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Reduced Exhaled Nitric Oxide in Children After Testing of Maximal Expiratory Pressures
Author(s) -
Barreto Mario,
Villa Maria P.,
Montesano Marilisa,
Rennerova Zuzana,
Monti Fabiana,
Darder Maria T.,
Martella Susy,
Ronchetti Roberto
Publication year - 2006
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.20358
Subject(s) - medicine , exhaled nitric oxide , exhalation , nitric oxide , cardiology , anesthesia , asthma , spirometry
Abstract Spirometry in adult subjects can induce a fall in concentration of exhaled nitric oxide (FE NO ). Scarce information is available on the FE NO decrease after spirometry or after other forced lung‐function maneuvers in children. We compared changes in FE NO induced by repeated spirometry and testing of maximal expiratory pressures (P Emax ). Twenty‐four sex‐ and age‐matched children aged 9–18 years (mean age ± SD, 13.3 ± 2.8 years; 12 healthy, 12 asthmatic) were allocated to 1‐week‐apart sessions of repeated maneuvers of either forced vital capacity (FVC) or P Emax . Baseline FE NO measurements were followed by FVC or P Emax maneuvers every 15 min for 45 min, whereas FE NO was measured at each step for 60 min. After repeated P Emax but not after FVC maneuvers, FE NO values decreased significantly from baseline in both groups. In healthy children, geometric mean FE NO (95% confidence intervals) decreased from 9.1 (7.0–11.8) ppb at baseline to 8.2 (6.3–10.6) ppb at 15 min and 7.7 (5.6–10.6) ppb at 30 min ( P < 0.05 and P < 0.01, respectively), and remained unchanged at 45 and 60 min. In asthmatic children, FE NO levels fell from 21.6 (13.3–34.9) ppb at baseline to 15.1 (9.1–25.1) ppb at 15 min and remained low at 30, 45, and 60 min: 17.8 (10.7–29.5) ppb, 17.5 (10.2–30.1) ppb, and 17.6 (10.6–29.2) ppb, P < 0.01, for all differences from baseline. Repeated P Emax and FVC maneuvers increased FE NO variability, as compared with repeated FE NO measurements alone. Previous forced lung‐function maneuvers may affect FE NO measurements in children. Although P Emax testing has a greater influence than spirometry on FE NO levels in children, both procedures should be avoided before measuring FE NO . Pediatr Pulmonol. © 2005 Wiley‐Liss, Inc.