Collect SST, send 2 mL.
Alternate sample: Red top or Green top Heparin
Freezing point depression
Room temp: 14 days, Refrigerated: 14 days, Frozen: 14 days
Evaluate electrolyte and water balance, hyperosmolar status, and hydration status; evaluate dehydration, acid-base balance; evaluate seizures; clue to alcoholism, methanol toxicity, ethylene glycol ingestion; evaluate antidiuretic hormone function, liver disease, hyperosmolar coma, evaluate hypernatremia. Osmolarity measures the concentration of particles in solution.