Hypoglycaemia Flashcards
Hypoglycaemia is the commonest endocrine emergency.
What constitutes hypoglycaemia?
- < 3 mmol/l
- Threshold varies
- 4-8 mmol/l is ‘normal’
Hypoglycaemic features can be divided into autonomic and neuroglycopenic symptoms.
What are autonomic features of hypoglycaemia?
- Sweating
- Anxiety
- Hunger
- Tremor
- Palpitations
- Dizziness
What are neuroglycopenic symptoms?
- Confusion
- Personality changes
- Drowsiness
- Visual trouble
- Seizures
- Coma
What are causes of hypoglycaemia?
- Most common → insulin or sulphonylurea in diabetics
In non-diabetics, you must EXPLAIN mechanism:
- Exogenous drugs (eg. insulin, alcohol binge, aspirin poisoning, ACE-i, beta-blockers)
- Pituitary insufficiency
- Liver failure
- Addison’s disease
- Islet cell tumours (insulinoma)
- Non-pancreatic neoplasms
What investigations are done for hypoglycaemia?
- Bloods → glucose, insulin, C-peptide and plasma ketones if symptomatic
- Document BM during attack and lab glucose if in hospital
- Take a drug history and exclude liver failure
How do you interpret: hypoglycaemic hyperinsulinaemic?
- Insulinoma / Sulfonylureas / Insulin injection
- C-peptide not detectable (a breakdown product of endogenous insulin)
How do you interpret: low insulin, no excess ketones?
- Non-pancreatic neoplasm
- Anti-insulin receptor antibodies
How do you interpret: low insulin, excess ketones?
- Alcohol
- Pituitary insufficiency
- Addison’s disease
Insulinomas are often benign (90-95%) pancreatic islet cell tumours, sporadic or seen with MEN-1. They present as fasting hypoglycaemia, with Whipple’s triad.
What is Whipple’s triad?
- Symptoms associated w/ fasting or exercise
- Recorded hypoglycaemia w/ symptoms
- Symptoms relieved w/ glucose
What is the screening for insulinoma?
Hypoglycaemia + increase plasma insulin during a long fast
What is the imaging for insulinoma?
- CT/MRI
- +/- endoscopic pancreatic USS
What is the management for insulinoma?
Excision
What is the management of hypoglycaemia if the patient is: conscious, orientated and able to swallow?
- 15-20g of quick-acting carbohydrate snack (eg. 200ml orange juice)
- Recheck blood glucose after 10-15mins
- Repeat snack up to 3 times
What is the management of hypoglycaemia if the patient is: conscious but uncooperative?
Squirt glucose gel between teeth and gums
What is the management of hypoglycaemia if the patient is: unconscious or not responding to already mentioned measures?
- IV glucose
- 10% at 200mL/h if conscious
- 10% at 200mL/15mins if unconscious
What is the hyperglycaemic hyperosmolar state (HHS)?
- Seen in unwell pts w/ T2DM, typically elderly
- History is longer than just hypoglycaemia (eg. 1 week)
- Hyperglycaemia → osmotic diuresis w/ associated loss of Na and K
- Severe vol depletion → significant raised serum osmolarity (>320) → hyperviscous blood
- Despite these severe electrolyte losses + total body vol depletion, typical pt w/ HHS may not look as dehydrated as they are bc hypertonicity leads to preservation of intravascular volume
- There is NO switch to ketone metabolism, so ketonaemia stays < 3mmol/L and pH > 3 (however, can get mixed picture)
What are clinical features of hyperglycaemic hyperosmolar state (HHS)?
- General → fatigue, lethargy, N+V
- Neurological → altered GCS, headaches, papilloedema, weakness
- Haem → hyperviscosity (MI, stroke)
- CVS → dehydration, hypotension, tachycardia
What is the management of HHS?
- Give LMWH prophylaxis to all unless contraindicated
- Rehydrate slowly w/ 0.9% NaCl IV / 48 hrs
- Typical deficits are 110-220ml/kg ie. 8-15L for 70kg adult
- Replace potassium when urine starts to flow
- Only use insulin if blood glucose not falling by 5mmol/L/h with rehydration or if ketonaemia
- Keep BM at least 10-15 mmol/L for first 24h to avoid cerebral oedema
