Emergency Management of Hypoglycaemia

• Hypoglycaemia is defined as blood glucose <3.0 mmol/L, but less than 2.5 mmol/L is considered pathological requiring investigation.¹
• The glucose level that is considered hypoglycaemic in children is still debated, particularly in neonates. Older literature suggests levels above 1.7 mmol/L are acceptable in this age group. Newer publications suggest levels below 2.5 mmol/L are inappropriate.

The diagnosis of hypoglycaemia rests on three criteria (Whipple's triad) of plasma hypoglycaemia, symptoms attributable to a low blood sugar level and resolution of symptoms with correction of the hypoglycaemia.

The annual prevalence of severe hypoglycaemia is around 30% in people with type 1 diabetes.² It is higher in those with risk factors e.g. strict glycaemic control, impaired awareness of hypoglycaemia and increasing duration of diabetes. It is also common during sleep - nocturnal hypoglycaemia.

Neurological manifestations include coma, convulsions, transient hemiparesis and stroke, while reduced consciousness and cognitive dysfunction may cause accidents and injuries. Cardiac events may be precipitated e.g. arrhythmias, myocardial ischaemia and cardiac failure.

Initially

• Glucose 10-20 g is given by mouth either in liquid form or as granulated sugar (2 teaspoons) or sugar lumps.³
• GlucoGel®- formerly known as Hypostop® Gel may be used.

If hypoglycaemia causes unconsciousness, or patient is unco-operative

• 50 mL of glucose intravenous (IV) infusion 20% can be given.
• Alternatively, 25 mL of glucose intravenous infusion 50% may be given, but this higher concentration is viscous, making administration difficult; it is also more irritant.

Once the patient regains consciousness oral glucose should be administered as above.

If the patient is at home, or IV access cannot be rapidly established

• Glucagon 1 mg should be given by intramuscular (IM), or subcutaneous (SC) injection.⁴
• This dose is used in insulin-induced hypoglycaemia (by subcutaneous, intramuscular, or intravenous injection), in adults and child over 8 years (or body-weight over 25 kg). N.B. 1 unit of glucagon = 1 mg of glucagon.

Glucagon

Glucagon can have variable absorption, as it is given SC or IM. It has a relatively slow onset of action and relies on glycogen stores. It may not be effective therefore in cachectic patients, those with liver disease and young children. It is contraindicated in insulinoma and phaeochromocytoma. It also causes more insulin to be released and creates the potential for secondary rebound hypoglycaemia.

This is usually caused by cerebral oedema, and follows profound hypoglycaemia lasting more than 5 hours:

• Use IV mannitol and dexamethasone with constant glucose monitoring and IV glucose to keep serum level at 5-10 mmol/L until either consciousness restored or permanent brain damage diagnosed.
• With overdoses of insulin or sulphonylurea, may require up to 80 g/hour glucose as 25-50% solution through a central line.

Prompt treatment of hypoglycaemia in children from any cause is essential to prevent subsequent neurological damage.⁵ Hyperinsulinism, fatty acid oxidation disorders and glycogen storage disease are less common causes of acute hypoglycaemia in children.

Initially

• Glucose 10-20 g is given by mouth either in liquid form e.g. milk 200 mL, or as granulated sugar (2 teaspoons) or sugar lumps.
• If necessary this may be repeated in 10-15 minutes.
• Further food is required to prevent recurrence of hypoglycaemia.

Hypoglycaemia which causes unconsciousness or fitting is an emergency

• In hypoglycaemia, if sugar cannot be given by mouth, glucagon can be given by injection.
  A child under 8 years or of body-weight under 25 kg should be given 500 micrograms.
• Carbohydrates should be given as soon as possible to restore liver glycogen.
• Glucagon may be issued to parents or carers of insulin-treated children for emergency use in hypoglycaemic attacks.
• It is often advisable to prescribe on an if necessary basis to hospitalised insulin-treated children, so that it may be given rapidly by the nurses during a hypoglycaemic emergency.
• If not effective in 10 minutes intravenous glucose should be given.

Alternatively, 2-5 mL/kg of glucose intravenous infusion 10% (200-500 mg/kg of glucose) may be given intravenously into a large vein through a large-gauge needle.

• This concentration is irritant especially if extravasation occurs.
• Glucose intravenous infusion 50% is not recommended, as it is very viscous and hypertonic.

The patient should be monitored closely, particularly in the case of an overdose with a long-acting insulin because further administration of glucose may be required.

Octreotide appears to be a safe and effective treatment where glucose therapy is escalating in sulphonylurea overdose. Bolus doses of 1-2 mcg/kg can be given every 6-8hrs or an infusion of 30 ng/kg/min, however the optimal dosing regime is debated and a toxicologist or endocrinologist should be consulted.

Glucagon is not effective in the treatment of hypoglycaemia due to fatty acid oxidation or glycogen storage disorders. Glucagon is not appropriate for chronic hypoglycaemia.

• Neonatal hypoglycaemia is treated with glucose intravenous infusion 10% given at a rate of 5 mL/kg/hour.
• An initial dose of 2.5 mL/kg over 5 minutes may be required if hypoglycaemia is severe enough to cause loss of consciousness or fitting.
• Mild asymptomatic persistent hypoglycaemia may respond to a single dose of glucagon.
• Dose is 20 mcg per kg.
• Glucagon has also been used in the short-term management of endogenous hyperinsulinism.