Diabetic Ketoacidosis

DKA – BSPED guidance 2021.

The potentially serious acute complication of diabetes.  In the absence of adequate insulin, glucose levels start to rise in the blood, spilling over the threshold for kidney resorption and causing a diuresis.  Metabolism switches to ketone bodies, causing acidosis.

Presents with weight loss, tiredness, vomiting, heavy breathing (Kussmaul), reduced consciousness.  Diabetes symptoms of course, if first presentation, which might just be new wetting, or unusually heavy nappies.  Can be confused with pneumonia, or appendicitis! Often missed diagnosis.  In 2020 Lanarkshire audit, half had seen GPs at least once before diagnosis, with many having had bloods done rather than BM, or being asked to hand in urine the next day… 40% had BM done by family member!

Traditionally 15-17% of new presentations of diabetes are DKA, but with pandemic went up to 66%

ISPAD def DKA = Bicarbonate pH under 7.3 (H+50) PLUS ketones 3+ (blood or urine).

Beware can develop with normal glucose levels IN THOSE TAKING INSULIN.  Suspect if blood ketones above 3 in known diabetic, refer to hospital.  Between 0.5 and 3, follow sick day rules.

Mild (over 7.2 or 63) vs moderate (7.1-7.2 or 79) vs severe (79+) categories.  Treat as 5 vs 7 vs 10% dehydrated respectively.

All get 10ml/kg over 30 mins (assuming you start IV fluids) unless shocked (10/kg over 15 mins, repeat up to 40 then inotropes).

Maintenance fluids (0.9% NaCl with 20mmol KCl per 500ml bag) as per traditional formula (Holliday-Segar method) – 100ml/kg/d for under 10kg; 50ml/kg/d additionally for each kilo between 10-20kg; 20ml/kg/d for each kilo above that.

  • Calculate deficit as above. Subtract initial 10/kg bolus (but not shock boluses) and correct over 48hrs
  • ONLINE CALCULATOR (dka-calculator.co.uk) comes with disclaimer, gives fluid calculations but then prints out 16 pages which you don’t need! [KB]
  • Note SCOTSTAR has separate DKASupportDocument for those likely to need transfer

See graphic in BMJ 2016.


If acidosis not correcting, check cannula, check fluid calculations, consider sepsis.  Replace insulin syringe! Acidosis can also be caused by hyperchloraemia (hence Plasmalyte preferred at RHC – less chloride).

Risk of thromboembolism due to dehydration and immobility during recovery.

Cerebral oedema

25% mortality from cerebral oedema, 34% long term neurodisability.  Headache, irritability, agitation.  Posturing, focal neurology eg eye movements, pupil asymmetry.  Cushings triad – bradycardia, hypertension, breathing irregularity.

Hypertonic saline (2.7 or 3%, 2.5-5ml/kg over 10-15 mins) or mannitol (20%, 0.5-1g/kg over 15 mins), no preference.  


Stay on DKA pathway (and not transfer to subcutaneous insulin) until:

  • The patient has been reviewed by a Consultant, or paediatric diabetes team medical staff and
  • The patient has no evidence of dehydration has no nausea or vomiting for 6 hours, and
  • Has blood glucose less than 10mmol/l, and
  • The blood ketones have fallen below 0.9mmol/l