Abstract
Background Carbon monoxide diffusion (DLCO) measured with reabreathing (RB) technique and hyperventilation has been found to equal breath holding (BH) measure in healthy adults using homemade device. No assessment of the commercially available RB machine has been performed in sick children in whom BH technique might be difficult to achieve.
Objectives 1) to assess feasibility and repeatability of DLCORB 2) to compare DLCOBH and DLCORB in sick children.
Methods Prospective monocentre study in 46 children with suspicion or actual interstitial disease, able to perform DLCOBH. DLCOBH and RB were measured in duplicate (Masterscreen, Jaeger, Hoechberg, Germany).
Results Correct DLCORB measurements during tidal breathing was obtained in 41 (89%) children (age median 11.8 [8.2 to 18.2]y). Median (IQR) z-score of DCLOAP was -1.94 (-3.30;-1.84)[-9.9 to 1.37].
Functional residual capacity of the two DCLORB measurements was reproducible (within 15%). Alveolar volume (VA) of DLCORB was lower to that of DCLOBH (VARB median 52.6 [41.9 to 75.1]% of VABH). The duplicated measurements of DLCORB and DLCOBH were within 15% in 76% and 95% of the children, respectively.
DLCORB and DLCOBH were highly correlated (r2 = 0.72, p<0.0001) even though DLCORB was lower than DLCOBH (median 3.26 vs 4.88 mMol/kPa/min; p<0.0001; DLCORB -33.5 [-58.3 to 23.6]% of DLCOBH).
Conclusion DLCORB technique is feasible (89%) and reproducible (76%) in children able to perform BH technique despite various level of interstitial impairment. DLCORB is highly correlated to DCLOAP. Further studies to determine reference values and measurement in younger children are warranted before using RB technique in routine.
- © 2013 ERS