title: Pulmonary vascular effects of inhaled nitric oxide and oxygen tension in bronchopulmonary dysplasia.
abstract: Pulmonary hypertension contributes significantly to morbidity and mortality in bronchopulmonary dysplasia (BPD), but little is known about the relative contribution of arterial tone, structural remodeling, and vessel density to pulmonary hypertension, especially in older patients. To determine the role of high pulmonary vascular tone in pulmonary hypertension, we studied the acute effects of oxygen tension, inhaled nitric oxide (iNO), and calcium channel blockers (CCB) in 10 patients with BPD who underwent cardiac catheterization for evaluation of pulmonary hypertension. During normoxic conditions, mean pulmonary arterial pressure (PAP) and pulmonary to systemic vascular resistance ratio (PVR/SVR) were 34 +/- 3 mm Hg and 0.42 +/- 0.07, respectively. In response to hypoxia, PAP and PVR/SVR increased by 50 +/- 8% and 82 +/- 14%, respectively (p < 0.01). Hyperoxia decreased PVR/SVR by 28 +/- 9% (p = 0.05). The addition of iNO treatment (20-40 ppm) to hyperoxia decreased PAP and PVR/SVR by 29 +/- 5% (p < 0.01) and 45 +/- 6% (p < 0.05) from baseline values, respectively, achieving near normal values. CCB did not alter PAP or PVR/SVR from baseline values. We conclude that hyperoxia plus iNO causes marked pulmonary vasodilatation in older patients with BPD, suggesting that heightened pulmonary vascular tone contributes to pulmonary vascular disease in BPD.
authors.affiliation: Division of Critical Care, The Pediatric Heart-Lung Center, Department of Pediatrics, The Children's Hospital, Denver, Colorado 80218, USA. Peter.Mourani@UCHSC.edu
authors.forename: Peter M
authors.initials: PM
authors.lastname: Mourani
authors.forename: D Dunbar
authors.initials: DD
authors.lastname: Ivy
authors.forename: Dexiang
authors.initials: D
authors.lastname: Gao
authors.forename: Steven H
authors.initials: SH
authors.lastname: Abman
mesh_terms: D000280:Administration, Inhalation; D001997:Bronchopulmonary Dysplasia / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D018496:Hyperoxia / Q000503:physiopathology; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality; D000860:Hypoxia / Q000503:physiopathology; D007231:Infant, Newborn; D008297:Male; D015999:Multivariate Analysis; D009569:Nitric Oxide / Q000008:administration & dosage*; D010100:Oxygen / Q000627:therapeutic use; D011336:Probability; D011379:Prognosis; D011652:Pulmonary Circulation / Q000187:drug effects; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D009569:Nitric Oxide; D010100:Oxygen