Case #1

An 85 year-old male presents to the emergency room with pneumonia. He has been febrile for several days and has had a cough productive of yellow sputum.

On physical exam he is a well-developed, thin male in moderate respiratory distress. Blood pressure (supine) 120/86, pulse 74, blood pressure (standing) 115/85, pulse 70, respirations 24 and labored. Temperature was 39oC. Bodyweight 60 kg. HEENT exam was unremarkable. Cardiopulmonary exam demonstrated decreased breath sounds at the base of the right lung. The remainder of the exam was within normal limits.

Laboratory Data

Chemistry 

 . Normal Values  Urine

Sodium 

 120  136-146 mmol/L  Sodium 60 mmol/L
Potassium 30 mmol/L
Osmolality 500 mosm/kg
Potassium  3.9  3.5-5.3 mmol/L 
Chloride  87  98-108 mmol/L 
Total CO2   24  23-27 mmol/L

BUN 

 10  7-22 mg/dl
Creatinine  0.8  0.7-1.5 mg/dl

Glucose 

 90  70-110 mg/dl
  1. Define hyponatremia?   Answer
  2. Is hyponatremia synonymous with hypo-osmolality?   Answer
  3. Calculate the serum osmolality in this patient?   Answer
  4. What is pseudohyponatremia and what conditions cause it?   Answer
  5. What is the cause of hyponatremia in this patient?  Answer
     
  6. Based on what criteria was this diagnosis made?   Answer
  7. What is the total body sodium in this patient?   Answer
  8. If furosemide is administered how will it change the urinary composition? Answer