DKA

Question 1

What is the pathophysiology of DKA?

Answer 1

Lipolysis produces free fatty acids (FFAs)
The liver converts these to ketone bodies (some ketoacids etc) for energy
= Î acidity of blood

Question 2

What is Kussmaul respiration?

Answer 2

The characteristic deep & laboured breathing seen in metabolic acidosis (like DKA) with respiratory compensation.
- to reduce CO2

Question 3

Why is hyperkalaemia a sign of DKA?

Answer 3

A cellular transporter exchanges the plentiful H+ ions for K+ in an attempt to correct the metabolic acidosis.
- this releases K+ into the ECF
- K+ would normally be taken back up into cells by Na/K/ATPase but this needs insulin!
- K+ sequesters in the blood = hyperkalaemia but ICC has low K+
HIGH ANION GAP

Question 4

What is a high anion gap?

Answer 4

Big difference between actual ion content of body & what is measurable due to ketoacid buildup

Question 5

What can induce DKA?

Answer 5

• poor glycaemic control/undiagnosed DM
• stress (infection) - adrenaline stimulates glucagon release (dehydration, ketoacidosis)

Question 6

Why does DKA cause dehydration?

Answer 6

High glucose levels = glucose lost in urine, water follows

Question 7

What is the initial management of a DKA?

Answer 7

Resus fluids (500ml IV bolus 0.9% saline stat) for raised anion gap MA, dehydration and low SBP

THEN: Actrapid insulin 6 units/hr