Hypoglycaemia Flashcards
What does management of hypoglycaemia depend on?
On the patient’s level of alertness
How do you treat hypoglycaemia if patient is alert and orientated?
Oral carbohydrates
- rapid acting: juice/sweets
- longer acting: sandwich
How do you treat hypoglycaemia if patient is drowsy but swallowing intact?
Buccal glucose (sublingual - hypostop/glucogel
AND start thinking about IV access
How do you treat hypoglycaemia if unconscious or concerned about swallowing?
IV access
20% glucose IV
What should you consider if patient is deteriorating / refractory hypoglycaemic /difficult IV access?
IM/SC 1mg glucagon
What must you consider when administering glucagon?
If the patient has sufficient hepatic glycogen stores
What is generally low glucose on a ward?
<4mmol/L
What is generally low glucose in ITU/neonates?
<2.5mmol/L
What are symptoms of hypoglycaemia
Adrenergic:
- tremor
- palpitations
- sweating
- hunger
Neuroglycopoenic
- somnolence
- confusion
- incoordination
- seizures
- coma
What occurs to symptoms if a patient has recurrent hypoglycaemic episodes?
HYPOGLYCAEMIA UNAWARENESS
so the lack of adrenergic symptoms due to hypoglycaemia
What is the triad for diagnosis of hypoglycaemia?
Low glucose
Symptoms
Relief of symptoms with glucose administration
What is the order of hormone changes following hypoglycaemia?
- Suppression of insulin
- Release of glucagon
- Release of adrenaline
- Release of cortisol
Explain counter regulation of hypoglycaemia
- Low glucose means insulin suppression
- Immediately after low glucose means increased glucagon
- Low insulin and high glucagon mean:
- reduce peripheral uptake of glucose
- increase glycogenolysis
- increase gluconeogenesis
- increase lipolysis
- This means increased glucose, increased FFA
What do FFAs do once produced by lipolysis?
The enter the beta oxidation cycle to generate ATP
Others will form ketone bodies
What are the two key ways of measuring glucose?
- VENOUS GLUCOSE
2. CAPILLARUY GLUCOSE
What is negative about measuring blood glucose via capillary?
POOR PRECISION at low glucose levels
What are common causes of hypoglycaemia in people without diabetes?
Critically unwell Organ failure Hyperinsulinism Post-gastric bypass, extreme weight loss Drugs
What are causes of hypoglycaemia in diabetics?
Medications Inadequate carbohydrate intake / missed meals Excessive alcohol Strenuous exercise Co-existing AI conditions
What are DIABETES medications that can cause hypoglycaemia
Sulphonylureas
GLP1 agents
Insulin (both short and long acting)
Which OTHER medications can cause hypoglycaemia?
Beta blockers
Saliclylate
Alcohol
What must you do to drug doses for diabetes in someone who also has liver /renal failure?
REDUCE THE DOSE
As they have impaired drug clearancer
What comorobidities are dangerous if someone is on drugs for diabetes=?
liver / renal failure
Addisons
autonomic neuropathy
What is C peptide a product of?
A product of PRO-insulin
What is the ratio between C peptide and insulin?
1:1 EQUIMOLAR
What are important biochemical tests to find the cause of hypoglycaemia?
- Insulin levels
- C peptide
- Drug screen
- Auto antibodies
- Cortisol, GH
- FFA
- Lactate
Explain the process behind normal insulin secretion
Glucose crosses the membrane and enters glycolysis via glucokinase
Glycolysis produces ATP
The rise in ATP leads to closure of the ATP sensitive K+ channel
K+ can no longer leave the cell
This leads to membrane depolarisation and calcium influx
This leads to insulin release from the cell
What is the MOA of sulpholynusrea?
They block the ATP sensitive K+ channel
So the rest of the pathway is always activated and insulin is always secreted
Which congenital disease are insolinoma associated with?
MEN1
Explain how paraneoplastic syndrome can cause hypoglycaemia
Mesenchymal tumours / epithelial tumours secrete “big IGF2”
Big IGF2 binds to IGF1 and insulin receptors
They behave like insulin, so endogenous insulin production is wswitched off and FFA production is suppressed
what is a specific pathogenic cause of low insulin, low glucose, low FFA
NON ISLET CELL TUMOUR HYPOGLYCAEMIA
what is a NON ISLET CELL TUMOUR HYPOGLYCAEMIA
tumour causing paraneoplastic syndrome
secretion of big IGF-2
IGF-2 binds to IGF1 receptors and insulin receptors
Behaves like insulin > switches off insulin production and FFA production
What are causes of NON ISLET CELL TUMOUR HYPOGLYCAEMIA
Mesenchymal tumour (mesothelioma,. fibroblastoma) Epithelial tumours (carcinoma)
