These spirometry reference equations, derived from randomly selected population-based cohorts with stringently monitored lung function measurements, provide data currently lacking in Canada.
The relationships between flow, expired volume and elapsed time during forced expiratory manoeuvres have been investigated in normal subjects and in patients with chronic obstructive bronchitis, using gas mixtures of different densities and viscosities. The results are summarised as follows: (1)Peak-flow-rate and the expired volume at which this occurs are greater in normal subjects than in patients with chronic obstructive bronchitis; (2) the time to reach peak flow does not differ significantly between the two groups; (3) the effect of respired gas density on all three factors is more marked in normal subjects than in patients; (4) when the peak flow of normal subjects is reduced to that of patients by addition of an external resistance in series, the time to peak flow is increased.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.