Hypoglycemia in the Newborn

Hypoglycemia is defined as a blood glucose level of less than 2.6 mmol/L, regardless of age and gestational age.

Associated with hyper-insulinism:

• IDM
• Beckwith-Wiedemann
• Nesidioblastoma/Islet cell adenoma (PHII)
• Erythroblastosis foetalis
• Post-EBT

Associated with decreased stores/production:

• Preterms
• SGAs (Small for Gestational Age)
• Glycogen storage disorders
• Galactosaemia
• Hypothermia

Associated with excessive utilization:

• Sepsis
• Polycythemia
• Perinatal asphyxia

Hormonal deficiencies:

• CAH (Congenital Adrenal Hyperplasia)
• Hypopituitarism
• Hypothalamic dysfunction

• Glucose homeostasis results from a net balance between organ requirements, production, and regulation of glucose.
• The neonate's ability to maintain homeostasis is less than optimal; they have to transition from continuous glucose supply to eating intermittently.
• In the 3rd trimester, some of the substrates of the fetus are redirected from meeting metabolic needs to energy storage in the form of fat/glycogen.

Endocrine Regulation of Glucose Homeostasis

Endocrine mechanisms play a pivotal role in maintaining glucose levels within the body:

• Insulin: Insulin, a key hormone produced by the pancreas, facilitates the uptake of glucose by cells. This process ultimately leads to a reduction in blood glucose levels.
• Counter-Regulatory Hormones: To counteract the effects of insulin and prevent hypoglycemia, several counter-regulatory hormones come into play:
• Glucagon: Produced by the pancreas, glucagon stimulates the liver to release stored glucose into the bloodstream, elevating blood glucose levels.
• Adrenalin/Noradrenalin: The adrenal glands release these hormones in response to stress. They enhance the breakdown of stored glycogen into glucose, increasing blood glucose.
• Cortisol: Released by the adrenal glands, cortisol promotes glucose production in the liver and limits glucose uptake by certain cells, contributing to higher blood glucose levels.
• Growth Hormone: Secreted by the pituitary gland, growth hormone decreases glucose uptake by cells and encourages the utilization of fats for energy, thereby raising blood glucose concentrations.

The combined action of these counter-regulatory hormones results in an overall increase in blood glucose levels.

Hypoglycemia in neonates can manifest through various clinical signs:

• Weak Cry: An infant's cry may be notably weak or feeble.
• Poor Feeding: Neonates experiencing hypoglycemia often exhibit reduced interest and capacity for feeding.
• Lethargy: A notable lack of energy and alertness may be observed.
• Jitteriness: Uncontrolled trembling or jitteriness, particularly of the extremities, might be apparent.
• Apnoea: Instances of interrupted breathing or apnea could arise.
• Cyanosis: A bluish or pale discoloration, known as cyanosis, may occur due to inadequate oxygen supply.
• Seizures: Seizures, characterized by abnormal and uncontrolled neuronal activity, can be a concerning symptom of hypoglycemia.

Diagnosing hypoglycemia involves assessing the blood glucose levels:

• Random Blood Glucose Measurement: A blood glucose level lower than 2.6 mmol/L is indicative of hypoglycemia.

When addressing hypoglycemia, the following measures are taken:

1. Bolus Dextrose: An initial administration of 200mg/kg of dextrose is given stat. This amount of glucose can be found in various concentrations: 2ml/kg of 10% dextrose, 0.4ml/kg of 50% dextrose, or 4ml/kg of 5% dextrose.
2. Maintenance Glucose: A continuous infusion of glucose at a rate of 4-6mg/kg/min is maintained to ensure a steady supply of energy.
3. Addressing the Underlying Cause: Treating the root cause of hypoglycemia is essential for effective management.

The outlook for neonates with hypoglycemia hinges on timely recognition and intervention:

• When hypoglycemia is swiftly recognized and corrected, the prognosis is generally favorable. Timely intervention helps prevent potential complications.
• However, if hypoglycemic episodes recur frequently or remain untreated, there is a risk of detrimental consequences, particularly for the developing brain.

Overall, early detection and appropriate management play a critical role in determining the outcome for neonates with hypoglycemia.