Osmolality Lab Values

Normal 261 – 280 mOsm/kg

Indications

• Monitor:
  • Electrolyte balance
  • Acid-Base balance
  • Hydration
• Evaluate function of antidiuretic hormone.

 

Description Osmolality is a measure of the particles in solution. The size, shape, and charge of the particles do not impact the osmolality

 

What would cause increased levels?

• Dehydration
• Azotemia
• Hypercalcemia
• Hyperglycemic Hyperosmolar Nonketotic State (HHNS)
• Hypernatremia
• Diabetes Insipidus
• Hyperglycemia
• Mannitol therapy
• Uremia
• Severe pyelonephritis
• Shock
• Ketosis

 

What would cause decreased levels?

• Hyponatremia
• Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
• Overhydration