Hypoglycaemia

Question 1

What is hypoglycaemia?

Answer 1

Clinical syndrome present when the blood glucose falls below the normal fasting glucose range, generally <3.3 mmol/L
- Whipple’s Triad → low blood glucose concentration, hypoglycaemic symptoms & resolution of symptoms after raising blood glucose concentration to normal

Question 2

What are the causes of hypoglycaemia?

Answer 2

1. Diabetic patients, e.g., missed dose/fasting
2. Exogenous drugs:
   - eg insulin, oral hypoglycaemics access through diabetic in the family? Body-builders may misuse insulin to help stamina
   - alcohol, eg a binge with no food
   - aspirin poisoning
   - ACE-i
   - b-blockers
   - pentamidine
   - quinine sulfate
   - aminoglutethamide
   - insulin-like growth factor.
3. Pituitary insufficiency.
4. Liver failure, plus some rare inherited enzyme defects.
5. Addison’s disease.
6. Islet cell tumours (insulinoma) and immune hypoglycaemia (eg anti-insulin receptor antibodies in Hodgkin’s disease).
7. Non-pancreatic neoplasms, eg fibrosarcomas and haemangiopericytomas.

Question 3

What are the presenting symptoms/ signs of hypoglycaemia?

Answer 3

• Increased Sympathetic Activity → sweating, anxiety, tachycardia, tremor, palpitations, pallor
• Increased Parasympathetic Activity → hunger, nausea, vomiting, paraesthesia
• Neuroglycopenic → confusion, seizures, agitation

Question 4

What investigations are used to diagnose/ monitor hypoglycaemia?

Answer 4

1. Serum Glucose → <2.8 mmol/L causes neuroglycopenic symptoms, <3.3 mmol/L causes autonomic symptoms
2. Serum Insulin → elevations may suggest insulinoma
3. Serum C-Peptide → elevated if endogenous insulin, suggests insulinoma (low if exogenous insulin)
4. Serum Cortisol → looking for adrenal insufficiency
5. Any patient presenting with confusion/neurological symptoms → MEASURE BLOOD GLUCOSE

Question 5

How is hypoglycaemia managed?

Answer 5

1. If Patient Conscious (and able to swallow) → oral glucose 15-20g (liquid, gel or tablet) & fast-acting carbohydrates (glucose tablets, candy, juice)
2. If Patient Unconscious → IM Glucagon (takes hours to work) & IV Dextrose (20% Glucose) (more rapid or if glucagon doesnt improve symptoms)
3. Insulinoma → surgical excision