The primary objective of the trial is to determine the feasibility and clinical safety and
efficacy of non-invasive inhaled nitric oxide in infants with PPHN without significant
pulmonary +-parenchymal disease who would normally receive inhaled nitric oxide only after
placement of a tracheal tube and the institution of mechanical ventilation.
Blending low doses of NO gas with oxygen in the inspiratory limb of mechanical ventilators
is an effective method for reducing pulmonary vascular resistance and decreasing
extrapulmonary right-to-left shunting at the ductus arteriosus and foramen ovale in many
patients with PPHN. However, in some patients with PPHN, sustained elevations of PVR may
occur in the absence of or despite improvement in the parenchymal lung disease such that
mechanical ventilation is not needed for maintaining adequate gas exchange.
PPN in the absence of pulmonary parenchymal disease or despite improvement in the
parenchymal lung disease occurs in a significant subset of newborn infants with hypoxemic
respiratory failure. Inhaled NO can be effectively delivered by non-invasive techniques to
newborn infants with PPHN, potentially reducing the duration of mechanical ventilation,
while safely treating the elevation in pulmonary artery pressure and right-to-left.
A dose of 10-20 ppm measured within the delivery device is sufficient to maintain
nasopharyngeal concentrations within a range of 1-10 ppm. My co-authors and I have also
reported a series of eleven infants with pulmonary hypertension treated with low dose iNO
delivered via nasal cannula after extubation at the 14th Annual CNMC Symposium on ECMO &
Advanced Therapies for Respiratory Failure, Keystone, CO, 1998.
- Newborn infants >/= 34 weeks with clinical or echocardiographic evidence of PPHN with
a PaO2 < 100 of Fio2 0.8 who are not mechanically ventilated
- Infants with significant lung disease
- Inability to sustain spontaneous respirations
- Lethal congenital anomalies
- Severe birth asphyxia
Golde Dudell, M.D.
Emory University, Department of Pediatrics, Division of Neonatology