ATS Pulmonary Function Laboratory Manual

ATS Pulmonary Function Laboratory Management & Procedure Manual | 3rd Edition

Appendix 10.1  Dl CO

Adjustment for Hemoglobin Because CO-Hb binding is such an important factor in CO transfer, Dl CO of hemoglobin concentration (19–24). The equation for adjusting predicted Dl CO

changes can be substantial as a function in adolescents and adult men is

(assuming Hb is in g/dL):

D L CO predicted for Hb = D L CO predicted 1 . 7 Hb/ ( 10 . 22 + Hb )

The equation for adjusting predicted Dl CO

in children under 15 yr of age and women is:

D L CO predicted for Hb = D L CO predicted 1 . 7 Hb/ ( 9 . 38 + Hb )

The equation for adjusting measured Dl CO

in adolescents and adult men is:

D L CO adjusted for Hb = Measured D L CO

× ( 10 . 22 + Hb ) / ( 1 . 7 × Hb )

The equation for adjusting measured Dl CO

in children under 15 yr of age and women is:

D L CO adjusted for Hb = Measured D L CO × ( 9 . 38 + Hb ) / ( 1 . 7 × Hb ) Please note that these equations assume that Hb is 13.4 g/dL in females and children, and 14.6 g/dL in males over age 15. These are approximate Caucasian value, but Hb levels vary significantly from these values with age and ethnicity (31). Example of measured Dl CO adjustment for Hb for an adult man with a measured Dl CO of 40.37 ml/min/mm Hg and Hb of 15.7 g/dL: D L CO adjusted for Hb = Measured D L CO × ( 10 . 22 + Hb ) / ( 1 . 7 × Hb ) D L CO adjusted for Hb = 40 . 37 × ( 10 . 22 + 15 . 7 ) / ( 1 . 7 × 15 . 7 ) D L CO adjusted for Hb = 40 . 37 × 0 . 9712 D L CO adjusted for Hb = 37 . 33 ml/min/mmHg

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