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

  1. Postcardiac arrest brain injury
    • Disruption on both a micro- and macro- circulatory levels may result in either ischaemia or hyperaemia
  2. Postcardiac arrest myocardial dysfunction
    • Although the heart initially becomes hyperkinetic, likely due to circulating catecholamines, global hypokinesis often follows
    • Usually resolves within 72 hours
  3. 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
  4. 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

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


CCC 700 6

Critical Care

Compendium

Specialist Intensive Care Physician working at the Austin Hospital, Melbourne. Interests: Shoulder Dislocations, Pain Management, End-of-life care, Organ Donation and ECGs | Linkedin |

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