EEM Rewind: A Workable Approach to PEA

Pulseless electrical activity is not a single diagnosis but a spectrum from electrical activity without cardiac motion to near-ROSC states with inadequate perfusion. A workable PEA approach starts by locating the patient on that spectrum, then using ultrasound, point-of-care labs, and core temperature to drive the differential.

Systematic Approach to PEA

• Four-step perfusion ladder: PEA is better framed as a progression toward ROSC: perfusion-capable rhythm, cardiac contractions, a pulse, then a blood pressure that can sustain life.
• Perfusion-capable rhythm check: Asystole is not perfusion-capable, and electrical activity alone is not enough; the key early question is whether the rhythm could plausibly generate forward flow.
• Cardiac motion distinction: Absent heart motion on ultrasound makes the arrest functionally asystole, even if the monitor shows organized electrical activity.
• POCUS pulse finding: Ultrasound of the carotid or femoral artery is more sensitive than fingers for detecting a pulse during a code, but it does not prove perfusion is adequate. We get into that bedside distinction in the episode.
• PRES and PREM labels: Scott's PRES and PREM terminology separates pulseless electrical activity with standstill from pulseless electrical activity with echocardiographic motion, clarifying what "PEA" misses.

PEA Differential and Treatment

• RUSH exam strategy: The RUSH exam anchors the PEA differential, with only a brief pause for cardiac views and lung ultrasound added when tension pneumothorax is on the table.
• Point-of-care lab triage: A VBG and chemistry panel rapidly identify acidosis, potassium disorders, and hypoglycemia, avoiding blind empiric treatment for reversible causes.
• Flat-heart hypovolemia clue: Severe hypovolemia or hemorrhage shows a strikingly empty heart on echo; free fluid in the abdomen or pleural space can help localize bleeding, though retroperitoneal hemorrhage may be missed.
• PE thrombolysis caution: A large right ventricle during CPR is not enough to diagnose pulmonary embolism, so thrombolytics should follow real pretest probability rather than reflex use.
• Basal pressor approach: A continuous norepinephrine infusion during the code is used to prevent immediate post-ROSC recollapse from hypotension, alongside epinephrine titrated to diastolic pressure. We walk through the pressor logic in the chapter.
• Selective adjunct medications: Calcium chloride earns a low threshold in undifferentiated PEA, while bicarbonate is reserved for sodium-channel blocker overdose rather than routine acidosis.