Cardiac Arrest

Cardiac Arrest

David Ray Velez, MD

Table of Contents

Classification
EKG Patterns
Prognosis
Treatment
Special Considerations

See Also:
*See Ventricular Tachycardia (VT/V-Tach)
*See Ventricular Fibrillation (VF/V-Fib)
*See Asystole
*See Pulseless Electrical Activity (PEA)

Classification

Shockable Rhythms

  • Pulseless Ventricular Tachycardia (pVT)
  • Ventricular Fibrillation (VF/V-Fib)

Non-Shockable Rhythms

  • Asystole
  • Pulseless Electrical Activity (PEA)

EKG Patterns

Pulseless Ventricular Tachycardia (pVT)

  • Heart Rate > 100 bpm
  • Wide QRS Complex (≥ 120 ms)
  • No Fixed Relationship of P Wave and QRS Complex
  • *No Palpable Pulse

Ventricular Tachycardia (VT/V-Tach)

Ventricular Fibrillation (VF/V-Fib)

  • Sudden Chaotic Irregular Deflections
  • No Identifiable P Waves, QRS Complexes or T Waves
  • Rate 150-500 bpm

Ventricular Fibrillation

Asystole

  • No Waveform
  • Only an Isoelectric “Flat Line”

Asystole

Pulseless Electrical Activity (PEA)

  • Sufficient Electrical Discharge to Maintain a Notable Rhythm
  • *No Palpable Pulse

Prognosis

True Prognosis

  • Survival to Discharge:
    • Out-of-Hospital Cardiac Arrest: 10-12%
    • In-Hospital Cardiac Arrest: 20-25%
  • Majority of Survivors Have Some Degree of Brain Injury and Impaired Consciousness
  • Shockable Rhythms (pVT and VF) Have a Higher Chance of Survival than Asystole/PEA
  • Factors with High Specificity for Poor Neurologic Outcomes After ROSC:
    • Absent or Extensor Motor Response After 72 Hours
    • Absent Pupillary or Corneal Reflexes After 72 Hours

“As Seen on TV”

  • The Public Often Has Falsely High Expectations
  • In the Media:
    • 46-75% Regain Spontaneous Circulation
    • 67% Appear to Survive to Discharge
    • Minimal Depiction of the Poor Medium-Long Term Outcomes
  • Patient and Family Members Often Require Significant Education on Cardiac Arrest and Code Status

Treatment

General Treatment

  • Follow ACLS Guidelines
  • Start Chest Compressions Immediately
  • Give Supplemental Oxygen (Bag Mask Ventilation)
  • Treat Any Reversible Causes
  • Pulse/Rhythm Check Every 2 Minutes

Appropriate Compressions

  • At Least 2 Inches Depth
  • At Least 100 per Minute
    • *Can Compress to the Rhythm of the 1977 Song “Stayin’ Alive” by the Bee Gees to Maintain the Appropriate Rate – The Song Has About 103 Beats per Minute
  • Maintain a Minimum Chest Compression Fraction of 60% (Time Spent Delivering Compressions During CPR)

Pulse/Rhythm Check

  • Pauses Should Not Exceed 10 Seconds
  • Continue Chest Compressions Immediately After Any Shock
  • Rhythms:
    • Shockable Rhythms: pVT and VF
    • Non-Shockable Rhythms: Asystole and PEA
  • Defibrillation Dose:
    • Initial Dose: Biphasic 120-200 J
    • Higher Subsequent Doses May Be Considered

Medication Therapy

  • Epinephrine
    • The Primary Agent Given for All Causes of Cardiac Arrest
    • Dose: 1 mg IV/IO
    • Give Initially and Repeat Every 3-5 Minutes
  • Amiodarone
    • Given Only for Shockable Rhythms (pVT/VF) and Not for Asystole or PEA
    • Dose: 300 mg (First Dose) and 150 mg (Second Dose)
    • Generally Given After Epinephrine if Still in Arrest After Next Rhythm Check
  • *See Antiarrhythmic Pharmacology

Adjuncts

  • Calcium Chloride
    • Dose: 1 g IV
    • Vasopressor and Inotropic Effects
    • Not Routinely Given but May Be Considered
  • Sodium Bicarbonate
    • Dose: 50-100 mEq IV (1-2 Amps/Ampules)
    • Can Mitigate the Effects of Acidosis and Hyperkalemia
    • Not Routinely Given but May Be Considered if Concerned for Significant Acidosis or Hyperkalemia

Cardiac Arrest Management Algorithm:

Immediate CPR and Oxygen

Check Rhythm Every 2 Minutes:

  • VF/pVT:
    • Defibrillate
    • Alternate Epinephrine and Amiodarone After Each Check
  • PEA/Asystole:
    • Epinephrine After Every Other Check

Adjuncts:

  • Calcium Chloride
  • Sodium Bicarbonate

Use of Capnography During Cardiac Arrest

  • Used to Monitor Adequacy of Compressions:
    • Gradual Decline Suggests Decreased Adequacy and Possible Performer Fatigue
    • Abrupt Increases Suggest ROSC
  • Used After 20 Minutes of CPR to Consider Prognosis:
    • ETCO2 > 20 mmHg Has a Higher Chance of ROSC
    • ETCO2 < 10 mmHg Has Almost No Chance (0.5%) of ROSC

Post-ROSC (Return of Spontaneous Circulation) Management

  • Optimize Oxygenation and Ventilation
  • Treat Hypotension (Fluid Bolus, Vasopressors, etc.)
  • Obtain a 12-Lead EKG
  • Consider Targeted Temperature Management (TTM) if No Purposeful Neurologic Activity is Seen After ROSC
    • *See Therapeutic Hypothermia(TH)/Targeted Temperature Management (TTM)
  • Admit to ICU

Special Considerations

Reversible Causes of Sudden Cardiac Arrest: “5 H’s and T’s”

  • 5 H’s:
    • Hypovolemia
    • Hypoxia
    • Hydrogen Ions (Acidosis)
    • Hypokalemia/Hyperkalemia
    • Hypothermia/Hyperthermia
  • 5 T’s:
    • Tension Pneumothorax
    • Trauma and Toxins
    • Tamponade (Cardiac)
    • Thrombosis (Pulmonary/PE)
    • Thrombosis (Coronary/MI)
  • “H’s and T’s” are More Often are Associated with PEA Than Asystole

Arrest After Cardiac Surgery

  • Assess Rhythm:
    • Shockable Rhythms (VF or pVT): Start with Early Defibrillation up to 3x Within 1 Minute Before Starting CPR
    • Asystole or Severe Bradycardia: Pace (If Wires Available) and Start CPR
    • PEA: Start with CPR and Turn Off Pacer (If Paced) to Exclude Underlying VF
  • Additional Considerations:
    • Plan Early Emergent Re-Sternotomy with Internal Cardiac Massage
      • External CPR Causes More Trauma and Damage to Underlying Bypass Graft
    • If IABP in Place, Change to a Pressure Trigger
    • CALS Advises Against Full-Dose (1 mg) Epinephrine – Significant HTN Can Harm Fresh Grafts

Cardiac Arrest in Trauma

  • *See Resuscitative Thoracotomy

Cardiac Arrest in Pregnancy

  • *See Resuscitative Hysterotomy/Perimortem Cesarean Delivery (PMCD)