In the immediate postoperative period, which patient requires a nasal cannula or simple face mask?

In the immediate postoperative period, a patient requiring a fractional inspired oxygen (FiO2) of 0.4 or less indicates that they can maintain adequate oxygen saturation levels with relatively low supplemental oxygen needs. A nasal cannula or simple face mask can effectively deliver this level of oxygen. These devices are generally appropriate for patients who do not need high levels of oxygen support, allowing for easier and more comfortable delivery of oxygen, especially in a postoperative setting where patients might be more amenable to less invasive modalities.

In contrast, patients requiring FiO2 of 0.5 or more typically need more robust oxygen delivery systems, such as a non-rebreather mask or high-flow oxygen therapy, to meet their respiratory demands. When there is a presence of respiratory distress or indications that a patient is not able to maintain adequate oxygenation on their own, more intensive measures for oxygen delivery may be necessary. Thus, while options related to respiratory distress and those with chest tubes may also necessitate careful consideration of oxygen needs, the focus on the specific FiO2 requirement of 0.4 or less as an appropriate indication for simple oxygen delivery makes this choice the most fitting.