Acute effects of inhaled nitric oxide on pulmonary and cardiac function in preterm infants with evolving bronchopulmonary dysplasia.
BACKGROUND
Inhaled nitric oxide (iNO) reduces pulmonary vascular resistance by preferential vasodilation in ventilated lung units. In experimental animals, iNO also reduces airway resistance by smooth muscle relaxation. Hence, there may be a therapeutic role for iNO in evolving bronchopulmonary dysplasia (BPD).


OBJECTIVE
To evaluate the acute effects of low-dose iNO on lung mechanics, ventilation distribution, oxygenation, and cardiac function in preterm infants with evolving BPD.


METHODS
Measurements of lung compliance (C(L)), airway resistance (R(L)), ventilation-distribution (N(2) clearance in multiple-breath washout), oxygenation (SpO(2)), left ventricular ejection fraction (LVEF) and right ventricular shortening fraction were obtained before and during 2 hours of iNO (10 ppm) in a group of ventilated preterm infants with evolving BPD.


RESULTS
A total of 13 preterm infants with (mean+/-SD) BW: 663.8+/-116 g, GA: 24.9+/-1.2 weeks, age: 32+/-14 days, mean airway pressure: 6.7+/-0.9 cmH(2)O and fraction of inspired oxygen: 0.35+/-0.06 were studied. iNO did not affect C(L), R(L) or N(2) clearance. There was a small increase in LVEF. Mean SpO(2) remained unchanged, but the duration of spontaneous hypoxemic episodes increased during iNO.


CONCLUSIONS
Low-dose iNO had no acute effects on lung function, cardiac function and oxygenation in evolving BPD.
Athavale
Kamlesh
K
Department of Pediatrics, University of Miami School of Medicine, Miami, FL 33101, USA.
Claure
Nelson
N
D'Ugard
Carmen
C
Everett
Ruth
R
Swaminathan
Sethuraman
S
Bancalari
Eduardo
E
D000280:Administration, Inhalation; D001993:Bronchodilator Agents / Q000008:administration & dosage*; D001997:Bronchopulmonary Dysplasia / Q000188:drug therapy; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D012123:Pulmonary Ventilation / Q000187:drug effects*; D015656:Respiratory Mechanics / Q000187:drug effects*; D016278:Ventricular Function, Right / Q000187:drug effects*
D001993:Bronchodilator Agents; D009569:Nitric Oxide; D010100:Oxygen