Hypoglycaemia Flashcards
What is the acute management of hypoglycaemia in an alert and orientated adult?
Oral Carbohydrates
Rapid acting: Juice/sweets
Longer acting: Sandwich
What is the acute management of hypoglycaemia in a drowsy/confused but swallow intact?
Buccal glucose e.g. Hypostop/glucogel
Start thinking about IV access
What is the acute management of hypoglycaemia in an unconscious or concerned about swallow adult?
IV access
50 ml, 50% glucose mini-jet
Or 100 mls, 20% glucose
What is the acute management of hypoglycaemia in a deteriorating/refractory/insulin induced/difficult IV access adult patient?
Consider IM /SC 1mg Glucagon
What are adrenergic symptoms of hypoglycaemia?
Tremors
Palpitations
Sweating
Hunger
What are neuroglycopaenic symptoms of hypoglycaemia?
Somnolence
Confusion
Incoordination
Seizures, coma
What is the normal physiological response to hypoglycaemia?
Reduce peripheral uptake of glucose
Increase glycogenolysis
Increase gluconeogenesis
Increase lipolysis
What is the normal physiological response to low neuronal glucose sensed in the hypothalamus?
Sympathetic Activation: Catecholamines
ACTH, cortisol and GH production
What occurs first in response to hypoglycaemia?
A. Suppression of insulin
B. Release of glucagon
C. Release of adrenaline
D. Release of cortisol
A. Suppression of insulin
What are appropriate investigations for hypoglycaemia?
Confirm there is hypoglycaemia
Easy in a patient with diabetes – usually monitor blood glucose (BG).
Difficult in an otherwise healthy person – May need to conduct a prolonged fast to demonstrate hypoglycaemia.
How is glucose measured in a lab?
- Grey top (flouride oxalate)
- Venous sample
- 2mls blood
- Gold std to make the diagnosis
- Delay in results
How is glucose measured using a glucometer?
- Point-of-care device
- Instant result
- Capillary blood
But:
- Poor precision at low glucose levels
- Often poorly maintained
What may hypoglycaemia in diabetes be related to?
- Medications
- Inadequate CHO intake/missed meal
- Impaired awareness
- Excessive alcohol
- Strenuous exercise
- Co-existing autoimmune conditions
Which diabetes medications can cause hypoglycaemia?
- Sulphonylureas
- Meglitinides
- GLP-1 agents
Insulin:
- Rapid acting with meals: Inadequate meal
- Long-acting: Hypos at night or in between meals
What other drugs can cause hypoglycaemia?
B-blockers
Salicylates
Alcohol (inhibits lipolysis)
Which comorbidities can result in hypoglycaemia when coexisting with diabetes?
Co-existing renal/liver failure alters drug clearance, and reduced doses needed.
Rarely concurrent Addison’s can result in hypos (polygladular autoimmune syndrome).
How can we differentiate the cause of hypoglycaemia?
Thorough history and examination.
Biochemical Tests:
- Insulin levels
- C-peptide
- Drug screen
- Auto-antibodies
- Cortisol /GH
- Free fatty acids / blood ketones
- Lactate
- Other specialist tests – IGFBP/IGF-2/Carnitines etc.
When should bloods be taken when investigating hypoglycaemia?
Take bloods at the time of hypoglycaemia.
C-peptide
A. Is the cleavage product of insulin
B. Is secreted in equimolar amounts to insulin
C. Has a half-life of 2 hours
D. Interferes with insulin measurement
B. Is secreted in equimolar amounts to insulin
What is C-peptide?
Product of cleavage of proinsulin.
Half-life, ~ 30 minutes
Renal clearance
Hypoglycaemia due to excess injected insulin would result in:
A. A low C-peptide
B. A high C-peptide
A. A low C-peptide
What does it mean if a patient is hypoglycaemic with low insulin and low C-peptide?
Hypoinsulinaemic hypoglycaemia
Appropriate response to hypoglycaemia:
- Fasting/starvation
- Strenuous exercise
- Critical illness
- Endocrine deficiencies:
- Hypopituitarism
- Adrenal failure
- Liver failure
- Anorexia Nervosa
What does it mean if a patient is hypoglycaemic with high insulin and high C-peptide?
Hyperinsulinaemic hypoglycaemia
What does it mean if a patient is hypoglycaemic with high insulin and low C-peptide?
Exogenous insulin
