Cardiac Arrests At Night And Weekends Linked To Lower Survival For In Patients

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Main Category: Cardiovascular / Cardiology
Article Date: 20 Feb 2008 - 9:00 PDT

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A nationwide US study has found that patients who are in hospital and have a cardiac arrest at night or at the weekend have a significantly lower rate of survival than counterparts who have a cardiac arrest during the day or on weekdays.

The research was the work of Virginia Commonwealth University (VCU) physician Dr Mary Ann Peberdy and colleagues, and is published in the 20 February issue of the Journal of the American Medical Association (JAMA).

The study suggested a range of factors contributed to less effective detection and treatment of cardiac arrests during the weekends and nighttime. These factors involved patient, hospital, staffing and response factors, said the VCU in a press release.

Cardiac arrest, where the blood suddenly stops circulating because the heart is not beating properly, is not the same as a heart attack (myocardial infarction), where the blood can still circulate after the heartbeat is interrupted. However, a heart attack can cause cardiac arrest.

Peberdy, who is associate professor in the cardiology division of the VCU School of Medicine's Department of Internal Medicine, and fellow team members, obtained data on cardiac arrest patients in hospitals nationwide that were enrolled in the American Heart Association's National Registry of CardioPulmonary Resuscitation.

The data covered adult, in-hospital cardiac arrests, at 507 medical and surgical hospitals between January 2000 and February 2007. The researchers used the data to evaluate survival rates hour by hour. They also evaluated secondary outcomes such as survival of the event, 24-hour survival and whether the neurological outcomes were favourable.

A day and evening was defined as 7 am to 10.59 pm, and night was defined as 11.00 pm to 6.59 am. A weekend started at 11.00 pm on a Friday and finished at 6.59 am on a Monday.

The main result was that survival to discharge after a cardiac arrest was lower when the event occurred during nights and weekends compared to day/evening times during weekdays. The result did not change after adjusting for factors relating to the patients themselves, the event, and the hospital.

In detail the results showed that:

• From a total of 86,748 cases of in-hospital cardiac arrests, 58,593 (68 per cent) occurred during day/evening and 28,155 (32 per cent) during nighttime.


• 43,483 (74 per cent) of the day/evening cases were on weekdays and 15,110 (26 per cent) at weekends.


• 20,365 (72 per cent) of the nighttime cases were on weekdays and 7,790 (28 per cent) at weekends.
• 
  
• Rates of survival to discharge, return of spontaneous circulation for longer than 20 minutes, and favourable neurological outcomes were substantially lower at nighttime than during day/evening.


• The most frequently first documented rhythm during the nighttime was asystole, and less frequently, ventricular fibrillation.


• For in-hospital cardiac arrests during day/evening, survival was higher on weekdays than on weekends (odds ratio 1.15).


• For in-hospital cardiac arrests during nighttime, survival to discharge on weekdays and weekends were largely similar (odds ratio 1.02).

The authors concluded that:

"Survival rates from in-hospital cardiac arrest are lower during nights and weekends, even when adjusted for potentially confounding patient, event, and hospital characteristics."

Commenting on the study in an editorial in Journal Watch Cardiology, Dr Harlan M. Krumholz, Harold H Hines, Jr Professor of Medicine in the Section of Cardiovascular Medicine at the Yale University School of Medicine, wrote that it was not clear why survival was better during the day/evening than at night, and whether opportunities for improvement exist. Also the researchers were not able to account for all possible confounders or unidentified, but potentially relevant, hospital factors.

This means, said Krumholz, that while it is not possible to make specific recommendations from this study, it should still prompt everyone who cares for cardiac arrest patients to look more closely at their own practice.

"Survival From In-Hospital Cardiac Arrest During Nights and Weekends."
Mary Ann Peberdy; Joseph P. Ornato; G. Luke Larkin; R. Scott Braithwaite; T. Michael Kashner; Scott M. Carey; Peter A. Meaney; Liyi Cen; Vinay M. Nadkarni; Amy H. Praestgaard; Robert A. Berg; for the National Registry of Cardiopulmonary Resuscitation Investigators.
JAMA. 2008;299(7):785-792.
Vol. 299 No. 7, February 20, 2008.

Click here for Abstract.

Sources: JAMA abstract, VCU press statement.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
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