Carter Ryan M, Cone David C
Department of Emergency Medicine,Yale University School of Medicine,New Haven,ConnecticutUSA.
Prehosp Disaster Med. 2017 Oct;32(5):523-527. doi: 10.1017/S1049023X17006446. Epub 2017 May 2.
Introduction While the overall survival rate for out-of-hospital cardiac arrest (OHCA) is low, ranging from 5%-10%, several characteristics have been shown to decrease mortality, such as presence of bystander cardiopulmonary resuscitation (CPR), witnessed vs unwitnessed events, and favorable initial rhythm (VF/VT). More recently, studies have shown that modified CPR algorithms, such as chest-compression only or cardio-cerebral resuscitation, can further increase survival rates in OHCA. Most of these studies have included only OHCA patients with "presumed cardiac etiology," on the assumption that airway management is of lesser impact than chest compressions in these patients. However, prehospital personnel often lack objective and consistent criteria to assess whether an OHCA is of cardiac or non-cardiac etiology. Hypothesis/Problem The relative proportions of cardiac vs non-cardiac etiology in published data sets of OHCA in the peer-reviewed literature were examined in order to assess the variability of prehospital clinical etiology assessment.
A Medline (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA) search was performed using the subject headings "OHCA" and "Emergency Medical Services" (EMS). Studies were included if they reported prevalence of cardiac etiology among OHCA in the entire patient sample, or in all arms of a comparison study. Studies that either did not report etiology of OHCA, or that excluded all cardiac or non-cardiac etiologies prior to reporting clinical data, were excluded.
Twenty-four studies were identified, containing 27 datasets of OHCA which reported the prevalence of presumed cardiac vs non-cardiac etiology. These 27 datasets were drawn from 15 different countries. The prevalence of cardiac etiology among OHCA ranged from 50% to 91%. No obvious patterns were found regarding database size, year of publication, or global region (continent) of origin.
There exists significant variation in published rates of cardiac etiology among OHCAs. While some of this variation likely reflects different actual rates of cardiac etiologies in the sampled populations, varying definitions of cardiac etiology among prehospital personnel or varying implementation of existing definitions may also play a role. Different proportions of cardiac vs non-cardiac etiology of OHCA in a sample could result in entirely different interpretations of data. A more specific consensus definition of cardiac etiology than that which currently exists in the Utstein template may provide better guidance to prehospital personnel and EMS researchers in the future. Carter RM , Cone DC . When is a cardiac arrest non-cardiac? Prehosp Disaster Med. 2017;32(5):523-527.
引言 虽然院外心脏骤停（OHCA）的总体生存率较低，在5%至10%之间，但已显示出一些特征可降低死亡率，例如旁观者进行心肺复苏（CPR）、有目击者与无目击者事件以及有利的初始心律（室颤/室速）。最近，研究表明，改良的CPR算法，如仅胸外按压或心肺脑复苏，可进一步提高OHCA的生存率。这些研究大多仅纳入了“推测为心脏病因”的OHCA患者，其假设是在这些患者中气道管理的影响小于胸外按压。然而，院前急救人员往往缺乏客观一致的标准来评估OHCA是心脏病因还是非心脏病因。假设/问题 为了评估院前临床病因评估的变异性，对同行评审文献中已发表的OHCA数据集中心脏病因与非心脏病因的相对比例进行了研究。
使用主题词“OHCA”和“紧急医疗服务”（EMS）在美国国立医学图书馆（美国国立卫生研究院；马里兰州贝塞斯达）进行了Medline搜索。如果研究报告了整个患者样本中OHCA中心脏病因的患病率，或比较研究所有组中的患病率，则纳入该研究。未报告OHCA病因或在报告临床数据之前排除所有心脏或非心脏病因的研究被排除。
共识别出24项研究，包含27个OHCA数据集，这些数据集报告了推测为心脏病因与非心脏病因的患病率。这27个数据集来自15个不同国家。OHCA中心脏病因的患病率在50%至91%之间。在数据库规模、发表年份或起源的全球区域（大洲）方面未发现明显模式。
已发表的OHCA中心脏病因发生率存在显著差异。虽然这种差异部分可能反映了抽样人群中不同的实际心脏病因发生率，但院前急救人员对心脏病因的不同定义或现有定义的不同实施情况也可能起作用。样本中OHCA心脏病因与非心脏病因的不同比例可能导致对数据的完全不同解释。比目前Utstein模板中存在的更具体的心脏病因共识定义可能会在未来为院前急救人员和EMS研究人员提供更好的指导。卡特RM，科恩DC。何时心脏骤停是非心脏性的？院前灾难医学。2017；32（5）：523 - 527。
