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Diabetic ketoacidosis

Prevalence
Causes
Clinical features
Investigations
Therapy
Prevention
Prognosis
Therapy

Monitor electrolytes c and capillary glucose frequently. d 
Give potassium supplementation a after insulin therapy has begun if K+ <5.5 mmol/l d . 
Provide 10 to 30 mmol/h c

A potassium supplement regimen d

serum K (mmol/l) Add the following to iv fluid bags
> 4.5 nil
3.5 to 4.5 20 mmol per hour
< 3.5 40 mmol per hour

Why?

  • Potassium abnormalities are common - 28% have hyperkalemia on admission (95% CI: 10% to 46%) and 12% have hypokalaemia (95% CI: 0% to 25%) c
  • Patients required on average 30-40 mmol of potassium per litre of fluid to keep serum potassium normal during rehydration. c
  • A patient whose serum sodium concentration falls or fails to rise during rehydration is at increased risk of developing cerebral oedema. A failure to rise suggests rehydration with excess free water. c

A failure of sodium to rise on rehydration increases the risk of cerebral oedema

Patient Prognostic Factor Outcome CER RR
(95% CI)		 NNF+
(95% CI)
DKA c no rise in serum sodium on rehydration
not independent		 cerebral oedema
at uncertain duration		 2.3%
(0.0% to 5.5%)		 6.56
(1.56 to 27.53)		 8
(2 to 76)

Expiry date: May 2004
Levels of Evidence used in grading these guides

Author   C   Ball
Reviewer   N   Chi
CAT Writers   CM   Ball , C   Wotton