Hyperosmolar Syndrome



  • Results from a relative insulin deficiency in the undiagnosed or untreated diabetic
  • Sustained hyperglycemia creates an osmotic diuresis and dehydration:
    • Extracellular space maintained by the osmotic gradient at the expense of the intracellular space
    • Eventually profound intracellular dehydration occurs
  • Total body deficits of H2O, Na+, Cl, K, PO4, Ca2+, and Mg2+
  • In contrast to diabetic ketoacidosis (DKA), severe ketoacidosis does not occur:
    • Circulating insulin levels are higher
    • The elevation of insulin counter-regulatory hormones is less marked
    • The hyperosmolar state itself inhibits lipolysis (the release of free fatty acids) and subsequent generation of keto acids

Geriatric Considerations
  • Most commonly seen in elderly type II diabetics who experience a stressful illness that precipitates worsening hyperglycemia and reduced renal function
  • In the elderly, 30–40% of cases are associated with the initial presentation of diabetes

Pediatric Considerations
Hyperosmolar hyperglycemic states (HHS) rare in pediatric patients


  • Hyperosmolar state precipitated by factors that:
    • Impair peripheral insulin action
    • Increase endogenous or exogenous glucose
    • Decrease patient's ability to replace fluid loss
  • Infection (esp pneumonia and UTI) most common precipitating factor
  • Other precipitating causes include:
    • Inadequate therapy/medication omission
    • Sepsis
    • Medications/drugs:
      • Diuretics
      • β-blockers
      • Calcium channel blockers
      • Atypical antipsychotics
      • Corticosteroids
      • Sympathomimetics
      • Phenytoin
      • Cimetidine
      • Amphetamines
      • Ethanol
    • Myocardial infarction
    • CVA
    • Renal failure
    • Heat stroke
    • Pancreatitis
    • Appendicitis
    • Intestinal obstruction
    • Endocrine disorders
    • Pregnancy
    • Trauma
    • Burns

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