Physicians treating heart patients may be drawing conclusions too soon about therapeutic hypothermia, a condition for bodies that go into a calming coma of patients surviving cardiac arrest.

Therapeutic hypothermia is said to delay the need for oxygen in the brain so as to recover the heart, lungs and kidney in patients surviving cardiac arrest. Patients surviving cardiac arrest go into a calming coma for a day to help the recovery and the brain recovery is assessed three days after the incident.

"It is definitely a clinical situation about which we have much more to learn in order to maximize care for our cardiac arrest patients," says Nisha Chandra-Strobos, a professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute.

Chandra-Strobos also serves as director of cardiology at Johns Hopkins Bayview Medical Center, where 47 men and women treated for cardiac arrest were analyzed for a study presented at the American Heart Association's (AHA) annual Scientific Sessions in Chicago. The study says that patients need to be analyzed for more than three days before taking decisions about brain function recovery and possible withdrawal of care by physicians. Patients stay an average of 13 days to allow neurological recovery at Johns Hopkins Bayview.

"We may need to be much more deliberate in allowing the brain to recover before adjudicating on the neurological benefits of therapeutic hypothermia, as there is obviously more variability in patient response to treatment than previously thought," she said.

"An obvious concern in light of these results is that we may be withdrawing support prematurely in selected patients," said Chandra-Strobos. "The concern is valid; however, our clinical and study experience are re-assuring since most patients are observed and treated more than seven days."