During mechanical ventilation, how many days should FiO2 greater than 0.6 be limited to, to prevent oxygen toxicity?

The recommendation to limit the use of a fraction of inspired oxygen (FiO2) greater than 0.6 to 2 to 3 days is based on the risk of oxygen toxicity and its associated complications. Prolonged exposure to high levels of oxygen can result in cellular damage due to the formation of reactive oxygen species, leading to conditions such as acute respiratory distress syndrome (ARDS) or intrapulmonary shunting.

Keeping the duration of high FiO2 levels short, specifically within the range of 2 to 3 days, helps mitigate the risks associated with oxygen toxicity while still providing sufficient oxygenation to prevent hypoxemia. This approach aligns with clinical guidelines aimed at balancing adequate oxygen delivery to tissues while minimizing potential harm from oxygen therapy.

In critical care, clinicians often monitor and adjust oxygen therapy to maintain appropriate oxygen saturations without relying on high FiO2 for extended periods, thus ensuring patient safety and optimal outcomes.