Hyperosmolar Hyperglycaemic State (HHS)

HHS (A.K.A. HONK) is a diabetic emergency, but unlike DKA we don’t always think about it.

Patients with HHS are often elderly with multiple co-morbidities, and they are always very sick.


  • Hypovolaemia
  • Hyperglycaemia – generally ≥30mmol/l
  • High Osmolality – generally ≥320mosmol/kg (Calculation= 2[Na] + [Glucose] + [Urea])
  • & NOT:
    • Acidotic – pH >7.3, HCO3 >15mmol/l
    • Ketotic – blood <3mmol/l, Urine <2+



  • Mainstay of treatment
  • Target 2-3l in the first 6 hrs – Initial 1l NaCl 0.9% over 1hr, then 0.5-1l/hr
    • May need to be quicker if SBP <90mmHg
    • May need to be cautions in renal OR cardiac failure patients
  • Glucose fall – >5mmol/l per hr


  • Only start if – Evidence of DKA, OR glucose falling by <5mmol/l per hr
  • 0.05unit/kg/hr – consider increase to 0.1unit/kg/hr if glucose falling by <5mmol/l per hr
  • Avoid hypoglycaemia – target 10-15mmol/l


  • [K] >5.5mmol/l – no added potassium
  • [K] 3.5-5.5mmol/l – Start KCL 40mmol/l infusion (max 10mmol/hr)
  • [K] <3.5mmol/l – Senior review


  • Patients at high risk thrombosis
  • Commence prophylactic LMWH – unless contraindicated

PDF: HSS guide

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