Pulseless Electrical Activity Workup

Updated: Nov 28, 2017
  • Author: Sandy N Shah, DO, MBA, FACC, FACP, FACOI; Chief Editor: Jose M Dizon, MD  more...
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Workup

Approach Considerations

The clinical scenario usually provides useful information in a patient with pulseless electrical activity (PEA). For example, in a previously intubated patient, tension pneumothorax and auto ̶ positive end-expiratory pressure (PEEP) are more likely to occur, whereas 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. [22]

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

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

Invasive monitoring (eg, arterial line) may be placed if it does not cause a delay in delivering standard advanced cardiac life support (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.

Electrocardiographic (ECG) changes on continous telemetry that appear to precede in-hospital cardiac arrest include ST-segment changes, atrial tachyarrhythmias, bradyarrhythmias, P-wave axis changes, QRS prolongation, PR prolongation, isorhythmic dissociation, nonsustained ventricular tachycardia, and PR shortening. [23] The main causes of these changes are respiratory or multiorgan failure. [23]

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.

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Echocardiography

Bedside echocardiography may rapidly identify reversible cardiac problems (eg, cardiac tamponade, tension pneumothorax, massive myocardial infarction, severe hypovolemia). [7, 24] The protocol proposed by Testa et al employs the acronym PEA in reference to pulmonary, epigastric, and abdominal scans used in the assessment for causes of pulseless electrical activity (PEA). [25]

Echocardiography also identifies patients with weak cardiac contractions who have pseudo-PEA. This group of patients is more likely to benefit from aggressive resuscitation, [7] and they may have a rapidly reversible cause (eg, auto–positive-end-expiratory pressure [PEEP]), hypovolemia).

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

Bedside ultrasonography appears to have the potential to identify a subset of patients who have different responses to advanced cardiac life support (ACLS) interventions. Secondary analysis of data from 225 patients from the Real-time Evaluation and Assessment Sonography Outcomes Network (REASON) trial who were in PEA cardiac arrest and had cardiac activity on bedside ultrasonography revealed that those with organized cardiac activity had an overall higher survival than patients with disorganized cardiac activity. [26]  The investigators noted improved survival to hospital admission in patients with PEA with organized cardiac activity that was treated with standard ACLS interventions and with continuous adrenergic agents during the resuscitation and before the return of spontaneous circulation compared to individuals who did not receive these treatments. [26]

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