University of Iowa Family Practice Handbook, Fourth Edition, Chapter 12

Pediatrics: Neonatal Metabolic Disorders

1. Hypoglycemia Defined as serum glucose <40 mg/dl at term, <30 mg/dl premature. Use a level of 40 mg/dl to begin looking for cause and treating.
   1. Causes. Neonatal gluconeogenesis is underdeveloped and is easily disrupted. Be aware of hypoglycemia in small-for-gestational-age and postdate infants and infants with a history of asphyxia, hypothermia, sepsis, prematurity, hypermetabolism (such as erythroblastosis), if mother diabetic (hyperinsulinism) or maternal ingestion of oral hypoglycemics or of beta-agonists. May also be secondary to sepsis.
   2. Diagnosis. Have a high index of suspicion. Clinical signs: pale, cool, irritable, jittery, poor feeding, apnea, seizures, or may be asymptomatic. Routinely screen as described in the "newborn nursery" section above and recheck if any clinical suspicion of hypoglycemia.
   3. Treatment should be given for 48 hours before tapering with frequent monitoring as follows:
      1. Stable and >34 weeks, blood glucose >30 mg/dl: 15 to 30 ml D5W PO or IV and then advance to breast feeding or formula. Check glucose Q2-3h until 3 normal.
      2. Unstable, <34 weeks or blood glucose <30 mg/dl: D₁₀W 5 ml/kg or D₂₅W 2 ml/kg IV over 10 minutes and then 2 to 4 ml/kg/hour IV. Advance to PO while continuing IV, follow serial glucose level and taper off IV.
      3. If no IV access attainable, glucagon 0.1 mg/kg IM SQ IV for <10 kg (up to 1 mg) Q30 min will raise glucose for 2 to 3 hours but depletes glycogen stores and is not effective when stores are not present (such as SGA). NG feeding is another option.
2. Hypocalcemia. Serum calcium <8 mg/dl associated with asphyxia, SGA, premature infant, or diabetic mother. Usually is transient.
   1. Diagnosis. Hypotonia, apnea, poor feeding, jitters, seizures, serum calcium <8 mg/dl.
   2. Treatment. Usually resolves in a couple of days; no need to treat asymptomatic infant.
      1. If asymptomatic and wish to treat. Give 5 to 10 ml/kg/24h of 10% solution of calcium gluconate either PO in feedings or by continuous IV over 24 hours.
      2. If symptomatic. Give 1.0 to 1.5 ml/kg of calcium gluconate 10% IV with a maximum of 5 ml in premature infants or 10 ml in a full-term infant. Should get a maximum of 1 ml/min. Can repeat if still symptomatic and then initiate treatment as in (1) above.
      3. Consider low magnesium level or congenital hypoparathyroidism if persistent.
3. Neonatal-Withdrawal Syndrome. Passive addiction of drugs by maternal use. Estimated 10% of urban births. Narcotics, and stimulants (such as cocaine) most common. These infants have an increased risk of SIDS.
   1. Diagnosis.
      1. Narcotics. Jittery, irritable, large appetite, vomiting, hypertonicity, and sneezing. Usually presents within first 72 hours of life.
      2. Cocaine. Lethargy, hypotonia, and poor feeding. Look for IUGR and cerebral infarctions. Usually presents within the first 72 hours.
      3. Methadone. Poor feeding, seizures, irritability. Presents at 2 to 4 weeks of life.
   2. Treatment. For all, swaddling and frequent high caloric feedings are helpful. Neonatal Narcotic Abstinence Scales are available. These scales provide an objective system that helps you determine when pharmacologic treatment is necessary. For narcotics use tincture of opium (10 mg/ml morphine) diluted 1:25 in water, 2 drops/kg Q4-6h to control symptoms, monitor closely. Alternatively, may use phenobarbital 5 mg/kg/day divided Q8 or 12 hours IV, IM, or PO. Taper either regiment gradually over 1 to 3 weeks.

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See related Provider Topics Child and Teen Health, Food, Nutrition and Metabolism, Genetics/Birth Defects, Metabolic Disorders, Pregnancy and Reproduction or Premature Babies.

See related Patient Topics Child and Teen Health, Food, Nutrition and Metabolism, Genetics/Birth Defects, Pregnancy and Reproduction or Premature Babies.

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