Hypoglycaemia

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

If you prefer video tutorials, check out Sweet & Salty.

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
  • 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 blood tests

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

References

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

How useful was this post?

Click on a star to rate it!

Average rating 4.7 / 5. Vote count: 6

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Leave a Comment

Your email address will not be published.

Follow us

Our Newsletter

Trending Now

Bradyarrhythmias
Bradyarrhythmias are abnormal heart rhythms with a pulse rate of <60 beats per minute (bpm). This...
Hypoglycaemia
Management of low blood sugar in conscious & unconscious patients, finding common causes, adjusting medications...
Hypercalcaemia
Serum calcium concentration is tightly regulated between 2.1-2.6mmol/L. Severe hypercalcaemia is a life-threatening...
Reporting Adverse Drug Reactions
The World Health Organization (WHO) defines adverse drug reactions (ADR) as “any response to a drug which...
Junior Doctor Pay Calculator
We’ve created a junior doctor pay calculator which will help you better understand your salary,...
PICC Lines and Midlines
You may well be asked to take blood from a PICC line or be called to see a patient because their PICC...
Safeguarding History – The Basics
Children are vulnerable. Unfortunately, child abuse does happen, and it has a significant and lifelong...
Scroll to Top

Sign up for our awesome resources

Free webinars every week, referral cheat sheet & other amazing content!