Diffusion hypoxia is a safety concern associated with nitrous oxide when:

Diffusion hypoxia is a safety concern associated with nitrous oxide when:

• A. It occurs when nitrous oxide rapidly diffuses into alveoli after discontinuation, diluting inspired oxygen
• B. It occurs when nitrous oxide diffuses into the blood
• C. It never occurs
• D. It occurs only with chronic use

Answer: (A)

Diffusion hypoxia happens because nitrous oxide, after you stop delivering it, rapidly moves from the blood back into the alveoli. Nitrous oxide is poorly soluble in blood, so it equilibrates quickly, and once the gas flow is discontinued, N2O diffuses into the alveolar air more quickly than oxygen can re-equilibrate. This influx of N2O dilutes the alveolar oxygen concentration, leading to decreased inspired O2 and potential hypoxemia. Giving 100% oxygen at the end of nitrous oxide use helps wash out the remaining N2O and prevent this temporary drop in oxygenation.

Diffusion hypoxia happens because nitrous oxide, after you stop delivering it, rapidly moves from the blood back into the alveoli. Nitrous oxide is poorly soluble in blood, so it equilibrates quickly, and once the gas flow is discontinued, N2O diffuses into the alveolar air more quickly than oxygen can re-equilibrate. This influx of N2O dilutes the alveolar oxygen concentration, leading to decreased inspired O2 and potential hypoxemia. Giving 100% oxygen at the end of nitrous oxide use helps wash out the remaining N2O and prevent this temporary drop in oxygenation.