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  3. Hyperosmolar Hyperglycaemia State (HHS)

Hyperosmolar Hyperglycaemia State (HHS)

JBDS 06 The management of the hyperosmolar hyperglycaemic state (HHS) in adults with diabetes

Diagnosis Guidelines

JBDS states that no precise definition has been agreed but lists the following characteristic features (ALL must be present):
  • Hypovolaemia (marked)
  • Osmolality ≥320 mOsm/kg
  • Hypergylcaemia (glucose ≥30 mmol/L)
  • NO ketonaemia (≤3.0 mmol/L)
  • NO acidosis (pH ≥7.3 or serum bicarbonate ≥15 mmol/L)
 
 

Note that a mixed picture of HHS and DKA occurs relatively frequently.

Management Guidelines

Just like in DKA, fluid replacement to rehydrate the patient is the FIRST PRIORITY in HHS management to restore circulatory volume and stabilise the patient.

Initial fluid regimen: IV 0.9% NaCl - 1L over 1 hour

Other considerations:

  • Maintain potassium in normal ranges (depending on serum potassium concentrations)
    • >5.5 mmol/L → no potassium replacement needed
    • 3.5-5.5 mmol/L → give 40 mmol/L potassium in infusion solution
    • <3.5 mmol/L → seek senior review (as additional potassium is required)
 
  • Prevent hypoglycaemia
    • If blood glucose falls <14 mmol/L → add 5% or 10% glucose at 125 mL/hr in addition to the running fluids
 
 

If the potassium delivery rate exceeds 20 mmol/hour, continuous cardiac monitoring is required.

Such that if 40 mmol/L of potassium replacement is indicated in the 2nd or 3rd bag of fluids, that corresponds to 20 mmol/hour as these fluids are 1L given over 2 hours. These patients would require cardiac monitoring.

Insulin should NOT be started as part of the initial treatment, it should only be started once fluid replacement is adequate and serum glucose has plateaued

  • Commence FRIIIFixed rate intravenous insulin infusion at 0.05 units/kg/hr
  • Only increase to 0.1 units/kg/hr if glucose concentration is not falling
 
 

If the HHS patient also meets the DKA criteria (blood ketones >3.0 mmol/L or urine ketones 2+ or more AND venous pH <7.3 and/or bicarbonate <15 mmol/L), JBDS guidelines recommend starting insulin infusion immediately following DKA protocol (FRIII 0.1 units/kg/hr).

This is of course, only after fluids have been started and are running. Again, important to emphasise that for both HHS and DKA, fluid replacement is the FIRST PRIORITY.

All HHS patients should receive prophylactic LMWHLow molecular weight heparin for the full duration of admission unless contraindicated.

The main parameter to monitor is serum osmolality [(2 x Na+) + glucose + urea]

References

Author: Adams Lau
Reviewer:
Last edited: 14/08/25