Introduction
Hypoglycemia is a blood glucose level less than 2.5 mmol/L (45 mg/dL).
It may occur in a fasting state or may be post prandial.
Causes of hypoglycemia
- Hypoglycemia is commonly iatrogenic
- Antidiabetic drugs use
- Associated with quinine and salicylates use
- After overnight fast
- Missed meal(s)
- Exercise
- Intensive insulin therapy
- May follow weight loss
- May follow alcohol ingestion
- Reduced insulin clearance
- Sepsis
- Secondary to non-B cell tumours/insulinoma
Symptoms of hypoglycemia
The two types of hypoglycemic symptoms are neuroglycopenic and neurogenic
1. Neurogenic manifestations of hypoglycemia
- Palpitations
- Tremors
- Anxiety
- Sweating
- Hunger
- Paresthesia
2. Neuroglycopenic manifestations of hypoglycemia
- Confusion
- Fatigue
- Seizures
- Loss of consciousness
- Death
Diagnosis of hypoglycemia
The Whipples’s triad provides a framework for diagnosis of hypoglycaemia:
- Symptoms of hypoglycaemia
- Alleviation of hypoglycemic symptoms after glucose administration
- Low plasma glucose concentration (< 2.5mmole/L)
Differential Diagnoses
- Other causes of acute confusional state
Investigations
- Random blood sugar on presentation
- Other tests to confirm the cause of hypoglycaemia
Treatment for hypoglycemia
Objectives
- Prompt restoration of normal blood glucose level
- Prevention of rebound or recurrent
hypoglycaemia - Prevention of occurrence of neural damage or death
Treatment
- Urgent treatment must be given if
irreversible complications are to be avoided - Oral glucose tablets or glucose drinks if tolerated (and if patient is conscious)
- If there is neuroglycopaenia preventing the use of oral glucose then:
1. Give 50% glucose (dextrose)
- 50 ml/25 g in double dilution intravenously
- Followed by 5 – 10% glucose (dextrose) for at least 48 hours in hypoglycaemia secondary to sulphonylurea therapy
2. Glucagon
- Intravenous glucagon 1mg stat (give
subcutaneously or intramuscularly if intravenous route is impractical)
Supportive measures
- Discontinue or reduce the dosage of causative drugs
- Treat identified underlying cause(s) if any.
Precaution
- Glucagon is not effective in glycogen depleted individuals e.g. those with alcohol induced-hypoglycaemia