Clinical paperThe impact of prehospital transport interval on survival in out-of-hospital cardiac arrest: Implications for regionalization of post-resuscitation care☆,☆☆
Introduction
For many years it was thought that the only significant determinants of survival from out-of-hospital cardiac arrest (OHCA) occurred in the prehospital setting.1, 2 Even with the restoration of spontaneous circulation a sense of futility often prevents aggressive in-hospital post-resuscitation care in patients without an immediate return of cerebral activity.3, 4, 5, 6 Recent evidence, however, suggests that survival and neurological outcome can be dramatically improved by in-hospital post-resuscitation care despite persistent coma after arrest.7, 8, 9 Subsequently, consideration has been given to bypassing local hospitals en route to regional cardiac arrest centers staffed and equipped to provide specialized post-resuscitation care.10, 11 The question remains whether it is detrimental to prolong the transport of critically ill ROSC patients.
Numerous EMS leaders in Arizona have suggested developing regional “Cardiac Arrest Centers” and EMS protocols aimed at taking comatose ROSC patients to these centers for specialized post-resuscitation care. However, we have been able to find only one evaluation of the association between TI and outcome in OHCA within the peer-reviewed literature.10 This prompted us to analyze our statewide OHCA database with the intent of identifying evidence for the safety of increased time spent in transport.
Section snippets
Methods
The State of Arizona, through its Bureau of Emergency Medical Services and Trauma System, initiated a statewide, prospective observational cohort study of OHCA victims on whom resuscitation was attempted in the field. The Save Hearts in Arizona Registry & Education (SHARE) Program database contains information on OHCA patients from 48 EMS agencies/fire departments responsible for responding to prehospital medical emergencies for approximately 70% of the 5.5 million residents of the state.
A
Results
Figure 1 shows the cases that were entered into the database during the study period. 1846 were adults with OHCA of presumed cardiac etiology occurring prior to EMS arrival. Among these cases, 1177 (63.8%) had complete TI data and this cohort comprised the overall study group. Table 1 shows the demographics, event characteristics, initial cardiac rhythms, and patient outcomes. 280 patients achieved ROSC (23.8%). 253 patients (21.5%) achieved ROSC but remained comatose and would have been
Discussion
For decades, despite remarkable survival rates in a few settings,19, 20 the vast majority of systems have reported dismal survival rates for OHCA.21, 22, 23, 24, 25 Additionally, many experts have considered prehospital care to be the only significant determinant of survival. In 1988, Kellerman and associates identified that OHCA patients who failed to be successfully resuscitated in the field had essentially no chance of being resuscitated in the hospital. This led to the conclusion that,
Limitations
The conclusions and significance of our findings are impacted by several limitations. First, although the OHCA cases in the SHARE registry are prospectively collected, this query was not an a priori hypothesis. Thus, the potential for impact by confounding issues is significant as with any retrospective evaluation of a data set. This was not a controlled trial but, rather, an observational analysis. In addition, the fact that data for TI was missing in 38% of cases introduces the potential for
Conclusion
Using a statewide database, we evaluated the association between TI and outcome in OHCA patients and in the subgroup of patients with ROSC who remained comatose in the field. No causal association was identified in any cohort. While not proof, this supports the concept that a modest increase in TI for the purpose of transport to a regional cardiac center is safe. This analysis is relevant to future trials that evaluate the impact of regionalized post-resuscitation care as well as to EMS systems
Conflict of interest
None.
Acknowledgement
This study was funded in part by the Arizona Department of Health Services, Bureau of EMS and Trauma System.
References (41)
- et al.
In-hospital resuscitation following unsuccessful prehospital advanced cardiac life support: ‘heroic efforts’ or an exercise, in futility?
Ann Emerg Med
(1988) - et al.
Continuation of CPR on admission to emergency department after out-of-hospital cardiac arrest: occurrence, characteristics and outcome
Resuscitation
(1997) - et al.
Post-resuscitation care: is it the missing link in the chain of survival?
Resuscitation
(2005) - et al.
Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation
Resuscitation
(2003) - et al.
Assessment of neurological prognosis in comatose survivors of cardiac arrest
Lancet
(1994) - et al.
Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: the Utstein style
Resuscitation
(2005) - et al.
Post resuscitation care: what are the therapeutic alternatives and what do we know?
Resuscitation
(2006) - et al.
Is hospital care of major importance for outcome after out-of-hospital cardiac arrest? Experience acquired from patients with out-of-hospital cardiac arrest resuscitated by the same Emergency Medical Service and admitted to one of two hospitals over a 16-year period in the municipality of Goteborg
Resuscitation
(2000) - et al.
In-hospital factors associated with improved outcome after out-of-hospital cardiac arrest. A comparison between four regions in Norway
Resuscitation
(2003) - et al.
The feasibility of a regional cardiac arrest receiving system
Resuscitation
(2007)
The Save Hearts in Arizona Registry and Education (SHARE) program: who is performing CPR and where are they doing it?
Resuscitation
Prospective validation of a new model for evaluating EMS systems by in-field observation of specific time intervals in prehospital care
Ann Emerg Med
Cardiac arrest and resuscitation: a tale of 29 cities
Ann Emerg Med
Cardiac arrest resuscitation evaluation in Los Angeles: CARE-LA
Ann Emerg Med
Outcome of CPR in a large metropolitan area—where are the survivors?
Ann Emerg Med
Efficacy of therapeutic hypothermia after out-of-hospital cardiac arrest due to ventricular fibrillation
Resuscitation
Induced hypothermia is underused after resuscitation from cardiac arrest: a current practice survey
Resuscitation
Early direct coronary angioplasty in survivors of out-of-hospital cardiac arrest
Am J Cardiol
Impact of percutaneous coronary intervention or coronary artery bypass grafting on outcome after nonfatal cardiac arrest outside the hospital
Am J Cardiol
Implementation of a standardized treatment protocol for post resuscitation care after out-of-hospital cardiac arrest
Resuscitation
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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.2008.05.006.
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Presented in part to the Annual Scientific Meeting of the National Association of EMS Physicians, 11 January 2008, Phoenix, AZ.