In the context of brachycephalic patients, what is the primary purpose of preoxygenation before sedation?

• A. To shorten the overall procedure time.
• B. To optimize patient comfort during recovery.
• C. To prevent hypoxemia during airway compromise.
• D. To diagnose airway obstruction using imaging.

Answer: (C)

The main idea is to prevent hypoxemia during airway compromise by building an oxygen reserve in the lungs before sedation. Brachycephalic patients have narrow airways and sedation can cause loss of tone and obstruction, so if the airway becomes momentarily blocked, you have more oxygen available to keep blood oxygen levels up. Preoxygenation fills the lungs with high‑concentration oxygen (displacing nitrogen) to extend the time you can safely wait before desaturation occurs, buying you a critical margin to secure the airway or ventilate. It’s not about shortening procedure time, comfort during recovery, or imaging-based diagnosis.