Investigation and Management of Hypoglycaemia in children (<16 years)

• Definition
• Clinical presentation and assessment
• Essential physiology
• Causes of persistent hypoglycaemia
• Management
• Treatment
• No IV Access

Definition

A true (laboratory) blood glucose of <2.6mmol/L is defined as hypoglycaemia. This is 10-15% lower than capillary blood glucose i.e. bedside finger prick test. Therefore investigation and treatment of hypoglycaemia should be initiated at a value of <3.0mmol/L on the bedside test.

It is well recognised that hypoglycaemia whether asymptomatic or clinically evident (jittery, pale, sweaty, drowsy, fits) can result in permanent neurological damage. Therefore unexpected, persistent or severe hypoglycaemia should be investigated and treated urgently. For management of hypoglycaemia in the vulnerable newborn and diabetic children please refer to the following guidelines:

Guideline for management of hypoglycaemia on the neonatal unit

Management of hypoglycaemia in children and young people with diabetes 

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Clinical presentation and assessment

The following are typical symptoms and signs of hypoglycaemia in infants and children. The list is not exhaustive and a blood sugar should be checked in any child who is unwell.

The following are some of the important features to elicit from the history and examination.

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Essential physiology

During hypoglycaemia, the metabolic pathways which help to maintain blood glucose are: glycogenolysis (glycogen breakdown), gluconeogenesis (generation of glucose from amino acids, glycerol and lactate), lipolysis (provides energy as well as substrate for gluconeogenesis) and ketogenesis (generation of ketones as alternative fuel for the brain). The counter-regulatory hormones (glucagon, growth hormone, cortisol and adrenaline) rise while insulin levels fall to undetectable levels during hypoglycaemia. Thus hypoglycaemia occurs if there is hyperinsulinism, a deficiency of one or more counter-regulatory hormones or a defect in any of the above metabolic pathways.

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Causes of persistent hypoglycaemia

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Management

Collect samples when the blood glucose is < 3.0 mmol/L. Insulin and C-peptide samples taken at higher blood glucose levels are rejected by the lab. Please inform the lab if a hypoglycaemia screen is being performed. Samples should be sent to the lab within 30 minutes of collection. If you are only able to get a small amount of blood ask the lab to freeze it and request tests after discussing with on-call consultant/endocrine team.
A hypoglycaemia kit (relevant bottles & Guthrie card) is kept in PUMA, L40 and A+E. Print the request form by logging in to ICE and selecting the following tabs: paediatric services; paediatric endocrine; hypoglycaemia.

*these blood tests must be taken at the time of hypoglycaemia

*these urine tests should be from the first sample during or immediately following hypoglycaemia

Other samples to consider include: blood alcohol and salicylates, blood growth hormone, blood cultures, urine toxicology screen.

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Treatment

Treat hypoglycaemia as per APLS and NLS guidelines

If the patient presents with gastroenteritis, manage as per Gastroenteritis CAT pathway.

IV access available

• Hypoglycaemia screen should be undertaken before dextrose treatment if the child is clinically stable. Do not delay correction of hypoglycaemia whilst awaiting confirmation of lab glucose.
• Administer IV bolus of 2 ml/kg of 10% glucose followed by IV maintenance fluids of 10% glucose with 0.9% sodium chloride (this is prepared by adding 50 ml of 50% glucose to pre-made 500 ml bag of 0.9% sodium chloride/5% glucose) with 1 hourly blood glucose monitoring.
• Recheck blood sugar after 20 minutes. The aim is to maintain the blood glucose in the normal range 4-6mmol/L.
• If blood sugar is still low, check that the cannula is patent, and check the dextrose infusion rate. It should be within 5-8mg/kg/min.

• If blood sugar is persistently low despite maintenance fluids, increase the dextrose saline infusion rate in steps to 8/10/12 mg/kg/min. This can be done by increasing the dextrose concentration i.e.12.5% and 15% (only via central line) etc.
• A persistent glucose requirement of >8mg/kg/min suggests congenital hyperinsulinism. Discuss with the Paediatric endocrine on-call team.
• If adrenal insufficiency is suspected, IV hydrocortisone may be required: contact Paediatric endocrine on call team.
• If the blood sugar is in the normal range on maintenance intravenous fluids, monitor hourly until it is stable for 24 hours and as guided by clinical condition of the child.

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No IV access

• Call for senior help.
• If not drowsy, can give carbohydrate (approximately 0.3g/kg) as per hypoglycaemia treatment box:

• If drowsy give IM/SC Glucagon:
  • Neonate        20mcg/kg
  • Child <25kg  0.5mg
  • Child >25kg   1.0mg
• Recheck blood sugar after 20 minutes.

After 20 minutes if blood glucose is still <3 mmol/L, obtain IV access and treat as per ‘IV access available’ guideline above.

If blood glucose >3mmol/L, gradually reintroduce feeds if safe to do so. Check pre-feed blood sugars. If <3mmol/L on hourly feeds start continuous nasogastric feeds and obtain IV access.

Prior to discharge

1. Ensure that a clear cause for the hypoglycaemia has been elucidated prior to discharge, and that a management plan is available for the family.
2. At least 4 hours between feeds must be safely tolerated without blood glucose dropping below 3 mmol/L (4mmol/L if non-ketotic hypoglycaemia).
3. Discuss with paediatric endocrinology team if a controlled fast is felt to be required.
4. Ensure family know how to treat hypoglycaemia with age appropriate treatment.
5. Arrange appropriate out-patient follow up, depending on cause of hypoglycaemia.