A 64-year-old woman is brought to the emergency department after her husband found
her obtunded. He also found open medication bottle of amitriptyline at her
bedside. She has a long history of chronic lower back pain and insomnia for
which she is taking zolpidem, naproxen, and amitriptyline. Her husband reports
that she has appeared depressed recently, but she did not seek any help. She
has no known cardiac history or history of a stroke. In the emergency department,
she is lethargic but arousable.
Her temperature is 36.7 C (98 F), blood pressure is 95/45 mm Hg, and pulse is 106/min.
Her oxygen saturation is 94% on room air. Heart sounds are normal. Lungs are
clear. She moves all extremities on command.
Which of the following would impact the further treatment of this patient the most?