When should extracorporeal membrane oxygenation (ECMO) be considered or activated for a patient in cardiac arrest and for other emergency department presentations?

When to Consider ECMO in Cardiac Arrest and Emergency Department Presentations

For cardiac arrest, consider activating ECMO (ECPR) when you have a witnessed arrest with a potentially reversible cause, the patient has received high-quality CPR for at least 10-20 minutes without return of spontaneous circulation (ROSC), and you can initiate ECMO within 60 minutes of arrest onset. 1, 2

Cardiac Arrest: ECPR Activation Criteria

Essential Prerequisites (All Must Be Present)

Patient Selection Factors:

• Witnessed arrest (in-hospital or out-of-hospital with bystander CPR) 2
• Age 18-75 years (some protocols extend to 80 years) 2
• Presumed cardiac origin or other reversible cause 2
• No ROSC after 10-20 minutes of conventional CPR 2, 3
• High-quality CPR maintained throughout 4

Timing is Critical:

• Initiate ECMO within 20 minutes of CPR start for optimal outcomes 3
• Acceptable window extends to 60 minutes, but survival decreases significantly after 40 minutes 5, 3
• Each 20-minute delay increases mortality risk (HR 2.20-2.63) 3

Absolute Exclusions

Do not consider ECPR if any of these are present:

• Severe irreversible brain damage or known poor neurologic baseline 2
• Terminal malignancy 2
• Uncontrolled bleeding or severe trauma 2
• Non-cardiac causes: drowning, drug overdose, asphyxia, exsanguination (unless specifically treatable) 2
• Prolonged unwitnessed arrest with unknown downtime 2

Rhythm-Specific Considerations

Shockable Rhythms (VF/pVT):

• Consider ECPR after initial defibrillation attempts fail (typically after 3 shocks) 6
• These patients have better outcomes with ECPR 2

Non-Shockable Rhythms:

• Consider ECPR if reversible cause identified (e.g., massive PE, acute MI, hypothermia) 1
• Lower success rates but may benefit select patients 2

Other Emergency Department ECMO Indications

Severe Refractory Cardiogenic Shock (VA-ECMO)

Activate when:

• Mean arterial pressure <60 mmHg despite maximal medical therapy (vasopressors + inotropes) 7
• Evidence of end-organ hypoperfusion (lactate >4 mmol/L, oliguria, altered mental status) 7
• Potentially reversible cardiac pathology: acute MI, myocarditis, post-cardiotomy shock, acute decompensated heart failure 7

Key distinction from ECPR: Patient still has pulse and cardiac output, but inadequate to sustain life 7

Refractory Ventricular Arrhythmias

Consider VA-ECMO for:

• Electrical storm unresponsive to antiarrhythmics and cardioversion 7
• Hemodynamically unstable VT/VF requiring continuous defibrillation 7

High-Risk Pulmonary Embolism

Consider ECMO when:

• Cardiac arrest from massive PE (ECMO plus thrombolysis reduces mortality: aOR 0.61) 8
• Refractory shock from PE despite thrombolysis 8
• Contraindication to thrombolysis but hemodynamic collapse 8

Critical point: ECMO alone without reperfusion therapy increases mortality (aOR 1.60); must combine with thrombolysis or embolectomy 8

Practical Implementation Algorithm

Step 1: Immediate Assessment (Within 2 Minutes)

• Confirm witnessed arrest with known downtime
• Verify age 18-75 years
• Check for absolute exclusions
• Assess quality of ongoing CPR

Step 2: Activate ECMO Team (At 10 Minutes of CPR)

If no ROSC and patient meets criteria:

• Call ECMO team immediately 2
• Continue high-quality CPR without interruption
• Prepare for cannulation (femoral access preferred) 5

Step 3: Decision Point (At 15-20 Minutes)

• If ECMO available within 20 minutes total arrest time: PROCEED 3
• If ECMO will take >40 minutes to initiate: RECONSIDER (mortality significantly higher) 3
• If end-tidal CO2 <10 mmHg after 20 minutes in intubated patient: Poor prognostic sign but don't use in isolation 2

Step 4: Cannulation Target

• Goal: ECMO flow established within 60 minutes of arrest 5
• Percutaneous femoral cannulation preferred (venous drainage, arterial return) 9, 5
• Target flow 3-4 L/min immediately upon initiation 9

Common Pitfalls to Avoid

Don't:

• Use ECMO as a "Hail Mary" for patients with irreversible conditions 7
• Delay decision-making beyond 20 minutes of CPR 3
• Initiate ECPR without a plan for post-arrest care and potential bridge to definitive therapy 7
• Use end-tidal CO2 alone to determine ECPR candidacy (it's affected by ECMO gas exchange) 2, 10
• Attempt ECPR without experienced team and institutional protocols 7, 4

Do:

• Maintain uninterrupted high-quality CPR during cannulation 1
• Have multidisciplinary team ready (ECMO specialists, perfusionists, ICU) 7, 10
• Establish right radial arterial line post-cannulation to monitor cerebral perfusion 9
• Plan for post-ECMO management: targeted temperature management, coronary angiography if indicated, neurologic monitoring 9

Institutional Requirements

ECPR should only be performed at centers with 7, 4:

• 24/7 ECMO capability with rapid deployment (<30 minutes from decision to flow)
• Experienced ECMO team (physicians, nurses, perfusionists)
• Advanced cardiac capabilities (catheterization lab, cardiac surgery, ability to bridge to VAD/transplant)
• Established protocols and regular training 10

The 2019 AHA guidelines give ECPR a Class IIb recommendation (may be considered) for select patients with refractory arrest and potentially reversible causes, emphasizing this requires specialized systems and expertise 6. The evidence shows 30-50% survival with good neurologic outcomes (CPC 1-2) when strict protocols are followed 11, 4, but outcomes are significantly worse without systematic implementation 4.