pCO.
Venous gases are suitable for initial evaluation of acid-base status in critically ill patients. Based on clinical evaluation, an arterial sample may then be considered for confirmation, and thereafter, venous blood gases could be sufficient for monitoring response to treatment.
确定静脉血气分析是否可以替代动脉采血来评估酸碱平衡状态。
检索大型学术医院临床实验室的数据库，查找同一患者在 10 分钟内采集的静脉血气分析和动脉血样记录。对来自 ICU 内和 ICU 外患者的样本分别进行 pH、pCO 和乳酸的 Bland-Altman 分析。
在 351 例 ICU 患者的 2296 对动脉-静脉样本中，pH、pCO 和乳酸的偏倚分别为 0.044、-6.2mmHg 和-0.07mEq·L。以该偏倚为中心的一致性范围（一致性上限减去下限）分别为 pH、pCO 和乳酸的 0.134、16.7mmHg 和 1.35mEq·L。pH、pCO 和乳酸的组内相关系数（ICC）分别为 0.79、0.76 和 0.99，表明具有极好的一致性。同一患者的多个样本的 pH、pCO 和乳酸的中位数标准差分别为 0.02、2.77mmHg 和 0.18mEq·L。在 ICU 外的患者样本中也观察到了类似的一致性，尽管 pCO 的 ICC 仅为 0.53。
静脉血气分析适用于危重症患者初始酸碱平衡状态的评估。根据临床评估，可能需要考虑采集动脉血样以进行确认，此后，静脉血气分析即可满足监测治疗反应的需求。
