BACKGROUND AND IMPORTANCE No large randomised controlled trial has assessed the potential benefits on neurologic outcomes of prehospital sodium bicarbonate administration in patients with nontraumatic out-of-hospital cardiac arrest (OHCA). OBJECTIVE To obtain information of assistance in designing a randomised controlled trial of bicarbonate therapy after OHCA in specific patient subgroups. DESIGN We conducted two, separate, simultaneous, retrospective studies of two distinct, unlinked datasets. SETTING AND PARTICIPANTS One dataset was a French nationwide population-based registry (RéAC Registry, French dataset) and the other was a randomised controlled trial comparing continuous to interrupted chest compressions in North America (ROC-CCC trial, North-American dataset). INTERVENTION We investigated whether prehospital bicarbonate administration was associated with better neurologic outcomes. OUTCOME MEASURES AND ANALYSES The main outcome measure was the functional outcome at hospital discharge. To adjust for potential confounders, we conducted a nested propensity-score-matched analysis with inverse probability-of-treatment weighting. MAIN RESULTS In the French dataset, of the 54 807 patients, 1234 (2.2%) received sodium bicarbonate and 450 were matched. After propensity-score matching, sodium bicarbonate was not associated with a higher likelihood of favourable functional outcomes on day 30 [adjusted odds ratio (aOR), 0.912; 95% confidence interval (95%CI), 0.501-1.655]. In the North-American dataset, of the 23 711 included patients, 4902 (20.6%) received sodium bicarbonate and 1238 were matched. After propensity-score matching, sodium bicarbonate was associated with a lower likelihood of favourable functional outcomes at hospital discharge (aOR, 0.45; 95% CI, 0.34-0.58). CONCLUSION In patients with OHCA, prehospital sodium bicarbonate administration was not associated with neurologic outcomes in a French dataset and was associated with worse neurologic outcomes in a North-American dataset. Given the considerable variability in sodium bicarbonate use by different prehospital care systems and the potential resuscitation-time bias in the present study, a large randomised clinical trial targeting specific patient subgroups may be needed to determine whether sodium bicarbonate has a role in the prehospital management of prolonged OHCA.

中文翻译：

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碳酸氢钠对院外心脏骤停患者功能结果的影响：对法国和北美数据集的事后分析。

背景和重要性尚无大型随机对照试验评估院前给予碳酸氢钠对非创伤性院外心脏骤停（OHCA）患者神经系统结局的潜在益处。目的 获得有助于设计 OHCA 后特定患者亚组碳酸氢盐治疗随机对照试验的信息。设计我们对两个不同的、不相关的数据集进行了两项单独、同时的回顾性研究。设置和参与者 一个数据集是法国全国人口登记处（RéAC 登记处，法国数据集），另一个数据集是一项比较北美连续胸外按压和间断胸外按压的随机对照试验（ROC-CCC 试验，北美数据集）。干预 我们调查了院前给予碳酸氢盐是否与更好的神经系统结局相关。结果测量和分析 主要结果测量是出院时的功能结果。为了调整潜在的混杂因素，我们使用逆治疗概率加权进行了嵌套倾向评分匹配分析。主要结果 在法国数据集中，54 807 名患者中，1234 名（2.2%）接受了碳酸氢钠治疗，450 名患者进行了匹配。倾向评分匹配后，碳酸氢钠与第 30 天良好功能结果的较高可能性无关[调整后的比值比 (aOR)，0.912；95% 置信区间 (95%CI), 0.501-1.655]。在北美数据集中，在 23711 名患者中，4902 名（20.6%）接受了碳酸氢钠治疗，1238 名患者进行了匹配。倾向评分匹配后，碳酸氢钠与出院时良好功能结果的可能性较低相关（aOR，0.45；95% CI，0.34-0.58）。结论 在法国数据集中，在 OHCA 患者中，院前给予碳酸氢钠与神经系统结果无关，但在北美数据集中与较差的神经系统结果相关。鉴于不同院前护理系统使用碳酸氢钠的情况存在相当大的差异，以及本研究中潜在的复苏时间偏差，可能需要针对特定​​患者亚组进行大型随机临床试验，以确定碳酸氢钠是否在院前治疗中发挥作用。延长 OHCA。