Post-cardiac arrest syndrome

Reviewed and revised 15 November 2016

OVERVIEW

aka post-resuscitation syndrome

occurs after return of spontaneous circulation (ROSC) following cardiorespiratory arrest and involves multiple systems
Reflects a state of whole-body ischaemia and subsequent reperfusion
Often super-imposed on the underlying condition, which caused the cardiac arrest and pre-existing comorbidities, and other complications of resuscitation
Severity depends on the duration and cause of cardiac arrest

Mortality and morbidity following cardiac arrest

Early mortality due to cardiovascular instability
Late mortality and morbidity occurs from brain injury (the most common cause of death after ROSC), multi-organ failure and sepsis

MECHANISM

Postcardiac arrest syndrome was once thought to be largely due to production of free radicals, although the pathophysiology is more complex

Hypoperfusion and ischaemia cause a cascade of events
- disruption of homeostasis
- free radical formation
- protease activation
- a SIRS response resembling severe sepsis
The disruption may continue for hours or days
Hypothermia may slow down this cascade

MAJOR MANIFESTATIONS

Postcardiac arrest brain injury
- Disruption on both a micro- and macro- circulatory levels may result in either ischaemia or hyperaemia
Postcardiac arrest myocardial dysfunction
- Although the heart initially becomes hyperkinetic, likely due to circulating catecholamines, global hypokinesis often follows
- Usually resolves within 72 hours
Systemic ischaemia/reperfusion response
- The response of the body is similar to the septic shock with activation of the immune and complement systems, and release of inflammatory cytokines and a wide range of cellular responses
Persistent precipitating pathology
- The cause of the arrest may continue to impact physiological parameters

CONTRIBUTING FACTORS

Post cardiac arrest brain injury

Impaired cerebrovascular autoregulation
Cerebral oedema
Neurodegeneration

Post cardiac arrest myocardial dysfunction

Myocardial stunning – global hypokinesis
Poor cardiac output
Acute coronary syndromes

Systemic ischaemia / reperfusion response

Systemic inflammatory response syndrome (SIRS)
Poor vasoregulation
Microcirculatory failure
Activation of coagulation cascade
Adrenal suppression
Poor tissue oxygen deliver and utilization
Susceptibility to infection

Persistent precipitating pathology

Cardiovascular disease (e.g. myocardial ischemia, cardiomyopathy)
Pulmonary disease (e.g. pulmonary embolus, asthma)
CNS disease (e.g. stroke, subarachnoid hemorrhage)
Poisoning
Infection / Sepsis
Hypovolaemia

Other complications of resuscitation such as injuries (e.g. rib fractures, sternal fractures), medication adverse effects and complications of invasive lines and monitoring.

References and Links

LITFL

CCC — Prognosis After Cardiac Arrest
CCC — Post-cardiac arrest care
CCC — Targeted temperature management (TTM) after cardiac arrest

Journal articles

Mongardon N, Dumas F, Ricome S, Grimaldi D, Hissem T, Pène F, Cariou A. Postcardiac arrest syndrome: from immediate resuscitation to long-term outcome. Ann Intensive Care. 2011 Nov 3;1(1):45. PMC3223497.
Neumar RW, et al. Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A consensus statement from the International Liaison Committee on Resuscitation. Circulation. 2008 Dec 2;118(23):2452-83. PMID: 18948368. [Free Full Text]
Stub D, Bernard S, Duffy SJ, Kaye DM. Post cardiac arrest syndrome: a review of therapeutic strategies. Circulation. 2011 Apr 5;123(13):1428-35. doi: 10.1161/CIRCULATIONAHA.110.988725. PMID: 21464058. [Free Full Text]
Zia A, Kern KB. Management of postcardiac arrest myocardial dysfunction. Curr Opin Crit Care. 2011 Jun;17(3):241-6. PMID: 21378558.

FOAM and web resources