Management of Hyperglycaemic Hyperosmolar State (HHS) 

The complex pathophysiology and management of HHS means that level 2 care is usually the most appropriate, with early input from specialist inpatient Diabetes Team via TrakCare.

Diagnosis criteria for HHS

  • Laboratory glucose >30mmol/L
  • Serum osmolality >320mosmol/kg [calculate serum osmolality: 2(Na+ + K+) + glucose + urea]
  • Venous blood gas [H+] <50nmol/L
  • Venous bicarbonate >15mmol/L 
  • Capillary blood ketones <3mmol/L (urine ketones <3+).


The NHSGGC guideline and care pathways on the management of HHS can be found here on the NHSGGC Clinical Guidelines Platform. It covers:

  • Five headline concepts to consider: 
    • Correct diagnosis - differentiating between HHS and diabetic ketoacidosis
    • Appropriate IV fluids to use
    • Insulin - when to commence it and at what rate
    • Treatment target ranges
    • Other issues - electrolytes, anticoagulation, co-presenting illness, pressure ulcer risk.
  • Care pathway 1: 0–6 hours of HHS management
  • Care pathway 2: >6hours – resolution
  • Appendix A - when to start fixed rate insulin.


Guideline reviewed: May 2023

Page updated: October 2023