STATIC LUNG-VOLUMES ESTIMATION BY SINGLE- BREATH NITROGEN WASHOUT

Total lung capacity (TLC) and residual volume (RV) estimations were ob tained from single-breath nitrogen washouts in 96 male and 77 female h ealthy never-smokers with normal spirometry from a non-polluted rural area in north-east France. TLC depended on height (both sexes) and dim inished slightly with age in males, with the body-mass index (kg/m2) i n females. RV increased with age in both sexes and with weight in male s. The RV/TLC ratio was related only to age. When compared wi values o btained using multiple-breath helium dilution, our results yielded low er predicted values. The test depends heavily on the subject's co-oper ation, and errors are frequent if a standard procedure is not observed . This method cannot thus be recommended for routine use in patients w ith respiratory diseases.