J. Mallol et al., INFLUENCE OF DURATION OF OCCLUSION TIME ON RESPIRATORY MECHANICS MEASURED WITH THE SINGLE-BREATH TECHNIQUE IN INFANTS, Pediatric pulmonology, 17(4), 1994, pp. 250-257
To determine the effect of the length of end-inspiratory occlusion on
the values of respiratory system compliance (C-rs) and resistance (R(r
s)) calculated from the single-breath technique, 6 infants with cystic
fibrosis were studied. End-inspiratory occlusions lasted between 0.3
and 1.2 seconds, and between 8 and 32 separate occlusions were made in
each infant. Examination of the individual data showed a systematic t
endency for C-rs to decrease as the length of the airway occlusion inc
reased, with statistical significance reached in two subjects. Using a
random effects model, it was demonstrated that there was a decrease o
f 0.15 mL/cmH(2)O in C-rs for each 0.1 s increase in occlusion time. T
he influence of length of plateau time for C-rs was similar to that of
total occlusion time. No such tendency was seen for R(rs). These data
reinforce the current emphasis on greater standardization in the meth
odologies used for infant lung function testing and for more fully rep
orting methodological details. (C) 1994 Wiley-Liss, Inc.