[Hyperoxia-induced pulmonary toxicity].

Area of Science:

• Critical Care Medicine
• Pulmonology
• Biomedical Engineering

Context:

• Mechanical ventilation, while life-saving, presents risks including ventilator-induced lung injury (VILI) and multi-organ failure.
• Alveolar hyperoxia, or excessive oxygen in the alveoli, is a proposed mechanism contributing to VILI.
• Existing human data on hyperoxia's direct impact on VILI is less conclusive than experimental models.

Purpose:

• To review the mechanisms by which mechanical ventilation and associated high oxygen levels (hyperoxia) may cause lung damage.
• To examine the evidence for hyperoxia's role in VILI and multi-organ failure in human patients.
• To highlight the association between oxygenation parameters and mortality in critically ill patients.

Summary:

• Experimental models show hyperoxia induces oxidative stress, inflammation, and cell death, contributing to lung damage.
• In humans, high fraction of inspired oxygen (FiO2) and resulting partial arterial oxygen pressure (PaO2) are linked to worse outcomes and increased lung de-recruitment.
• Both FiO2 and PaO2 levels within the first 24 hours of admission correlate with patient mortality.

Impact:

• Findings underscore the need for careful oxygen management in mechanically ventilated patients to mitigate potential harm.
• The association between oxygenation and mortality emphasizes the clinical relevance of monitoring and adjusting oxygen therapy.
• Calls for clinical trials to establish safe oxygen thresholds (FiO2 and oxygen saturation) are crucial for optimizing patient care and reducing adverse events.