Management of Hypoglycaemia
Hypoglycaemia is a lower than normal blood-glucose concentration. It results from an imbalance between glucose supply, glucose utilisation, and existing insulin concentration. It can be defined as 'mild' if the episode is self-treated and 'severe' if assistance is required. For the purposes of hospital inpatients diagnosed with diabetes, anyone with a blood-glucose concentration less than 4 mmol/litre should be treated.
- Blood-glucose concentration > 4 mmol/L
- Adults with symptoms of hypoglycaemia who have a blood-glucose concentration greater than 4 mmol/litre, should be treated with a small carbohydrate snack such as a slice of bread or a normal meal, if due.
- Blood-glucose concentration < 4 mmol/L, conscious and able to swallow
- Any patient with a blood-glucose concentration less than 4 mmol/litre, with or without symptoms, and who is conscious and able to swallow, should be treated with a fast-acting carbohydrate by mouth. Fast-acting carbohydrates include Lift® glucose liquid (previously Glucojuice®), glucose tablets, glucose 40% gels (e.g. Glucogel®, Dextrogel®, or Rapilose®), pure fruit juice, and sugar (sucrose) dissolved in an appropriate volume of water. Oral glucose formulations are preferred as absorption occurs more quickly. Chocolates and biscuits should be avoided if possible, as they have a lower sugar content and their high fat content may delay stomach emptying.
- If necessary, repeat treatment after 15 minutes, up to a maximum of 3 treatments in total. Once blood-glucose concentration is above 4 mmol/litre and the patient has recovered, a snack providing a long-acting carbohydrate should be given to prevent blood glucose from falling again (e.g. two biscuits, one slice of bread, 200–300 mL of milk, or a normal carbohydrate-containing meal if due). Insulin should not be omitted if due, but the dose regimen may need review.
- Hypoglycaemia which does not respond (blood-glucose concentration remains below 4 mmol/litre after 30–45 minutes or after 3 treatment cycles), should be treated with intramuscular glucagon or glucose 10% intravenous infusion. In alcoholic patients, thiamine supplementation should be given with, or following, the administration of intravenous glucose to minimise the risk of Wernicke's encephalopathy.
- Blood-glucose concentration < 4 mmol/L, with decreased consciousness
- In an emergency, if the patient has a decreased level of consciousness caused by hypoglycaemia, intramuscular glucagon can be given by a family member or friend who has been shown how to use it. If glucagon is not effective after 10 minutes, glucose 10% intravenous infusion should be given.
- Hypoglycaemia which causes unconsciousness is an emergency. Patients who are unconscious, having seizures, or who are very aggressive, should have any intravenous insulin stopped, and be treated initially with glucagon. If glucagon is unsuitable, or there is no response after 10 minutes, glucose 10% intravenous infusion, or alternatively glucose 20% intravenous infusion should be given. Glucose 50% intravenous infusion is not recommended as it is hypertonic, thus increases the risk of extravasation injury, and is viscous, making administration difficult.
- A long-acting carbohydrate should be given as soon as possible once the patient has recovered and their blood-glucose concentration is above 4 mmol/litre (e.g. two biscuits, one slice of bread, 200–300 mL of milk (not soya or other forms of 'alternative' milk, e.g. almond or coconut), or a normal carbohydrate-containing meal if due). Patients who have received glucagon require a larger portion of long-acting carbohydrate to replenish glycogen stores (e.g. four biscuits, two slices of bread, 400–600 mL of milk (not soya or other forms of 'alternative' milk, e.g. almond or coconut), or a normal carbohydrate containing meal if due). Glucose 10% intravenous infusion should be given to patients who are nil by mouth.
- If an insulin injection is due, it should not be omitted; however, a review of the usual insulin regimen may be required. Patients who self-manage their insulin pump may need to adjust their pump infusion rate. If the patient was on intravenous insulin, continue to check blood-glucose concentration every 15 minutes until above 3.5 mmol/litre, then re-start intravenous insulin after review of the dose regimen. Concurrent glucose 10% intravenous infusion should be considered.
- Hypoglycaemia caused by a sulfonylurea or long-acting insulin, may persist for up to 24–36 hours following the last dose, especially if there is concurrent renal impairment. Blood-glucose monitoring should be continued for at least 24–48 hours.
- N.B. Glucagon is a polypeptide hormone produced by the alpha cells of the islets of Langerhans, which increases blood-glucose concentration by mobilising glycogen stored in the liver. The manufacturer advises that it is ineffective in patients whose liver glycogen is depleted, therefore should not be used in anyone who has fasted for a prolonged period or has adrenal insufficiency, chronic hypoglycaemia, or alcohol-induced hypoglycaemia. Glucagon may also be less effective in patients taking a sulfonylurea; in these cases, intravenous glucose will be required.
Drug |
Adult Dose |
Oral glucose |
- 15-20 g oral glucose liquid orally OR
- 4-5 glucose tablets orally OR
- 1.5-2 tubes of glucose 40% oral gel orally OR
- 150-200 mL pure fruit juice orally OR
- 3-4 heaped teaspoons of sugar dissolved in water orally OR
- 15-20g (1.5–2 tubes of glucose 40% oral gel) buccally
|
IM glucagon |
|
IV glucose |
- Glucose 10% intravenous infusion 150–200 mL infused over 15 minutes OR
- Glucose 20% intravenous infusion 75–100 mL infused over 15 minutes
|