Automated external defibrillation versus manual defibrillation for prolonged ventricular fibrillation

Immediate post-shock chest compressions improve outcome from prolonged ventricular fibrillation

“…4,5,13,20,21 If the second rhythm analysis indicated a shockable rhythm (VT/VF), then the animal received a second shock of 300J, followed by another 55-s rhythm analysis and shock advisory period.…”

“…9-11 These hemodynamic phenomena can result in both worse myocardial blood flow and a lower survival rate. [9][10][11][12][13] We have previously established that delays in chest compressions associated with AED rhythm analysis and shock advisory before and after defibrillation attempts for prolonged VF result in worse survival compared with prompt manual defibrillation and CPR (i.e., minimal interruptions and delays). 13 Numerous animal and clinical studies have demonstrated that preshock chest compressions can improve outcome for VF in the circulatory phase.…”

Automated External Defibrillators and Survival After In-Hospital Cardiac Arrest

“…While it is possible that the time of arrival of an AED to a patient's bedside was shorter than the time required for a conventional defibrillator, this gain may have been offset by the time required to manually apply defibrillator pads and await automated rhythm analysis. In addition, it has been shown that repeat rhythm assessment with an AED after defibrillation takes, on average, 46-seconds prior to resumption of chest compressions, 26,31 which is 24 seconds longer than with a conventional defibrillator, thus extending the period without continuous chest compressions for patients who do not initially respond to defibrillation. 26 It is also possible that AEDs may not be as effective in the initial treatment of ventricular tachyarrhythmias as compared with conventional defibrillators, in which defibrillation energies are manually chosen.…”

“…Manual application of defibrillator pads and initial rhythm analysis with an AED have been shown to take between 46 and 52 seconds. 26,27 Therefore, the time required to use an AED to assess these non-shockable cardiac arrest rhythms may lead to longer interruptions of continuous chest compressions during the first few minutes of resuscitation, when effective cardiac perfusion to vital organs is most critical. [28][29][30] Indeed, we found that, among patients surviving the acute resuscitation, AED use was associated with longer resuscitation periods to achieve ROSC for asystole and pulseless electrical activity -perhaps owing to longer periods without chest compressions during the initial minutes -and lower survival as early as 24 hours after cardiac arrest.…”

“…Our cohort was derived from 550 acute-care hospitals that provided at least 6 months of data to the NRCPR between January 1, 2000 and August 26,2008. Within these hospitals, we identified 110,132 patients 18 years of age or older with an index pulseless in-hospital cardiac arrest (Figure 1).…”