II. Pathophysiology: Primary Post-Cardiac Arrest Syndrome Components

  1. Systemic ischemic perfusion response
    1. Cytokine mediated injury with severity increasing with duration of downtime, comorbities and arrest Mechanism
    2. Triggers intravascular volume depletion and altered vasoregulation
  2. Anoxic brain injury
    1. Most common early cause of post-Cardiac Arrest related mortality (first 24 hours)
    2. Oxygen free-radical mediated cellular injury (protein peroxidation and apoptosis)
    3. Results in cerebral edema and decreased cerebral autoregulation
  3. Myocardial dysfunction
    1. Stunned Myocardium with both Systolic Dysfunction and Diastolic Dysfunction in 70% of post-arrest patients
    2. Onset within hours or ROSC and improves after 3-4 days with intensive supportive care
  4. Mechanism behind original Cardiac Arrest
    1. See Reversible Causes of Cardiopulmonary Arrest (6H6T)

III. Pathophysiology: Other Post-Cardiac Arrest Syndrome Components

  1. Pulmonary Dysfunction (with risk of ARDS and other lung injury)
    1. Aspiration
    2. Ventilation-perfusion mismatch
    3. Pulmonary edema
  2. Recurrent Cardiac Arrest
    1. Remain vigilant for signs of non-perfusing rhythm
    2. Loss of EtCO2 wave form may be first warning (esp. if rhythm is PEA)

IV. Management: Respiratory: Lung Protective Strategy

  1. Avoid hyperoxia
    1. Titrate FIO2
      1. Keep Oxygen Saturation 93-97%
      2. Keep PaO2 near 100 mmHg
    2. Poor outcomes associated with PaO2 >300 mmHg or PaO2 <60 mmHg
    3. Kilgannon (2010) JAMA 303(21): 2165-71 [PubMed]
  2. Avoid Hyperventilation
    1. Keep Tidal Volumes low: 6-8 ml/kg Ideal Body Weight
    2. Keep ventilation rates low (titrate to etCO2 or PaCO2)
      1. End-Tidal CO2: 35-40
      2. PaCO2: 40-45
        1. Risk of falsely elevated PaCO2 in hypothermic patients (discuss with lab)
    3. Hyperventilation decreases cerebral perfusion
      1. Hyperventilation increases intrathoracic pressure and decreases venous return and Cardiac Output
      2. Hyperventilation results in decreased CO2 and compensatory cerebral Vasoconstriction

V. Management: Circulatory

  1. Prevent Hypotension
    1. Keep Mean arterial pressure (MAP) 65-100 (preferably 70-80 or higher)
    2. Start low dose pressor and increase if Blood Pressure begins to fall
    3. Replace fluids to treat hypovolemia
      1. Cold fluids if initiating Therapeutic Hypothermia
      2. Anticipate significant diuresis with induced Hypothermia with risk of hypovolemia and electrolyte disturbance
    4. Follow serum Lactic Acid levels
    5. Monitor for decreased cardiac contractility with bedside Echocardiogram and consult cardiology early
      1. Inotropes are commonly required
        1. Milrinone
        2. Dobutamine 2.5-10 mcg/kg/min
      2. Consider intra-aortic balloon pump
    6. Consider Arterial Line
      1. Allows for closer titration of Vasopressors and inotropes
      2. Allows for serial Arterial Blood Gas monitoring (PaO2 and PaCO2)
    7. Consider ECMO
      1. May be indicated as bridging supportive therapy to post-arrest definitive management (e.g. PTCA)
      2. Improved neurologic outcomes
        1. Younger patients (<65 to 75 years old)
        2. Witnessed Cardiac Arrest and CPR started immediately
        3. Reversible cause (e.g. Acute Coronary Syndrome)
  2. Early Coronary Angiography (PCI) for Acute Coronary Syndrome
    1. Background
      1. Coronary events are responsible for 40% of Cardiac Arrests
      2. In medical centers distant from PCI, Thrombolytics could be considered
    2. Obtain immediate post-arrest Electrocardiogram (and repeat in 10-15 minutes)
      1. Initial EKG (first 10-15 minutes) may demonstrate ST changes due to Defibrillation, Epinephrine
    3. Early Angioplasty (PCI) indications
      1. History of Chest Pain prior to Cardiac Arrest
      2. Post-arrest EKG signs of ST Elevation Myocardial Infarction (STEMI)
      3. Ventricular Fibrillation as initial heart rhythm from EMS
        1. Any shockable rhythm may predict benefit with early PCI
    4. Relative contraindications to early PCI (patients less likely to benefit)
      1. Unwitnessed arrest
      2. No bystander CPR
      3. Duration of Cardiac Arrest to ROSC >30 minutes
      4. Ongoing CPR
      5. Arterial pH <7.2
      6. Serum Lactic Acid >7
      7. Age over 85 years old
      8. End-stage renal disease
      9. Noncardiac cause of Cardiac Arrest (e.g. Traumatic Arrest)
    5. References
      1. Orman and Mattu in Herbert (2015) EM:Rap 15(11): 8-9
      2. Dumas (2010) Circ Cardiovasc Interv 3(3):200-7 [PubMed]
      3. Hollenbeck (2014) Resuscitation 85(1): 88-95 [PubMed]

VI. Management: Neurologic

  1. Pupillary response is a strong predictor of outcome
    1. Absent pupillary response is associated with a worse outcome
  2. Induced Therapeutic Hypothermia
    1. Goal is Return of Neurologic Function (RONF)
    2. Class I indications
      1. Comatose patient with STEMI
      2. Out of hospital Cardiac Arrest with Ventricular Fibrillation or Pulseless Ventricular Tachycardia
  3. Seizures (20% of cases)
    1. Treat with Ativan
    2. Prophylaxis not initially needed unless Seizure occurs
  4. Imaging
    1. Consider Head CT for any focal neurologic changes or atypical arrhythmia

VII. Management: Miscellaneous

  1. Monitor serum electrolytes including calcium, Magnesium and phosphorus
    1. Induced Hypothermia increases risk of electrolyte disturbance via significant diuresis
    2. Risk of arrhythmia with electrolyte disturbance
  2. Avoid Hyperglycemia (and Hypoglycemia)
    1. Target Blood Glucose near 150 mg/dl
  3. Treat fever
    1. Higher Body Temperatures are associated with worse neurologic outcomes
    2. See Induced Therapeutic Hypothermia
  4. Elevate head of bed
    1. Prevents aspiration in intubated patients
    2. Decreases Intracranial Pressure
  5. Empiric antibiotics for bacteremia (investigational)
    1. In one study, bacteremia was present in 38% of Cardiac Arrest patients who had significantly worse survival rates
    2. Hypothesized that Cardiac Arrest in some cases may be due to overwhelming Sepsis
    3. Consider obtaining Blood Cultures and administering broad spectrum antibiotics after ROSC
    4. Coba (2014) Resuscitation 85(2): 196-202 [PubMed]
  6. Post-arrest intubation precautions
    1. Exercise caution if patient not intubated prior to ROSC (e.g. Extraglottic Device)
    2. Right heart involvement places at high risk of recurrent and refractory Cardiac Arrest on intubation
    3. Limit RSI to cardiac-stable agents
      1. Use paralytic (Succinylcholine or Rocuronium) for maximal first-pass success
      2. Etomidate (some recommend half dose after ROSC at 0.15 mg/kg)
      3. Ketamine (some recommend half dose after ROSC at 0.75 mg/kg)
    4. Involve anesthesiology if possible
    5. Consider not intubating post-arrest unless otherwise indicated
      1. However, Extraglottic Devices are replaced with definitive airways in most cases after ROSC
      2. Definitive airway is required when Transferring to cath lab
  7. Post-arrest Sedation
    1. As with RSI, use cardiac stable agents at lower dose
      1. Etomidate (half dose)
      2. Ketamine (half dose)
      3. Avoid Propofol if possible (however if used, dose at 10% the typical dose)

VIII. References

  1. Mattu and Herbert (2012) EM: Rap 12(4): 5-6
  2. Winters et al in Majoewsky (2013) EM:Rap 13(7): 9-10
  3. Weingart and Orman in Herbert (2015) EM:Rap 15(8): 13-4
  4. Orman and Weingart in Herbert (2015) EM:Rap 15(1): 14-6
  5. Stub (2011) Circulation 123(13): 1428-­35 [PubMed]

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Ontology: Cardiac arrest with successful resuscitation (C0340514)

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Korean 인공소생술에 성공한 심장정지
Dutch stilstand; hart, met geslaagde reanimatie, Hartstilstand met geslaagde reanimatie
Spanish paro cardíaco con reanimación exitosa (trastorno), paro cardíaco con reanimación exitosa

Ontology: Resuscitated Cardiac Arrest Event (C1882942)

Definition (NCI) Cardiac arrest that is reversed, usually by CPR and/or defibrillation or cardioversion, or cardiac pacing.
Definition (NCI) Date that resuscitated cardiac arrest occurred.(NIH Roadmap Cardiovascular Data Standards Working Group)
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English Resuscitated Cardiac Arrest Event, Resuscitated Cardiac Arrest

Ontology: Cardiopulmonary resuscitation discontinued - return of spontaneous circulation (C1960718)

Concepts Health Care Activity (T058)
SnomedCT 426970003
English Cardiopulmonary resuscitation discontinued due to return of spontaneous circulation, Cardiopulmonary resuscitation discontinued due to return of spontaneous circulation (situation), Cardiopulmonary resuscitation discontinued - return of spontaneous circulation
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