Diabetic Ketoacidosis (DKA)

Question 1

How does ketoacidosis occur in DKA?

Answer 1

1. Decrease insulin levels -
2. glucose unable to be processed
3. loss of inhibition of fatty acid beta oxidation in mitochondria
4. Ketogenesis occurs - build up of ketone bodies
5. Initially kidneys produce bicarbonate to buffer ketone acids
6. Over time, bicarbonate gets used up - blood becomes acidic

Question 2

How do you get dehydration in DKA?

Answer 2

1. Hyperglycaemia overwhelms kidneys
2. Glucose starts being filtered into kidneys
3. Glucose in urine draws water through osmotic diuresis
4. Patient urinate a lot (polyuria)

Question 3

Describe the potassium imbalance in DKA

Answer 3

1. No insulin > loss of K drive into cells
2. K excreted through urine
3. Plasma K high but total body K low
4. If pt started on insulin, severe hypokalaemia can develop

Question 4

What ECG changes would you see on hypokalaemia?

*think mild and severe

Answer 4

Mild

• Flattening T wave
• Inverse T wave

Severe

• QT prolongation
• U wave
• ST depression
• Torsades de points
• VT

Question 5

Which age group is at risk of developing Cerebral Oedema in DKA?

Answer 5

Children

*cause is unknown

Question 6

Describe the Px of CO in DKA

Answer 6

1. Dehydration + hyperglycaemia > water in brani cells moves from intracellular to extracellular space
2. Brain cells shrink
3. Rapid correction of dehydration and hyperglycaemia > rapid water shift from extracellular to intracellular
4. Brain cells become oedematous > brain cell destruction and death

Question 7

What are the signs of CO?

Answer 7

• headaches
• altered behaviour
• bradychardia
• changes to concioussness

Question 8

How would you Mx CO?

Answer 8

• Slowing IV fluids
• IV mannitol
• IV hypertonic saline

Question 9

What are the Sx of DKA?

Answer 9

• Drowsiness
• Vomiting
• Dehydration
• Abdo pain
• Polyuria
• Polydipsia
• Lethargy
• Ketotic breath
• Kussmaul breathing

Question 10

What are the trigger factors for DKA?

Answer 10

• Infection
• Insulin withdrawal
• Intoxication
• Illness

Question 11

What is the diagnosis of DKA?

Answer 11

• glucose >11mmol/L
• venous pH <7.3 / HCO3 <15mmol/L
• ketone equal or > 3.0mmol/L or urine ketones > 2

Question 12

How would you Ix for DKA?

Answer 12

Bloods

• Routine (FBC, U&E, CRP)
• VBG
• Ketones
• HbA1C
• Blood culture
• Troponin

Bedside

• BA
• ECG
• Urine dip stick, MSU

Imaging

• CXR

Question 14

How would you Mx DKA?

Answer 14

• A to E approach
• Fluid replacement
• 10% glucose 500ml infusion at 125ml/hr - if glucose <14mmol/L
• Insulin
  
  • Actrapid : 50 units add into 50ml saline
    
    • 0.1units/kg/hr (fixed rate infusion)
  • Continue long acting insulin (Levemir, Lantus)
• Mx K
• Monitoring

Question 15

What is Actrapid?

Answer 15

• Rapid acting insulin analogue
• Human Soluble Insulin

Question 16

What is the fluid regimen for DKA?

Answer 16

• 1st L over 1hr
• 2nd L over 2hrs
• 3rd L over 2hrs
• 4th L over 4hrs
• 5th L over 4hrs
• 6th L over 6hrs
• 7th L over 6hrs

Question 17

What is the K regimen like in DKA?

Answer 17

• if K >6.5 or >6.0 with ecg changes: ensure insulin infusion and iv fluids have started w/o delay
• if K > 5.5: Nil
• if K 3.5 - 5.5: add 40mmol
• if K < 3.5: add 60mmol

Question 18

Why ketonuria does not equate to ketoacidosis?

Answer 18

• Anyone can have lots of ketone in urine after overnight fast
• Alcoholics can also have ketonuria

Question 19

What is the Cx of DKA?

Answer 19

• CO (young)
• Aspiration pneumonia
• Thromboembolism
• Hypokalaemia
• Hypomagnesaemia
• Hypophosphotaemia

Question 20

What is the monitoring regimen for DKA?

Answer 20

• Hourly Check:
  
  • Capillary blood glucose
  • Ketones
  • EWS
• 2h, 4h, 8h, 12h, 24h
  
  • VBG
• pulse, BP, SpO2
• ECG if K out of range
• UO
• changes in GCS

Question 21

How do you confirm if DKA has resolved?

Answer 21

• blood ketones <0.3mmol/L
• venous pH >7.3
• bicarbonate >18mmol/L