A patient has Na⁺ 128 mmol/L, glucose 180 mg/dL and urea (BUN) 14 mg/dL. What is the calculated serum osmolality (mOsm/kg)? Use .
Answer and explanation
Correct answer: B. 271 mOsm/kg
- Step 1: Sodium contributes ; glucose ; urea .
- Step 2: Total mOsm/kg.
Answer
271 mOsm/kg.
Why not the others: 256 mOsm/kg: Glucose and urea were left out. 143 mOsm/kg: Sodium was not doubled. 450 mOsm/kg: The conversion factors were ignored.
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