A 35-year-old man who passed out in his garage is taken to the emergency room. He recently acquired a vintage 1960s convertible, which he was restoring when he passed out. The garage door was partially open when the patient was inside. After two hours of working on the automobile with the engine running, he passed out. The patient does not use any drugs and has no known medical conditions. He doesn't consume any alcohol, tobacco, or illegal substances. What combination of results from an arterial blood sample collected when the patient lost consciousness best reflects the rest of the options?

Question

Quizplus · Accepted Answer

Eductional Objective: Carbon monoxide (CO) binds to hemoglobin with much higher affinity than oxygen, thereby preventing oxygen binding to hemoglobin.  It also reduces oxygen unloading from hemoglobin in the tissues.  CO poisoning increases carboxyhemoglobin concentrations but does not affect the partial pressure of oxygen and does not precipitate methemoglobinemia.

A 35-Year-Old Man Who Passed Out in His Garage Is