Groups Urge Treatment of Post-Arrest Syndrome

Strong evidence shows that prompt treatment of patients who are successfully resuscitated after cardiac arrest can improve outcomes, including mortality, according to a consensus statement on post-cardiac arrest syndrome.

Post-cardiac arrest syndrome, a new term proposed by the authors of the statement, “is a unique and complex combination of pathophysiological processes,” they said. The components are brain injury; myocardial dysfunction; the systemic ischemia/reperfusion response (including intravascular volume depletion, impaired oxygen delivery and utilization, and increased susceptibility to infection); and the underlying disease that caused the arrest (such as acute coronary syndrome [ACS] or pulmonary disease), which contribute to the high mortality rate among patients who are resuscitated, according to the statement. But this syndrome “will not occur” if resumption of spontaneous circulation (ROSC) is rapidly achieved after a cardiac arrest, they said.

They also point out that an increasing body of evidence suggests that the components of post-cardiac arrest syndrome are “potentially treatable” and “provides the essential proof of concept that interventions initiated after ROSC can improve outcome.”

The statement, which focuses on the epidemiology, pathophysiology, and prognostication of post-cardiac arrest syndrome, is intended to “provide a resource for organization of post-cardiac arrest care,” and to identify areas of research that could potentially improve outcomes of patients who are successfully resuscitated after a cardiac arrest. It was issued by the International Liaison Committee on Resuscitation and other medical organizations, and published online in Circulation (doi:10.1161/CIRCULATIONAHA.108.190652).

“Resuscitation of the cardiac arrest patient does not end when the patient regains a pulse,” at which point, the patient has only has a 30% chance of surviving to hospital discharge, Dr. Robert W. Neumar, head of the statement writing committee, said in an interview.

Interventions initiated after a pulse is restarted will improve outcomes, and include therapeutic hypothermia and percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI), which is common in patients with out-of-hospital cardiac arrest, noted Dr. Neumar, associate professor of emergency medicine and associate director of the Center for Resuscitation Science at the University of Pennsylvania, Philadelphia.

The statement points out that the overall prognosis after ROSC has not improved since the first large report on patients treated for cardiac arrest was published in 1953, reporting an in-hospital mortality rate of 50%. The authors cite the National Registry of CardioPulmonary Resuscitation, published in 2006, which found that in-hospital mortality was 67% among nearly 20,000 adults and 55% among 524 children who regained spontaneous circulation after a cardiac arrest. These rates also vary by region and institution, and despite advances that have improved ROSC rates, they have not translated into improvements in hospital discharge rates and long-term survival.

Recommendations for treatment strategies include using mild therapeutic hypothermia (cooling down to 32° C to 34° C, or 86.9° F to 93.2° F for at least 12–24 hours), started as soon as possible for unconscious adults with who are successfully resuscitated outside of the hospital after a cardiac arrest. Preclinical and clinical data “strongly” support the use of this modality as an effective treatment for post-cardiac arrest syndrome, the authors wrote.

They also recommend immediate coronary angiography for patients with electrocardiographic evidence of STEMI, “with subsequent PCI if indicated,” or thrombolytic therapy if PCI is not available. In consideration of how common ACS is among patients who have a cardiac arrest outside of the hospital, it is “appropriate” to consider angiography whenever ACS is suspected in post-cardiac arrest patients, they added.

Other recommendations include prompt treatment of prolonged seizures, frequent monitoring of blood glucose, treatment of hyperglycemia, and avoidance of unnecessary arterial hyperoxia.

The statement includes a section on post-cardiac arrest prognostication. “We need to reevaluate how we prognosticate poor outcomes in post-cardiac arrest patients,” Dr. Neumar said in the interview. “With the advent of neuroprotective interventions such as therapeutic hypothermia, currently used prognostication strategies may not be reliable.”

The statement was from the International Liaison Committee on Resuscitation (the American Heart Association, Australian Resuscitation Council, the Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, Resuscitation Council of South Africa, and the New Zealand Resuscitation Council) and the AHA Emergency Cardiovascular Care Committee; Council on Cardiovascular Surgery and Anesthesia; Council on Cardiopulmonary, Perioperative, and Critical Care; Council on Clinical Cardiology; and the Stroke Council. It was endorsed by the American College of Emergency Physicians, Society for Academic Emergency Medicine, and Society of Critical Care Medicine.

'We need to reevaluate how we prognosticate poor outcomes in post-cardiac arrest patients.' DR. NEUMAR