Seven's On Call with Dr. Jay Adlersberg.
Heart disease is one of the most common reasons for hospitalizations, and with some heart conditions, the heart can suddenly stop circulating blood and delivering oxygen.
That is known as cardiac arrest. Many patients are revived when this happens, but the new study says a patient's chances are associated with time.
A hospitalized heart patient can have a episode where the heart suddenly stops circulating blood and he or she goes into cardiac arrest.
Whether the patient survives the episode depends not only on their own condition, but also on a well-trained staff that knows how to quickly respond.
Dr. Kyle Gunnerson is a critical care specialist who has resuscitated numerous patients.
"The two most important things about survival in cardiac arrest is identifying an abnormal rhythm quickly and then delivering the appropriate therapy," he said.
But a new study in the Journal of the American Medical Association says some patients may be less likely to survive.
Dr. Mary Ann Peberdy examined data from some 500 hospitals and 86,000 episodes of cardiac arrest.
She and her colleagues found that patients who went into cardiac arrest during the night were more likely to die. At night, there was a 15 percent survival rate compared to a 20 percent survival rate during the day.
Weekends also had a lower survival rate.
The reasons are not clear.
"It may be a physiologic difference in patients that accounts for the study," Dr. Perberdy said. "It may be that hospital staffing patterns are different."
Cardiac arrests happening in the emergency room were the only exception, perhaps because staffing there is more consistent. Also, adequate staff response skills are more likely.
The study recommends hospital-wide resuscitation training at all hospitals, particularly for night and weekend staffs.
"I think that the difference in survival that we identified should be a wake-up call to hospitals, to at least try and improve the parts of the resuscitation process that they can improve."
The study was one of the most comprehensive of its kind. The difference between survival and death was sometimes simply a matter of minutes. In a previous study, Canadian researchers found that strokes treated on a weekend were deadlier than those treated during the week.