Anemia of Prematurity - Portal Neonatal

• Excessive glucose loads may increase oxygen consumption, respiratory drive, carbon dioxide
production, and glucosuria.
• Calcium and phosphorus requirements greatly increase in preterm infants. Most mineral
stores in the fetus occur during the third trimester, leaving the extremely preterm infant
calcium and phosphorus deficient and at increased risk of rickets. Supplemental furosemide
therapy and limited intravenous calcium use may worsen bone mineralization and secondary
hyperparathyroidism.
• Vitamin A supplementation may improve lung repair and decrease incidence of BPD.
• Trace mineral supplementations (ie, copper, zinc, manganese) are essential cofactors in the
AO defenses.
MEDICATION Section 7 of 11
Many different drug therapies are employed to treat infants with severe BPD. The efficacy, exact
mechanisms of action, and potential adverse effects of these medications have not been definitively
established.
Thiazide diuretics with inhibitors of aldosterone have been used in infants with BPD. Several trials of
thiazide diuretics combined with spironolactone have shown increased urine output with or without
improvement in pulmonary mechanics in infants with BPD. In 2000, Hoffman reported that
spironolactone administration does not reduce the need for supplemental electrolyte administration in
preterm infants with BPD. Long-term efficacy studies comparing furosemide to thiazides plus
spironolactone therapy have not been performed.
Bronchodilators are typically prescribed. Ipratropium bromide is a muscarinic antagonist that is related
to atropine but may have more potent bronchodilator effects. Improvements in pulmonary mechanics
have been demonstrated in BPD after ipratropium bromide inhalation. Combination therapy of
albuterol and ipratropium bromide may be more efficacious than either agent alone. Few adverse
effects are noted.
Systemic bronchodilators include methylxanthines, which are used to increase respiratory drive,
decrease apnea, and improve diaphragmatic contractility. Methylxanthines are routinely used in
preterm infants to treat BPD and apnea of prematurity. Methylxanthines have been shown to improve
diaphragmatic contractility, improve lung compliance, and decrease pulmonary resistance in infants
with BPD, probably through direct smooth muscle relaxation. They exhibit diuretic effects. All of the
above effects may increase success at weaning from mechanical ventilation. Synergy between
theophylline and diuretics has been demonstrated.
Theophylline has a half-life of 30-40 h, is metabolized primarily to caffeine in the liver, and may
produce adverse effects (eg, increased heart rate, gastroesophageal reflux, agitation, seizures).
Caffeine has a longer half-life than theophylline (approximately 90-100 h) and is excreted unchanged
in the urine. Both are available in IV and parenteral formulations. Caffeine has fewer adverse effects
than theophylline. Long-term comparison studies of these 2 agents are needed.
Oral albuterol and subcutaneous terbutaline have also been used to treat infants with BPD, but they
appear to offer no therapeutic advantage when compared to the methylxanthines.
Systemic and inhaled corticosteroids have been studied extensively in preterm infants to prevent and
treat BPD. Dexamethasone is the primary systemic synthetic corticosteroid that has been studied in
preterm neonates.
In 1999, Banks and colleagues studied the effect of inhaled nitric oxide in 16 preterm infants with
severe BPD. Eleven of 16 infants had improved oxygenation after 1 hour of inhalation, an effect that
persisted in some infants. Further controlled studies are necessary to define nitric oxide use in the
prevention and treatment of BPD.