Use of automated external defibrillators might suggest higher chances of survival for heart attacks at places like airports and casinos, but a new study says that use of the same in a hospital might prove fatal as it actually increases the risk of dying.

"The common sense was that AEDs in hospitals would save lives," said Dr. Robert Ruelaz, an electrophysiologist at Hollywood Presbyterian Medical Center who was not involved in the research. "Common sense doesn't always give us the answers, however. … This really opens our eyes to how difficult it is to save these patients."

About 50,000 such devices were sold in hospitals between 2003 and 2008. Researchers used data from the National Registry of Cardiopulmonary Resuscitation of 11,695 patients who suffered heart attacks between Jan. 1, 2000, and Aug. 26, 2008. Only 17.8 per cent of them had arrests that could react to shocks.

18 per cent of them survived to hospital discharge. Among the ones who were given shock treatment, about 16.3 per cent survived as against the 19.3 per cent who survived without such treatment. They found that use of such defibrillators was not exactly increasing chances of survival. The study by Dr. Paul S. Chan of St. Luke's Mid America Heart Institute in Kansas City, Mo was reported in the Journal of the American Medical Association.

“The compelling conclusions from the study … should lead to a consideration of a change in practice for in-hospital cardiac arrest,” wrote Dr David E. Haines in an editorial accompanying the report. “Initiation of prompt and effective chest compressions should be the highest priority by first responders to the arrest.”