2) A 70-year-old woman presents with complaints of headache, chest pain, and weakness that began a few hours earlier. She has a past medical history of hypertension and diabetes mellitus. Her medications include lisinopril and metformin. She lives alone, and family members have noted her to be more confused over the last 6 months. On exams, she appears uncomfortable and anxious. Her vitals are oxygen saturation at 90%, respiratory rate 22 breaths/minute, blood pressure 98/70 mmHg, heart rate 96 bpm, and she is afebrile. She is forgetful and disoriented. The remainder of her exam is unremarkable. What is the most likely cause of her pulse oximeter reading?
