Summary Hypoglycemia is a medical emergency because it can result in irreversible cellular damage. In a diabetic patient, a blood glucose level < 3.9 mmol/L is considered an alert value for hypoglycemia and it should be treated. In non-diabetic patients, hypoglycemia is diagnosed using Whipple's triad. The clinical manifestations include autonomic and neuroglycopenic features.Treatment depeneds on the severity of hypoglycemia. Recurrent episodes of hypoglycemia result in "hypoglycemia unawareness."

Caution THIS IS AN EMERGENCY. Hypoglycemia can result in irreversible cellular damage.

Diagnosis and Classification

Level 1 (Glucose alert value) Blood glucose < 3.9 mmol/L
Level 2 (Significant hypoglycemia) Blood glucose < 3.0 mmol/L
Level 3 (Severe hypoglycemia): Any low blood glucose levels accompanied by cognitive dysfunction, and a NEED for external assistance to correct this hypoglycemia. There is no specific glucose level.

The SEMDSA guidelines state that in a NON-DIABETIC, hypoglycemia is defined clinically by “Whipple’s triad”: Symptoms of hypoglycemia, plasma glucose concentration < 3mmol/L AND resolution of those symptoms after the plasma glucose concentration is raised.

Clinical Manifestations

Autonomic:
1. These are due to sympathetic activation
2. Sweating, warmth, anxiety, tremor, nausea, palpitations, tachycardia, hunger
Neurologlycopaenic : Poor concentration, drowsiness/dizziness, confusion, weakness, visual disturbances, speech abnormalities, headaches, seizures, coma

Precipitants

Decreased exogenous glucose production: Missed meals, fasting
Decreased endogenous glucose production: Excess alcohol intake
Increased utilization of carbohydrates: exercise
Decreased insulin failure: progressive renal failure
Incorrect drug administration: Excessive insulin taken by the patient, wrong dose, wrong timing relative to food intake, incorrect insulin type taken

Step-Wise Approach

Test the blood sugar if suspected of clinical features. Home glucose meters may not be sensitive enough to detect hypoglycemia. Perform a blood gas and send blood for formal blood tests.
If the patient is conscious AND tolerates ORAL feeding:
1. Breastfeeding child: Breastfeed
2. Older child: Formula feed @ 5ml/kg or Oral Sugar Solution (OSS) [ Dissolve 3 teaspoons of sugar (15g – 20g) in 200ml cup of water and administer 5ml/kg] OR sweets, sugar, glucose by mouth.
3. Adult: Provide the patient with either:
  1. Glucose 15 – 20g by mouth (powder/tablets)
  2. 3-4 teaspoons of sugar/sucrose dissolved in water
  3. ¾ cup or ½ a can (175ml) of fruit juice or soft-drink
  4. Sweets (2-3 Super C sweets)
  5. 1 to 1 ½ tablespoon (15 – 20ml) of honey
4. If NECESSARY, these steps may be repeated within 10-15mins. Then provide the patient with carbohydrates that are digested slowly such as bread.
If the patient is conscious AND does NOT tolerate ORAL feeding:
1. Via a NGT tube, administer Dextrose 10% @ 5ml/kg. This is made by mixing 1 par Dextrose 50% with 4 parts of water 1:4. OR giving milk via NGT OR Oral Sugar Solution via NGT.
If the patient is Unconscious/ SEVERE HYPOGLYCEMIA:
1. Establish an IV line
2. Child: Dextrose 10% IVI 2-5ml/kg @ 2ml/kg/hour. Check after for improvement of blood sugar levels and initiate oral feeding as soon as possible.
3. Adult: Dextrose 10% IVI 2-5ml/kg. Re-assess after 5 – 10 minutes. If the blood glucose remains < 4.4 mmol/L then repeat bolus AND start an infusion (Dextrose 10% 3-5ml/kg/hour for a period of 6 hours). This will prevent recurrent hypoglycemia. If alcoholic, continue the infusion with Dextrose 5% instead of 10%.
  1. NB: If there is no IV access, you may use Glucagon 1mg SC/IM. Glucagon is a hormone that stimulates the conversion of stored glycogen (stored in the liver) to glucose, which is then released into the bloodstream. Glucagon should not be used in patients with sulphonylurea-induced hypoglycemia as it may worsen the condition by further stimulating insulin release (dropping the glucose levels more)
  2. NB: The EML Guidelines advise Dextrose 10% (as above), but the SEMDSA Guidelines advice using Dextrose 50% 20 – 50ml (instead of D10% 2-5ml/kg).

Continue monitoring the patient
Alcoholics: These patients may become deficient in vitamin B1 (Thiamine), which increases the risk of Wernicke-Korsakoff Syndrome, cerebellar degeneration, and cardiovascular dysfunction. BEFORE administering a glucose-containing IV fluid (Dextrose 10%), these patients need to be given a stat dose of Thiamine 100mg IVI.
1. Reason: Thiamine is required in the Tricarboxylic acid cycle (TCA). Alcoholics have lower levels of Thiamine. Therefore, pyruvate is not converted into energy (ATP) since it cannot be used in the TCA cycle. If a patient takes glucose, this glucose is converted into pyruvate via the glycolysis pathway. Hence, pyruvate continues to accumulate. This accumulated pyruvate then becomes converted into lactate (lactic acid). This results in acidosis and the creation of reactive oxygen species leading to cellular damage.
  Summary: Glucose before Thiamine results in cellular damage because of the formation of lactic acidosis and ROS. Read more, “Why Alcoholics Should Receive Vitamin B1 (Thiamine) by IV Before any Glucose Infusions.”
Once the patient is awake and have normal glucose levels provide them with a snack
If after 30mins, the patient has not regained consciousness you should consider other causes of altered mental status (acute confusional state)
All patients with severe hypoglycemia should be admitted/referred to the hospital. Blood glucose should be monitored 4 hourly for a period of 24-48 hours.
Find/treat the cause of hypoglycemia

Hypoglycaemia unawareness

Recurrent hypoglycemic events may result in hypoglycemic unawareness. These patients do not show the early autonomic features of hypoglycemia and mainly present with features of neuroglycopenia. These patients require assistance from an endocrinologist.

References and Further Reading 1. Why alcoholics should receive vitamin B1 (thiamine) by IV before any glucose infusions (no date) EBM Consult. Available at: https://www.ebmconsult.com/ articles/thiamine-administration-before-iv-glucose-alcoholics (Accessed: November 23, 2022).
2. SEMDSA Guidelines: SEMDSA 2017 Guidelines for the Management of Type 2 diabetes mellitus. Available at: https://www.semdsa.org.za/for-members/guidelines (Accessed: November 23, 2022).

Published on 5 July 2022

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Hypoglycemia