TY - JOUR T1 - Relationship between age and online nasal nitric oxide measured using different techniques in children with suspected primary ciliary dyskinesia JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P3424 AU - Nicole Beydon AU - Arnaud Chambellan AU - Véronique Nève AU - Estelle Escudier AU - Alberti Corinne AU - Muriel Le Bourgeois Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P3424.abstract N2 - Background Variable thresholds of nasal nitric oxide (nNO) are proposed to screen children for primary ciliary dyskinesia (PCD) without taking age into account. But very few young children have been studied in whom false positive were tests were found.Objectives 1) to study the relationship between age and nNO measured using apnea (AP) or expiration against resistance (ExRe), and the tidal breathing (VT) techniques in non PCD children.Methods Multicentre online nNO measurements study (chemiluminescence, Seres, France, Aerocrine, Sweden, flow sample 0.3L.min-1) in children with suspected PCD. Values recorded were the best value of AP or ExRe, and means of 5 maximal peaks, 10s during controlled regular VT, and last 30s during VT measurement.Results 79 children with complete diagnosis procedure (47 with PCD, age, median [range] 11.0 [3.2-17.8]y) were studied. In non PCD children, nNO measurement was correlated with age (AR or ExRe p=0.0002, r2 = 0.38; 5 peaks p<0.03, r2 = 0.17; 10s p<0.02, r2 = 0.22) (Figure). nNO values according to techniques are shown in table.View this table:ConclusionnNO thresholds value to discriminate for PCD cannot be independent of age in children whichever the nNO technique of measure used. ER -