Airway function in infants treated with inhaled nitric oxide for persistent pulmonary hypertension.
BACKGROUND
Inhaled nitric oxide (iNO), used for treatment of persistent pulmonary hypertension of newborn (PPHN), is an oxygen free radical with potential for lung injury. Deferring ECMO with iNO in these neonates could potentially have long-term detrimental effects on lung function. We studied respiratory morbidity (defined as occurrence of respiratory infections requiring treatment, episodes of wheezing, and/or need for ongoing medications following discharge) and airway function at 1 year postnatal age in term neonates treated with iNO but not ECMO for PPHN, and compared data from similar infants recruited to the UK ECMO Trial randomized to receive ECMO or conventional management (CM).


METHODS
Maximal expiratory flow at FRC (V(') (maxFRC)) was measured in infants treated with iNO for PPHN (oxygenation index >or=25) at birth.


RESULTS
V(') (maxFRC) was measured in 23 infants and expressed as z-scores, to adjust for sex and body size and compared to data from 71 (46 ECMO, 25 CM) infants studied at a similar age in the ECMO Trial. Respiratory morbidity was low in iNO group. V(') (maxFRC) z-score was lower than predicted in all groups (P < 0.001), with no significant difference between those treated with iNO [mean (SD) z-score: -1.65 (1.2)] and those treated with ECMO [-1.59 (1.2)] or CM [-2.1(1.0)]. Within iNO, ECMO and CM groups; 26%, 37% and 56%, respectively, had V(') (maxFRC) z-scores below normal.


CONCLUSIONS
Respiratory outcome at 1 year in iNO treated neonates with moderately severe PPHN is encouraging, with no apparent increase in respiratory morbidity when compared to the general population. Sub-clinical reductions in airway function are evident at 1 year, suggesting that continuing efforts to minimize lung injury in the neonatal period are warranted to maximize lung health in later life.
Hoskote
Aparna U
AU
Paediatric Intensive Care Unit, Great Ormond Street Hospital for Children NHS Trust, London, UK. hoskoa@gosh.nhs.uk
Castle
Rosemary A
RA
Hoo
Ah-Fong
AF
Lum
Sooky
S
Ranganathan
Sarath C
SC
Mok
Quen Q
QQ
Stocks
Janet
J
D015331:Cohort Studies; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D005500:Follow-Up Studies; D006612:High-Frequency Ventilation; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008448:Maximal Expiratory Flow Rate; D009569:Nitric Oxide / Q000008:administration & dosage*; D010547:Persistent Fetal Circulation Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D012138:Respiratory Therapy
D009569:Nitric Oxide