Pulseless Electrical Activity Workup

Updated: Jan 03, 2016
  • Author: Sandy N Shah, DO, MBA, FACC, FACP, FACOI; Chief Editor: Jeffrey N Rottman, MD  more...
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Approach Considerations

The clinical scenario usually provides useful information. For example, in a previously intubated patient, tension pneumothorax and auto ̶ positive end-expiratory pressure (PEEP) are more likely to occur, while in a patient with prior myocardial infarction or congestive heart failure (CHF), myocardial dysfunction is likely. In a patient on dialysis, consider hyperkalemia.

A core temperature should always be obtained if the patient is thought to have hypothermia. In patients diagnosed with hypothermia, resuscitative efforts should be continued at least until the patient is rewarmed, because patient survival is possible even after prolonged resuscitation. [13]

Measure QRS duration, since it has prognostic significance. Patients with QRS duration of less than 0.2 second are more likely to recover, and high-dose epinephrine may be administered. Acute rightward axis shifts can suggest possible pulmonary embolus.

Because of the emergent nature of the problem, lab tests are not likely to be helpful in the immediate management of a patient with pulseless electrical activity (PEA). If available rapidly, however, values for arterial blood gases (ABGs) and serum electrolytes may provide information regarding serum pH, oxygenation, and serum potassium. Glucose evaluation can also be useful.

Invasive monitoring (eg, arterial line) may be placed if it does not cause a delay in delivering standard ACLS care. Placement of an arterial line may identify patients with a recordable (but very low) blood pressure; these patients are likely to have a better outcome if given aggressive resuscitation.

ECG changes on continous telemetry that appear to precede in-hospital cardiac arrest include ST segment changes, atrial tachyarrhythmias, bradyarrhythmias, P-wave axis change, QRS prolongation, PR prolongation, isorhythmic dissociation, nonsustained ventricular tachycardia, and PR shortening. [14] The main causes of these changes are respiratory or multiorgan failure. [14]

A 12-lead ECG is difficult to obtain during ongoing resuscitation but, if available, can provide clues to the presence of hyperkalemia (eg, peaked T waves, complete heart block, ventricular escape rhythm) or acute myocardial infarction. Hypothermia, if not already diagnosed, may be suspected by the presence of Osborne waves. Certain drug overdoses (eg, tricyclic antidepressants) prolong QRS duration.



Bedside echocardiography may rapidly identify reversible cardiac problems (eg, cardiac tamponade, tension pneumothorax, massive myocardial infarction, severe hypovolemia). [5, 15] The protocol proposed by Testa et al uses the acronym PEA, in reference to pulmonary, epigastric, and abdominal scans used to assess for causes of pulseless electrical activity (PEA). [16]

Echocardiography also identifies patients with weak cardiac contractions who have pseudo-PEA. This group of patients is more likely to benefit from aggressive resuscitation. [5] Patients with pseudo-PEA may have a rapidly reversible cause (eg, auto-PEEP, hypovolemia).

Echocardiography is also invaluable in identifying right ventricular enlargement, pulmonary hypertension suggestive of pulmonary emboli, cardiorrhexis, and ventricular septal rupture.