Cardiac Arrest

Source: Barletta JR, Wilt JR. Cardiac Arrest. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. http://accesspharmacy.com/content.aspx?aid=7969590. Accessed June 25, 2012

• Cardiopulmonary arrest
• Circulatory arrest

• Cessation of cardiac mechanical activity as confirmed by absence of signs of circulation (e.g., undetectable pulse, unresponsiveness, apnea).

• Coronary artery disease
• Cardiomyopathies (e.g., hypertrophic or dilated cardiomyopathy)
• Structurally abnormal congenital cardiac conditions
• Structurally normal but electrically abnormal heart conditions
• In pediatric patients, cardiac arrest may follow respiratory failure or progressive shock.
• Out-of-hospital arrests often associated with trauma, sudden infant death syndrome, drowning, poisoning, choking, severe asthma, and pneumonia.
• In-hospital arrests associated with sepsis, respiratory failure, drug toxicity, metabolic disorders, and arrhythmias.

• Primary cardiac arrest: Arterial blood fully oxygenated at time of arrest.
• Secondary cardiac arrest: Results from respiratory failure, leading to hypoxemia, hypotension, and cardiac arrest.
• Usually results from arrhythmias in adults (e.g., ventricular fibrillation [VF], pulseless ventricular tachycardia [PVT]).
• Most pediatric arrests related to respiratory rather than cardiac causes.

• Sudden cardiac death accounts for ~15% of all death in Western countries (330,000 per year in United States).
• Lifetime risk 3 times greater in men than women.

• Because primary cause is coronary artery disease, preventive measures include healthy diet, appropriate exercise, smoking cessation, blood pressure control, and management of dyslipidemia.

• Family history of coronary artery disease
• Personal history of myocardial infarction (MI) or previous cardiac arrest
• Smoking
• Hypertension
• Dyslipidemia
• Obesity
• Diabetes
• Sedentary lifestyle
• Increasing age
• Male sex
• Use of certain illegal drugs (cocaine, amphetamines)

Signs and Symptoms

• Onset may be associated with:
  • Anxiety, mental status changes, or unconsciousness
  • Cold, clammy extremities
  • Dyspnea, shortness of breath, or no respiration
  • Chest pain
  • Diaphoresis
  • Nausea or vomiting
• Physical signs may include
  • Hypotension
  • Tachycardia
  • Bradycardia
  • Irregular or no pulse
  • Cyanosis
  • Hypothermia
  • Distant or absent heart and lung sounds

Means of Confirmation and Diagnosis

• Observation of clinical findings consistent with cardiac arrest
• Confirmation by evaluating vital signs, especially heart rate and respirations

Diagnostic Procedures

• Electrocardiography (ECG) to determine cardiac rhythm
  • VF: Electrical anarchy of ventricle resulting in no cardiac output and cardiovascular collapse.
  • Pulseless electrical activity (PEA): Absence of detectable pulse and presence of electrical activity other than VF or PVT.
  • Asystole: Flat line on ECG monitor.

Differential Diagnosis

• Acute coronary syndrome
• Trauma
• Hypovolemia
• Hypoxia
• Metabolic acidosis
• Tension pneumothorax
• Cardiac tamponade
• Electrolyte abnormality
• Drug overdose

• Return of spontaneous circulation (ROSC) with effective ventilation and perfusion.
• After successful resuscitation, optimize tissue oxygenation, identify precipitating causes, and prevent subsequent episodes.

• Implement each of 5 elements in “chain of survival” promptly:
  • Immediate recognition of cardiac arrest and activation of the emergency response system
  • Early CPR with an emphasis on ...