Background

Early recognition and rapid defibrillation of shockable rhythms is strongly associated with survival in out of hospital cardiac arrest (OHCA). Little is known about the accuracy of paramedic rhythm interpretation and its impact on survival. We hypothesized that inaccurate paramedic interpretation of initial rhythm would be associated with worse survival.

Methods

This is a retrospective cohort analysis of prospectively collected OHCA data over a nine-year period within a single, urban, fire-based EMS system that utilizes manual defibrillators equipped with rhythm-filtering technology. We compared paramedic-documented initial rhythm with a reference standard of post-event physician interpretation to estimate sensitivity and specificity of paramedic identification of and shock delivery to shockable rhythms. We assessed the association between misclassification of initial rhythm and neurologically intact survival to hospital discharge using multivariable logistic regression.

Results

A total of 863 OHCA cases were available for analysis with 1,756 shocks delivered during 542 (63%) resuscitation attempts. Eleven percent of shocks were delivered to pulseless electrical activity (PEA). Sensitivity and specificity for paramedic initial rhythm interpretation were 176/197 (0.89, 95% CI 0.84–0.93) and 463/504 (0.92, 95% CI 0.89–0.94) respectively. No patient survived to hospital discharge when paramedics misclassified the initial rhythm.

Conclusions

Paramedics achieved high sensitivity for shock delivery to shockable rhythms, but with an 11% shock delivery rate to PEA. Misclassification of initial rhythm was associated with poor survival. Technologies that assist in rhythm identification during CPR, rapid shock delivery, and minimal hands-off time may improve outcomes.

中文翻译：

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护理人员节律解释错误分类与院外心脏骤停的低生存率有关

背景

可电击节律的早期识别和快速除颤与院外心脏骤停 (OHCA) 的存活率密切相关。关于护理人员节律解释的准确性及其对生存的影响知之甚少。我们假设护理人员对初始节律的不准确解释与较差的生存率有关。

方法

这是一项回顾性队列分析，在一个单一的、城市的、基于火灾的 EMS 系统中，在 9 年内前瞻性收集的 OHCA 数据，该系统利用配备有节律过滤技术的手动除颤器。我们将护理人员记录的初始节律与事件后医生解释的参考标准进行了比较，以估计护理人员识别和电击传递对可电击节律的敏感性和特异性。我们使用多变量逻辑回归评估了初始节律的错误分类与神经系统完整生存与出院之间的关联。

结果

共有 863 例 OHCA 病例可供分析，在 542 次 (63%) 复苏尝试中实施了 1,756 次电击。11% 的电击发生在无脉冲电活动 (PEA) 上。护理人员初始节律解释的敏感性和特异性分别为 176/197 (0.89, 95% CI 0.84–0.93) 和 463/504 (0.92, 95% CI 0.89–0.94)。当护理人员错误分类初始节律时，没有患者存活到出院。

结论

医护人员对可电击节律的电击传递具有高灵敏度，但对 PEA 的电击传递率为 11%。初始节律的错误分类与较差的生存率有关。在 CPR 期间帮助识别节律、快速传递电击和最短的放手时间的技术可能会改善结果。