A 30-year-old patient requires rapid sequence induction for emergency surgery. The anesthesiologist performs preoxygenation with 100% oxygen. How long does it take with normal tidal volume breathing to achieve adequate denitrogenation?
- A 1 minute
- B 3 minutes ✓
- C 5 minutes
- D 10 minutes
Correct answer: B. 3 minutes
Explanation
With normal tidal volume breathing of 100% oxygen, denitrogenation is achieved in approximately 3 minutes. This replaces the nitrogen in the functional residual capacity with oxygen, creating an oxygen reservoir that prolongs the safe apnea time. Eight vital capacity breaths in 60 seconds is an alternative method that achieves similar denitrogenation more rapidly.
Reference: Miller's Anesthesia, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.