After being discovered unresponsive in her apartment, a 20-year-old woman is brought to the emergency department by her boyfriend. She has a history of major depression as well as generalized anxiety disorder. There is no indication of trauma. The patient is obtunded on examination and responds only to painful stimuli. There is no evidence of recent vomiting. Auscultation reveals that the lungs are clear. A toxicology screen revealed that benzodiazepines were present. Which of the following sets of arterial blood gas findings (in mm Hg) are most likely present in this patient?

Question

Quizplus · Accepted Answer

Eductional Objective: Acute benzodiazepine overdose (e.g., alprazolam, lorazepam) results in central respiratory depression and hypoventilation. Hypoventilation causes CO₂ retention as well as acute respiratory acidosis. It also reduces PAO₂, resulting in hypoxemia (PaO₂ 75 mm Hg). Because gas transfer efficiency between the lungs and the circulation is intact, a normal alveolar-arterial O₂ gradient (eg, 15 mm Hg) is expected.

After Being Discovered Unresponsive in Her Apartment, a 20-Year-Old Woman