Comparison of single breath and steady state methods for measurement of lung transfer factor for CO in normal subjects and smokers
Mahajan, K.K.; Mahajan, A.; Mishra, N.
Indian Journal of Physiology and Pharmacology 40(3): 267-270
1996
ISSN/ISBN: 0019-5499 PMID: 8950147 Document Number: 459499
Pulmonary diffusing capacity (lung transfer factor for carbon monoxide) has been assessed by the single breath (TLCO-SB) and steady state (TLCO-SS) techniques in well matched 90 females, 31 non-smoker and 29 smoker males, 18-50 years of age. Both TLCO-SB and TLCO-SS are significantly lower in females compared to non-smoker males (P lt 0.001). Tobacco smoking statistically significantly reduces TLCO-SB as well as TLCO-SS in smokers as compared to non-smokers. There is a statistically significant correlation of age with TLCO-SB and TLCO-SS in all the three groups (r = -0.702, -0.360 and 0.300 for TLCO-SB and r = -0.481, -0.355 and 0.380 for TLCO-SS in nonsmoker males, smoker males and females respectively). TLCO-SB is 30.43 +- 4.89, 27.29 +- 4.54 and 26.13 +- 3.60 ml/mmHg/min, while TLCO-SS is 19.47 +- 5.26, 16.69 +- 3.27 and 18.24 +- 3.78 ml/mmHg/min in nonsmoker males, smoker males and females respectively. A fairly good correlation between the TLCO-SB and TLCO-SS in male, both non-smoker and smoker, as well as the female subjects was observed. TLCO-SS is lower than TLCO-SB in all the three groups. Even in smokers of moderate intensity both of these tests are, influenced to a nearly similar extent.