Cardiac Arrest


  • NOTE: The following information is based on 2015 Advanced Cardiac Life Support (ACLS) Guidelines. Any revisions made by the American Heart Association (AHA) since then are not available at time of publication
  • Major ACLS changes for the 2015 revision include:
    • Removal of vasopressin from the adult cardiac arrest algorithm
    • End-tidal CO2 (ETCO2) can be used to assess CPR quality and detect return of spontaneous circulation (ROSC)
    • Upper limits of compression rate to 120/min and compression depth to 2.4 in (6 cm), to improve diastolic filling
    • Ultrasound may be considered if it does not interfere with standard ACLS, although its usefulness has not been well established
    • Continued emphasis on postcardiac arrest care, particularly implementation of targeted temperature management (TTM)


  • Cardiac arrest is characterized by acute:
    • Unresponsiveness
    • Pulselessness
    • Little to no respiratory effort
  • Factors affecting survival:
    • Initial rhythm
    • Total “no flow” and “low-flow” (CPR) time
    • Time to high-quality CPR
    • Time to successful defibrillation (as indicated)
    • Time to basic life-support interventions


Potentially reversible causes of cardiac arrest (“5 Hs and Ts”):
  • Hypovolemia
  • Hypoxia
  • Hydrogen ion (acidosis)
  • Hypo-/hyperkalemia
  • Hypothermia
  • Toxins, including:
    • Calcium channel blockers, β-blockers, digoxin
    • Tricyclic antidepressants
    • Opiates, cocaine
  • Tamponade, cardiac
  • Tension pneumothorax
  • Thrombosis (pulmonary, coronary)
  • Trauma

Pediatric Considerations
  • Sudden cardiac arrest in children is often of a respiratory rather than cardiac etiology
  • Follow current ACLS guidelines for pediatric cardiac arrest. Major differences between adult and pediatric cardiac arrest management include:
    • Depth of compressions for pediatric populations should be ∼1/3 to 1/2 the depth of the chest
    • For two-rescuer CPR, a 15:2 compression to ventilation rate is recommended
    • Infants should receive CPR using the two-thumb-encircling-hands technique
    • Drug dosage differences: See Medications

Pregnancy Considerations
Follow current ACLS guidelines for management of a pregnant cardiac arrest patient:
  • Awareness that airway may be difficult
  • Compressions should be performed at a higher location than conventional CPR, slightly above the center of the sternum
  • Follow Adult ACLS guidelines for defibrillation
  • Pre- or postcardiac arrest pregnant patients should be placed in the left lateral recumbent position; during arrest, perform manual left uterine displacement to relieve aortocaval compression
  • To ensure a best possible outcome for the fetus, all efforts must be geared toward maternal survival
  • Concomitantly prepare for a perimortem cesarean section
    • Assuming no maternal ROSC, this procedure should be considered at 4 min after arrest to optimize maternal and fetal outcomes

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