Electrolyte Disorders USMLE Step 1 Practice Question
A 19-year-old male runner collapses during a marathon after consuming 12 liters of hypotonic fluid over 4 hours. He presents with severe headache, confusion, and generalized seizures. Vital signs show BP 148/92, HR 102, RR 18, temp 37.2°C, SpO2 98%. Serum sodium is 112 mEq/L with normal potassium. Head CT shows no acute intracranial hemorrhage. He denies recent medication use. Which of the following is the most appropriate acute management?
Answer choices
- ADesmopressin to increase water reabsorption
- B3% hypertonic saline bolus of 2 mL/kg over 10-20 minutesCorrect answer
- CObservation and symptomatic treatment
- DLoop diuretics with normal saline
- EFree water restriction to 400 mL/day
- FHypotonic saline infusion at 1 mL/kg/hour until sodium reaches 120 mEq/L
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