Inhalation of low-dose nitric oxide to evaluate pulmonary vascular reactivity in children with congenital heart disease.
The objective of this study was to investigate the efficacy of low-dose nitric oxide (NO). The study used fifteen consecutive Japanese preoperative patients (7 males and 8 females) with congenital heart disease and pulmonary hyptertension (mean pulmonary arterial pressure >30 mmHg), 6 of these patients had Down's syndrome. Hemodynamic measurements were taken in room air, 100% oxygen, 5 and 40 parts per million NO (NO5 and NO40) by inhalation. The differences between two observations within the same group were determined by the two-tailed paired t-test. A pulmonary vascular resistance (Rp) regression curve was constructed by using linear regression analysis. The percentage change in pulmonary arterial pressure per systemic arterial pressure (Pp/Ps) with NO40 (Pp/Ps-40) exceeded that of Pp/Ps-5 (p < 0.0001). The percentage change for the Rp with NO40 (Rp-40) was larger than that for the Rp-5 (p = 0.0003). The percentage change of Pp/Ps-5 and that with oxygen were similar (p = 0.266). The relationship between Rp-5 and Rp-40 was linear. In conclusion, the effects of NO5 were equivalent to 100% oxygen but less than NO40. NO5 should initially be used to test pulmonary reactivity. If there is no response, patients should still be given NO40.
Yasuda
T
T
Department of Pediatrics, Nagoya University, School of Medicine, Tsurumai-cho 65, Showa-ku, Nagoya City, Aich, Japan.
Tauchi
N
N
Baba
R
R
Nishibata
K
K
Hatano
T
T
Nakamura
S
S
Nagashima
M
M
D000280:Administration, Inhalation; D004305:Dose-Response Relationship, Drug; D005260:Female; D006330:Heart Defects, Congenital / Q000150:complications* / Q000601:surgery; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*; D007223:Infant; D016014:Linear Models; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D010100:Oxygen / Q000008:administration & dosage; D011652:Pulmonary Circulation / Q000187:drug effects*; D012016:Reference Values; D014655:Vascular Resistance / Q000187:drug effects* / Q000502:physiology
D009569:Nitric Oxide; D010100:Oxygen