In-Hospital Defibrillation

This letter was written in response to the article "To focus on the forest: recognizing the value of early defibrillation despite isolated failures," by Mary M. Newman, the immediate past editor of Currents in Emergency Cardiac Care. Her article appeared in the May 1994 issue of Journal of Emergency Medical Services (JEMS); I don't have the exact page reference. The reference for my letter is:

         Stewart JA. Shock value. JEMS. 1994;19(8);17,105.

Shock value

To the Editor:

"To focus on the forest: recognizing the value of early defibrillation despite isolated failures" in your May issue cast much-needed light on the controversy about defibrillator safety brought about by recent FDA actions. I agree completely with the author's analysis of the situation. As she says, defibrillators do not cause death--they may only fail to restore life. This fundamental realization leads to the conclusion that the primary public health problem related to defibrillators is underuse: not having enough defibrillators, not having them in the right places, and not using them early or often enough. I believe that this perspective also has clear implications beyond the current controversy, suggesting not only that the FDA's approach may be ill-considered but also that the defibrillation policy currently accepted in most hospitals and EMS systems may be flawed.

As stated in the article, incorrect shocks given to pulseless patients have virtually no clinical significance, but shocks that are delayed or omitted entirely represent missed opportunities to save lives. Given the much greater importance of sensitivity errors as compared to specificity errors, it would seem that requiring positive identification of ventricular fibrillation (VF) or ventricular tachycardia (VT) before shocking a pulseless patient may well be detrimental to survival. Is it in the patient's interest to withhold a shock while troubleshooting for monitor artifact? Speaking as a potential patient (aren't we all?), I wouldn't want a delay of a single second just to get a nice clean tracing for the record. And is shocking flat line really so bad? It could be artifact, and there is no definite line dividing fine VF from asystole anyway (this is the main source of automated external defibrillator (AED) sensitivity errors).

Maximizing survival rates calls for an aggressive defibrillation policy: a training approach that strongly stresses VF/VT as the default diagnosis for pulseless patients (when in any doubt, shock) or even a policy of blind defibrillation (simply ignoring the monitor)--at least for the first shock. Such a policy could be expected to virtually eliminate incorrectly withheld shocks. Of course, shocks would be given to patients not in VF or VT, and such shocks have traditionally been considered treatment errors--but is an action with no apparent adverse effect on clinical outcomes really an error in any meaningful sense?

A more aggressive defibrillation policy would also make it easier to achieve more widespread defibrillation capability. As Ms. Newman states, a rational assessment of the defibrillation risk/benefit ratio leads to the conclusion that policies and attitudes restricting access to early defibrillation are generally detrimental to public health. The perceived need for positive rhythm identification, though not supported by patient outcome data, provides the principal rationale for restricting authorization to defibrillate and advocating the purchase AEDs. Removing this barrier would simplify the implementation of early defibrillation programs, and perhaps in the process make the controversy over alleged AED malfunctions moot.

John A. Stewart, RN, MA
University of Washington School of Nursing
Seattle, WA

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