For how long can a patient safely be on 100% FiO2 during mechanical ventilation?

When a patient is on 100% FiO2 during mechanical ventilation, the primary concern is the risk of oxygen toxicity and the adverse effects associated with prolonged exposure to high concentrations of oxygen. Prolonged exposure to 100% oxygen can lead to pulmonary toxicity, which may result in inflammatory responses and damage to the alveolar-capillary membrane.

The guidelines suggest that patients can typically be maintained on 100% FiO2 for approximately 24 hours without significant risk of developing oxygen toxicity. This timeframe allows for adequate oxygenation of tissues while minimizing the potential adverse effects of prolonged oxygen exposure. Beyond this duration, the risks increase, necessitating monitoring and potential adjustments to FiO2 levels, typically aiming to maintain the lowest FiO2 that can achieve adequate oxygenation and ventilation.

This understanding highlights the importance of balancing the need for oxygen therapy with the risks associated with it, guiding clinicians in their management of patients requiring mechanical ventilation.