If your patient's skin color is cyanotic, you should suspect?

• A. Hypocarbia.
• B. DNA abnormalities.
• C. Hypovolemia.
• D. Deoxyhemoglobin.

Answer: (D)

Cyanosis shows up when there is more deoxygenated hemoglobin in the blood, meaning the blood’s oxygen content is low. The blue tint comes from deoxyhemoglobin, so the skin and mucous membranes appear cyanotic when oxygen saturation falls. That makes deoxyhemoglobin the best fit for why a cyanotic patient would be suspected of having low oxygen levels.

The other ideas don’t explain the color change. Hypocarbia is about low carbon dioxide, not oxygen content. DNA abnormalities aren’t related to the skin’s color in this context. Hypovolemia affects circulation and perfusion, which can alter skin color in other ways, but the hallmark cyanosis specifically points to elevated deoxygenated hemoglobin.