In this article, we’ll provide a quick overview of the treatment and investigations of patients with hypoglycaemia.

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Definition

Diabetic: Glucose <4mmol/L usually warrants treatment.

Non-Diabetic: Cut off <2.8mmol/L.
Above this value is usually physiological, but if below 3.5mmol/L with symptoms that improve on correction, an endocrine referral is warranted.

Emergency Treatment

Conscious – 100-150ml of juice or 5-7 tablets of glucose or 4 jelly babies.
Recheck every 10-15 minutes until 4 mmol/L.

Unconscious – 100ml of 20% glucose or 200ml of 10% glucose intravenously
If unable to obtain IV access or difficult to obtain, give Glucagon 1mg IM.

Once the patient has recovered, give them a longer-acting carbohydrate snack such as a biscuit or slice of toast to ensure they don’t develop hypoglycaemia. You might need to give a continuous glucose infusion to a patient with long-acting insulin on board particularly if they have AKI impairing insulin clearance.

Important Tips

• Nurses should be able to give the emergency treatment with a verbal order in an emergency
• Glucagon doesn’t work well in a malnourished/liver disease patient (minimal glycogen stores to release) & can cause significant nausea so do give an antiemetic
• Foods with high-fat content impair sugar release therefore avoid things like chocolate
• Avoid 50% dextrose as this is too viscous & 5% dextrose as this has far too little sugar. 10% or 20% tends to be what is typically used.
• Don’t treat high CBGs post-treatment, it can be corrected with the next meal & also a single episode of hyperglycaemia is rarely dangerous!

Next Steps – Identify the Cause

The most common cause is a patient on diabetes medication with reduced oral intake, alcohol, infection or exercise.

Other causes

• Sepsis
• Starvation (if ketones are raised this can be a clue!)
• Acute liver failure (usually acidotic and high lactate, deranged LFTs)
• Adrenal crisis (check cortisol)
• Rapidly spreading malignancy, usually haematological (raised lactate, history)
• Medications e.g. Quinine, Co-Trimoxazole (Septrin)
• Post-bariatric surgery
• Reactive hypoglycaemia (after a large meal)
• End of life (reconsider whether blood glucose measurement is appropriate)
• (And very, very rarely insulinoma)

How to adjust diabetes medication

• The most common medications to cause hypoglycaemia are insulin & sulphonylureas (i.e. gliclazide)
• Remember that hypoglycaemia is caused by the medication before the event (i.e. early morning hypoglycaemia is caused by the evening medication)
• If the patient is on gliclazide, reducing it by about 40mg is usually enough
• If the hypoglycaemia is due to basal insulin (early morning/before meals) then reduce it by 10-20%. Never omit basal insulin!
• If due to meal-time short-acting insulin, then reduce this by typically 2-4 units

Referral

• If you’re unsure how to adjust the diabetes medication, refer to the diabetes specialist nurse
• If the patient is complicated (e.g. on NG/TPN feed) then refer to the diabetes specialist doctor
• If the patient does not have diabetes, have a low threshold to refer to the endocrine registrar.

For non-diabetics, it is helpful to take the following tests prior to correction

• Lab glucose (otherwise we can’t interpret any tests below!)
• C-peptide
• Insulin
• Beta-hydroxybutyrate
• Urine sulphonylurea screen

References

• Endobible

Written by Dr Akash Doshi (Endocrine & Diabetes ST4) & Dr Tom Crabtree (Endocrine SpR)