Clinical Reasoning: An 87-year-old man with chronic obstructive pulmonary disease and acute encephalopathy

An 87-year-old man with diastolic heart failure, coronary artery disease, TIAs, chronic obstructive pulmonary disease (COPD), hypothyroidism, chronic kidney disease, aplastic anemia, and benign prostatic hypertrophy with chronic indwelling catheter was transferred to the neurocritical care unit for acute encephalopathy. The patient initially presented to an outside facility with progressive lethargy evolving over 12 hours from a fully functional baseline. At the outside hospital, he was febrile (103.7°F) and hypotensive (62/40 mm Hg), without leukocytosis (white count 5.6 K/μL) but with urinalysis demonstrating evidence of infection. Empiric IV vancomycin and cefepime were started. CT scan of the chest, abdomen, and pelvis was unrevealing of an infectious source. MRI of the brain was also unremarkable. His mental status declined further over the following 4 days, prompting an EEG that revealed generalized periodic discharges (GPDs). The patient was treated with levetiracetam and transferred to our hospital out of concern for nonconvulsive status epilepticus (NCSE). Upon arrival to the neurocritical care unit, physical examination revealed persistent hypotension (79/44 mm Hg) that responded well to IV fluids without vasopressors and a Glasgow Coma Scale score of 8 with eyes opening to noxious stimulus only. He was mumbling unintelligible words and withdrew all 4 limbs antigravity to pain.