Elsevier

Resuscitation

Volume 82, Issue 3, March 2011, Pages 277-284
Resuscitation

Clinical paper
Variation in out-of-hospital cardiac arrest resuscitation and transport practices in the Resuscitation Outcomes Consortium: ROC Epistry–Cardiac Arrest

https://doi.org/10.1016/j.resuscitation.2010.10.022Get rights and content

Abstract

Objectives

To identify variation in patient, event, and scene characteristics of out-of-hospital cardiac arrest (OOHCA) patients assessed by emergency medical services (EMS), and to investigate variation in transport practices in relation to documented prehospital return of spontaneous circulation (ROSC) within eight regional clinical centers participating in the Resuscitation Outcomes Consortium (ROC) EpistryCardiac Arrest.

Methods

OOHCA patient, event, and scene characteristics were compared to identify variation in treatment and transport practices across sites. Findings were adjusted for site and standard Utstein covariates. Using logistic regression, these covariates were modeled to identify factors related to the initiation of transport without documented prehospital ROSC as well as survival in these patients. Setting: Eight US and Canadian sites participating in the ROC EpistryCardiac Arrest. Population: Persons ≥20 years with OOHCA who (a) received compressions or shock by EMS providers and/or received bystander AED shock or (b) were pulseless but received no EMS compressions or shock between December 2005 and May 2007.

Results

23,233 OOHCA cases were assessed by EMS in the defined period. Resuscitation (treatment) was initiated by EMS in 13,518 cases (58%, site range: 36–69%, p < 0.0001). Of treated cases, 59% were transported (site range: 49–88%, p < 0.0001). Transport was initiated in the absence of documented ROSC for 58% of transported cases (site range: 14–95%, p < 0.0001). Of these transported cases, 8% achieved ROSC before hospital arrival (site range: 5–21%, p < 0.0001) and 4% survived to hospital discharge (site range: 1–21%, p < 0.0001). In cases with transport from the scene initiated after documented ROSC, 28% survived to hospital discharge (site range: 18–44%, p < 0.0001).

Conclusion

Initiation of resuscitation and transport of OOHCA and the reporting of ROSC prior to transport markedly varies among ROC sites. This variation may help clarify reported differences in survival rates among sites and provide a target for identifying EMS practices most likely to enhance survival from OOHCA.

Introduction

Out-of-hospital cardiac arrest (OOHCA) is a major cause of death in North America.1, 2, 3, 4 Witnessed events, bystander initiated cardiopulmonary resuscitation (CPR), presenting rhythm of ventricular fibrillation, arrest location and the prehospital return of spontaneous circulation (ROSC) have all been associated with increased survival.1, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 Assessments of incidence and outcome also indicate community-level variation as a significant factor in EMS treatment and survival from OOHCA.1, 6, 19 Reported survival to hospital discharge ranges from 2% to 25% in twenty-nine communities, and from 3.0% to 16.3% of EMS-treated patients in ten ROC communities.1, 6

Understanding regional survival is complicated by definitions used in reporting outcomes.6, 20, 21 Variation may be related to patient, event, system, and therapy factors, including treatment initiation and duration, field termination of resuscitation (TOR) efforts or local regulations guiding transport of non-resuscitated patients to the Emergency Department (ED). EMS strategies for OOHCA treatment and transport differ widely. In some communities, EMS is dispatched for every OOHCA, including those with clear signs of death. Some EMS agencies initiate transport regardless of circulatory status and after little time on scene while others do not initiate transport unless there is ROSC.

The objective of this study was to identify site-level variation in the proportion of OOHCA patients assessed by EMS for whom efforts are initiated, the proportion of patients transported to EDs, and variation in transport practices in relation to ROSC. We also examined predictors of transport in relation to ROSC and survival in the subgroup of patients whose transport was initiated in the absence of ROSC. Differences in treatment and transport practices could account for some of the variation in reported OOHCA survival across ROC sites.1

Section snippets

Setting and population

The Resuscitation Outcomes Consortium (ROC) is a network of 9 Regional Clinical Centers consisting of 11 major North American sites investigating OOHCA including US and Canadian communities with geographic dispersion and diversity, serving an estimated 23.7 million population. ROC includes more than 260 EMS agencies including urban and rural, private and municipal agencies.22

The ROC Epistry–Cardiac Arrest is a prospective, multicenter, observational registry that collects uniform data on all

Results

Aggregate findings are summarized in Fig. 1. Resuscitation by EMS was attempted for 13,518 patients (58%), with 7945 of these patients (59%) transported. A total of 1124 transported patients survived to hospital discharge (8.3% of patients for whom resuscitation was attempted). We investigated subgroups of those transported after documented field ROSC (42% of all treated patients) and those for whom transport was initiated without documented prehospital ROSC (58% of all treated patients) and

Discussion

The use of standardized data collection (a single web-based data entry platform used by all sites) and definitions within the ROC Epistry–Cardiac Arrest allows consistent definition of data content and denominators for survival calculations across sites as opposed to chart review or other disparate data collection approaches. The need for consistent denominators in survival calculations has been previously noted, with Eisenberg et al., calling for “national and international agreement about

Further directions

Better knowledge of protocols guiding EMS initiation, timing, and termination of resuscitation, along with transport practices, both overall and in relation to documented ROSC, is critical for understanding OOHCA survival. Systematic research is needed to compare these protocols and practices with a better understanding of ROSC documentation in the prehospital setting to identify patients who are most likely to achieve ROSC either on scene or en route to continued care, and ultimately survive.

Limitations

ROC Epistry–Cardiac Arrest records the first out-of-hospital ROSC of any duration, and is unable to distinguish sustained from intermittent ROSC. Timing of ROSC and transport were determined using reported time of first documented ROSC and recorded time of transport from the scene. To be included in this analysis, all cases were required to have the time of transport recorded. Those cases with no time of first ROSC were considered to have no documented ROSC. Only the initial cardiac arrest

Conclusions

There is marked site variation in the initiation of resuscitation of OOHCA by EMS, which could affect the overall reported survival rates in communities. Similarly, the proportion and type of patients transported without ROSC varies widely. Finally, the site-level variation in survival following transport initiation without documented ROSC is also significant. There is a critical need for further investigation of this variation for the interpretation of reported OOHCA resuscitation and

Conflict of interest statement

No authors had potential conflicts of interest relevant to the subject matter of this manuscript.

Funding

The ROC is supported by a series of cooperative agreements to 10 regional clinical centers and one Data Coordinating Center (5U01HL077863, HL077881, HL077871, HL077872, HL077866, HL077908, HL077867, HL077885, HL077887, HL077873, HL077865) from the National Heart, Lung and Blood Institute in partnership with the National Institute of Neurological Disorders and Stroke, U.S. Army Medical Research & Material Command, The Canadian Institutes of Health Research (CIHR) – Institute of Circulatory and

References (41)

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A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2010.10.022.

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