EMmedonline

• The incidence of hypoglycemia is 1-5 per 1000 new borns.

• Hypoglycemia is the most common metabolic disorder seen in newborns.

• The incidence among LGA and LBW infants are 80/1000 and 150/1000 newborns respectively.

Definition

• Hypoglycemia is defined as a plasma glucose level <45 mg/dl in symptomatic neonate or <35 mg/dl in an asymptomatic neonate.

• In first few hours after birth, hypoglycemia defined as <30 – 35 mg/dl in preterm newborn and <35 -40 mg/dl in the term infant.

• In exclusively breastfed full term AGA newborn blood glucose may fall after birth to approximately 1.8 mmol/L by 1hr of age with subsequent rise to levels over 2.0 mmol/L in first three days of life.

Symptoms

• Jitterniness or tremors

• Apathy

• Episodes of cyanosis

• Intermittent apneic spells

• Tachypnea

• Weak or high pitched cry

• Lethargy & porr feeding

• Convulsions

• Neonatal brain can utilize ketones and lactate as substrate of energy, hence newborns tolerate low blood glucose levels without symptoms.

Investigations

• Urine ketones : Presence of urine ketones suggest ketotic hypoglycemia, adrenal or growth hormone deficiency,& other inborn errors of metabolism.

• Serum Insulin levels, C-Peptide, Glucagon

• S. Cortisol

Treatment

• Asymptomatic hypoglycemia : Increase the breastfeeding frequency, supplement with a breast milk substitute or intravenous glucose therapy. Blood glucose levels should be checked 30 minutes to one hour after feeding to ascertain that the levels have increased in infants.

• Symptomatic

• Lucas et al found that intellectual performenace was poor at 18 months in infants who had been born prematurely and who had experienced serum glucose levels persistently <47 mg/dl. Thus any child having blood glucose level <45mg/dl should be treated.

• Intravenous glucose should be administrated.

• Blood glucose should be checked 30 min after starting the infusion.

• Glucose infusion rate (GIR) of 5 -8mg/kg/min is normally required to maintain blood glucose levels.

• GIR > 12mg/kg/min hyperinsulinemia or inborn error of metabolism is suspected. GIR>20 mg/kg/mi is diagnostic of hyperinsulinemia.

• GIR = Volume (ml/kg/d) * glucose concentration /144

• If adrenal insufficiency is suspected Hydrocortisone 25mg IV in neonates and 50 mg for children's should be administrated.

• Other drugs used : glucagon, hydrocortisone, thiazides, nifedipine and octerotide.

Updated on 21/1/2015

Reference

• Tintinalli