Emergency medical services/original researchImproved Out-of-Hospital Cardiac Arrest Survival After the Sequential Implementation of 2005 AHA Guidelines for Compressions, Ventilations, and Induced Hypothermia: The Wake County Experience
Introduction
Out-of-hospital cardiac arrest is a global public health problem with a pattern of high incidence and variable rates of survival to hospital discharge, ranging from 1% to 20%.1, 2 The strength of the community response, known as the American Heart Association's (AHA's) “chain of survival” may account for higher survival rates in some communities.3, 4, 5
The chain of survival is a community approach to improving out-of-hospital cardiac arrest outcomes, comprising 4 links: (1) early recognition and access to emergency medical services (EMS), (2) early cardiopulmonary resuscitation (CPR), (3) early defibrillation, and (4) early advanced cardiac life support. Although early CPR and defibrillation are the only independent interventions proven to increase cardiac arrest survival, a community-wide approach incorporating elements from each “link” may substantially improve cardiac arrest outcomes.5, 6, 7
The AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care were updated in 2005 to emphasize minimal interruption in chest compressions, strict control of ventilation rates to avoid hyperventilation, and induction of postresuscitation hypothermia to improve neurologic status for survivors.4, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 Adjuncts to assist with compression and ventilation quality, including mechanical CPR devices and the impedance threshold device, were also recommended.4, 9, 18, 19, 20 The impedance threshold device is an airway adjunct that purports to decrease intrathoracic pressure between ventilations (ie, it blocks air from entering the lungs during the decompression phase of CPR) and helps avoid hyperventilation through the use of a timing light.
Although each of the new recommendations has been studied independently, the effect of broad implementation at the community level is unknown.18, 21, 22, 23, 24, 25, 26 The primary objective of this study was to evaluate survival to hospital discharge from out-of-hospital cardiac arrest after community-wide implementation of the new guidelines in a large urban/suburban setting in North Carolina with an existing firefighter first-responder defibrillation program.
Section snippets
Study Design
We performed an analysis of out-of-hospital and clinical data from a natural experiment occurring during 46 consecutive months, using a 4-phase “before-after” controlled design for all patients treated for out-of-hospital cardiac arrest. During the baseline phase (16 months), patients were treated according to 2000 AHA guidelines with 15:2 compression-ventilation ratios and a “stacked” sequence of up to 3 shocks, without interposed chest compressions.4, 27 Emphases for phase 1, “new CPR,” (12
Results
Overall, EMS responded to 3,018 cardiac arrest calls. Figure 1 displays the disposition of patients throughout the study. The proportion of patients meeting criteria for obvious death remained unchanged throughout the study phases. A total of 1,365 consecutive patients received resuscitative care and were included: 425 patients in the baseline phase (January 1, 2004, to April 14, 2005), 369 in phase 1 (April 15, 2005, to April 17, 2006), 161 in phase 2 (April 18, 2006, to October 4, 2006), and
Limitations
Although randomized controlled trials best identify causal associations between individual interventions and outcome, our community did not approach the implementation of these treatments with clinical equipoise; rather, we were implementing treatments supported by existing evidence and believed that our EMS providers and other health care providers would be concerned about withholding treatments from patients.37 Our system adopted a progressive, evidence-based approach to protocol change, with
Discussion
This is a report of a community-wide health system's implementation of the AHA 2005 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care through all components of the Chain of Survival. Sequentially and additively, our EMS system implemented the updated protocols (minimally interrupted chest compressions, strict avoidance of hyperventilation, and postresuscitation hypothermia therapy to improve neurologic status of survivors). This approach more than doubled the
References (45)
- et al.
Cardiac arrest and resuscitation: a tale of 29 cities
Ann Emerg Med.
(1990) - et al.
Incomplete chest wall decompression: a clinical evaluation of CPR performance by trained laypersons and an assessment of alternative manual chest compression-decompression techniques
Resuscitation
(2006) Cardiac arrest—guideline changes urgently needed
Lancet
(2007)- et al.
Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest
Am J Med.
(2006) - et al.
Use of an impedance threshold device improves short-term outcomes following out-of-hospital cardiac arrest
Resuscitation
(2005) - et al.
Survival rates from out-of-hospital cardiac arrest: recommendations for uniform definitions and data to report
Ann Emerg Med.
(1990) - et al.
Optimal defibrillation response intervals for maximum out-of-hospital cardiac arrest survival rates
Ann Emerg Med.
(2003) - et al.
The Ontario Prehospital Advanced Life Support (OPALS) Study: rationale and methodology for cardiac arrest patients
Ann Emerg Med.
(1998) - et al.
Therapeutic hypothermia induced during cardiopulmonary resuscitation using large-volume, ice-cold intravenous fluid
Resuscitation
(2008) - et al.
Rationale, development and implementation of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest
Resuscitation
(2008)
Regional variation in out-of-hospital cardiac arrest incidence and outcome
JAMA
Improving survival from sudden cardiac arrest: the “chain of survival” conceptA statement for health professionals from the Advanced Cardiac Life Support Subcommittee and the Emergency Cardiac Care Committee, American Heart Association
Circulation
American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiac care
Circulation
Advanced cardiac life support in out-of-hospital cardiac arrest
N Engl J Med.
Progress in resuscitation: an evolution, not a revolution
JAMA
Improved out-of-hospital cardiac arrest survival through the inexpensive optimization of an existing defibrillation program: OPALS study phase IIOntario Prehospital Advanced Life Support
JAMA
Adverse outcomes of interrupted precordial compression during automated defibrillation
Circulation
Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation
Crit Care Med.
Hyperventilation-induced hypotension during cardiopulmonary resuscitation
Circulation
Therapeutic hypothermia after cardiac arrest: now a standard of care
Crit Care Med.
Effects of interrupting precordial compressions on the calculated probability of defibrillation success during out-of-hospital cardiac arrest
Circulation
How does interruption of cardiopulmonary resuscitation affect survival from cardiac arrest?
Curr Opin Crit Care
Cited by (118)
A systematic review and evaluation of post-stroke depression clinical practice guidelines
2023, Journal of Stroke and Cerebrovascular DiseasesMeta-Analysis Comparing Cardiac Arrest Outcomes Before and After Resuscitation Guideline Updates
2020, American Journal of CardiologyLarge urban center improves out-of-hospital cardiac arrest survival
2019, Resuscitation
Supervising editor: Amy H. Kaji, MD, PhD, MPH
Author contributions: PRH, JBM, RL, and VJD conceived the study design and designed the trial. PRH, JBM, RL, VJD, ER, DL, JZ, and GS supervised the conduct of the trial and data collection. PRH, JBM, RL, ER, and DL, undertook the recruitment of participating centers and patients. PRH, JBM, RL, ER, DL, JZ, and GS managed the data, including quality control. VJD provided statistical advice on study design and analyzed the data. PRH and JBM cochaired the oversight committee of the Capital County Research Consortium. PRH, JBM, RL, and VJD drafted the article, and all authors contributed substantially to its revision. PRH takes responsibility for the paper as a whole.
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article that might create any potential conflict of interest. The authors have stated that no such relationships exist. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Drs. Hinchey and Myers and Mr. Reyer report having served on the speakers' bureau for Alsius Corporation. Drs. Hinchey and Myers receive no direct compensation for speaking engagements other than travel expenses. Mr. Reyer accepts an honorarium in addition to expenses when offered.
Reprints not available from the authors.
Please see page 349 for the Editor's Capsule Summary of this article.
Provide feedback on this article at the journal's Web site, www.annemergmed.com.