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Before the advent of public‐access defibrillation, EMS medical directors sought ways to shorten the delays to initial defibrillation. One solution was to equip first‐responders with AEDs, because these individuals could often reach a cardiac arrest victim faster than an advanced life support (ALS) ambulance could. The first important report of this concept involved firefighter first‐responders in King County, Washington in 1989 [65]. Police first‐responders in Rochester, Minnesota and suburban areas near Pittsburgh, Pennsylvania successfully used AEDs [19,66–68]. These programs demonstrated benefit even if the first‐responders arrived only 2 minutes before EMS. Cardiac arrest survival was 50% in Rochester, Minnesota after introducing a police AED program [68]. The use of motorcycles in urban settings to reduce response time has also been described [69].

The OPALS study specifically evaluated the effect of optimizing time to defibrillation by basic life support (BLS) responders, with a goal of having a defibrillator‐equipped vehicle on scene within 8 minutes of 9‐1‐1 call receipt for 90% of calls. Increasing the proportion of responses that met the 8‐minute standard from 77% to 92% improved survival to hospital discharge from 3.9% to 5.2% [70]. A subsequent analysis found that increasing time to defibrillation was associated with decreased survival (Figure 12.4) [1]. These observations further underscored the greater importance of bystander action in facilitating additional survival.

Performing high‐quality, continuous chest compressions is another important role for first responders. Research indicates that the quality of CPR is vitally important, especially rate, depth, and reducing prolonged interruption of chest compressions, as interruptions result in less cycle time and lower coronary perfusion pressures [5771–75]. Deploying multiple first‐responders (teams of four or more) to enable closely supervised BLS has also been advocated as “high‐performance CPR.” Also, use of mechanical CPR has been recommended, especially if transport with on‐going CPR is needed, for example in BLS ambulance systems [76], though data showing a survival benefit to mechanical CPR are lacking.

Figure 12.4 Predicted survival versus defibrillation response interval.

Source: De Maio VJ, Stiell IG, Wells GA, and Spaite DW. Optimal defibrillation response intervals for maximum out‐of‐hospital cardiac arrest survival rates. Ann Emerg Med. 2003; 42(2):242–50. Reproduced with permission from Elsevier.