Survival from In-Hospital Cardiac Arrest is Worse at Night and on Weekends
Abstract & Commentary
By David J. Pierson, MD, Editor, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, is Editor for Critical Care Alert.
Synopsis: This study of a very large prospective series of cardiac arrests in over 500 US hospitals found that survival rates were lower during nights and weekends, differences that persisted despite adjustments for patient, resuscitation event, and hospital characteristics.
Source: Peberdy MA, et al. JAMA. 2008; 20:299(7):7850-792.
This study sought to determine whether the occurrence of in-hospital cardiac arrest at night and on weekends was associated with worse outcomes as compared with arrests during day/evening shifts and on weekdays. The investigators used data from the National Registry of Cardiopulmonary Resuscitation, a prospective registry of in-hospital resuscitation events sponsored by the American Heart Association. At each of 507 participating hospitals, specially trained quality improvement personnel prospectively recorded extensive data on each adult cardiac arrest, including the time and day of the week as well as initial electrocardiographic rhythm, aspects of the resuscitation attempt, return of circulation, survival at 24 hours and to hospital discharge, and neurological outcome. Day/evening was defined as the interval from 7:00 am to 10:59 pm, and night from 11:00 pm to 6:59 am. Weekends were the period from 11:00 pm Friday to 6:59 am Monday. In patients with more than one resuscitation event in the database, only the initial cardiac arrest was included.
Between January 1, 2000, and February 1, 2007, data from 86,748 consecutive cardiac arrests were included, 58,593 (68%) during day/evening hours and 28,155 (32%) at night. Patients who had cardiac arrests at night were less likely to have telemetry or other electrocardiographic monitoring or to have their arrests witnessed, than those who arrested during day/evening hours. Asystolic arrests were substantially more common at night than during day/evening (39.6% vs 33.5%), whereas pulseless electrical activity and ventricular fibrillation/ventricular tachycardia were less common at night (34.6% vs 36.9%, and 19.8% vs 22.9%, respectively; all differences p < 0.001).
Patients who arrested at night had poorer survival to discharge than those who arrested during day/evening hours (14.7% vs 19.8%; unadjusted odds ratio for failure to survive, 1.43, with 95% confidence interval 1.38-1.49.). Rates of initial return of spontaneous circulation, and also of survival to 24 hours, showed similar results. A favorable neurological outcome occurred in 11.0% of patients who arrested at night, as compared with 15.2% of patients who arrested on days/evenings (OR, 1.45; 95% CI, 1.39-1.52).
Among cardiac arrests occurring during day/evening hours, survival was significantly better on weekdays than on weekends (20.6% vs 17.4%), whereas this difference in survival between weekday and weekend arrests was not seen in patients whose arrests occurred at night (14.6% vs 14.8%). These survival differences between day/evening and night-time arrests, and between weekday and weekend arrests, persisted with adjustment of the data for potentially confounding patient, resuscitation event, and hospital characteristics.
Commentary
It is not possible using the findings of this study to tell whether there may be biological differences between cardiac arrests occurring during the day and evening shifts and those that happen at night. Such differences could conceivably have contributed to the results, although a more plausible explanation is that the patients who arrested at night were not found as quickly or resuscitated as well as their day/evening counterparts. This contention, which should not surprise anyone who works in a hospital, is supported by the greater proportion of night-arresting patients whose first-detected rhythm was asystole—typically a late manifestation in arrests that are precipitated by ventricular fibrillation or other arrhythmia. In any case, biological differences could hardly account for the worse survival on weekend days and evenings as compared to arrests during the same hours during the week.
The authors rightly conclude that "it is reasonable to focus on the potential for decreased physical and psychological performance on the part of the health care worker, different staffing patterns, and less patient surveillance during nights and weekends as possible contributing factors in poorer survival at night." Not only do these explanations provide a rational explanation for the findings, but also they point toward areas for possible intervention in efforts to decrease or eliminate the observed discrepancies.
This study sought to determine whether the occurrence of in-hospital cardiac arrest at night and on weekends was associated with worse outcomes as compared with arrests during day/evening shifts and on weekdays.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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