Department of Emergency Medicine, Yonsei University College of Medicine, Seoul, 06273, Republic of Korea; Department of Emergency Medicine, Graduate School of Medicine, Kangwon National University, Chuncheon, 24289, Republic of Korea.
Department of Radiology, Yonsei University College of Medicine, Seoul, 06273, Republic of Korea.
Am J Emerg Med. 2021 May;43:69-76. doi: 10.1016/j.ajem.2021.01.027. Epub 2021 Jan 16.
Chloride is an important electrolyte in the body. In this study, we aimed to evaluate the associations between chloride levels on emergency department (ED) admission and neurologic outcomes by stratifying patients undergoing targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA) into three groups (hyper/normo/hypochloremia); we also assessed the effect of changes in chloride levels from baseline over time on outcomes.
This retrospective, observational cohort study of 346 patients was conducted between 2011 and 2019. The chloride levels were categorized as hypochloremia, normochloremia, and hyperchloremia by predetermined definitions. The primary endpoint was poor neurologic outcomes after hospital discharge. We evaluated the associations between chloride levels on ED admission and neurologic outcomes and assess the effect of changes in chloride levels over time on clinical outcomes.
On ED admission, compared with normochloremia, hypochloremia was significantly associated with unfavorable neurologic outcomes (OR, 2.668; 95% CI, 1.217-5.850, P = 0.014). Over time, unfavorable neurologic outcomes were significantly associated with increases in chloride levels in the hyperchloremia and normochloremia groups after ED admission. The rates of poor neurologic outcomes in the hyperchloremia and normochloremia groups were increased by 14.2% at Time-12, 20.1% at Time-24, and 9.3% at Time-48 with a 1-mEq/L increase in chloride levels.
In clinical practice, chloride levels can be routinely and serially measured cost-effectively. Thus, baseline chloride levels may be a promising tool for rapid risk stratification of patients after OHCA. For fluid resuscitation after cardiac arrest, a chloride-restricted solution may be an early therapeutic strategy.
氯是体内一种重要的电解质。本研究旨在通过将接受院外心脏骤停（OHCA）后目标温度管理（TTM）的患者分层为高/正常/低氯血症三组，评估入院时氯水平与神经结局之间的关联；我们还评估了氯水平随时间从基线变化对结局的影响。
这是一项回顾性、观察性队列研究，共纳入 346 例患者，研究时间为 2011 年至 2019 年。根据预先确定的定义，氯水平分为低氯血症、正常氯血症和高氯血症。主要终点是出院后神经功能不良结局。我们评估了入院时氯水平与神经结局之间的关联，并评估了氯水平随时间变化对临床结局的影响。
入院时，与正常氯血症相比，低氯血症与不良神经结局显著相关（OR，2.668；95%CI，1.217-5.850，P=0.014）。随着时间的推移，入院后高氯血症和正常氯血症组氯水平升高与不良神经结局显著相关。入院后氯水平每增加 1 mEq/L，高氯血症组和正常氯血症组不良神经结局的发生率在 12 小时时增加 14.2%，在 24 小时时增加 20.1%，在 48 小时时增加 9.3%。
在临床实践中，氯水平可以常规且连续地进行成本效益测量。因此，基线氯水平可能是 OHCA 后患者快速风险分层的有前途的工具。对于心脏骤停后的液体复苏，限制氯的溶液可能是一种早期治疗策略。
