Hyperglycemic hyperosmolar state
ICD-10 E14.0 · ICD-11 5A20

HHS with Significant Ketonaemia and Acidosis: Managing a Mixed DKA/HHS Presentation

This protocol addresses patients presenting with the full clinical picture of hyperglycemic hyperosmolar state who simultaneously meet criteria for significant ketonaemia or ketonuria with metabolic acidosis — a mixed DKA/HHS state that requires immediate, structured intervention on both biochemical axes.

Clinical scenario

Defining features

  • Marked hypovolaemia and marked hyperosmolality
  • Serum osmolality at least 320 mOsm/kg and blood glucose at least 30 mmol/L
  • Significant ketonaemia (3β-hydroxybutyrate above 3.0 mmol/L) or ketonuria (2+ or greater)
  • Venous pH below 7.3 and bicarbonate below 15 mmol/L

The simultaneous presence of marked hyperosmolality and significant ketoacidosis defines this as a mixed DKA/HHS state. Management must address both components concurrently.

Treatment approach

Overview — partial

Management follows the DKA pathway and centres on immediate intravenous fluid resuscitation combined with a fixed-rate intravenous insulin infusion commenced without delay. Venous thromboembolism prophylaxis with low molecular weight heparin is maintained throughout the full duration of admission, alongside regular foot surveillance.

The complete structured regimen — including fluid volumes, infusion rates, electrolyte replacement criteria, and step-by-step monitoring — is available in the full protocol below.

Clinical goals

Treatment targets

The immediate aim is to achieve a positive fluid balance in the first twelve hours alongside clearance of blood ketones. Full biochemical normalisation may take considerably longer.

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References

  1. If there is significant ketonaemia (3β-hydroxybutyrate >3.0 mmol/L) or ketonuria (≥ 2+) with a pH <7.3 and bicarbonate <15 mmol/L (i.e. mixed DKA and HHS) and use the DKA guideline at 0.1 units/kg/hr
  2. Treat as mixed DKA/HHS if the following is criteria are met. Start FRIII and IV fluids immediately and treat according to DKA pathway using 0.1 units/kg/hr
  3. Commence IV fluids and FRIII of 0.1 units/kg/hr
  4. IV fluid replacement should aim to achieve a positive balance of 3-6 litres during the first 12 hours and the remaining replacement of estimated fluid loss during the following 12 hours, although complete normalisation of biochemistry may take up to 72 hours
  5. Everyone with HHS should receive prophylactic low molecular weight heparin (LMWH) for the full duration of admission unless contraindicated.
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