Hypoglycaemia (E&M) Flashcards
Define hypoglycaemia.
Clinical syndrome present when BGC falls below the normal fasting glucose range, generally <3.3mmol/L
What is Whipple’s Triad (hypoglycaemia)?
- low BGC
- hypoglycaemic symptoms
- resolution of symptoms after raising BGC to normal
What are some causes of hypoglycaemia? (7)
- diabetes - insulin/sulfonylurea use, fasting/missing meals
- drug causes - sulfonylureas and insulin, SGLT-2 inhibitors, DPP-4 inhibitors
- hormone deficiency causes - hypopituitarism, adrenal insufficiency (Addison’s disease), GH deficiency
- insulinoma - excessive secretion of insulin due to pancreatic tumour
- liver failure
- sepsis
- post-prandial hypoglycaemia in malnourished individuals
What happens if you administer exogenous insulin (stress test) in insulinoma (hypoglycaemia)?
C-peptide does not fall
Which tumours have been reported to secrete IGF-II?
Sarcomas, fibromas, fibrosarcomas and renal cell carcinomas
What are the most worrying causes of hypoglycaemia? (2)
- insulinoma
- tumour-related hypoglycaemia
What are the three groups of clinical features seen in hypoglycaemia?
- increased sympathetic activity
- increased parasympathetic activity
- neuroglycopenic symptoms
What features of increased sympathetic activity are seen in hypoglycaemia? (6)
- sweating
- anxiety
- tachycardia
- tremor
- palpitations
- pallor
What features of increased parasympathetic activity are seen in hypoglycaemia? (4)
- hunger
- nausea
- vomiting
- paraesthesia
What neuroglycopenic symptoms are seen in hypoglycaemia? (3)
- confusion
- seizures
- agitation
What are some risk factors for hypoglycaemia? (4)
- middle age
- female sex
- insulinoma
- exogenous insulin
What are the first-line investigations in hypoglycaemia?
- serum glucose
- LFTs
- renal function
- serum insulin and C-peptide
What serum glucose levels might we see in hypoglycaemia? (2)
- <3.3mmol/L –> autonomic symptoms
- <2.8mmol/L –> neuroglycopenic symptoms
What does raised serum insulin indicate (hypoglycaemia)?
Insulinoma
What C-peptide levels might we see in hypoglycaemia? (2)
- elevated if endogenous insulin –> insulinoma
- low if exogenous insulin
Why do we check serum cortisol in hypoglycaemia?
Looking for adrenal insufficiency
When do we check BGC in patients in general?
In any patient presenting with confusion/neurological symptoms
How do we manage hypoglycaemia if patient conscious and able to swallow?
Oral glucose 15-20g (liquid, gel or tablet) + fast-acting carbohydrates (glucose tablets, sweets, juice, starchy snack)
How do we manage hypoglycaemia if patient unconscious?
1mg IM glucagon (takes hours to work) + IV dextrose (20% glucose - more rapid, or if glucagon does not improve Sx)
How do we manage hypoglycaemia with impaired GCS?
IV glucose if there is access e.g. cannula (50ml of 50% glucose IV)
or 1mg IM glucagon
How do we manage hypoglycaemia if overdose, toxin or ethanol-related?
Supportive care, psychiatric evaluation and treatment
How do we manage hypoglycaemia due to insulinoma? (4)
- surgical excision
- medical therapy
- embolisation
- chemotherapy
How do we manage hypoglycaemia due to IGF-II secreting tumour?
Surgical excision + chemo/radiotherapy
How do we manage hypoglycaemia due to renal failure/liver failure/sepsis?
Treat underlying disease
What are some complications of hypoglycaemia? (2)
- seizure
- coma
