Management Strategies for Patients on Veno-Venous (VV) ECMO
Anticoagulation with unfractionated heparin is the standard approach for VV ECMO patients, with anti-Xa monitoring preferred over aPTT for more accurate therapeutic range management. 1
Anticoagulation Management
Anticoagulation Approach
- Standard agent: Unfractionated heparin (UFH) is the primary anticoagulant for VV ECMO 1
- Monitoring methods:
Special Considerations
- Heparin-free VV ECMO: May be considered in patients with high bleeding risk 1
Physiological Targets and Monitoring
Respiratory Parameters
- Oxygenation targets: 1
- Avoid arterial hypoxemia (PaO₂ < 70 mmHg)
- Avoid severe arterial hyperoxia (PaO₂ > 300 mmHg)
- Serial arterial blood gas sampling in first 24 hours
Carbon Dioxide Management
- For patients with hypercapnia (PaCO₂ > 45 mmHg), avoid rapid changes in PaCO₂ within first 24 hours 1
- VV ECMO is primarily focused on CO₂ removal rather than oxygenation 2
Hemodynamic Targets
- Maintain mean arterial pressure > 70 mmHg 1
- VV ECMO does not provide direct hemodynamic support, requiring adequate cardiac function 2
Temperature Management
- Continuous monitoring of core temperature 1
- Active prevention of fever (> 37.7°C) 1
- Hypothermia is NOT recommended in VV ECMO 1
Neurological Monitoring and Management
Neurological Assessment
- Perform comprehensive neurological assessment for early detection of complications 1
- Non-contrast head CT is imperative to rule out intracranial hemorrhage with acute neurological changes 1
Stroke Management
- Ischemic stroke: 1
- tPA is NOT recommended due to high bleeding risk with systemic anticoagulation
- Mechanical thrombectomy is recommended for large vessel occlusion
Intracranial Hemorrhage Management
- Discontinue systemic anticoagulation 1
- Control blood pressure (systolic BP < 140 mmHg) 1
- Consider resumption of anticoagulation with repeated neuroimaging 1
Complications and Prevention
Common Complications
- Bleeding: Most frequent complication in VV ECMO patients 1
- Thrombotic events: Circuit thrombosis, deep vein thrombosis 3
- Recirculation issues: Higher risk in VV ECMO compared to VA ECMO 2
Prevention Strategies
- Regular circuit inspection for signs of thrombosis
- Maintain optimal flow rates
- Consider TEG-based protocol for monitoring (target 16-24 min of R parameter) 1
Indications and Outcomes
Primary Indications
- Severe respiratory failure refractory to conventional ventilation 2, 4
- Bridge to recovery of pulmonary function 2
- Bridge to lung transplantation 2
Outcomes
- VV ECMO may improve survival rates in appropriately selected patients with severe respiratory failure 5
- Recent data shows 70% survival rate at discharge for trauma patients on VV ECMO versus 41% with conventional management 5
Special Clinical Scenarios
Surgical Procedures During VV ECMO
- VV ECMO can provide total respiratory support during complex tracheo-bronchial or single-lung procedures 6
- Can be weaned intraoperatively or within 24 hours in 75% of patients undergoing such procedures 6
Conversion Considerations
- Approximately 4% of patients initially placed on VV ECMO require conversion to VA ECMO due to development of hemodynamic instability 2
- Monitor for signs of cardiac decompensation that may necessitate conversion