Defibrillation time intervals and outcomes of cardiac arrest in hospital: retrospective cohort study from Get With The Guidelines-Resuscitation registry

The authors mince words in their conclusions: “Significantly worse” outcomes from deferred defibrillation for return of spontaneous circulation, survival to 24 hours, and survival to hospital discharge (all P < 0.01) become “not associated with improved survival.” Still, the study offers strong evidence that the guideline calling for deferred defibrillation for persistent VF/VT is a bad idea, at least in hospitals.

The guideline itself was clearly the result of belated recognition that the long hands-off periods required by automated external defibrillators (AEDs) significantly decrease shock success and survival; thus the rationale for deferring defibrillation in the hope of producing better pre-hospital outcomes with AEDs. But the guideline inexplicably was applied to manual defibrillation as well—with absolutely no rationale [1].

The poor results from deferred defibrillation in hospitals may be largely due to the fact that the great majority of defibrillations in that setting are manual: only about 20% of cases in the present study were assessed with an AED. Deferring defibrillation to decrease hands-off time is totally inappropriate with manual defibrillation: with a manual device, a shock can be delivered in less than 5 seconds if it is done correctly.

This is another manifestation of negative effects from the over-selling of AED technology—by defibrillator manufacturers, to be sure, but also by AHA/ILCOR. AHA publications have promoted AEDs for hospital use since before the official imprimatur was bestowed—based on no evidence [2] —in the 2000 Guidelines. Good evidence for a negative effect from AED use on in-hospital survival, drawing on GWTG-R data, appeared in 2010 [3], but the AHA appears reluctant to acknowledge it. An AHA consensus statement in 2013 included a faulty and tortured analysis of available evidence that essentially equated the large multicenter study from 2010 with a weak single-center before-and-after study susceptible to a huge Hawthorne effect. The conclusion, unsurprisingly, was that randomized controlled trials are needed to resolve the issue—with no hint as to how RCTs comparing AEDs with manual defibrillators could conceivably be done in the hospital setting [4]. More recently, the 2015 Guidelines completely ignored the issue [5].

Adding to that direct negative impact of AED use on in-hospital survival, the present study now shows a further indirect negative effect on survival from distortion of a guideline due to an inappropriate focus on AED technology. Why was the deferred-defibrillation guideline applied to manual defibrillations? The answer is unclear and probably will remain so, but possibilities must include a desire to paper over a major shortcoming of AEDs vis-a-vis manual defibrillators.

The authors are tentative in their recommendation for further study “to understand whether current guidelines…need reconsideration,” raising the hope of a change in perhaps a decade or two. Maybe this mistake will eventually be revised in the face of truly overwhelming evidence, but I’m not holding my breath.

John A Stewart RN, MA
jastewart325@gmail.com

1) 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Part 5: Electrical Therapies. Circulation 2005;112:IV-35-IV-46. DOI: 10.1161/CIRCULATIONAHA.105.166554.
2) Atkins DL, Bossaert LL, Hazinski MF, et al. Automated external defibrillation/public access defibrillation. Ann Emerg Med 2001;37[4 Suppl]:S60-67. DOI: http://dx.doi.org/10.1067/mem.2001.114124.
3) Chan PS, Krumholz HM, Spertus JA, Jones PG, Cram P, Berg RA, et al. Automated external defibrillators and survival after in-hospital cardiac arrest. JAMA 2010 November 17; 304(19): 2129–2136.
4) Morrison LJ, Neumar RW, Zimmerman JL, Link MS, Newby LK, McMullan PW, et al. Strategies for improving survival after in-hospital cardiac arrest in the United States: 2013 consensus recommendations: a consensus statement from the American Heart Association. Circulation 2013 Apr 9;127(14):1538-63. DOI: 10.1161/CTR.0b013e31828b2770.
5) 2015 American Heart Association Guidelines for CPR & ECC. Accessed on April 17, 2016 at: https://eccguidelines.heart.org/index.php/circulation/cpr-ecc-guidelines-2/.