DKA

Question 1

Explain the pathophysiology behind DKA

Answer 1

Insulin deficiency
There is unrestrained increase in hepatic gluconeogenesis and peripheral uptake by tissues such as muscle is reduced
High circulating glucose leads to osmotic diuresis - increased glucose in urine pulls more water into urine - dehydration + loss of electrolytes
Plasma osmolality rises, renal perfusion falls
Accumulation of keno bodies from peripheral lipolysis produces a metabolic acidosis
Vomiting - further loss of fluid and electrolytes
Resp compensation of acidosis -> hyperventilation
Dehydration impairs renal excretion of H+ ions and ketones - aggravates
acidosis

Question 2

What accelerates DKA?

Answer 2

Stress hormones - adrenaline, noradrenaline, glucagon and cortisol release in response to dehydration and intercurrent illness

Question 3

What is the presentation of DKA?

Answer 3

Gradual drowsiness
Vomiting
Polyuria, polydipsia 
Dehydration - sunken eyes, tissue turgor ↓, dry tongue 
Pear drops in breath 
Kussmaul's respiration 
abdo pain

Question 4

What is kussmauls respiration?

Answer 4

deep and laboured breathing in association with metabolic acidosis

Question 5

What confirms a diagnosis of DKA?

Answer 5

1. Ketonaemia > 3.0mmol/L or significant ketonuria (more than 2+ on standard urine sticks) 2. Blood glucose > 11.0mmol/L or known diabetes mellitus
2. Bicarbonate (HCO3-) < 15.0mmol/L and/or venous pH < 7.3 (ketones are acidic!!)

Question 6

GIVE THE INITIAL MANAGEMENT OF DKA (HOUR 1)

Answer 6

1. ABC + 2 large-bore cannula + IV fluids
2. Initial Ix: blood ketones, capillary blood glucose, venous plasma glucose, U&Es, VBG, FBC, blood cultures, ECG, CXR (if indicated), pregnancy test
3. K+ replacement - don’t add to the first bag!
4. Fixed rate IV insulin infusion (FRIII) - 50 units human soluble insulin made up w 50ml 0.9% saline, infuse at 0.1 unit/kg/kr

Question 7

GIVE THE MANAGEMENT OF DKA (60 MINS TO 6HRS)

Answer 7

1. Review hourly fall in ketones and glucose conc
2. Catheter if not passed urine by hr 1
3. Consider NG tube if vomiting or drowsy
4. Give LMWH
5. If glucose <14mmol/L, start 10% glucose at 125ml/hr alongside saline and prevent hypoglycaemia

Question 8

When should the FRIII be continued until ?

Answer 8

Until ketones <0.6mmol/L, venous pH >7.3 and/or venous bicarb >18mmol/L

Question 9

What urine output should be aimed for?

Answer 9

0.5ml/kg/h

Question 10

What shouldnt be relied upon to tell whether DKA has resolved>?

Answer 10

urinary ketones - they stay positive after DKA as resolved

Question 11

What is the typical fluid deficit in DKA?

Answer 11

100ml/kg

Question 12

What DM is DKA associated w?

Answer 12

DM 1

Question 13

What is the typical K+ deficit in DKA?

Answer 13

3-5mmol/kg

Question 14

How much KCl needs to be added per litre of IV fluid with a serum K+ of:

i. >5.5
ii. 3.5-5.5

Answer 14

i. nil

ii. 40mmol

Question 15

Explain the fluid replacement regimen for pt w systolic BP 90mmHg and over

Answer 15

1L 0.9% saline over 1st hour 
1L 0.9% saline + KCl over next 2 hrs
1L 0.9% saline + KCl over next 2 hrs
1L 0.9% saline + KCl over next 4 hrs
1L 0.9% saline + KCl over next 4 hrs
1L 0.9% saline + KCl over next 6 hrs
REASSESS CV STATUS AT 12 HRS

Question 16

What are some of the triggers of DKA?

Answer 16

Infection
Intoxication 
Inappropriate withdrawal of insulin 
Illness
Infarction

Question 17

Why is it important to monitor K+ when giving insulin?

Answer 17

Insulin causes hypokalaemia which can lead to arrhythmias

Question 18

Explain how potassium levels change during treatment of DKA?

Answer 18

Osmotic diuresis leads to potassium being lost in the urine

Insulin leads to movement of K+ from blood into cells

Question 19

What are the complications?

Answer 19

cerebral oedema
aspiration pneumonia
hypokalaemia
hypomagnesaemia
hypophosphataemia
Thromboembolism