The goal of selecting a specific oxygen concentration is to try to achieve clinically acceptable arterial oxygen tensions within which range?

• A. 40-80 mm Hg
• B. 80-110 mm Hg
• C. 50-120 mm Hg
• D. 60-100 mm Hg

Answer: (D)

Balancing oxygen delivery and safety is the key. The goal with inspired oxygen in ventilated patients is to keep arterial oxygen tension high enough to prevent tissue hypoxia but not so high that oxygen-related harm occurs. For most adults, a PaO2 in the range of about 60 to 100 mmHg achieves that balance. If PaO2 drops below 60, tissues can become hypoxic even if hemoglobin is normal. If PaO2 rises above 100, the risk of oxygen toxicity and unnecessary oxidative stress increases, and pushing oxygen higher often doesn’t improve tissue oxygen delivery. The normal healthy range is roughly 80–100 mmHg, so aiming for 60–100 keeps patients in a safe, effective zone.