Welcome to this month’s What’s Your Diagnosis Challenge!
But before we begin, check to see if you got the previous case on Emergency Department Management of Knee Pain correct.
Case Presentation: Sodium Disorders in the Emergency Department: A Review of Hypernatremia and Hyponatremia
A 93-year-old man with a history of dementia, diabetes, and hypertension arrives from a skilled nursing facility for confusion and weakness…
- The patient has had diarrhea and vomiting for the previous 4 days. Current medications include metformin, hydrochlorothiazide, lisinopril, and aspirin.
- His vital signs on arrival in the ED are: oral temperature, 38.7°C; heart rate, 114 beats/min; blood pressure, 86/53 mm Hg; respiratory rate, 24 breaths/min; and oxygen saturation, 94% on 3 L nasal cannula.
- On physical examination, he is cachectic, with dry oral mucous membranes, and is reportedly more confused than his baseline. His abdomen is soft and nontender, with no rebound or guarding. However, he does have an episode of nonbloody, nonbilious emesis during your examination.
- Blood is obtained, and a serum chemistry panel shows: sodium, 154 mEq/L; potassium, 3.9 mEq/L; chloride, 108 mEq/L; bicarbonate, 14 mEq/L; BUN, 55 mg/dL; creatinine, 2.0 mg/dL; and glucose, 112 mg/dL. The nurse asks you what IV fluids you want and how fast…
Case Conclusion
This patient had multiple medical concerns that required emergent evaluation. You diagnosed him with severe hypernatremia, likely secondary to his underlying disease processes, combined with a lack of access to free water. The patient had been having gastrointestinal losses from vomiting, along with his known underlying renal insufficiency.
On arrival, he was hypotensive and febrile. You immediately established 2 large-bore IVs, placed him on 2 L of oxygen via nasal cannula, and obtained a finger-stick blood glucose. After the pulmonary examination and confirmation of his past medical history, you corrected his hypoperfusion and hypovolemia with a 500-mL IV bolus of normal saline, followed by a second 500-mL IV bolus of normal saline for his persistent hypotension. You then began treatment of the underlying causes of his hypernatremia with antipyretics and antiemetics for his fever and vomiting.
After these interventions, his vital signs normalized, and slow correction of hypernatremia as an inpatient was initiated with 0.45% saline IV at 100 mL/hr over 48 hours.

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Last Updated on June 9, 2025