Chances Of Survival Depends On What Time Cardiac Arrest Occurs

If you are in the hospital and have cardiac arrest at night or on the weekend, you have a significantly lower chance of survival to discharge than if you had the arrest during day or evening times on weekdays, according to Mary Ann Peberdy of Virginia Commonwealth University in Richmond, VA and colleagues. The results of their study are published in The Journal of the American Medical Association (JAMA).

The researchers suggest that patient, hospital, staffing, and response factors could come together to reduce the effectiveness of detecting and treating cardiac arrests at night. The findings are essential to inform decisions regarding hospital staffing, training, care delivery processes, and equipment - especially if in-hospital cardiac arrests are more frequent or survival is less likely on nights and weekends.

The study data consisted of 86,748 adult, in-hospital cardiac arrest events occurring at 507 medical/surgical hospitals from January 2000 to February 2007. All of the hospitals participate in the American Heart Association's National Registry of Cardiopulmonary Resuscitation. Peberdy and colleagues evaluated survival rates for adults with in-hospital cardiac arrest by time of day and day of week. They examined survival from cardiac arrest using the following definitions:

• Day/evening is 7:00 a.m. to 10:59 p.m.
• Night is 11:00 p.m. to 6:59 a.m.
• Weekend is 11:00 p.m. on Friday to 6:59 a.m. on Monday

There were 58,593 in-hospital cardiac arrest events that occurred during day/evening hours (15,110 on weekends) and 28,155 cases during night hours (7,790 on weekends).

Key findings include that compared to day/evening cardiac arrest events:

• Rates of survival to discharge were lower at night, 14.7% vs. 19.8%,
• Rates of return of spontaneous circulation for longer than 20 minutes were lower at night, 44.7% vs. 51.1%,
• Rates of survival at 24 hours were lower at night, 28.9% vs. 35.4%,
• Rates of favorable neurological outcomes were lower at night, 11.0% vs. 15.2%,

There was only a slight difference between survival to discharge at night during the week (14.6%) and during weekends (14.8%). However, the rate of survival during day/evening weekdays was higher than on weekends (20.6% vs. 17.4%).

The researchers write, "The principal finding of this study was that survival to discharge following in-hospital cardiac arrest was lower [when the arrest occurred] during nights and weekends compared with day/evening times on weekdays, even after accounting for many potentially confounding patient, arrest event, and hospital factors.".

"The mechanism for the decreased survival during the night is likely multifactorial, potentially including biological differences in patients as well as health care staff and hospital staffing and operational factors. These data suggest the need to focus on night and weekend hospitalwide resuscitation system processes of care that can potentially improve patient safety and survival following cardiac arrest," conclude the authors.