Reproducibility of forced expiratory flow and volume measurements in infants with bronchiolitis

Sensitivity of Bronchial Responsiveness Measurements in Young Infants

“…Studies using similar equipment and technique (irrespective of inflation pressure) reported CVs (FEV 0.5 ) of 4% 11,12 to 5%. 4,13 The CV (Ptco 2 ) was 1% 14 to 3% 10 for Ptco 2 in previous reports. The young age of the infants in our study may contribute to the higher CVs.…”

“…There is no general agreement on the optimal inflation pressure for the RVRTC technique; some centers aim at 2 kPa, 11,24 while others aim at 3 kPa. 12,13,31 The centers using 3 kPa for inflation pressure uses variable transmission pressures to obtain maximal values for flow and volume. It is possible that higher inflation pressure increase the sensitivity of the RVRTC technique.…”

Variability of the raised volume rapid thoracic compression technique in infants with recurrent wheezing

“…One of the more important characteristic of a new technique is to prove to be reproducible enough as to warrant reliable comparison either for intra-subject measurements as for inter-subject evolution of their pulmonary function, in health and disease. There is a limited number of publications describing the variability of the RVRTC technique, either in normal infants as in those with lower respiratory disease 2,[5][6][7][8] and figures are similar to what reported using maximal expiratory maneuvers in older children and adults [9][10][11] . The reported intra-subject variability for the different forced flow parameters obtained by means of RVRTC varies according to different laboratories, but are in general low with FEVt ranging from 3,7 to 7,6 % and FEF from 5,2 to 10,9 % 2,5-8 and the mean intra-subject variability of RVRTC is notoriously lower than for VmaxFRC which would range between 9-17 % 2,6,8,[12][13][14][15][16][17] .…”

“…The variability of RVRTC whatever be the procedure or technique employed has been reported to be lower than 6 %, which is much better than what reported in the past for other forced expiratory flow techniques, as VmaxFRC 2,6,8,[12][13][14][15][16][17] .…”

“…We only found 5 studies with RVRTC technique where the variability is described 2,[5][6][7][8] . They have marked differences according to the number of infants involved, the modality of the technique employed, the presence or not of respiratory disease and the parameters analyzed; those studies are resumed on table I.…”