ORIGINAL CONTRIBUTION Influence of Cardiopulmonary Resuscitation Prior to Defibrillation in Patients With

THERE IS LITTLE DOUBT THAT SPEEDin providing care represents themajor determinant of survivalfor patients with out-of-hospital ventricular fibrillation (VF). That relationship has been docu-mented for initiation of cardiopulmo-nary resuscitation (CPR)1,2 as well as for the arrival of personnel and devices nec-essary for defibrillation.3,4 Since 1970, the pattern for delivering out-of-hospital emergency care in Seattle, Wash, has in-corporated rapidly responding first units staffed by emergency medical techni-cians (EMTs), followed as soon as pos-sible by a later-arriving paramedic unit.5 In 1980, we initiated the use of early de-fibril lation by EMTs in 4 first-responding units.6 Later, automated ex-ternal defibrillators (AEDs) were extensively used. Whereas the survival experience of subsets of VF patients in Seattle seemed to be improved with AEDs,7 the overall survival rate re-mained virtually unchanged (FIGURE 1) despite an approximately 3- to 4- minute shortened time to defibrillatory shock in most cases. Such a time saving had been predicted to increase survival by several percentage points.3 Prompted by the lack of overall improvement i