Nitrogen dead space in heavy smokers aged 44–58 years
1989; Wiley; Volume: 9; Issue: 3 Linguagem: Inglês
10.1111/j.1475-097x.1989.tb00975.x
ISSN1365-2281
AutoresHans‐Eric Rosberg, R. Wiberg, M Arborelius,
Tópico(s)Air Quality and Health Impacts
ResumoSummary. Functional and alveolar dead spaces for nitrogen (V d f and V d alv) were calculated in a population of 20 male and 20 female heavy smokers and compared to data from static and forced spirometry (functional residual capacity [FRC], residual volume [RV], lung clearance index [LCI] and volume of trapped gas [VTG]) obtained with the same multiple‐breath nitrogen wash‐out as the dead spaces, and to variables considered sensitive to small airways disease measured with a single‐breath nitrogen elimination (closing volume in per cent of vital capacity [CV%], closing capacity in per cent of total lung capacity [CC%] and slope index [SI]). Both nitrogen dead spaces increased with tidal volume in smokers as well as in healthy non‐smokers. The majority of smokers were outside the predicted mean+2 SD for VTG (75%), CC and V D alv (70%) and SI (65%). The following variables were less sensitive for disclosing abnormality: CV (55%), RV (53%), LCI (38%) and forced expired volume in the first second (FEV 1 , 33%). If high sensitivity is considered preferable in epidemiological studies, the nitrogen dead spaces are equally as sensitive as the better of earlier described tests, and significantly superior to LCI and FEV 1 . Being tests that measure alveolar distribution of inhaled gas, they are probably sensitive to small airways disease.
Referência(s)