Hypoglycaemia


Hypoglycaemia is an abnormally low concentration of blood glucose. Severe hypoglycaemia can be fatal or lead to irreversible neurological damage.

Blood glucose levels should be measured whenever possible in patients presenting symptoms of hypoglycaemia. If hypoglycaemia is suspected but blood glucose measurement is not available, glucose (or another available sugar) should be given empirically.

Always consider hypoglycaemia in patients presenting impaired consciousness (lethargy, coma) or seizures.

For diagnosis and treatment of hypoglycaemia in neonates, refer to the guide Essential obstetric and newborn care, MSF.

Clinical features

Rapid onset of non-specific signs, mild to severe depending on the degree of the hypoglycaemia: sensation of hunger and fatigue, tremors, tachycardia, pallor, sweats, anxiety, blurred vision, difficulty speaking, confusion, convulsions, lethargy, coma.

Diagnosis

Capillary blood glucose concentration (reagent strip test):

– Non-diabetic patients:
• Hypoglycaemia: < 3.3 mmol/litre (< 60 mg/dl)
• Severe hypoglycaemia: < 2.2 mmol/litre (< 40 mg/dl)

– Diabetic patients on home treatment: < 3.9 mmol/litre (< 70 mg/dl)1

If blood glucose measurement is not available, diagnosis is confirmed when symptoms resolve after the administration of sugar or glucose.

Symptomatic treatment

– Conscious patients:
Children: a teaspoon of powdered sugar in a few ml of water or 50 ml of fruit juice, maternal or therapeutic milk or 10 ml/kg of 10% glucose by oral route or nasogastric tube.
Adults: 15 to 20 g of sugar (3 or 4 cubes) or sugar water, fruit juice, soda, etc.
Symptoms improve approximately 15 minutes after taking sugar by oral route.

– Patients with impaired consciousness or prolonged convulsions:
Children: 5 ml/kg of 10% glucose by slow IV (2 to 3 minutes) 
Adults: 1 ml/kg of 50% glucose by slow IV (3 to 5 minutes)
Neurological symptoms improve a few minutes after the injection.

Check blood glucose after 15 minutes. If it is still low, re-administer glucose by IV route or sugar by oral route according to the patient’s clinical condition.

If there is no clinical improvement, differential diagnoses should be considered: e.g. serious infection (severe malaria, meningitis, etc.), epilepsy.

In all cases, after stabilisation, give a meal or snack rich in complex carbohydrates and monitor the patients for a few hours.

If patient does not return to full alertness after an episode of severe hypoglycaemia, monitor blood glucose levels regularly.

Treat the cause

– Other than diabetes:
• Treat severe malnutrition, neonatal sepsis, severe malaria, acute alcohol intoxication, etc.
• End prolonged fast.
• Replace drugs inducing hypoglycaemia (e.g. quinine IV, pentamidine, ciprofloxacin, enalapril, beta-blockers, high-dose aspirin, tramadol), or anticipate hypoglycaemia (e.g. administer quinine IV in a glucose infusion).

– In diabetic patients:
• Avoid missing meals, increase intake of carbohydrates if necessary.
• Adjust dosage of insulin according to blood glucose levels and physical activity.
• Adjust dosage of oral antidiabetics, taking into account possible drug interactions.



References

  1. American Diabetes Association Standards of Medical Care in Diabetes, 2017.
    http://care.diabetesjournals.org/content/diacare/suppl/2016/12/15/40.Supplement_1.DC1/DC_40_S1_final.pdf [Accessed 24 May 2018]