Background The knowledge of new prognostic factors in out-of-hospital cardiac arrest (OHCA) that can be evaluated since the beginning of cardiopulmonary resuscitation (CPR) manoeuvres could be helpful in the decision-making process of prehospital care. We aim to identify metabolic variables at the start of advanced CPR at the scene that may be associated with two main outcomes of CPR (recovery of spontaneous circulation (ROSC) and neurological outcome). Methods Prospective observational study of all non-traumatic OHCA in patients older than 17 years assisted by emergency medical services (EMS), with doctor and nurse on board, between January 2012 and December 2017. Venous blood gases were sampled upon initially obtaining venous access to determine the initial values of pH, pCO 2 , HCO 3 − , base excess (BE), Na + , K + , Ca 2+ and lactate. ROSC upon arrival at the hospital and neurological status 30 days later (Cerebral Performance Categories (CPC) scale) were recorded. Results We included 1552 patients with OHCA with blood test data in a 6-year period. ROSC was achieved in 906 cases (58.4%), and good neurological recovery at 30 days (CPC I-II) occurred in 383 cases (24.68%). In multivariate analysis, we found a significant relationship between non-recovery of spontaneous circulation (no-ROSC) and low pH levels (adjusted odds ratio (OR) 0.03 (0.002–0.59), p = 0.020), high pCO 2 levels (adjusted OR 1.03 [1.01–1.05], p = 0.008) and high potassium levels (adjusted OR 2.28 [1.43–3.61], p = 0.008). Poor neurological outcomes were associated with low pH levels (adjusted OR 0.06 [0.02–0.18], p < 0.001), high pCO 2 (adjusted OR 1.05 [1.03–1.08], p < 0.001), low HCO 3 − (adjusted OR 0.97 [0.94–0.999], p = 0.044), low BE (adjusted OR 0.96 [0.93–0.98], p < 0.001) and high potassium levels (adjusted OR 1.37 [1.16–1.60], p < 0.001). Conclusion There is a significant relationship between severe alterations of venous blood-gas variables and potassium at the start of CPR of non-traumatic OHCA and low-ROSC rate and neurological prognosis.

中文翻译：

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非创伤性院外心脏骤停 CPR 开始时静脉血分析的预后价值：与 ROSC 和神经系统结果的关联

背景 了解院外心脏骤停 (OHCA) 的新预后因素，可在心肺复苏 (CPR) 操作开始后对其进行评估，这可能有助于院前护理的决策过程。我们的目标是在现场进行高级 CPR 开始时确定可能与 CPR 的两个主要结果（自主循环恢复 (ROSC) 和神经系统结果）相关的代谢变量。方法 2012 年 1 月至 2017 年 12 月期间，在急诊医疗服务 (EMS) 协助下，在医生和护士的协助下，对 17 岁以上患者的所有非创伤性 OHCA 进行前瞻性观察研究。确定 pH、pCO 2 、HCO 3 - 、碱过量 (BE)、Na + 、K + 、Ca 2+ 和乳酸盐的初始值。记录到达医院时的 ROSC 和 30 天后的神经系统状态（脑功能分类 (CPC) 量表）。结果 我们纳入了 1552 名 OHCA 患者，并在 6 年内提供了血液检测数据。ROSC 906 例（58.4%），30 天神经功能恢复良好（CPC I-II）383 例（24.68%）。在多变量分析中，我们发现自主循环无法恢复 (no-ROSC) 与低 pH 水平（调整后的优势比 (OR) 0.03 (0.002–0.59)，p = 0.020）、高 pCO 2 水平（调整后的OR 1.03 [1.01–1.05]，p = 0.008）和高钾水平（调整后的 OR 2.28 [1.43–3.61]，p = 0.008）。较差的神经系统结果与低 pH 水平（调整后的 OR 0.06 [0.02-0.18]，p < 0.001）、高 pCO 2（调整后的 OR 1.05 [1.03-1.08]，p < 0.001）、低 HCO 3 -（调整后的 OR 0）相关. 97 [0.94–0.999]，p = 0.044)，低 BE（调整后的 OR 0.96 [0.93–0.98]，p < 0.001）和高钾水平（调整后的 OR 1.37 [1.16-1.60]，p < 0.001）。结论 非创伤性 OHCA CPR 开始时静脉血气变量和钾的严重改变与低 ROSC 率和神经系统预后之间存在显着相关性。