Elsevier

Resuscitation

Volume 80, Issue 3, March 2009, Pages 324-328
Resuscitation

Clinical paper
Validation of a universal prehospital termination of resuscitation clinical prediction rule for advanced and basic life support providers

https://doi.org/10.1016/j.resuscitation.2008.11.014Get rights and content

Summary

Background

Prehospital termination of resuscitation rules have been derived for Emergency Medical Technician-Paramedics providing advanced life support care and defibrillation-only Emergency Medical Technicians providing basic life support care. We sought to externally validate each rule on a prospective cohort of prehospital cardiac arrest patients to determine if either rule could be proposed as a universal prehospital termination of resuscitation rule.

Methods

Investigators at the University of Toronto performed a secondary cohort analysis of data prospectively collected for the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest trial from 1 April 2006 to 1 April 2007 by one site. The diagnostic test characteristics and predicted transportation rate were calculated for each rule.

Results

Of the 2415 patients with cardiac arrest of presumed cardiac etiology, the advanced life support rule recommended termination of resuscitation for 743 patients. No survivors were identified in this group. It had a specificity of 100% for recommending transport of potential survivors, a positive predictive value of 100% for death and a predicted transport rate of 69%. The basic life support rule recommended termination of resuscitation for 1302 patients, with no survivors. This rule had a specificity of 100%, a positive predictive value of 100% and a predicted transport rate of 46%.

Conclusions

Implementing the basic life support rule as a universal termination of resuscitation clinical prediction rule would result in a lower overall transport rate without missing any potential survivors. The universal rule would recommend termination of resuscitation when there was no return of spontaneous circulation prior to transport, no shock was given and the arrest was not witnessed by Emergency Medical Services personnel. This rule may be useful for emergency medical services systems with mixed levels of providers responding to cardiac arrest patients.

Introduction

Sudden cardiac arrest is a leading cause of death in North America,1, 2, 3with approximately 30,000 to 45,000 cases reported in Canada per year and the majority of these occur in the prehospital environment.4 Despite recent improvements in advanced cardiac life support, the survival rates for out of hospital cardiac arrest remain quite low ranging from 4% to 9%.2, 5 Traditionally, these patients have been transported with ongoing resuscitative efforts to the closest emergency department.6 However, there is a growing body of evidence to suggest that termination of resuscitation clinical prediction rules can be safely and logistically applied to a subset of prehospital cardiac arrest patients that are considered futile based on response to treatment provided by either paramedics6, 7, 8, 9, 10, 11, 12 or defibrillation-only emergency medical technicians.13, 14, 15

In addition to the accumulating scientific evidence, national and international bodies such as the American Heart Association and the National Association of Emergency Medical Services Physicians have weighed in on this contentious topic by issuing their own guidelines for termination of resuscitation by paramedics in the prehospital environment.

In 2000, the National Association of Emergency Medical Services Physicians published a position statement on termination of resuscitation in adults with nontraumatic out of hospital cardiac arrest, stating that resuscitative efforts could be terminated in patients who do not respond to at least 20 min of advanced life support treatments such as cardiopulmonary resuscitation, definitive airway management, medication and defibrillation as needed.6

According to the 2005 American Heart Association guidelines, termination of resuscitation in the prehospital setting following system-specific criteria and under direct medical control should be standard practice in all Emergency Medical Services systems, as evidence confirms that ongoing advanced life support care in the Emergency Department offers no advantage over similar care in the field.16 Variability in termination of resuscitation rates has been recorded when termination is left to the discretion of individual physicians providing medical control.17 To address this variability, investigators from the University of Toronto derived an advanced life support clinical prediction rule through a secondary analysis of a study where adult cardiac arrest patients were treated by paramedics.18 The rule predicted that prehospital cardiac arrest patients could be considered for termination of resuscitation by advanced life support paramedics if there was no return of spontaneous circulation at any point during resuscitation, no shock was given, the arrest was not witnessed by Emergency Medical Services personnel or bystanders and no bystander cardiopulmonary resuscitation was delivered (Fig. 1).

Investigators from the University of Toronto also derived and validated a basic life support termination of resuscitation clinical prediction rule addressing the lack of prospective data and treatment guidelines on this subject in the current literature.15, 19 Patients treated solely by defibrillation-only emergency medical technicians could be considered for termination of resuscitation if there was no return of spontaneous circulation prior to transport, no shock was given and the arrest was not witnessed by Emergency Medical Services personnel (Fig. 2).

Ideally, a single universal termination of resuscitation rule that could be employed by all levels of Emergency Medical Services providers should be developed to optimize consistency in practice across EMS services. Therefore, we sought to conduct an external validation of each rule on an identical prehospital patient cohort attended by both levels of providers. Diagnostic test characteristics and the transport rate for both the advanced life support termination of resuscitation and the basic life support termination of resuscitation clinical prediction rules were measured and compared with the aim of determining which rule, if either, could be recommended as a universal termination of resuscitation rule.

Section snippets

Study design

This investigation is an external validation of each rule retrospectively applied to data originally collected by the University of Toronto for the Resuscitation Outcomes Consortium Epistry – Cardiac Arrest trial; a population based registry of all out of hospital cardiac arrests.20 The University of Toronto center is comprised of the Emergency Medical Services Systems within the city of Toronto and 5 adjacent municipalities (Peel, Durham, Hamilton, Muskoka and Simcoe) and the province-wide air

Results

From 1 April 2006 to 1 April 2007, a total of 4854 cases of out of hospital cardiac arrest occurred in our catchment area. Of this total, 2439 were excluded where 472 cases were deaths due to obvious cause; 259 cases recorded ‘Do Not Resuscitate’ advance directives, 1553 cases were obviously dead as defined by legislation and 155 cases were less than 18 years of age. The remaining 2415 cardiac arrest patients attended to by paramedics (n = 1992; 82.5%) or defibrillation-only emergency medical

Discussion

Both rules achieved high specificity and high positive predictive value when applied to a patient cohort attended by either paramedics or defibrillation-only emergency medical technicians or both. Our findings support using the basic life support termination of resuscitation rule as a universal clinical prediction rule in emergency medical services systems employing providers with either or both levels of certification. We suggest that implementation of this rule would result in a lower overall

Conclusion

We have conducted an external validation of two termination of resuscitation clinical prediction rules on a patient cohort attended by advanced life support paramedics and defibrillation-only emergency medical technicians, and found both rules to have high specificity and high positive predictive value for patients unlikely to benefit from further resuscitation. Transport rates and sensitivities varied greatly between the two rules. Implementing the basic life support rule as a universal

Funding

The Resuscitation Outcome Consortium (ROC) is supported by a series of cooperative agreements to 10 regional clinical centers and one data Coordinating Center (5U01 HL077863, HL077881, HL077871, HL077872, HL077866, HL077908, HL077867, HL077885, HL077885, HL077863) from the National Heart, Lung and Blood Institute in partnership with the National Institute of Newurological Disorders and Stroke, The Canadian Institutes of Health Research (CIHR) – Institute of Circulatory and Respiratory Health,

Conflict of interest statement

None to declare.

References (25)

  • M.J. Bonnin et al.

    Distinct criteria for termination of resuscitation in the out-of-hospital setting

    JAMA

    (1993)
  • D.C. Cone et al.

    The safety of a field termination-of-resuscitation protocol

    Prehosp Emerg Care

    (2005)
  • Cited by (132)

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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.2008.11.014.

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