Public Release: 

Penn study: Hospital CPR quality is worse at night

Findings reveal potential cause of lower survival from nighttime in-hospital cardiac arrest

University of Pennsylvania School of Medicine

CHICAGO -- CPR quality is worse during in-hospital cardiac arrests occurring overnight than those that happen during the day, according to a new University of Pennsylvania School of Medicine study that will be presented at the American Heart Association's annual Scientific Sessions on November 14. The researchers found that chest compression rates varied more at night - often dipping well below the rate per minute that's necessary to properly circulate blood - than during resuscitation efforts during the day, and rescuers paused for longer when switching between chest compressions and defibrillator shocks at night.

"Our study reveals an important factor to explain why, as previous studies have shown, patients who have cardiac arrests in hospitals during daytime hours are more likely to survive," says senior author Benjamin Abella, MD, MPhil, an assistant professor of Emergency Medicine and clinical research director in Penn's Center for Resuscitation Science. "These findings suggest that more attention to clinical emergency training and staffing at night may be an important way to improve hospital safety and patient outcomes."

The authors studied 173 cardiac arrests that occurred in non-intensive care settings over the course of two years at three urban teaching hospitals. Resuscitation efforts were monitored via a device that tracks compression depth and rates during CPR and the duration of pauses during defibrillation attempts. The results showed that mean chest compression rate was lower during resuscitations that took place at night, between 11 p.m. and 7 a.m., compared to those during the day -- 102 compressions per minute, with rates varying between 86 and 118, compared to 107, with variance between 100 and 114. One hundred chest compressions per minute is the recommended rate, and previous research shows that when compressions are performed at lower rates, patients are more likely to die or suffer permanent brain damage from prolonged oxygen deprivation. In addition, the researchers observed that staff members appeared to move slower when alternating between chest compressions and defibrillation during night resuscitations - they stopped compressions for a mean of 15.8 seconds before shocking patients at night, vs. 11.9 seconds during the day, and for 4.6 vs. 2.8 seconds after shocking patients.

Among factors that the authors say may influence the variability in CPR quality between night and day: fatigue, lower staffing levels, and lack of supervision from supervising physicians, who are less likely to be present during overnight resuscitations. But Abella says these disparities could be addressed with a variety of interventions, including more widespread use of cardiac arrest simulated event drills, devices that monitor CPR quality and provide real-time feedback, staff debriefings following resuscitations, and more supervising physician involvement in cardiac arrest care.

"Although these results show a disparity in the care cardiac arrest patients may receive overnight, we now have one answer about where to concentrate our efforts to better ensure the safety of patients around the clock," he says.

Other study authors include Sarah Perman, MD, Douglas Smith, Marion Leary, RN, and Lance Becker, MD, at the University of Pennsylvania, and Noah Swann and Dana Edelson, MD at the University of Chicago.


Other study authors include Sarah Perman, MD, Douglas Smith, Marion Leary, RN, and Lance Becker, MD, at the University of Pennsylvania, and Noah Swann and Dana Edelson, MD at the University of Chicago.

At the AHA Scientific Sessions
Jessica Mikulski
C: 215-796-4829

Following the Scientific Sessions
Holly Auer
O: 215-349-5659
C: 215-200-2313

Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $3.6 billion enterprise.

Penn's School of Medicine is currently ranked #3 in U.S. News & World Report's survey of research-oriented medical schools, and is consistently among the nation's top recipients of funding from the National Institutes of Health, with $367.2 million awarded in the 2008 fiscal year.

Penn Medicine's patient care facilities include:

  • The Hospital of the University of Pennsylvania - the nation's first teaching hospital, recognized as one of the nation's top 10 hospitals by U.S. News & World Report.

  • Penn Presbyterian Medical Center - named one of the top 100 hospitals for cardiovascular care by Thomson Reuters for six years.

  • Pennsylvania Hospital - the nation's first hospital, founded in 1751, nationally recognized for excellence in orthopaedics, obstetrics & gynecology, and behavioral health.

Additional patient care facilities and services include Penn Medicine at Rittenhouse, a Philadelphia campus offering inpatient rehabilitation and outpatient care in many specialties; as well as a primary care provider network; a faculty practice plan; home care and hospice services; and several multispecialty outpatient facilities across the Philadelphia region.

Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2009, Penn Medicine provided $733.5 million to benefit our community.

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