Endo - DKA

Question 1

When does ketogenesis occur?

Answer 1

Insufficient glucose and glycogen stores used up

Question 2

How are ketones measured?

Answer 2

Urine dipstick
Ketone meter (blood)

Question 3

What is the pathophysiology of DKA?

Answer 3

Insufficient insulin, body unable to use glucose and no glycogen stores

Ketoacidosis
Ketogensis occurs when there is very low glucose in cells
Initially kidneys produce bicarbonate to buffer acids to maintain pH
Over time ketones use up bicarb and blood becomes acidic

Dehydration
Kidneys absorb excess glucose, but become unable to do this, so there is high glucose excretion

Glucose draws water with it causing polyuria this causes severe dehydration leading to polydipsia

Potassium imbalance
Insulin normally drives potassium into cells
Serum potassium can be normal or high, as kidneys balance serum potassium in urine
Total body potassium is low as no potassium stored in cells

When insulin is given patients can develop severe hypokalaemia

Question 4

What is it called when glucose attracts water in urine?

Answer 4

Osmotic diuresis

Question 5

Why are children with DKA at high risk of developing cerebral oedema?

Answer 5

Dehydration and hyperglycaemia cause water to move from intracellular space in the brain to extracellular space

Brain cells shrink and become dehydrated

Rapid correction of dehydration and hyperglycaemia causes a rapid shift from extracellular space to intracellular space in brain cells

Causes brain to swell and become oedematous

Brain cell destruction and death

Question 6

How is potential cerebral oedema monitored?

Answer 6

Neurological observations e.g. GCS

Headaches
Altered behaviour
Bradycardia
Consciousness

Question 7

How is cerebral oedema managed?

Answer 7

Slowing IV fluids
IV mannitol
IV hypertonic saline

Question 8

How does DKA present?

Answer 8

Present with symptoms of underlying hyperglycaemia, dehydration and acidosis

Polyuria
Polydipsia
Dehydration and hypotension
Acetone breath
Nausea + Vomiting
Weight loss
Altered consciousness
Symptoms of underlying triggers e.g. sepsis

Question 9

What are the criteria for DKA diagnosis?

Answer 9

Hyperglycaemia > 11mmol/l
Ketosis > 3mmol/l
Acidosis pH < 7.3

Question 10

What are the two main principles of correcting DKA?

Answer 10

Correct dehydration over 48 hours
Corrects dehydration and dilutes the hyperglycaemia and ketones - if done too quickly risk of cerebral oedema

Fixed rate insulin infusion
Allows cells to use glucose
Reduces ketone production

Question 11

How is DKA managed?

Answer 11

FIGPICK
Fluids- IV resuscitation
Insulin
Glucose, closely monitor
Potassum- add potassium to IV fluids
Infection- treat any underlying
Chart fluid balance
Ketones-monitor blood pH