Electrolyte Disorders USMLE Step 1 Practice Question
A 52-year-old man with severe alcoholism and malnutrition presents with weakness and respiratory difficulty five days after initiating parenteral nutrition support. Vital signs: BP 118/76 mmHg, HR 102 bpm, RR 22/min, temp 37.2°C, SpO2 98% on room air. Laboratory studies reveal serum phosphate 1.1 mg/dL (normal 2.5-4.5), with normal serum calcium and magnesium levels. Electrocardiogram shows no peaked T waves. Which complication is most likely if this electrolyte disturbance remains uncorrected?
Answer choices
- ACentral pontine myelinolysis
- BTorsades de pointes from delayed repolarization
- CNephrogenic diabetes insipidus
- DRespiratory muscle weakness and hemolysisCorrect answer
- EPseudogout due to calcium pyrophosphate deposition
- FHypercalcemia-induced acute kidney injury
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