BG disturbances

Question 1

Who would have a DKA?

Answer 1

4 I’s aetiology
-Infection (UTI, skin infection)
-Infarction (MI, stroke, GI tract, peripheries)
-Insufficient insulin (T1DM)
-Intercurrent illness

Question 2

What causes a DKA?

Answer 2

1.INSULIN levels drop to undetectable levels
2.Circulating blood glucose cannot enter liver and muscle cells
3.BG levels become dangerously high
4.Body is pushed into starvation and LIPOLYSIS is commenced as a result
5.Adipose tissue is broken down into free fatty acids which are then broken down into KETONES

Question 3

What are the symptoms of a DKA?

Answer 3

-Dehydration - polydipsia, polyuria, weight loss, dry mouth, hypotension
-N+V, non-specific abdo pain
-Hyperventilation - Kussmaul breathing = compensation for metabolic acidosis (blowing off CO2)
-Ketone breath (pear drops)
-Altered state of consciousness in severe cases

Question 4

What 3 findings must be present to diagnose DKA?

Answer 4

-Ketones >3 mmol/L in blood or 2+ on urine dip
-Blood glucose >11 mmol/L or known T1DM
-Bicarb <15 mmol/L and/or venous pH <7.3

Question 5

What investigations should you order for someone with a DKA?

Answer 5

-BG, U+Es, creatinine, FBC (?infection), ketones
-ABG - metabolic acidosis (often with respiratory compensation)
-Urinalysis - glucose, ketones, ?infection
-ECG - tall tented T waves, prolonged PR, broad QRS (K+)
-CXR (?infection)
-Pregnancy test

Question 6

Why are K+, Na+, urea and creatinine raised in DKA?

Answer 6

-K+ = insulin normally drives K+ into cells
-Na+ = may be high due to dehydration
-U + Cr = pre-renal AKI

Question 7

How should you manage a DKA?

Answer 7

1. Insert 2 wide bore cannulas
2. Start 1L normal saline over 1hr
   –If BP <90m, give repeated 500ml boluses over 10-15 min until BP improves (max 2L)
3. Start IV insulin
   –Give 50 units in 49.5ml of 0.9% NaCl via syringe driver at rate of 0.1 units/kg/hr
4. Continue fluids:
   –1L NaCl 0.9% over 1hr already given then
   –1L KCl 0.9% over 2hrs then
   –1L KCl 0.9% over 2hrs then
   –1L KCl 0.9% over 4 hrs
5. When BG is <15mmol/L, add 5% dextrose at 125ml/hr to prevent hypoglycaemia
6. Consider adding in KCl as insulin may cause hypoK+

Question 8

What additional management strategies should be considered?

Answer 8

-Infection –> abx
-Start doac / LMWH as hyperglycaemia causes hyper-coagulability
-Monitor urine output

Question 9

What are the complications of DKA?

Answer 9

-Gastric stasis
-VTE
-Arrhythmias secondary to hyperkalaemia
-Cerebral oedema
-ARDS
-AKI

Question 10

How is hypoglycaemia defined?

Answer 10

-BG <4mmol/L

Question 11

What triad is used for diagnosis and what does it involve?

Answer 11

Whipple’s triad
-Plasma hypoglycaemia
-Symptoms associated with low BG
-Resolution of symptoms after correction of hypoglycaemia

Question 12

What are the presenting symptoms of hypoglycaemia?

Answer 12

-Coma
-Convulsions
-Sweating / tachycardia
-Transient hemiparesis
-Stroke / cardiac events

Question 13

What are the causes of hypoglycaemia?

Answer 13

-Insulinoma
-Self-administration of insulin / sulphonylureas
-Liver failure
-Addison’s
-Alcohol
-Malnutrition