What might occur if a patient under nitrous oxide is returned directly to room air instead of 100% oxygen?

Administering nitrous oxide for sedation has specific protocols to ensure patient safety. When nitrous oxide is used, it can create a state of hypoxia upon discontinuation if the patient is returned directly to room air. This occurs due to the potential for diffusion hypoxia, which is a condition where nitrous oxide rapidly diffuses out of the bloodstream and into the lungs, displacing oxygen. The sudden release of nitrous oxide can lead to decreased levels of oxygen in the bloodstream, causing symptoms such as confusion, dizziness, and in severe cases, hypoxic effects that could impair the patient’s oxygenation and overall wellness.

To prevent diffusion hypoxia, it's standard practice to administer 100% oxygen to the patient for a short period following the termination of nitrous oxide sedation. This practice helps to flush out the nitrous oxide more effectively from the body and replenish oxygen levels. Failing to do so could cause the patient to experience the adverse effects associated with insufficient oxygen, thus illustrating why the correct answer focuses on diffusion hypoxia as a concern when a patient is not returned to an oxygen-rich environment after nitrous oxide sedation.