DKA

Question 1

Describe the pathophysiology of DKA

Answer 1

Lack of insulin: unable to utilise glucose, leads to hyperglycaemia

Lipolysis increases serum free fatty acids.
FFAs used as alternative energy source through ketogenesis.

Increases levels of ketone bodies (weak acids) leads to acidosis

Question 2

What exacerbates the hyperglycaemia in DKA as glucose can’t be used?

Answer 2

Increased hepatic glucose production through breakdown of glycogen stores (glycogenolysis) + increased formation of glucose from other substrates (gluconeogenesis).

Increased counter-regulatory hormone release (e.g. cortisol, glucagon, GH) further increases glucose levels

Question 3

What is the pathophysiological consequence of hyperglycaemia?

Answer 3

Osmotic diuresis with significant fluid + electrolyte loss

Question 4

List the 3 most common precipitating factors to DKA

Answer 4

Infection
Missed insulin doses
MI

Question 5

List 4 symptoms of DKA

Answer 5

Abdominal pain
Polyuria
Polydipsia
N+V

Question 6

Give 3 signs of DKA

Answer 6

Kussmaul respiration (deep hyperventilation)
Acetone-smelling breath (‘pear drops’)
Reduced consciousness

Question 7

What are the diagnostic criteria of DKA?

Answer 7

Glucose >11 or known DM
pH <7.3
Bicarbonate <15
Blood Ketones >3 or Urine ketones ++

Question 8

Which 6 features indicate severe DKA?

Answer 8

pH < 7.0
Bicarb < 5mmol/L
Blood ketone >6 mmol/L
GCS ≤ 12
SBP < 90 mmHg
Hypokalaemia on admission <3.5 mmol/L

Question 9

Describe the initial investigations/ interventions in DKA

Answer 9

IV access (2 large bore cannula)
Blood / urinary KETONES
Capillary + plasma blood GLUCOSE
FBC, U&Es, VBG
Blood cultures
Urinalysis +/- MSU, Pregnancy test
ECG
Cardiac monitoring
Establish usual diabetic pharmacotherapy

Question 10

What bedside investigations should be performed in suspected DKA?

Answer 10

ECG
Urinalysis +/- MSU
Urinary pregnancy test

Question 11

What bloods should be performed in suspected DKA?

Answer 11

FBC ?infection
U&Es ?electrolyte imbalance
CRP
LFTs ?hepatic precipitant
Blood cultures ?infectious precipitant
Troponin ?MI

Question 12

What imaging may be performed in DKA?

Answer 12

CXR: if low O2 sats

Question 13

What are the 3 main principles of management in DKA?

Answer 13

IV fluids
IV Insulin
Correct electrolyte disturbance

Question 14

Describe the insulin delivery in DKA

Answer 14

Fixed Rate IV Insulin Infusion (FRIII) at 0.1 unit/kg/ hour
Once blood glucose <14, start 10% Dextrose at 125 ml/h
Continue LONG acting insulin
Stop SHORT acting insulin

Question 15

Describe fluid resus in DKA when SBP is <90mmHg on admission

Answer 15

1. 500mL bolus 0.9% NaCl over 10-15 mins.
   2.
   If SBP remains <90: repeat + contact senior
   If SBP >90: give 1L NaCl over 1h
2. Add K+ to next 1L bag (if K+ <5.5)

Question 16

Describe fluid resus in DKA when SBP is >90mmHg on admission

Answer 16

1. 1L NaCl over 1h
2. 1L NaCl over 2h (add K+ if K+ <5.5)
3. 1L NaCl over 2h (add K+ if K+ <5.5)
4. 1L NaCl over 4h (add K+ if K+ <5.5)
5. 1L NaCl over 4h (add K+ if K+ <5.5)
6. 1L NaCl over 6h (add K+ if K+ <5.5)

Question 17

In which patients with DKA is a slower infusion of IV fluids indicated? Why?

Answer 17

Young adults (18-25) as greater risk of cerebral oedema

Question 18

When is cardiac monitoring required in management of DKA?

Answer 18

If rate of potassium infusion is >20mmol/h

Question 19

At what rate should potassium be infused in DKA?

Answer 19

K+ >5.5: None
K+ 3.5-5.5: 40mmol/h
K+ <3.5: senior review as additional K+ needs to be given

Question 20

What defines resolution of DKA?

Answer 20

pH >7.3 +
Blood ketones <0.6 mmol/L +
Bicarbonate >15 mmol/L

Question 21

What should have been resolved within the first 24h?

Answer 21

Both ketonaemia + acidosis
If not requires review by senior endocrinologist

Question 22

When should a patient be switched to subcutaneous insulin from FRIII in management of DKA?

Answer 22

When eating + drinking

Question 23

List 6 complications of DKA/ treatment of DKA

Answer 23

Gastric stasis
Thromboembolism
Arrythmias secondary to hyperkalaemia/ iatrogenic hypokalaemia
Iatrogenic due to incorrect fluid therapy: cerebral oedema, hypokalaemia, hypoglycaemia
ARDS
AKI

Question 24

What signs may indicate cerebral oedema during management of DKA?

Answer 24

Headache
Irritability
Visual disturbance
Focal neurology

Question 25

When does cerebral oedema usually occur during management of DKA? What should be performed if there is suspicion?

Answer 25

4-12h following commencement of Tx
Can present at any time

CT head + senior review

Question 26

Why is fluid resus needed in management of DKA?

Answer 26

Most patients are deplete 5-8L