ECMO as a Solution for Preventing Ventilator-Induced Lung Injury: Understanding Volutrauma, Barotrauma, and Atelectrauma
The different types of lung injury can be very confusing, especially for the ECMO specialist who is not a respiratory therapist. To prevent ventilator-induced lung injuries, it is critical to initiate veno-venous extracorporeal membrane oxygenation (VV ECMO). Hopefully, this post will simplify the various terms.
1. Volutrauma
Definition: Volutrauma refers to lung injury that results from overdistension of the alveoli due to excessive volume delivered during mechanical ventilation.
Example: In a patient receiving mechanical ventilation, the alveoli can become overstretched if the ventilator settings deliver excessively large tidal volumes (the amount of air delivered to the lungs with each breath). This overdistension can cause damage to the alveolar walls, leading to inflammation, increased permeability, and subsequent lung injury. For instance, if a patient with acute respiratory distress syndrome (ARDS) is ventilated with tidal volumes that are too high, volutrauma can occur.
Reason for VV ECMO: When efforts to reduce tidal volumes to safe levels are insufficient to maintain adequate gas exchange, VV ECMO can be initiated. VV ECMO provides an alternative method of oxygenation and carbon dioxide removal, allowing the lungs to rest and heal while minimizing the risk of further volutrauma.
2. Barotrauma
Definition: Barotrauma refers to lung injury caused by excessive pressure during mechanical ventilation, leading to the rupture of alveoli or airways.
Example: A common scenario for barotrauma is when a patient is on positive pressure ventilation with settings that generate high peak airway pressures. This can cause air to escape from the alveoli into the surrounding structures, potentially leading to conditions such as pneumothorax (air in the pleural space), pneumomediastinum (air in the mediastinum), or subcutaneous emphysema (air under the skin). For example, if the ventilator’s pressure settings are too high in a patient with stiff, non-compliant lungs, barotrauma can occur, resulting in a pneumothorax.
Reason for VV ECMO: If high ventilatory pressures are necessary to maintain oxygenation and these pressures lead to barotrauma, VV ECMO can be considered. VV ECMO allows lung-protective ventilation strategies with lower pressures, reducing the risk of further barotrauma while ensuring adequate gas exchange.
3. Atelectrauma
Definition: Atelectrauma refers to lung injury that results from the repetitive opening and closing of alveoli during mechanical ventilation.
Example: In mechanical ventilation, if the applied positive end-expiratory pressure (PEEP) is too low, some alveoli may collapse at the end of expiration and then reopen with each breath. This repetitive opening and closing can cause shear stress and damage the alveolar walls. For instance, in a patient with ARDS, inadequate PEEP may lead to atelectrauma, exacerbating lung injury by promoting alveolar collapse and reopening with each breath cycle.
Reason for VV ECMO: When achieving optimal PEEP levels is difficult without causing further lung injury, VV ECMO can be utilized. By taking over the gas exchange function, VV ECMO allows for minimal ventilator settings, reducing the occurrence of atelectrauma and giving the lungs a chance to recover.
Summary
Volutrauma: Lung injury from excessive volume (overdistension of alveoli).
Barotrauma: Lung injury from excessive pressure (alveolar rupture).
Atelectrauma: Lung injury from repetitive opening and closing of alveoli.
In each case, VV ECMO is a crucial intervention to prevent further lung injury while ensuring adequate oxygenation and carbon dioxide removal in patients with severe respiratory failure.
Note: This article reflects my learning journey in ECMO and is intended for educational purposes only. It should not be used as a substitute for professional medical advice or guidance. Always consult with qualified healthcare professionals for clinical decisions and patient care.
Other Links:
Follow me on LinkedIn: Jonathan B. Jung, RRT-NPS
Follow me on X (Twitter) “ECMO 143-Stay Uptodate” List on X
Acknowledgments:
I developed three custom GPTs, “AI ECMO Expert,” “ECMO Specialist Handover Practice,” and “Micro Definitions (MD-GPT),” for specialized research. These tools draw primarily from the ELSO Redbook (6th Edition), the ELSO Specialist Training Manual (4th Edition), various research papers, and articles. Additional research was supported by GPT-4o/o1, Claude 3.5 Sonnet/Opus, and Perplexity. Editing was performed with Grammarly. A.I. images and charts were created using Leonardo AI, DALL-E3 AI Image Generator, Microsoft Designer, and Adobe Express. Content for all articles sourced from Extracorporeal Life Support: The ELSO Red Book, 6th Edition, and ECMO Specialist Training Manual, 4th Edition.