In the described pulmonary embolism case, which sign was observed?

• A. Dried blood around the mouth
• B. Facial cyanosis
• C. Arterial blood gas showing high pCO2
• D. No signs of distress

Answer: (B)

When a pulmonary embolism significantly hinders oxygen transfer in the lungs, the body often shows signs of inadequate oxygenation. Facial cyanosis is a visible cue that oxygen levels in the blood are dropping, which is why it’s the clearest and most relevant sign in this context. It directly reflects the patient’s distressed oxygen status.

The other options don’t fit as well. Dried blood around the mouth isn’t a typical sign of a PE and would point to trauma or another issue. An arterial blood gas with a high pCO2 would suggest poor ventilation, but in acute PE patients the common pattern is reduced oxygen with either normal or low CO2 because many patients hyperventilate in response to the hypoxemia. And no signs of distress would be inconsistent with the usual presentation of PE, which commonly involves shortness of breath and increased work of breathing.