Glucose Management Flashcards
What is glucose vital for?
Cellular metabolism
What determines blood glucose concentration?
Balance between intake/production of glucose and glucose use by the body
What happens to excess glucose intake in the body?
Converted to glycogen and stored in liver, heart, and skeletal muscle
What is glycogenolysis?
The process of breaking down glycogen to re-form glucose
Define gluconeogenesis.
Production of glucose and glycogen in the liver using non-glucose precursors
What are the end products of glucose metabolism through glycolysis?
Carbon dioxide, water, and energy in the form of ATP
What percentage of cerebral energy production does glucose provide?
99%
During hypoglycemia, what substrates can the brain use for energy?
- Ketone bodies
- Lactate
- Glycerol
- Amino acids
What is the role of insulin in glucose regulation?
Decreases blood glucose level by promoting glycogen formation
What is the function of glucagon?
Increases blood glucose level by promoting glycogenolysis and gluconeogenesis
How does glucose reach the fetus?
By facilitated diffusion across the placenta at 60% - 80% of mother’s glucose level
When does a neonate’s blood glucose typically fall after birth?
Lowest level 1 – 2 hours after delivery
What mechanism helps the neonatal brain protect itself from hypoglycemia?
Metabolizes lactate, which is abundant
What is the typical glucose production rate in a neonate?
4-6 mg/kg/minute
What is the definition of hypoglycemia in infants according to AAP?
Blood glucose < 40 mg/dl in any infant, regardless of gestational age or presence of symptoms
What are some risk factors for neonatal hypoglycemia?
- Large for gestational age
- Small for gestational age
- Infant of diabetic mother
- Premature and sick or stressed infants
What happens to blood flow in the brain during hypoglycemia?
Increases to improve glucose delivery
What biochemical changes can prolonged hypoglycemia induce?
Damage to neuronal and glial cells of the brain, impairing growth and causing cell death
What are the two main groups of causes for inadequate glucose supply or production?
- Decreased substrate
- Immature or altered enzyme pathways
What is a common complication of hyperinsulinism in neonates?
Persistent neonatal hyperinsulinism
What are some clinical signs of hypoglycemia in neonates?
- Tremors
- Jitteriness
- Irritability
- High-pitched cry
- Hypothermia
What is the main goal in the management of hypoglycemia in neonates?
Achieve and maintain euglycemia
What should be done if a neonate’s glucose level is between 25-40 mg/dl and they are asymptomatic?
Feed infant breast milk or formula and recheck glucose after 30 minutes
What management is indicated if glucose levels remain < 25 mg/dl after feeding?
IV glucose bolus D10W 2mL/kg
What is a potential long-term outcome of persistent neonatal hyperinsulinism?
Subsequent mental retardation
What complications can arise from hypoglycemia management?
- Recurrence of hypoglycemia
- Necrosis from extravasation
- Reactive hypoglycemia
What is the risk of perinatal mortality associated with infants of diabetic mothers?
Increased due to high rates of congenital malformations and stillbirths
What is the incidence of hypoglycemia in infants of diabetic mothers?
~20% in those with gestational diabetes, 35% with other forms of diabetes
What is the expected clinical outcome for SGA infants of mothers with gestational diabetes?
Worse than AGA or LGA infants
