Hypoglycaemia

Question 1

What is hypoglycaemia?

Answer 1

Low blood sugar levels, when then fall below 4 or 3mmol/L

Question 2

When does hypoglycaemia develop?

Answer 2

When hepatic glucose output falls below the rate of glucose uptake by peripheral tissues

Question 3

What are the causes of hypoglycaemia?

Answer 3

1. Inhibition of heptic glycogenolysis and gluconeogenesis by insulin
2. People with diabetes treated with insulin or sulfonylureas
3. Depletion of hepatic glycogen reserves by malnutrition, fasting, exercise or advanced liver disease
4. Impaired gluconeogenesis (e.g. following alcohol ingestion)

Question 4

What hormones act to increase plasma glucose?

Answer 4

• Glucagon
• Growth hormone
• Cortisol
• Epinephrine

Question 5

What does insulin do?

Answer 5

• Hormone which lowers blood glucose levels

* Stimulates liver (store as glycogen), muscle and fat cells to take in glucose from blood

Question 6

What is the pathophysiology of hypoglycaemia?

Answer 6

1. Insulinomas (pancreatic cell tumours which secret too much insulin)
2. Diabetes treated with insulin / sulfonylurea = poor glycaemia control/ overdose
3. Depletion of hepatic glycogen reserves by malnutrition, fasting, exercise or advanced liver disease
4. Alcohol inhibition of gluconeogenesis

Question 7

What is the presentation of hypoglycaemia?

Answer 7

• Shaking and trembling
• Sweating
• Pins and needles in lips and tongue
• Hunger
• Headache
• Double vision
• Confusion
• Slurring of speech

Question 8

How is hypoglycaemia diagnosed?

Answer 8

*Blood glucose test

Extra tests to find cause:
>HbA1c
>LFTS
>TFTS
>Insulin radioimmunoassay if islet cell tumour

Question 9

What is the management of hypoglycaemia?

Answer 9

1. A-E assessment & GCS score
   2a. Glucose 10-20g given by mouth (Glucogel)

2b. If unconscious IV 80ml 20% glucose or 150ml of 10% glucose
>50% glucose viscious =irritant and difficult to administer

2c. No IV access 1mg Glucagon given IM or SC
3. Repeat cap blood glucose after 10-15mins
4. Prolonged hypoglycaemia use IV mannitol and dexamethason with constant glucose monitoring and IV glucose

Question 10

If an overdose of insulin or sulfonylurea, what dose of glucose should be given?

Answer 10

80g/hr glucose at 25-50% solution through central venous line