Cardiac Arrest

SOURCE

Source: Barletta JF. Cardiac arrest. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861&sectionid=146055661. Accessed May 22, 2017.

CONDITION/DISORDER SYNONYMS

• Cardiopulmonary arrest.

• Circulatory arrest.

DEFINITION

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

ETIOLOGY

• Coronary artery disease.

• Cardiomyopathies (eg, 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.

PATHOPHYSIOLOGY

• 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 (eg, ventricular fibrillation [VF], pulseless ventricular tachycardia [PVT]).

EPIDEMIOLOGY

• An estimated 320,000 or more people in the United States who experience emergency medical services (EMS)-assessed out-of-hospital cardiac arrest.

• Survival to hospital discharge following out-of-hospital cardiac arrest is only 10.6% and survival with good neurologic function is only 8.3%.

• In-hospital cardiac arrests occur in roughly 200,000 patients in the United States annually and this rate may be increasing.

PREVENTION AND SCREENING

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

RISK FACTORS

• 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)

CLINICAL PRESENTATION

SIGNS AND SYMPTOMS

• Preceeding an arrest:

  • Anxiety.

  • Crushing chest pain.

  • Diaphoresis.

  • Nausea or vomiting.

• Following an arrest.

  • Hypotension.

  • Unresponsive.

  • Apnea.

  • Hypotension with no detectable pulse.

  • Cold and clammy extremities.

DIAGNOSIS

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.