Cardiac Arrest




Clinical Manifestations

General Comments

Post-Cardiac Arrest Syndrome

  • General Comments
    • Determination of Severity of Post-Cardiac Arrest Syndrome: SOFA score at ICU admission is associated with the 28-day mortality rate [MEDLINE]
  • Hypoxic-Ischemic Brain Injury (see Hypoxic-Ischemic Brain Injury, [[Hypoxic-Ischemic Brain Injury]])
    • Physiology
      • Cell Death Signaling Pathways
      • Cerebral Edema (Limited Extent): increased intracranial pressure is not a prominent feature of post-cardiac arrest syndrome
      • Disrupted Calcium Homeostasis
      • Free Radical Formation
      • Impaired Cerebrovascular Autoregulation: with impaired cerebral microcirculatory blood flow
      • No Reflow
      • Reperfusion Injury
      • Additional Brain Insults: due to pyrexia, hyperglycemia, hyperoxygenation, etc
  • Post-Cardiac Arrest Myocardial Dysfunction (see Congestive Heart Failure, [[Congestive Heart Failure]])
    • Physiology
      • Elevated Left Ventricular End-Diastolic Pressure (LV-EDP)
      • Global Hypokinesis
      • Myocardial Stunning
      • Preserved Coronary Blood Flow (in Patients Who Do Not Have an Associated Acute Coronary Syndrome)
  • Systemic Ischemia/Reperfusion Response
    • Physiology
      • Activation of Clotting Cascade: with fibrin deposition contributing to impaired microcirculatory blood flow
      • Disturbed Vasoregulation
      • Endothelial Activation
      • Intra-Arrest Global Tissue Hypotension
      • Intravascular Volume Depletion
      • Neutrophil Activation
      • Reperfusion Injury
      • Risk of Infection
      • Systemic Inflammation
  • Persistent Precipitating Pathologies
    • Acute Coronary Syndrome/Thrombus Formation
    • Acute Pulmonary Embolism (PE)
    • Chronic Ischemic Myocardial Scar
    • Cardiomyopathy: dilated, restrictive, hypertrophic, genetic, channelopathy, congenital, etc

Cardiovascular Manifestations

Hypotension/Shock (see Hypotension, [[Hypotension]])

  • Physiologic Mechanisms
    • Intravascular Volume Depletion
    • Myocardial Dysfunction
    • Therapeutic Hypothermia (see Therapeutic Hypothermia, [[Therapeutic Hypothermia]]): if used, may cause hypotension in some cases (although therapeutic hypothermia usually increases SVR)

Neurologic Manifestations

Hypoxic-Ischemic Brain Injury (see Hypoxic-Ischemic Brain Injury, [[Hypoxic-Ischemic Brain Injury]])

  • Epidemiology: anoxic brain injury is responsible for 66% of deaths in the post-cardiac arrest period
  • Assessment/Optimization of Neurologic Function After Cardiac Arrest
    • Cerebral Performance Category (CPC) [MEDLINE]: CPC at hospital discharge is a useful surrogate measure of long-term survival after cardiac arrest
    • Electroencephalogram (EEG) (see Electroencephalogram, [[Electroencephalogram]])
      • American Academy of Neurology Practice Parameter (Neurology, 2006) [MEDLINE]: burst suppression or generalized epileptiform discharges predict poor outcome, but with insufficient prognostic accuracy (recommendation level C)
    • Intracranial Pressure (ICP) Monitoring/Brain Oxygenation Monitoring: ICP >20 mm Hg has been associated with poor outcome in comatose patients in some studies
      • American Academy of Neurology Practice Parameter (Neurology, 2006) [MEDLINE]: insufficient data to determine the utility of monitoring of brain oxygenation (SjO2) and intracranial pressure monitoring
    • Neurologic Exam
    • Peripheral Blood Neuron-Specific Enolase (NSE) and S100 Beta (see Neuron-Specific Enolase, [[Neuron-Specific Enolase]])
      • Neuron-specific enolase is released into cerebrospinal fluid, cerebral circulation, and systemic circulation after brain injury: elevated levels 72 hrs after cardiac arrest are an indicator of hypoxic brain damage and correlate significantly with neurologic outcome
      • American Academy of Neurology Practice Parameter (Neurology, 2006) [MEDLINE]: serum neuro-specific enolase level >33 g/L at days 1-3 post-CPR accurately predicts poor outcome (recommendation level B)
    • Somatosensory Evoked Potentials (SSEP) (see Somatosensory Evoked Potentials, [[Somatosensory Evoked Potentials]])
      • American Academy of Neurology Practice Parameter (Neurology, 2006) [MEDLINE]: the assessment of poor prognosis can be guided by the bilateral absence of cortical SSEPs (N2O response) within 1-3 days (recommendation level B)
      • However, the presence of somatosensory evoked potentials does not necessarily guarantee a good neurological outcome
  • Clinical Patterns
    • Akinetic Mutism
    • Brain Death (see Brain Death, [[Brain Death]])
    • Coma (see Obtundation-Coma, [[Obtundation-Coma]])
    • Dementia (see Dementia, [[Dementia]])
    • Locked-In Syndrome (see Locked-In Syndrome, [[Locked-In Syndrome]])
    • Persistent Vegetative State: term was first used in 1972
    • Minimally Conscious State


Myoclonus (see Myoclonus, [[Myoclonus]])

  • Multifocal Myoclonus
  • Myoclonic Status Epilepticus (MSE)
    • Physiology: post-mortem studies indicate severe ischemic brain/brainstem/spinal cord damage (a pathologic pattern which is distinct from that of status epilepticus) [MEDLINE]
    • Clinical
      • Persistent Bilaterally Synchronous Myoclonus in the Face/Limbs/Axial Musculature, Often with Eye Opening and Upward Deviation of the Eyes: importantly this must be distinguished from status epilepticus (see Seizures, [[Seizures]])
    • Prognosis
      • Myoclonic Status Epilepticus has Been associated with Poor Outcome (Even in Patients with Intact Brainstem Reflexes and Some Motor Response): however, cases with good recovery have been reported where the circulatory arrest was secondary to respiratory failure
      • American Academy of Neurology Practice Parameter (Neurology, 2006) [MEDLINE]: myoclonic status epilepticus within the first day after a primary circulatory arrest carries a poor prognosis (Recommendation Level B)

Seizures (see Seizures, [[Seizures]])

  • Epidemiology: seizures/nonconvulsive status epilepticus/other epileptiform activity occur in 12-22% of comatose patients after cardiac arrest
  • Diagnosis
  • Clinical
    • Nonconvulsive Status Epilepticus: may result in coma (see Obtundation-Coma, [[Obtundation-Coma]])

Pulmonary Manifestations

Aspiration Pneumonia (see Aspiration Pneumonia, [[Aspiration Pneumonia]])

  • Epidemiology: may occur

Renal Manifestations

Acute Kidney Injury (AKI) (see Acute Kidney Injury, [[Acute Kidney Injury]])

  • Epidemiology: may occur

Treatment-Immediate Care

Active Chest Compression-Decompression Cardiopulmonary Resuscitation (CPR)

Sodium Bicarbonate (see Sodium Bicarbonate, [[Sodium Bicarbonate]])

Bystander Cardiopulmonary Resuscitation (CPR)

Early Defibrillation (see Defibrillation, [[Defibrillation]])

Early Echocardiographic Assessment

Mechanical Chest Compressions with Defibrillation During Ongoing Compressions (Mechanical CPR)

Mechanical Ventilation

Minimally Interrupted Cardiac Resuscitation (MICR) (Cardiocerebral Resuscitation)

Pre-Hospital Therapeutic Hypothermia (see Therapeutic Hypothermia, [[Therapeutic Hypothermia]])

Treatment-First 24 Hours of Hospital Care

Acute Coronary Syndrome (ACS) Management

Early Echocardiographic Assessment

Fever Management (see Fever, [[Fever]])

Glucose Management

Hemodynamic Management

Respiratory Management

Myoclonic Status Epilepticus Management

Seizure Management (see Seizures, [[Seizures]])

Therapeutic Hypothermia (see Therapeutic Hypothermia, [[Therapeutic Hypothermia]])

Treatment-Further Care

Consideration of Need for Automatic Implantable Cardioverter-Defibrillator (AICD) Placement (see Automatic Implantable Cardioverter-Defibrillator, [[Automatic Implantable Cardioverter-Defibrillator]])

Consideration of Need for Rehabilitation


Survival from Out-of-Hospital Cardiac Arrest (2010 Meta-Analysis) [MEDLINE]

Survival Rates from Out-of-Hospital Cardiac Arrest Have Been Stable for the Past 30 Years

Positive Predictors of Survival to Hospital Discharge in Out-of-Hospital Cardiac Arrest

Neurologic Prognosis Related to the Duration of Cardiopulmonary Resuscitation (CPR)

Neurologic Prognosis Related to Clinical Findings [MEDLINE]

Neurologic Prognostication Guidelines (2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care) [MEDLINE]

Neurologic Prognosis Post-Anoxic Vegetative State in Subacute Setting





Acute Coronary Syndrome (ACS) Management

Defibrillation/Chest Compression

Early Echocardiogram

Hemodynamic Management

Respiratory Management

Seizure Management

Sodium Bicarbonate

Therapeutic Hypothermia