Asymptomatic (Incidental) or Mildly Symptomatic Hypoglycaemia

Give 20g of oral glucose (as a sugary drink, snack (e.g. five soft sweets) or glucose gel).

If the patient is drowsy or fitting (this may sometimes occur with mild hypoglycaemia, especially in young patients with diabetes):

• Give 100 mL of 20% glucose or 200 mL of 10% glucose over 15–30 min IV, or glucagon 1 mg IV/IM/SC.
• Recheck blood glucose after 10 min, if still below 4.0 mmol/L, repeat the above IV glucose treatment.
• In patients with malnourishment or alcohol-use disorder, there is a remote risk of precipitating Wernicke encephalopathy by a glucose load: prevent this by giving thiamine 100 mg IV before or shortly after glucose administration.

When the patient is alert and able to swallow, and blood glucose is >4 mmol/L, give a long-acting carbohydrate of the patient's choice, for example two biscuits, one slice of bread/toast or a 200–300 mL glass of milk.

If hypoglycaemia recurs or is likely to recur (e.g. liver disease, sepsis, excess sulphonylurea):

• Give 20g of oral long-acting carbohydrate if able to eat.
• If unable to eat, start an IV infusion of glucose 10% at 100 mL/h via a central or large peripheral vein. Adjust the rate to keep the blood glucose level at 5–10 mmol/L.

After excess sulphonylurea therapy, maintain the glucose infusion for 24–36h as the risk of hypoglycaemia may persist for up to 24–36h following the last dose, especially if there is concurrent renal impairment.

If hypoglycaemia is only partially responsive to glucose 10% infusion:

• Give glucose 20% 100 mL/h IV via a central vein.
• If the cause is intentional insulin overdose, consider local excision of the injection site.

Prevent Further or Recurrent Hypoglycaemia