Is Extracorporeal Membrane Oxygenation (ECMO) a viable treatment option for patients with Traumatic Brain Injury (TBI) and severe respiratory failure?

ECMO in Traumatic Brain Injury with Severe Respiratory Failure

Venovenous ECMO is a viable and potentially life-saving treatment option for TBI patients with severe respiratory failure, and traumatic brain injury should not be considered an absolute contraindication to ECMO. 1, 2

Key Evidence Supporting ECMO Use in TBI

The most recent and highest-quality evidence demonstrates that TBI patients on VV-ECMO achieve survival rates of 72% with favorable neurologic outcomes, comparable to trauma patients without TBI (64%, p=0.45). 2 This 2024 single-center study of 36 TBI patients on VV-ECMO showed that survivors had good neurologic outcomes at discharge based on Rancho Los Amigos Scale (mean 6.5), median Cerebral Performance Category (2), and Glasgow Outcome Scale-Extended (median 7.5). 2

The primary benefit of ECMO in TBI is rapid correction of hypoxemia and hypercarbia, which prevents secondary brain injury—a critical consideration that may outweigh bleeding risks. 2

Patient Selection Criteria

Select TBI patients for VV-ECMO based on these specific parameters:

• Admission Glasgow Coma Scale ≥7: TBI survivors on ECMO had significantly higher admission GCS compared to non-survivors (7 vs. 3, p<0.001). 2
• Rotterdam CT score of 2: 62% of TBI survivors had this score versus only 20% of non-survivors (p=0.03). 2
• Marshall score <4: No survivors had a Marshall score ≥4, making this a critical exclusion criterion. 2
• Severe hypoxemia: Median pre-ECMO PaO2:FiO2 ratio of 58 (IQR 47-74.5) despite optimal conventional ventilation. 1
• High injury severity: Median ISS of 48-50 in successful cases. 1, 3

Anticoagulation Management Strategy

Systemic anticoagulation can be safely withheld in TBI patients on ECMO without increased thrombotic complications. 1, 4

The evidence supports this approach:

• In a 2021 series, only 46% of TBI patients received systemic anticoagulation while on ECMO, with no patient experiencing worsening intracranial hemorrhage on repeat CT imaging. 1
• Three cases of prolonged heparin-free VV-ECMO in TBI patients demonstrated neither ECMO-associated bleeding nor clotting of the extracorporeal circuit, with 100% survival. 4
• High-flow technique without anticoagulation can be used specifically in patients with coagulopathy or TBI. 3
• Among 29 TBI patients (81%) who had repeat head CT on ECMO, only one had expanding hematoma and one had new bleeding focus—neither received anticoagulation. 2

Bleeding Risk Assessment

Active intracranial hemorrhage is not an absolute contraindication to ECMO. 3

A 2013 study demonstrated that among seven TBI patients on ECMO, four had active intracranial hemorrhage at initiation, yet achieved 60-80% survival rates on ECMO/iLA support. 3 The two patients who developed new or worsening intracranial bleeding were not on anticoagulation, suggesting the bleeding was related to the underlying injury rather than ECMO therapy. 2

Institutional Requirements Before Considering ECMO

ECMO should only be performed at centers meeting these specific criteria:

• Minimum annual volume of 20-25 ECMO cases for significantly better outcomes. 5
• 24/7 multidisciplinary ECMO team with quality assurance review procedures. 5
• Learning curve requirement: At least 20 cases needed to establish competence. 5
• Mobile ECMO teams should be available for retrieval from non-ECMO centers. 5

Pre-ECMO Optimization Requirements

Before initiating ECMO, exhaust all conventional therapies: 5, 6

• Lung-protective ventilation with tidal volumes 4-8 mL/kg predicted body weight and plateau pressures <30 cmH2O. 6
• Prone positioning for 12-16 hours daily if PaO2/FiO2 <150 mmHg. 6
• Neuromuscular blockade. 7
• Higher PEEP strategies. 7
• Inhaled vasodilators (nitric oxide/prostacyclin). 7

Timing Considerations

Initiate VV-ECMO within 7 days of respiratory failure onset for optimal outcomes. 5 Prolonged mechanical ventilation (>9.6 days) before ECMO is associated with worse outcomes. 5

Common Pitfalls to Avoid

• Do not automatically exclude TBI patients from ECMO consideration based solely on presence of intracranial hemorrhage. 1, 3
• Do not routinely anticoagulate TBI patients on ECMO—withholding anticoagulation does not increase oxygenator thrombosis requiring exchange. 1
• Do not delay ECMO in appropriate TBI candidates with refractory hypoxemia, as rapid correction of hypoxemia/hypercarbia prevents secondary brain injury. 2
• Do not attempt ECMO at low-volume centers—transfer to high-volume ECMO centers (>20 cases/year) is essential. 5

Monitoring Protocol on ECMO

• Serial head CT imaging to detect progression of intracranial hemorrhage. 1, 2
• Continuous arterial blood pressure and ECMO flow monitoring. 5
• Daily echocardiography, particularly for right ventricular function assessment. 5
• Regular arterial blood gas analysis and lactate levels. 5
• Meticulous fluid balance tracking. 5

Evidence Quality Considerations

While the American Thoracic Society provides only a conditional recommendation for VV-ECMO in severe ARDS with low certainty of evidence 5, 7, the specific TBI population demonstrates more compelling outcomes in recent observational studies. The 2024 retrospective analysis of 36 TBI patients represents the largest and most recent series, showing 72% survival with favorable neurologic outcomes. 2 This is supported by earlier series showing 38-60% survival in TBI patients on ECMO. 1, 3

The decision to use ECMO in TBI requires weighing the benefits of preventing secondary brain injury through rapid correction of hypoxemia against hemorrhagic risks, with current evidence favoring ECMO use in carefully selected patients at experienced centers. 1, 3, 2