ECMO & MCS Course Summary: Ventilation Goals on VV ECMO
By: Dr. Abdelhameed Ahmed
Presentation focused on mechanical ventilation goals in patients supported with VV ECMO.
• Divided into key phases:
o Pre-ECMO
o Early ECMO
o Recovery phase
o Path to weaning and outcome-focused ventilation
Pre-ECMO Phase
• Collect essential data: age, comorbidities, ARDS cause, organ dysfunction, ventilator settings (P/F ratio, compliance, driving pressure).
• Use prediction scores: RESP and PRESERVE to estimate survival likelihood.
Role of Mechanical Ventilation During VV ECMO
• Though ECMO handles gas exchange, ventilation:
o Maintains alveolar recruitment
o Prevents atelectasis
o Aids secretion clearance
• However, mechanical ventilation can worsen lung injury (VILI).
Ventilator-Induced Lung Injury (VILI)
• VV ECMO patients have fragile lungs; added ventilator injury can delay recovery.
• Mechanical Power is a relatively new concept in VILI, aimed at unifying different ventilator parameters into single,energy input concept.
• Mechanical Power (MP):
o Represents energy transferred per minute from ventilator to lungs.
o Calculating MP in pressurecontrolled modes
MPPCV = 0.1 x RR x VTI (L)x P plateau
o Calculating MP in volumecontrolled modes
MP (J/min) = 0.1 × Exp MinVol × (peak pressure−1/2 × driving pressure).
• Components of VILI:
o Ergotrauma high mechanical power
o Barotrauma : Excessive peak airway pressures
o Volutrauma Excessive peak airway pressures
o Atelectrauma Repetitive opening and closing of collapsed or semi-collapsed alveoli (in adequate PEEP)
o Chronotrauma Excessive Respiratory rate
o Energytrauma Excessive Driving pressure
o Rheotrauma Excessive flow rates
o Biotrauma Biological and inflammatory responses
Ultra-Protective Ventilation Goals
• Minimize VILI using:
o TV ≤ 4 mL/PBW
o Plateau pressure < 25 further reduction below 20 had better outcomes.
o Driving pressure < 14
o PEEP: 10–24 cmH₂O
o FiO₂: 30–50%
o Mechanical power Some aim for < 8 J/min
NB In Very poor compliant lung >>we can go for Extreme lung protective strategies like Near Apneic ventilation and Apneic ventilation.
ECMO Recovery and Weaning
• Signs of Recovery:
o ↑ compliance = lower plateau pressure
o Stable ABG = lung gas exchange function restored
o ↓ IL-6 & other inflammatory markers = reduced inflammation
o Imaging: CXR, CT, lung US = improving consolidation
o Able to Wean ECMO flow/FDO2/sweep
o Able to wean ventilator FiO₂ & PEEP = improving oxygenation
Recovery Categories:
1. Rapid responders (wean in <7 days) ECMO decannulated and Patient extubated.
2. Slow but complete (7–21 days) Decannulation + Tracheostomy.
3. Fibroproliferative (>21 days) Awake ECMO bridge to lung transplant
4. Non-recoverable → withdrawal
Challenges During Weaning
• Patient Self-Inflicted Lung Injury (P-SILI):
o Caused by vigorous spontaneous effort
o Signs: ↑ RR, ↑ TV, desaturation, high P0.1
o Prevention: light sedation, check readiness, Gradual ECMO Weaning in a controlled, slow manner to find the “balanced spot” where the patient spontaneous breathing is therapeutic, not injurious.
• Ventilator-Induced Diaphragmatic Dysfunction (VIDD):
o Caused by over-sedation and diaphragm disuse
o Mitigation:
▪ Allow for Spontaneous Breathing Efforts with Modest Inspiratory Effort, Maintaining Synchronous Expiratory Cycling
▪ Avoid excessive sedation
▪ Optimize Nutrition.
▪ Monitor with ultrasound (thickening fraction, excursion)
Weaning Approach
Conventional Weaning Most Common
(Wean ECMO first→ extubation):
• Most common method
• Advantages:
o Prioritizes Safety
o Protects Lungs (Against P-SILI>> VIDD).
o Familiar Process
• Risks: sedation complications, delayed rehab
• After Successful Weaning of ECMO and Decannulation >> Liberalize the Patient into Conventional Protective lung ventilation
o Liberalize by 1 ml /PBW increment up to 6ml with target plateau pressure less than or equal 28
NB: Awake ECMO Approach (High Center Experience )
(extubate on ECMO):
ELSO guidelines 2021
Some well selected patients may tolerate extubation first ,but others may have profound tachypnea , which itself may be injurious.
• Benefits:
o Reduced sedation
o Early mobilization
o Preserved diaphragm function
• Ideal for:
o Cooperative, stable patients
o Low respiratory drive
o No neuro impairment
Example for this Approach like bridge to lung transplantpatients.
• Contraindications:
o Agitation/delirium
o High risk of decannulation
o Severe P-SILI
• Risks:
o Requires significant resources and expertise
o Balance between spontaneous effort vs. lung injury
Final Takeaway
• ECMO is not just about correction of ABG — it’s about multi-organ protection:
o Lungs: rest and recovery
o Heart: ↓ PVR and RV strain
o Kidneys: ↓ inflammation and perfusion injury
o Brain: Adequate oxygenation and reduced inflammation can have a positive impact on brain protection &↓ sedation and preserve neuro function in awake ECMO
• It is Iterative Process:
o starts with initial risk stratification and evolves into daily monitoring of lung mechanics, ventilator parameters, and imaging.
o Start with sufficient lung rest (ECMO support).
o Gradually reduce sedation and encourage spontaneous breathing.
o Paying close attention to monitor for P-SILI&VIDD
o Adjust ventilator support and sedation to find the “balanced spot” where spontaneous breathing is therapeutic, not injurious.
o Wean ECMO Parameters in a controlled, slow manner to find the “balanced spot” where the patient spontaneous breathing is therapeutic, not injurious.