(February 19, 2008 - Insidermedicine) Hospitalized patients who experience a cardiac arrest are more likely to survive to be discharged if they experience the event during the day on a weekday than during the night or on a weekend, according to research published in the Journal of the American Medical Association.

Here are some facts about cardiac arrest occurring in hospitalized patients:

•    Cardiac arrest, even when it occurs in a hospital setting, is a serious event. Generally, less than 20% of adults who experience a cardiac arrest in hospital live to be discharged.

•    Most adults who survive a cardiac arrest in hospital are suffering from a heart condition, are being closely monitored, and are treated as soon as early signs occur.

•    In patients without heart disease, cardiac arrest typically follows a period of slowly declining health, usually involving unnoticed or inadequately treated low blood pressure and insufficient oxygenation of the blood.

Researchers from Virginia Commonwealth University analyzed the survival rates among over 86,000 cardiac arrests that occurred in adults in any of 507 hospitals in the U.S. between 2000 and 2007. They explored whether the time of day and the day of the week these arrests occurred affected survival rates.

Those who experienced a cardiac arrest on the weekend or between 11:00 at night and 7:00 in the morning were less likely to survive to be discharged from hospital than those who experienced a cardiac arrest during the week in the daytime. Overall, the survival rate was about 15% for those who had cardiac arrests at night and about 20% for those who had them during the day. Those who experienced cardiac arrests during the daytime on a weekday had about a 21% survival rate, compared with only 17% for those who had one during the day but on a weekend.

Today’s research demonstrates how the time of day and the day of the week that a cardiac arrest occurs in hospitalized patients can affect whether they survive. The authors suggest that both biological factors and hospital processes could account for this difference and anticipate that improving nighttime and weekend hospital resuscitation procedures could save lives.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.