A pilot study of inhaled nitric oxide in preterm infants treated with nasal continuous positive airway pressure for respiratory distress syndrome.
OBJECTIVE
To explore the acute effects of inhaled nitric oxide (iNO) on oxygenation, respiratory rate, and CO2 levels in spontaneously breathing preterm infants treated with nasal continuous positive airway pressure (nCPAP) for moderate respiratory distress syndrome (RDS).


METHODS
Randomized, prospective, double-blind, cross-over study in the neonatal intensive care units of a university hospital.


METHODS
15 infants treated for RDS, with a median gestational age of 32 weeks (27-36), birth weight 1940 g (1100-4125), and postnatal age at the beginning of study 23 h (3-91). nCPAP pressure was kept constant at 4.3 cmH2O (3.4-5.1).


METHODS
We examined effects on gas exchange and vital signs during a 30-min exposure to 10 ppm iNO or placebo gas (nitrogen).


RESULTS
Before administering test gases the baseline arterial to alveolar oxygen tension ratio (aAPO2) was 0.19+/-0.06. aAPO2 remained unchanged during placebo but increased to 0.22+/-0.05 (+20%) during iNO exposure. Respiratory rate and arterial carbon dioxide tension remained unchanged, as did heart rate, blood pressure, and methemoglobin. Follow-up at 30 days of age showed no deaths, delayed morbidity, or need for supplemental oxygen.


CONCLUSIONS
Adding 10 ppm nitric oxide to nasal CPAP treatment in preterm infants suffering from RDS results in a moderate but statistically significant improvement in oxygenation, with no effect on respiratory drive or systemic circulatory parameters.
Lindwall
Robert
R
Department of Anesthesia and Intensive Care, Danderyd Hospital, Karolinska Institutet, 18288, Stockholm, Sweden.
Blennow
Mats
M
Svensson
Mats
M
Jonsson
Baldvin
B
Berggren-Boström
Eva
E
Flanby
Martino
M
Lönnqvist
Per-Arne
PA
Frostell
Claes
C
Norman
Mikael
M
D000280:Administration, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D009569:Nitric Oxide / Q000008:administration & dosage / Q000627:therapeutic use*; D010865:Pilot Projects; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy*
D001993:Bronchodilator Agents; D009569:Nitric Oxide