What is the recommended FiO2 for a patient with mild hypoxemia?

In the context of mild hypoxemia, which is typically defined as a saturation level (SpO2) of around 89-93%, the recommended fraction of inspired oxygen (FiO2) falls within the range of 24% to 40%. This moderate oxygen concentration is often sufficient to achieve an adequate arterial oxygen pressure (PaO2) and improve the patient's oxygenation without leading to potential complications associated with higher levels of supplemental oxygen.

Using an FiO2 higher than 40% may be unnecessary for mild hypoxemia and can lead to oxygen toxicity or other adverse effects, particularly in the long term. The goal is to provide just enough supplemental oxygen to alleviate hypoxemia while minimizing the risk of hyperoxia. Therefore, maintaining the FiO2 within the 24%-40% range is optimal for patients experiencing mild hypoxemia, as it balances effective treatment with safety considerations.