What are the indications and management strategies for Extracorporeal Membrane Oxygenation (ECMO) therapy?

ECMO: Indications and Management Strategies

ECMO should be initiated for severe refractory respiratory failure with hypoxemia (PaO2/FiO2 < 80 mmHg despite optimal ventilation) or cardiac failure with cardiogenic shock unresponsive to conventional therapies, with veno-venous (VV) ECMO for respiratory failure and veno-arterial (VA) ECMO for cardiac failure. 1, 2

Primary Indications

Respiratory Failure (VV-ECMO)

• Refractory hypoxemia despite maximal conventional therapies including lung-protective ventilation, prone positioning, and neuromuscular blockade 3, 2
• Uncompensated hypercapnia with severe respiratory acidosis not responding to optimal mechanical ventilation 3, 2
• Acute respiratory distress syndrome (ARDS) with severe gas exchange abnormalities 3, 4
• Bridge to lung transplantation in selected patients 5

Cardiac Failure (VA-ECMO)

• Severe refractory cardiogenic shock unresponsive to inotropes and vasopressors 1, 6
• Extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest requiring rapid initiation to improve neurologic outcomes 2, 6
• Refractory ventricular arrhythmias 6
• Acute or decompensated right heart failure 6
• Failure to wean from cardiopulmonary bypass 1
• Bridge to durable ventricular assist device or heart transplantation 6

Critical Management Strategies

Neurological Monitoring and Complications

Daily neurological assessments are mandatory, with immediate non-contrast head CT for any acute neurological change to rule out intracranial hemorrhage (ICH). 1

Stroke Management

• Tissue plasminogen activator (tPA) is contraindicated in ECMO patients due to high bleeding risk with systemic anticoagulation and platelet dysfunction 1
• Mechanical thrombectomy is recommended for acute large vessel occlusion detected by CT angiogram 1
• CT angiogram with perfusion scan should be obtained to assess salvageable penumbra 1

Intracranial Hemorrhage Management

• For ICH during VV-ECMO: prolonged cessation of systemic anticoagulation (>2 days) is recommended 1
• For ICH during VA-ECMO: balance thromboembolism risk against bleeding risk, as VA-ECMO carries higher thrombotic risk when anticoagulation is held 1
• VV-ECMO can be maintained without anticoagulation longer than VA-ECMO due to lower thromboembolism risk 1
• Early cessation and judicious resumption of anticoagulation with repeated neuroimaging is the recommended approach 1

Neurosurgical Interventions

• Decompressive craniectomy may be considered for space-occupying lesions with malignant edema after multidisciplinary risk-benefit discussion 1
• Careful anticoagulation monitoring and resumption post-operatively is essential 1
• External ventricular drain placement may be considered only in patients at imminent risk of death from intraventricular hemorrhage with hydrocephalus, despite high bleeding risk 1
• Invasive ICP monitoring should be used cautiously as no data suggests improved outcomes and may increase parenchymal hemorrhage risk 1

Neurological Prognostication

Neurological prognostication must use a multimodality approach combining clinical examination, electrophysiological tests, and neuroimaging—never rely on a single factor. 1

Key Prognostic Elements

• Rule out confounding factors: sedatives, electrolyte disturbances, hypothermia 1
• Assess pupillary and corneal reflexes at ≥72 hours 1
• Bilateral absence of N20 cortical waves on somatosensory evoked potentials at ≥24 hours suggests poor prognosis 1
• Highly malignant EEG patterns at >24 hours 1
• Neuron-specific enolase threshold for poor outcome in ECPR likely exceeds 100 μg/L (higher than non-ECMO patients due to hemolysis) 1
• Extensive diffuse anoxic injury on brain CT/MRI 1

ICH during anticoagulated ECMO carries extremely high mortality and morbidity, though data on withdrawal of life-sustaining therapy are sparse 1

Brain Death Determination

Apnea testing can be performed by reducing sweep gas flow or adding exogenous CO2. 1

When apnea testing is contraindicated due to hemodynamic/cardiopulmonary instability, cerebral angiogram or radionuclide brain scan are the preferred ancillary tests 1

Goals of Care and Family Communication

Frequent family meetings should begin within 72 hours of cannulation, focusing on informed consent, early goal-setting with timelines, clear communication, and emotional support. 1

• Routine ethics consultation within 72 hours of cannulation can mitigate conflicts by setting clear expectations 1
• Families experience significant anxiety, depression, and PTSD long after discharge 1
• Withdrawal from ECMO should be structured with preparatory family meetings, symptom management, technical circuit management, and bereavement support 1
• Decisions regarding withdrawal should be highly individualized with multidisciplinary discussions considering patient preferences 1

Long-Term Outcomes and Follow-Up

37-52% of adult ECMO survivors have cerebral infarction or hemorrhage on long-term MRI, associated with cognitive impairment. 1

Pre-Discharge Care

• Clinical examination using modified Rankin Scale before discharge is recommended 1
• Brain MRI after decannulation for those with neurological or cognitive dysfunction 1
• Comprehensive education and psychosocial support for patients, families, and caretakers 1
• Nutritional assessment and planning for optimal recovery 1

Post-Discharge Care

• Outpatient visits at 3,6, and 12 months preferably at ECMO clinics or with neurologist 1
• Serial neurological and quality of life assessments 1
• For patients with neurological complications: neurological specialist examination, MRI, and tailored testing 1
• Follow-up with disease-specific specialists (pulmonologist, cardiologist, neurologist, nephrologist) as needed 1

Timing and Patient Selection

Early initiation of ECMO should be considered when hypoxemia and uncompensated hypercapnia do not respond to optimal conventional treatment. 3

• Prompt referral by emergency clinicians is necessary for optimal outcomes 2
• ECPR requires rapid initiation to prevent further decompensation and improve neurologic outcomes 2
• Multidisciplinary team assessment is essential for emergent deployment, particularly for cardiac failure 6
• Futility should not be determined solely by duration of ECMO; prolonged support for lung recovery may be worthwhile 3

Common Pitfalls

• Avoid overly pessimistic prognosis without ruling out confounding factors (sedation, electrolytes, hypothermia) 1
• Beware of "self-fulfilling prophecy" bias where poor prognostic tests influence premature withdrawal decisions 1
• Do not use single prognostic factors in isolation 1
• Recognize that standard neuron-specific enolase thresholds do not apply to ECMO patients due to hemolysis 1