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Exhaled nitric oxide concentrations: Online versus offline values in healthy children
Author(s) -
Kissoon Niranjan,
Duckworth Laurie J.,
Blake Kathryn V.,
Murphy Suzanne P.,
Taylor Christopher L.,
DeNicola Lindsay R.,
Silkoff Philip E.
Publication year - 2002
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.10023
Subject(s) - medicine , exhaled nitric oxide , intraclass correlation , nitric oxide , exhalation , asthma , cardiology , anesthesia , spirometry , clinical psychology , psychometrics
Exhaled nitric oxide (FE NO ) is a noninvasive and practical method to assess airway inflammation. We conducted this investigation to determine the most appropriate flow rate to measure FE NO and to obtain reference values for FE NO in children. FE NO was measured in 112 healthy 6–18 year olds (60 males) at 4 expiratory flow rates (46, 31, 23, and 15 mL/sec) using a chemiluminescent nitric oxide analyzer. Offline and online analyses were done to determine FE NO intraclass correlation coefficients, the relationship between FE NO and expiratory flow rates, and the effects of age and gender on these measurements. The major findings were: 1) intraclass correlation coefficients for FE NO and flow rates ranged from 0.92–0.99 for offline values, and 0.99 for all online values; 2) variation at an expiratory flow rate of 46 mL/sec (SD, 9.39) was considerably less than at other flows, especially at 15 mL/sec (SD, 26.55); 3) FE NO increased as flow rates decreased for both offline and online values; 4) there were no significant differences and good agreement between offline bag and online FE NO values at 31 and 46 mL/sec expiratory flows; and 5) using multiple regression, significant predictors of FE NO were flow, body surface area, age, and FEF 25–75 . We have provided FE NO values in healthy children and propose that the ideal expiratory flow rate for FE NO measurements in children using the single breath technique is between 30–50 mL/sec. Pediatr Pulmonol. 2002; 33:283‐292. © 2002 Wiley‐Liss, Inc.