How is nitrous oxide eliminated from the body?

Nitrous oxide is primarily eliminated from the body through the lungs, making rapid expulsion a key characteristic of its pharmacokinetics. After the administration of nitrous oxide, it diffuses out of the bloodstream and is expelled from the body via exhalation. This process can occur within minutes, as nitrous oxide has a low solubility in blood, allowing it to quickly enter and exit the bloodstream. This rapid elimination contributes to the effective management of sedation and allows patients to recover quickly after the use of nitrous oxide in dental procedures.

The other options suggest slower elimination processes or other organs that do not play a primary role in the clearance of nitrous oxide. Option A incorrectly implies that elimination occurs slowly through the kidneys, which is not the case for this particular anesthetic. Option C suggests metabolic processing in the liver, which does not significantly occur with nitrous oxide. Finally, option D points to elimination through the gastrointestinal tract, which is not applicable for this type of gas. Therefore, the most accurate description of how nitrous oxide is eliminated from the body is through rapid expulsion from the lungs within minutes.