A patient has Na⁺ 133 mmol/L, glucose 180 mg/dL and urea (BUN) 42 mg/dL. What is the calculated serum osmolality (mOsm/kg)? Use .
Answer and explanation
Correct answer: D. 291 mOsm/kg
- Step 1: Sodium contributes ; glucose ; urea .
- Step 2: Total mOsm/kg.
Answer
291 mOsm/kg.
Why not the others: 266 mOsm/kg: Glucose and urea were left out. 158 mOsm/kg: Sodium was not doubled. 488 mOsm/kg: The conversion factors were ignored.
Practise more Internal Medicine and Clinical Therapeutics.
Free questions with an explanation for every one, and full timed Jordanian Medical Licensing Examination (JMLE) mock tests.
More Internal Medicine and Clinical Therapeutics questions
- A 58-year-old male with long-standing type 2 diabetes presents for routine follow-up. Blood pressure is 148/92 mmHg, and urine albumin-to-cr…
- A 65-year-old female presents to the emergency department with acute crushing substernal chest pain radiating to her left arm. ECG demonstra…
- A 42-year-old male presents with fatigue, cold intolerance, constipation, and a 5 kg weight gain over 3 months. Laboratory testing reveals a…
- A 30-year-old female presents with acute shortness of breath and right-sided pleuritic chest pain 5 days after returning from a 12-hour inte…
- A 72-year-old male with chronic atrial fibrillation is evaluated for stroke risk. He has a history of hypertension, type 2 diabetes, and a p…
- A 24-year-old university student is brought to the hospital with a 1-day history of high fever, severe headache, photophobia, and neck stiff…