Aim

To analyze the impact of a time-gain selective, first-responder dispatch system on the presence of a shockable initial rhythm (SIR), return of spontaneous circulation (ROSC) and 30-day survival after out-of-hospital cardiac arrest (OHCA).

Method

A retrospective observational study comprising OHCA registry data and dispatch data in the Skåne Region, Sweden (2010–2018). Data were categorized according to dispatch procedures, two ambulances (AMB-only) versus two ambulances and firefighter first-responders (DUAL-dispatch), based on the dispatcher’s estimation of a time-gain. Dual dispatch was sub-categorized by arrival of first vehicle (first-responder or ambulance). Logistic regressions were used, additionally with groups matched (1:1) for age, sex, location, witnessed event, bystander cardiopulmonary resuscitation and ambulance response time. Adjusted and conditional odds-ratios (aOR, cOR) with 95% confidence intervals (CI) are presented.

Results

Of 3,245 eligible cases, 43% were DUAL-dispatches with first-responders first on scene (FR-first) in 72%. Despite a five-minute median reduction in response time in the FR-first group, no association with SIR was found (aOR 0.83, 95%CI 0.64–1.07) nor improved 30-day survival (aOR 1.03, 95%CI 0.72–1.47). A positive association between ROSC and the FR-first group (aOR 1.25, 95%CI 1.02–1.54) disappeared in the matched analysis (cOR 1.12, 95%CI 0.87–1.43). Time to first monitored rhythm was 7:06 minutes in the FR-first group versus 3:01 in the combined AMB-only/AMB-first groups.

Conclusion

In this time-gain selective first-responder dispatch system, a shorter response time was not associated with increased SIR, improved ROSC rate or survival. Process measures differed between the study groups which could account for the observed findings and requires further investigation.

中文翻译：

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消防员作为院外心脏骤停的第一响应者——瑞典斯科讷地区时间增益选择性调度系统的回顾性研究

目标

分析时间增益选择性急救调度系统对可电击初始节律 (SIR)、自主循环恢复 (ROSC) 和院外心脏骤停 (OHCA) 后 30 天生存率的影响）。

方法

一项回顾性观察研究，包括瑞典斯科讷地区的 OHCA 注册数据和调度数据（2010-2018 年）。根据调度员对时间增益的估计，数据根据调度程序、两辆救护车（仅限 AMB）与两辆救护车和消防员急救人员（双调度）进行分类。双重调度按第一辆车（急救人员或救护车）的到来进行细分。使用逻辑回归，另外与年龄、性别、位置、目击事件、旁观者心肺复苏和救护车响应时间匹配 (1:1) 的组。给出了具有 95% 置信区间 (CI) 的调整和条件优势比 (aOR, cOR)​​。

结果

在 3,245 名符合条件的病例中，43% 是双重调度，其中 72% 是急救人员首先到达现场（FR-first）。尽管FR-first组的反应时间中位数减少了 5 分钟，但未发现与 SIR 相关（aOR 0.83, 95%CI 0.64–1.07），也没有改善 30 天生存率（aOR 1.03, 95%CI 0.72–1.47） ）。ROSC 和FR 第一组之间的正相关（aOR 1.25, 95%CI 1.02-1.54）在匹配分析中消失了（cOR 1.12, 95%CI 0.87-1.43）。FR-first组首次监测心律的时间为 7:06 分钟，而AMB-only / AMB-first组合组为 3:01 。

结论

在这种时间增益选择性急救调度系统中，较短的响应时间与增加的 SIR、提高的 ROSC 率或生存率无关。研究组之间的过程测量值不同，这可以解释观察到的结果并需要进一步调查。