What condition is suggested by a cyanotic patient with a normal pulse oximeter reading?

A cyanotic patient displaying bluish discoloration of the skin, particularly in areas like the lips and fingertips, alongside a normal pulse oximeter reading, strongly suggests carbon monoxide poisoning. This is because carbon monoxide binds to hemoglobin more readily than oxygen, forming carboxyhemoglobin. The presence of carbon monoxide in the bloodstream can lead to inadequate oxygen delivery to the tissues, resulting in symptoms such as cyanosis.

Pulse oximeters are unable to differentiate between oxyhemoglobin and carboxyhemoglobin, which is why the readings might indicate normal oxygen saturation levels despite the patient's cyanosis. Therefore, the normal pulse oximetry result does not negate the presence of carbon monoxide poisoning, making it a critical and potentially life-threatening condition that needs immediate attention.

Other conditions like severe pulmonary edema or cold extremities can also cause cyanosis, but they would typically show varying readings on a pulse oximeter, reflecting issues with ventilation or perfusion that would affect oxygenation. Increased body temperature does not directly relate to cyanosis and would not explain the pulse oximeter reading. Hence, carbon monoxide poisoning is the most fitting explanation for the symptoms observed.