General anesthesia typically uses how much oxygen supplementation?

• A. 100%
• B. 50%
• C. 0%
• D. 25%

Answer: (A)

General anesthesia aims to prevent desaturation by delivering a high fraction of inspired oxygen, since airway management and controlled ventilation can be interrupted and the patient’s own breathing is suppressed. Providing 100% oxygen ensures the maximum amount of oxygen is available in the lungs and bloodstream, giving a safety margin during induction, periods of apnea, and any brief ventilation inefficiencies. While long-term use of 100% oxygen isn’t ideal due to risks like oxygen toxicity and atelectasis, the typical approach during induction and early maintenance is to use full oxygen supplementation, making it the best choice among the options. The other levels deliver substantially less oxygen, increasing the risk of hypoxemia during these critical moments.