Knowledge Base

Diabetic Ketoacidosis (DKA)

Knowledge Base

Diabetic Ketoacidosis (DKA)

Key Facts

DKA triad: Hyperglycaemia (BSL >11 mmol/L) + ketosis (blood ketones >3 mmol/L) + metabolic acidosis (pH <7.3 or HCO₃ <15).

Source: Australian Diabetes Society.

Warning

Cerebral oedema is the leading cause of DKA mortality in children. Avoid rapid fluid boluses and aggressive correction of sodium. If altered consciousness develops, give mannitol 0.5–1 g/kg IV or 3% saline 2.5 mL/kg.

Pathophysiology

Insulin deficiency → unrestrained lipolysis → free fatty acids → hepatic ketogenesis → ketoacids (β-hydroxybutyrate, acetoacetate) → anion gap metabolic acidosis.

Key metabolic derangements:

  • Hyperglycaemia → osmotic diuresis → dehydration
  • Hyperkalaemia (initially) despite total body K⁺ depletion
  • Ketonaemia → Kussmaul breathing (respiratory compensation)

Diagnosis

CriterionMildModerateSevere
pH7.25–7.307.00–7.24<7.00
HCO₃15–1810–14<10
Mental stateAlertAlert/drowsyStupor/coma

Management

Fluids First

  • 0.9% NaCl 15–20 mL/kg/hr for the first hour
  • Then 4–14 mL/kg/hr guided by haemodynamics
  • Switch to dextrose-containing fluid when BSL <14 mmol/L

Insulin

  • Fixed rate IV insulin 0.1 units/kg/hr (start after first hour of fluids)
  • Target BSL fall 3–5 mmol/L/hr
  • Do NOT bolus insulin

Potassium

  • If K⁺ <3.3: hold insulin, replace K⁺ aggressively
  • If K⁺ 3.3–5.3: add 20–40 mmol KCl per litre of fluid
  • If K⁺ >5.3: do not supplement, recheck in 2 hours

Resolution Criteria

  • pH >7.3 AND HCO₃ >15 AND ketones <0.6
  • Patient eating and drinking
  • Overlap SC insulin 1–2 hours before stopping IV insulin