A recent study in JAMA found:
Results Of 11 695 patients, 9616 (82.2%) had nonshockable rhythms (asystole and pulseless electrical activity) and 2079 (17.8%) had shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia). AEDs were used in 4515 patients (38.6%). Overall, 2117 patients (18.1%) survived to hospital discharge. Within the entire study population, AED use was associated with a lower rate of survival after in-hospital cardiac arrest compared with no AED use (16.3% vs 19.3%; adjusted rate ratio [RR], 0.85; 95% confidence interval [CI], 0.78-0.92; P less than .001).
This result was driven by patients with non-shockable rhythms. For patients with shockable rhythms there was no difference between AED and non-AED use.
An editorial in the same issue cited prior research with similar results and also noted studies showing more and longer interruptions of compressions when the AED is used as opposed to a manual defibrillator and concluded:
As the authors suggest, it appears that routine AED use cannot be recommended in the in-hospital setting...