Efficacy of an automated external defibrillator in the management of out-of-hospital cardiac arrest: validation of the diagnostic algorithm and initial clinical experience in a rural environment.

Abstract

Automatic external defibrillators (AEDs) may have advantages over manual defibrillation in managing prehospital cardiac arrest, particularly in rural communities. We conducted a two-part evaluation of a commercially available AED. We first established the diagnostic accuracy of the AED's rhythm recognition algorithm by challenging it with 205 cardiac arrest rhythms previously recorded from actual patients in the field. The AED demonstrated 100% specificity and 92% sensitivity for ventricular fibrillation (VF) in this nonclinical setting. We then compared the clinical efficacy of AEDs in 18 small communities (study group) with that of manual defibrillation in 18 additional communities (control group) of similar size. Ambulance technicians using manual defibrillators correctly diagnosed VF more frequently than the AEDs (98% vs 83%; p < .025). Specificity for VF was similar in the two groups (100% for AEDs vs 94% for technicians; p > .10). AEDs were able to deliver shocks more quickly than was possible with the manual defibrillators (1.56 vs 2.77 min; p < .001). The ability of the AEDs to terminate VF was excellent, converting VF in 28 of 29 (97%) patients to some other rhythm compared with only 37 of 53 (70%) patients in the control group (p < .01). Hospital admission and discharge rates were similar for the two groups. Ten of the 35 (29%) patients managed with AEDs achieved admission and six (17%) were ultimately discharged. In the control group 17 of 53 (33%) patients with VF were admitted and seven (13%) were discharged (p > .75). AEDs are an effective alternative to manual defibrillation in small communities.Circulation 73, No. 4, 701-709, 1986. CARDIOVASCULAR DISEASE continues to be the leading cause of death in the United States, particularly sudden cardiac death occurring outside of the hospital.

Part 6: Defibrillation

“…94 One good concurrent controlled OHCA study in 36 rural communities showed no improvements in ROSC, survival, or neurologic outcome but significantly shorter times to first shock and higher VF conversion rates when paramedics used AEDs in semiautomatic mode compared with manual mode (LOE 2). 95 One retrospective study demonstrated no improvement in survival to hospital discharge for adult IHCA when comparing AED with manual defibrillators (LOE 4). 96 In patients with initial asystole or pulseless electric activity (PEA), AEDs were associated with a significantly lower survival (15%) compared with manual defibrillators (23%, Pϭ0.04).…”

Part 12: From Science to Survival : Strengthening the Chain of Survival in Every Community

“…1,[47][48][49][50][51] The placement of AEDs in the hands of large numbers of people trained in their use may be the key intervention to increase the chances of survival of patients with out-of-hospital cardiac arrest. 51 AEDs are computerized, low-maintenance, user-friendly defibrillators that analyze the victim's rhythm to determine whether a shockable rhythm is present.…”

“…Even so, manual defibrillation by emergency medical technicians trained to recognize VF improves survival. 47,53 The widespread effectiveness and demonstrated safety of the AED have made it acceptable for use by nonprofessional responders. Lay responders must still be trained in CPR and use of the defibrillators.…”

Emergency Medical Services and Sudden Cardiac Arrest: The

“…With few exceptions, the defibrillator used should be an automated external defibrillator (24, 26, 28-30, 86, 98, 107). Automated external defibrillators perform with high accuracy (5,28,35,98,109) and eliminate the need to train the operator in the complex skills of rhythm recognition. Their simplicity of operation decreases the time and expense of initial training and continuing education and markedly expands the range of people who can operate the devices.…”

“…Their simplicity of operation decreases the time and expense of initial training and continuing education and markedly expands the range of people who can operate the devices. Clinical studies also show that systems using automated defibrillators can deliver the first shock up to one minute faster than with conventional defibrillators (28,98).…”