Term
| Blood glucose concentration is determined by |
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Definition
Balance between intake/production of glucose and glucose use by the body |
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Term
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Definition
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Term
| Excess glucose intake is converted to |
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Definition
| glycogen and stored in liver, heart, and skeletal muscle |
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Term
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Definition
When glycogen is broken down to re-form glucose and than released from the liver |
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Term
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Definition
the production of glucose and glycogen in the liver using non glucose precursors such as lactate, pyruvate, fat and amino acids |
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Term
99% of cerebral energy production |
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Definition
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Term
| During hypoglycemia what other substrates can be converted to pyruvate |
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Definition
| ketone bodies, lactate, glycerol and amino acids |
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Term
Insulin Hormonal Regulation |
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Definition
Secreted by pancreatic B cells in respose to increase in plasma glucose
Decreases blood glucose level by promoting glycogen formation |
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Term
Glucagon Hormonal Regulation |
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Definition
Secreted by pancreatic B cells in response to decrease in plasma glucose
Increases blood glucose level by promoting glycogenolysis and gluconeogenesis |
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Term
| Insulin and glucagon Relationship |
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Definition
Insulin does not control the entry of glucose into the brain or liver.
Insulin and glucagon are counter-regulatory hormones because they oppose each other. This balance is needed to maintain euglycemia. |
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Term
Fetal Glucose Homeostasis |
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Definition
Glucose reaches fetus by facilitated diffusion across placenta at 60% - 80% of mother’s glucose level
Glycogen storage 3rd trimester
Insulin needed for fetal growth |
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Term
| Neonate mobilizes glucose to meet energy needs by |
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Definition
secreting glucagon and catecholamine and suppressing insulin release – blood glucose rises in 3 to 4 hours, even if the baby does not eat
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Term
| Neonatal brain metabolizes |
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Definition
| lactate, which is abundant, protecting it from hypoglycemia |
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Term
| What is the fall in the neonate’s blood glucose after birth |
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Definition
| lowest level 1 – 2 hours after delivery |
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Term
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Definition
| a blood glucose < 35 - 40 mg/dl in any infant, regardless of gestational age or presence of symptoms |
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Term
| Risk factors for hypoglycemia |
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Definition
large for gestational age, small for gestational age, infant of diabetic mother, premature and sick or stressed infants
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Term
| During hypoglycemia the brain |
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Definition
increases blood flow to improve glucose delivery.
Increased blood flow may predispose the neonatal brain to hemorrhagic and hyperoxic injury if there is decreased cerebral autoregulatory ability.
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Term
| Ketone Production in the healthy term infant |
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Definition
| by day 2-3 of life, thus protecting their brains if blood glucose levels fall while feedings are being established |
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Term
| Ketone production in preterm or SGA |
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Definition
| severely limited ability to mount a ketogenic response. This makes them heavily dependent of an adequate glucose supply |
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Term
Inadequate supply or production of glucose
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Definition
Most common cause of hypoglycemia
Involve decreased substrate, immature or altered enzyme pathways or altered responses to neural or hormonal factors
Prematurity -Insufficient glycogen stores, immature regulatory response to low glucose
IUGR-Low glycogen and fat stores, increased substrate utilization
Delayed feedings, insufficient breastfeeding or fluid restriction
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Term
| Inadequate supply or storage of production glucose |
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Definition
Inborn errors of metabolism
Defective gluconeogenesis and/or glycogenolysis - eg. Galactosemia, amino acid disorders, organic acid deficiencies
Glycogen storage disease
Autosomal recessive defects causing a deficiency in formation or degradation of glycogen in the liver
Perinatal stress/hypoxia, respiratory distress, hypothermia, infection, polycythemia
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Term
| Signs and Symptoms of Hypoglycemia |
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Definition
Most neonates are asymptomatic
S/S of hypoglycemia are often non specific
Tremors, jitteriness, irritability, exaggerated Moro reflex
Abnormal cry: high pitched or weak
Respiratory distress: apnea, irregular respirations, tachypnea, cyanosis
Stupor, hypotonia, lethargy, refusal to feed
Hypothermia, temperature instability
Seizures
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Term
| Causes of Hyperinsulinism |
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Definition
Rh incompatibility
High glucose infusion and tocolytics use before delivery Position of tip of UAC near pancreas (T11- L1) can cause glucose to be directly delivered via the celiac artery, causing excessive insulin secretion
Infant of a diabetic mother
Persistent neonatal hyperinsulinism-
Autosomal recessive disorder cause by regulatory defects in pancreatic B cell function
Beckwith-Wiedemann syndrome
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Term
| Management of Hypoglycemia |
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Definition
If glucose level 20 – 40mg/dl and infant is asymptomatic:
Feed infant
Breast milk or formula
Recheck glucose 30 minutes after feeding
If < 20 mg/dl or if infant is symptomatic:
IV glucose bolus D10W 2mL/kg
If hypoglycemia persists despite feeding, IV glucose infusion is indicated.
Glucose bolus D10W 2mL/kg/dose
Continuous infusion of minimum 80 mL/kg/day
Persistent hypoglycemia raises the possibility of hyperinsulinism.
May require high IV glucose infusion rates (12 to 16 mg/kg/min).
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Term
| Complications of Hypoglycemia |
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Definition
Hypoglycemia will often recur when bolus is not followed by continuous infusion.
Extravasations of peripheral glucose infusions may cause necrosis of skin and other tissues.
Reactive hypoglycemia with return of symptoms may occur if IV glucose infiltrates or is stopped abruptly
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Term
| Pathophysiology Infant of the Diabetic Mother |
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Definition
Higher incidence of congenital anomalies
Throughout pregnancy-Insulin resistance and hyperglycemia
Glucose crosses placenta, insulin does not
After birth-Persistent hyperinsulinism
Decreased ability to mobilize glycogen stores, persistent hyperinsulinism,decreased ability to mobilize glycogen stores
Risk of neural impairment due to suppressed ketogenesis and lipolysis, leaving the brain without a supply of alternative fuels for metabolism during hypoglycemia.
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Term
| Infant of the Diabetic Mother Clinical Presentation |
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Definition
Hypoglycemia
Macrosomia/LGA
Respiratory distress syndrome
Polycythemia
Venous Hct > 65%
Hypocalcemia/hypomagnesemia
Functional hypoparathyroidism due to maternal magnesium loss
Cardiomyopathy
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Term
| Infant of the Diabetic Mother Management |
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Definition
Main goal is to achieve and maintain euglycemia.
Anticipate problems of IDM prior to delivery
Prompt recognition and treatment post delivery
Provide early feeding of human milk or formula
Orally or gavage
IV administration of glucose in unable to tolerate enteral feedings.
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Term
| Infant of the Diabetic Mother Complications |
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Definition
Shoulder dystocia or other birth trauma
Renal vein thrombosis
Secondary to polycythemia/hyperviscosity
Birth asphyxia
Development of juvenile insulin dependent diabetes
2% risk for female IDM
6% risk for male IDM
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