DKA

Question 1

Pathophysiology of DKA

Answer 1

DKA is caused by uncontrolled lipolysis (not proteolysis) which results in an excess of free fatty acids that are ultimately converted to ketone bodies

Question 2

Precipitating factors of DKA

Answer 2

-Infection (30%)
-Errors/ omissions (15%)
-No cause found (40%)
-Myocardial infarction

Question 3

Presentation of DKA

Answer 3

-Abdominal pain (and muscle cramps) with nausea and vomiting
-Polyuria, polydipsia, dehydration (5L deficit)
-Hypovolemia (JVP down, BP down, Increase HR)
-Electrolyte deficit
-Kussmaul respiration (deep hyperventilation)
-Acetone-smelling breath (‘pear drops’ smell)
-Drowsiness and coma (cerebral oedema)
-Hypothermia

Question 4

Diagnostic criteria- Joint British Diabetes Society

Answer 4

-Glucose > 11 mmol/l or known diabetes mellitus
-pH < 7.3 (metabolic acidosis)
-Bicarbonate < 15 mmol/l
-Ketones > 3 mmol/l or urine ketones ++ on dipstick

Question 5

Management of DKA

Answer 5

-Fluid replacement
=Most patients with DKA are deplete around 5-8 litres (1L stat, 1L in 1hr, 1L in 2 hr)
=Isotonic saline is used initially, even if the patient is severely acidotic

-Correction of electrolyte disturbance
=Serum potassium is often high on admission despite total body potassium being low, often falls quickly following treatment with insulin resulting in hypokalaemia
=Potassium may therefore need to be added to the replacement fluids (wait for UE first)
=If the rate of potassium infusion is greater than 20 mmol/hour then cardiac monitoring may be required

-Insulin
=IV infusion should be started at 0.1 unit/kg/hour/ 6U/h via sliding scale (fixed rate)
=Once blood glucose is < 14 mmol/l an infusion of 10% dextrose should be started at 125 mls/hr in addition to the 0.9% sodium chloride regime

-Long-acting insulin should be continued, short-acting insulin should be stopped

Question 6

Definition of DKA resolution

Answer 6

-pH >7.3 and
-blood ketones < 0.6 mmol/L and
-bicarbonate > 15.0mmol/L

Question 7

Complications of DKA and DKA treatment

Answer 7

-Gastric stasis
-Thromboembolism
-Arrhythmias secondary to hyperkalaemia/iatrogenic hypokalaemia
-Iatrogenic due to incorrect fluid therapy: cerebral oedema*, hypokalaemia, hypoglycaemia
-Acute respiratory distress syndrome
-Acute kidney injury

Question 8

Fluids in DKA

Answer 8

-0.9% NaCl (with variable potassium –replaces lost volume)
=This rehydrates – normally continues until the acid is cleared and patient rehydrated
=After 4 hours usually running at 150ml/hr
=Beware wary of hyperchloraemic acidosis

-10% Dextrose (with 20mmol/L KCL– stops hypokalaemia on insulin)
=This helps get rid of ketones alongside insulin
=This continues until patient is on s/c insulin
=Starts once glucose is less than 14
=Once started, don’t stop!!!