A 78-year-old female resident of a nursing home is found by staff to be lethargic, disoriented, and incontinent of urine. She has a history of dementia and frequent urinary tract infections. Her temperature is 101.5°F (38.6°C), HR 98 bpm, BP 100/70 mmHg, RR 20 breaths/min. Her blood glucose is 120 mg/dL. What is the MOST likely cause of her altered mental status?
- ADehydration
- BHypoglycemia
- CAcute stroke
- DSepsis secondary to UTI
Show answer & explanationAnswer & explanation
Correct answer: D. Sepsis secondary to UTI
Elderly patients, especially those with dementia, often present atypically with infections. Altered mental status, lethargy, and disorientation, combined with a low-grade fever and a history of frequent UTIs, are highly suggestive of sepsis originating from a urinary tract infection, rather than classic signs of infection. Hypoglycemia and stroke are less likely given the blood glucose and stable vital signs (though BP is borderline).
Why the other options are wrong
- A. Dehydration could contribute to altered mental status, but the fever points more strongly towards an infectious process like sepsis, especially with a history of UTIs.
- B. Hypoglycemia is ruled out by the blood glucose of 120 mg/dL.
- C. While possible, the lack of focal neurological deficits makes acute stroke less likely as the primary cause for generalized lethargy/disorientation.
Sepsis in Elderly
Sepsis in elderly patients often presents atypically with subtle signs like altered mental status, confusion, and generalized weakness, rather than classic fever and chills, making early recognition challenging.
- Altered mental status is a common early sign of sepsis in the elderly.
- Low-grade fever or even hypothermia can occur.
- Urinary tract infections are a common source of sepsis in this population.
Memory trick: Old, confused, and febrile? Think infection!