Hyperosmolar hyperglycaemic state

Non-ketotic hyperglycaemia (Hyperosmolar Hyperglycaemic State - HHS)

• Severe hyperglycaemia without ketosis
• Typically occurs in patients with T2DM who have enough endogenous insulin to prevent ketogenesis, but not enough to maintain normoglycaemia (BSL >30-50)
• Usually precipitated by infection, MI, stroke or trauma
• Glycosuria is marked, and the resulting osmotic diuresis results in hypovolaemia
• The combination of hyperglycaemia and hypotonic fluid loss produces a considerable increase in plasma osmolality
• Plasma sodium is an unreliable marker of ECV because of the dilutional effect of hyperglycaemia
• For every increase by 5 of the BSL above 5, the plasma sodium concentration will decrease about 2mEq/L
• Mortality rate is higher than in DKA!
• Presentation
  • BSL > 30-50
  • Minimal ketosis
  • Hypovolaemia
  • Precipitating event
  • Obtundation occurs more frequently with HHS than DKA, because of the higher degree of hyperosmolality
• Management
  • Aggressive IVF resuscitation with isotonic fluids - 1-2L in first hour, guided by usual metrics
  • Withhold insulin until vascular volume is restored (insulin draws both glucose and water into cells, so can aggravate hypovolaemia)
  • Insulin requirement will decrease as the hypertonic condition is corrected - monitor BSL closely