Nitrous oxide is described as a form of moderate sedation that uses which route?

• A. Intravenous
• B. Subcutaneous
• C. Pulmonary
• D. Transdermal

Answer: (C)

Nitrous oxide is given by inhalation, so its route is pulmonary. It is delivered as a gas through a nasal hood or mask and is absorbed through the lungs into the bloodstream, allowing rapid onset and easy titration of sedation. Its effects wear off quickly once inhalation stops because it is eliminated by the lungs. This is why other routes like intravenous, subcutaneous, or transdermal don’t apply to nitrous oxide—those are systemic or local delivery methods, not how this gas is administered. For safety, it is used as a mixture with oxygen to avoid diffusion hypoxia after discontinuation.