Effects of AED device features on performance by untrained laypersons.

OBJECTIVE: Our study evaluates the impact of features of automated external defibrillators (AEDs) on the performance and speed of untrained laypersons to deliver a shock and initiate CPR after a shock. METHODS: This was a randomized trial of volunteer laypersons without AED or advanced medical training. Subjects were assigned to use one of six different models of AEDs on a manikin in simulated cardiac arrest. No instructions on AED operation were provided. Primary endpoints were shock delivery and elapsed time from start to shock. Secondary endpoints included time to power-on, initiation of CPR, adequacy of pad placement and subjects' ratings of ease of use (1=very easy, 5=very difficult). RESULTS: Most subjects (109/120; 91%) were able to deliver a shock. Median time from start of scenario to shock delivery was 79 s (IQR: 67-99). Of the 11 participants who did not deliver shock, eight never powered on the device. Time to power-on was shorter in devices with open lid (median 12s, IQR 8-27 s) and pull handle (17s, IQR 9-20s) mechanisms than with a push button (37s, IQR 18-69 s; p=0.000). Pad position on the manikin was judged adequate for 86 (77%) of the 111 subjects who placed pads. Devices which gave more detailed voice instruction for pad placement had higher rates of adequate pad position [38/39 (97%) versus 50/73 (68%), p=0.001]. With AEDs that provided step-by-step CPR instruction, 49/58 (84%) subjects began CPR compared to 26/51 (51%) with AEDs that only prompted to start CPR (p=0.01). Participants rated all the models easy to use (overall mean 1.48; individual device means 1.28-1.71). CONCLUSIONS: Most untrained laypersons were successful in delivering a shock. Device features had the most impact on these functions: ability and time to power-on device, adequacy of pad position and initiation of CPR.

The role of law enforcement agencies in out-of-hospital emergency care.

BACKGROUND: A key component of out-of-hospital emergency care is the rapid response of trained providers with appropriate medical equipment. In some communities, law enforcement agents function as first responders to accomplish this goal. The purpose of this national survey was to assess the proportion of law enforcement agencies that provide medical care to determine the extent of care they provide, to identify how many use AEDs, and to assess the attitudes of agency leaders regarding their roles as medical first responders. METHODS: Eight hundred agencies were selected at random from a national database of 43,000 agencies available through the National Public Safety Bureau (Stevens Pt, WI). These agencies were sent a 19-question survey either by US mail or telephone. RESULTS: Four-hundred and fifty-four (57%) surveys were returned, and 420 (53%) were available for use after exclusion criteria were applied. Eighty percent of law enforcement agencies respond routinely to medical emergencies and 39% of these reported they deploy AEDs. Thirty-one percent of all law enforcement agencies are equipped with AEDs, a ten-fold increase from 2.6% reported in a previous national study in 1997. Funding issues were the most common reasons cited for not using AEDs. Approximately 75% of respondents agreed that law enforcement agencies should provide initial emergency medical care and indicated that officers in their agency would be willing to receive additional training to accomplish this. CONCLUSION: Based on this survey, law enforcement agents often serve as medical first responders. Nearly three quarters of responding agencies felt this role was appropriate. AEDs are now deployed much more frequently than indicated by a previous national study, but still less than one-third of law enforcement agencies carry AEDs as part of their standard response equipment.