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Ch. 16 Clinical Scenarios: Cardiac Arrest

At 13:00, two paramedics responded to a call for a cardiac arrest at a local restaurant. Per the 911 dispatcher, a 66-year-old man was eating at the restaurant with his wife when he collapsed. A bystander attempted to palpate a pulse and was unsuccessful. CPR (compressions only) was started. An AED (automated external defibrillator) had been applied to the patient’s chest. A shock was advised, and the bystanders continued CPR following the shock.

Cardiac Arrest

There are an estimated 435,000 out-of-hospital cardiac arrests each year, according to the American Heart Association’s Heart Disease and Stroke update 2014. Thus it is important to review adult and pediatric advanced cardiac life support algorithms, which have changed as of the American Heart Association’s 2015 update. The most recent guidelines are not a significant change from those released in 2010 in relation to basic life support (BLS) and the use of automated external defibrillators (AED); however, key changes are important to note, including employment of a “pit crew” approach, quality of chest compressions, use of mechanical compression devices, changes to medications utilized, and implementation of therapeutic hypothermia in return of spontaneous circulation (ROSC).

The employment of the pit crew, or assignment of roles to each team member, optimizes utilization of resources. For in- stance, the 2 most important determinants of outcome follow- ing cardiac arrest are early defibrillation and quality of CPR.1 By- stander-initiated CPR, as well as a shock delivered in <5 minutes, have been shown to significantly improve a patient’s survival following cardiac arrest.1,2 Yet, historical information can play a huge role in patient outcomes:1

  • Did anyone witness the arrest?
  • What time was the person last seen “normal”?
  • What time did the arrest occur, and what was the person doing at that time?
  • Was there any intervention prior to arrival (CPR initiated, AED applied, shock delivered)?
  • Is there any pertinent past medical history (PMH)?
  • What medications does the patient take?
  • Any possibility for ingestion or overdose?
  • Determine code status.

A cardiac arrest in the field should be organized similar to a cardiac arrest in the hospital (number of personnel may vary by system):

  1. A recorder to keep track of the time and interventions
  2. 2 people performing CPR
  3. 1 person to draw up medications

The paramedics arrived on scene approximately 5 minutes after ar- rest. An engine crew from the local fire department arrived simultaneously. Two firefighters take over CPR from the bystanders and continue with high-quality chest compressions and begin bag-valve mask ventilation. One paramedic starts recording, noting times of interventions and changes in the patient’s status. The second paramedic assesses the AED, finding it to be connected to the patient correctly. He then applies a cardiac monitor. He speaks with the patient’s wife and bystanders, gathering pertinent past medical history and events prior to the cardiac arrest. Prior to lunch the patient had been complaining of chest discomfort. While eating he fell over and was found by a bystander to have no palpable pulse. CPR was started, and the AED was applied.  One shock was given. The patient’s past medical history is significant for hypertension and hyperlipidemia. He takes Lisinopril and Lipitor and has a 20-pack year tobacco history.

CPR Quality

It is important to monitor CPR quality.3 In the best scenarios, CPR will:

  • Push hard and fast: compress at least 5 cm (2 inches) and between 100-120 compression/minute
  • Allow for full relaxation between compressions (avoid leaning on the patient)
  • Minimize interruptions in compressions, including when rotating and between defibrillation
  • It is also important to avoid hyperventilation as this can lead to reduced cardiac output1
  • No advanced airway: 30:2 (adult) or 15:2 (pediatric) compression-to-ventilation ratio
  • Advanced airway: continuous compressions and 1 breath every 6 seconds (10 breaths/minute)
  • If advanced airway is placed remember to confirm placement:
  • Visualizing endotracheal tube passing between vocal cords
  • Confirm bilateral breath sounds
  • End-tidal CO2
  • Waveform capnography

Be cognizant of the reversible causes.4 Some conditions to keep in mind include:

  • Hypovolemia
  • Hypoxia
  • Hydrogen Ion (acidosis)
  • Hypo/Hyperkalemia
  • Hypothermia
  • Tension pneumothorax
  • Tamponade (cardiac)
  • Toxins
  • Thrombosis (pulmonary)
  • Thrombosis (coronary)

If return of spontaneous circulation (ROSC) is achieved:

  • Check pulses and blood pressure
  • PETCO2 typically will show an abrupt and sustained increased (usually >40 mmHg)1
  • Proceed to the ROSC pathway **AHA post arrest guidelines**5
  • Obtain 12 lead EKG ↦ Prioritize transport to a STEMI/ Hypothermia center

The firefighters continued CPR. IV access was obtained and an ad- vanced airway was placed. At 2 minutes, pulse and rhythm checks were done. The patient was still pulseless, and ventricular fibrillation was seen on the monitor. A shock was given, followed by epinephrine 1mg.  Capnography showed an ETCO2 of 22. The firefighters continued with high-quality CPR, and 2 minutes later another pulse and rhythm check was completed. The patient was found to have a pulse, and NSR was seen on the monitor. Capnography showed an ETCO2 of 55. The ASA post-arrest guidelines were intiated12 and the patient was prepared for transport to the nearest STEMI center. An EKG obtained post-arrest showed ST-segment elevation in the anterior leads. This was relayed to the accepting STEMI center and the cardiac catheterization suite was readied.


  1. Ward KR, Neumar RW. Adult Resuscitation. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice, 7th edition. Philadelphia: Mosby, 2009:53-63.
  2. Ornato JP. Sudden Cardiac Death. In: Tintinalli JE, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th edition. New York, NY: McGraw, 2009:63-67.
  3. Friedlander AD, Hirshon JM. Basic Cardiopulmonary Resuscitation in Adults. Tintinalli JE, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th edition. New York, NY: McGraw, 2009:67-73.
  4. American Heart Association. Doses/Details for the Cardiac Arrest Algorithms. ACLS: Cardiac Arrest, Arrhythmias, and Their Treatment.
  5. American Heart Association. Immediate Post-Cardiac Arrest Care Algorithm. ACLS: Cardiac Arrest, Arrhythmias, and Their Treatment.
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