TABLE 3

Lung function in terms of the maximum flow at functional residual capacity, the agreement between flow signals derived from impedance pneumography and pneumotachography, and tidal breathing flow volume parameters (TPTEF/TE and VPTEF/VE) determined by the same at baseline, during methacholine-induced bronchoconstriction and after bronchodilator inhalation in the subgroup of infants in the bronchial challenge test (n=20)

BLMIBBRD
V′maxFRC mL264 (82)129 (64)*234 (96)
Agreement
 DSS (% of TPIF)4.8 (0.8)5.4 (1.2)6.2 (1.9)**
 DL (% of TPIF)3.2 (1.1)3.3 (1.1)3.8 (1.6)
Tidal parameters
TPTEF/TE (IP)0.28 (0.09)0.24 (0.09)0.24 (0.07)
TPTEF/TE (PNT)0.30 (1.1)0.26 (0.07)0.27 (0.09)
VPTEF/VE (IP)0.30 (0.08)0.27 (0.09)0.28 (0.06)
VPTEF/VE (PNT)0.32 (0.09)0.28 (0.05)*0.30 (0.07)
  • Results are expressed as mean (sd). The agreement was expressed as the sample-by-sample difference (DSS), and the average deviation of linearity (DL). BL: baseline; MIB, methacholine-induced bronchoconstriction; BRD: after bronchodilator inhalation; V′maxFRC: the maximum flow at functional residual capacity; TPIF: tidal peak inspiratory flow; TPTEF/TE: time to peak tidal expiratory flow to total expiratory time ratio; VPTEF/VE: volume to peak tidal expiratory flow to total expiratory volume ratio; IP: impedance pneumography; PNT: pneumotachography; *: p<0.05; **: p<0.01 compared to baseline.