Mean transit time and partial mean transit time of spirogram in 628 normal adolescents
Huang, G.; Du, J.; Luo, Y.
Hua Xi Yi Ke Da Xue Xue Bao 21(2): 166-170
1990
ISSN/ISBN: 0257-7712 PMID: 2391098 Document Number: 350880
The mean transit time (MTT) and partial mean transit time (MTTp) were measured and analysed by "direct method" in 628 cases of normal adolescents in Chengdu. The results showed that both MTT and MTTp were increased with age and prolonged with the decay of lung volume. Besides, the FVC-t curve was not single exponential in nature. The specific mean transit time (SMTT) was introduced by correcting MTT with 0.5 FVC and represented the MTT when unit volume of gas passed through just at that lung volume. SMTT was highly negatively correlated with age. This reflected the development and growth of the lung recoil and airway conductance in adolescents.