Snapshot A 42-year-old man falls to the ground abruptly. Prior to the fall, he felt lightheaded and experienced palpitations. Chest compressions are immediately performed and he was placed on a Lucas device en route to the emergency department. In the emergency department, a defibrillator is placed on the patient, which does not show a shockable rhythm. The electrocardiogram demonstrates electrocardiographic activity but he does not have a pulse. The patient is given epinephrine in addition to chest compressions. After 1 hour of management, he returns to spontaneous circulation. (Pulseless electrical activity) Introduction Definition pulseless electrical activity (PEA) the presence of electrocardiographic rhythm without a palpable pulse or measurable blood pressure the heart is unable to generate enough mechanical contraction this is a non-perfusing rhythm, thus requiring effective cardiopulmonary resuscitation asystole an absence of electrocardiographic and mechanical cardiac activity Etiology The H's and T's Hypothermia H+ (acidosis) Hypo- or hyperkalemia Hypoxia Hypovolemia Thrombosis Tamponade Tension pneumothorax Toxins Presentation Symptoms cardiac arrest Physical exam absent pulses Studies Electrocardiogram required to make the diagnosis Treatment Initiate advanced cardiovascular life support (ACLS) begin with CAB Circulation Airway Breathing perform chest compressions, give oxygen, and connect the patient to a defibrillator next determine if the patient has a shockable rhythm note that PEA and asystole are not shockable rhythms PEA and asystole give epinephrine every 3-5 minutes along with chest compressions until the patient has a shockable rhythm or a return of spontaneous circulation Manage the underlying cause (H's and T's) Hypothermia warming H+ (acidosis) reverse the acidosis Hypo- or hyperkalemia hypokalemia provide potassium hyperkalemia e.g., calcium gluconate and insulin-dextrose Hypoxia oxygen and secure the airway Hypovolemia fluid replacement Thrombosis (e.g., myocardial infarction and pulmonary embolism) thrombolytics Tamponade pericardiocentesis Tension pneumothorax needle decompression Toxins antidotes (e.g., hydroxocobalamin in cyanide toxicity) Complications If systemic perfusion is not restored, will inevitably lead to death