Anemia of Prematurity - Portal Neonatal

Drug Category: Pulmonary vasodilators -- NO was recently approved for treatment of pulmonary
hypertension. NO is an important mediator of vascular tone.
Drug Name
Nitric oxide (INOmax) -- A short-acting inhaled gas that relaxes the
pulmonary vasculature. Produced endogenously from action of enzyme
NO synthetase on arginine. Relaxes vascular smooth muscle by binding
to heme moiety of cytosolic guanylate cyclase, activating guanylate
cyclase and increasing intracellular levels of cGMP, which then leads to
vasodilation. When inhaled, NO decreases pulmonary vascular
resistance and improves lung blood flow. Metabolized rapidly by RBCs,
thereby minimizing systemic hypotension. In vitro may have direct effects
on the tracheobronchial tree.
Pediatric Dose Not established; currently investigational for BPD
Contraindications Right-to-left shunting of blood; methemoglobin reductase deficiency
Interactions
NO donor compounds (eg, nitroprusside, nitroglycerin) may increase risk
of developing methemoglobinemia
Pregnancy C - Safety for use during pregnancy has not been established.
Precautions
Toxic effects include methemoglobinemia and pulmonary inflammation
resulting from reactive nitrogen intermediates; caution in
thrombocytopenia, anemia, leukopenia, or bleeding disorders; monitor
PaO2, methemoglobin, and NO2; abrupt withdrawal causes rebound
pulmonary hypertension
FOLLOW-UP Section 8 of 11
Further Outpatient Care:
• Infection
o Increased susceptibility to respiration infections is frequent in infants with BPD in the first 2
years of life.
o Respiratory syncytial virus (RSV) infection in infants with BPD may cause severe illness
and even death.
o RSV immunoglobulin infusion and RSV antibody injection administered on a monthly basis
may prevent or reduce risk of rehospitalization of infants with BPD and may mitigate
illness severity.
o The AAP has published guidelines on the use of these medications during RSV season
(November-March) in preterm infants discharged from the NICU.
• Growth and development
o Poor growth and delayed development are frequently observed in infants with BPD.
Secondary to abnormal pulmonary function, increased energy requirements are noted. In
addition, many of these infants may have worsening pulmonary function with liberalization
of fluid intake. Use of diuretics, high-energy formulas and breast milk additives, or both are
the mainstays of treatment in and out of the hospital.
o In 1981, Markestad et al found the degree of catch-up growth correlated directly with
respiratory function. Long-term survivors are at increased risk for neurodevelopmental
disabilities.
o Vohr and Singer et al found no difference in full-scale IQ scores between infants with BPD
and control preterm infants.
o Therapies used to treat BPD as well as other perinatal and postnatal events may impair
neurodevelopmental outcome. In 1992, O'Shea et al reported on the outcome of infants
with BPD who were treated with a 42-day course of dexamethasone. A 42-day course of
dexamethasone was associated with an increased risk of cerebral palsy. Cummings' 1989
study refutes these findings.