Hypoglycaemia

Question 1

Hypoglycaemia treatment

Answer 1

Depends on conscious state
- Alert - oral glucose first then complex carbs to maintain
- Drowsy - glucose gel
- Unconscious / no swallow - iv 100ml 20% glucose
(If difficult to manage or insulin-induced consider IM/SC glucagon 1mg)

Question 2

Physiology of hypoglycaemia

Answer 2

Low glucose stimulates insulin + glucagon release
4 main actions - reduced glucose uptake, glycogen breakdown, lipid breakdown, gluconeogenesis
Raised glucose + B-oxidation of FFA (ketone production)

Question 3

Algorithm hypoglycaemia

Answer 3

1. Confirm hypoglycaemia (grey top lab glucose)
2. Measure insulin levels
3. Measure C-peptide
4. If hypoinsulinaemic measure ketones

Question 4

Raised C-peptide

Answer 4

Endogenous insulin (C-peptide is pro-insulin cleavage product)

Question 5

Low C-peptide

Answer 5

Exogenous insulin (no cleavage)

Question 6

Hyperinsulinaemic hypoglycaemia

Answer 6

• High C-peptide: Endogenous insulin - insulinoma (MEN), sulphonylureas, islet cell hyperplasia, quinine, pentamidine
  Low C-peptide: Exogenous insulin - Insulin overdose in diabetics

Question 7

Low glucose
Low insulin ('hypoinsulinaemic')

Answer 7

Adult - Fasting, strenuous exercise, endocrine deficiency, anorexia, liver failure, non-islet cell tumour (paraneoplastic IGF-2 production which stimulates

Neonates - raised ketones = premature, IUGR, co-morbodity; low ketones = metabolic disorder

Question 8

How do non-islet cell tumours cause hypoinsulinaemic hypoglycaemia?

Answer 8

Paraneoplastic syndrome - IGF2 production

Binds insulin to ‘hide’ insulin whilst stimulating glucose absorption by binding IGF-1 receptors

Question 9

Whipple’s triad of hypoglycaemia

Answer 9

Low glucose
Symptoms relieved by giving glucose
Adrenergic (palpitations, sweating, tremors) then neuroglycopaenic (confusion, seizures, coma) symptoms

Question 10

Hypoglycaemia values

Answer 10

<4mmol/L adult
<2.5mmol/L children
(But depends on person)