The Hidden Risks of Mechanical Ventilation: A Closer Look at Ventilator-Induced Lung Injuries

Mechanical ventilation is a critical intervention in intensive care units, especially during the COVID-19 pandemic. While it saves lives by providing respiratory support to patients with respiratory failure, improper use can lead to severe lung injuries.

Mechanisms of Ventilator-Induced Lung Injury

One of the primary mechanisms of damage is atelectrauma, which occurs when alveoli repeatedly collapse and reopen during mechanical ventilation. This cycle creates significant mechanical stress, similar to "micro-explosions," leading to inflammation and tissue damage. This phenomenon has been observed in experimental models and is considered a major cause of acute lung injury. (scielo.org.mx)

In addition to atelectrauma, other types of ventilator-induced lung injuries include:

• Barotrauma: Damage caused by excessive airway pressures, leading to pneumothorax and interstitial emphysema.
• Volutrauma: Injury resulting from high tidal volumes that cause alveolar overdistension.
• Biotrauma: Systemic inflammatory response due to the release of inflammatory mediators triggered by lung damage.
• Reotrauma: Injury caused by rapid gas flow during ventilation, generating shear forces in lung tissue.

These mechanisms can interact and worsen lung damage, increasing the risk of acute respiratory distress syndrome (ARDS).

Impact of Mechanical Ventilation During the COVID-19 Pandemic

During the COVID-19 pandemic, mechanical ventilation became essential for treating patients with severe respiratory failure. However, a significant proportion of these patients developed ARDS while on ventilatory support. This highlights the importance of using protective ventilation strategies to minimize ventilator-induced lung injury.

Strategies to Minimize Lung Damage

To reduce the risk of ventilator-induced lung injuries, several protective strategies have been developed:

• Low tidal volume ventilation: Using smaller tidal volumes (6 ml/kg of ideal body weight) to prevent alveolar overdistension.
• Appropriate application of PEEP (Positive End-Expiratory Pressure): Keeping alveoli open to prevent cyclic collapse.
• Limiting plateau pressure: Keeping alveolar pressure below 30 cm H₂O to reduce the risk of barotrauma.
• Using alveolar recruitment maneuvers: Applying techniques to reopen collapsed alveoli in a controlled manner.

Implementing these strategies has been shown to reduce mortality and complications associated with ARDS.

Conclusion

Although mechanical ventilation is a lifesaving intervention for critically ill patients, recognizing and mitigating its potential risks is essential. Protective ventilation strategies and close monitoring can help minimize ventilator-induced lung injuries, improving clinical outcomes and patient quality of life.