In field care, which statement best describes hypoxemia?

• A. High oxygen level.
• B. Oxygen saturation is unaffected by altitude.
• C. Low oxygen level with signs such as confusion or cyanosis.
• D. Oxygen saturation always normal in casualty.

Answer: (C)

Hypoxemia means there isn’t enough oxygen in the blood to meet the body's needs, and in field care you combine what you measure with how the patient looks. Describing it as a low oxygen level with signs such as confusion or cyanosis fits practical reality: when oxygen delivery drops, the brain can become confused or altered, and deoxygenated blood can produce a bluish tint in the lips or fingertips (cyanosis). The other ideas don’t fit because an elevated oxygen level is the opposite of hypoxemia; altitude can lower oxygen saturation, so saying saturation is unaffected by altitude isn’t true; and saturation isn’t guaranteed to be normal in a casualty who is hypoxemic.