PT  - JOURNAL ARTICLE
AU  - Inon Cohen
AU  - Adam LaPrad
AU  - Ori Adam
AU  - Zachi Peles
AU  - Robert Brown
AU  - Julian Solway
AU  - Jeffrey Fredberg
TI  - Determination of total lung capacity (TLC) without body plethysmography
DP  - 2013 Sep 01
TA  - European Respiratory Journal
PG  - 1793
VI  - 42
IP  - Suppl 57
4099  - http://erj.ersjournals.com/content/42/Suppl_57/1793.short
4100  - http://erj.ersjournals.com/content/42/Suppl_57/1793.full
SO  - Eur Respir J2013 Sep 01; 42
AB  - We report here a new method to determine TLC that requires neither body plethysmography (PLETH), gas dilution, nor thoracic imaging. With cheeks supported, the subject breathes through a flow interruption valve downstream of a parallel chamber of known gas volume, comprising a so-called MiniBox (Fig.1 inset). The subject also performs standard spirometry. Pressure and flow metrics were derived from both these maneuvers in a training population, as well as TLCPLETH measured on the same day (Platinum Elite, MGC, and ZAN 500, nSpire). Data mining methods were used to generate a formula from which we calculated TLC of any individual subject. Our population comprised 59 healthy adult women (31.5+15.5y, 23.3+4.9 BMI), 83 healthy adults men, (31.0+14.9y, 24.1+3.3 BMI), 25 patients with restrictive disease (48.8+16.4y, 29.4+6.8 BMI), and 101 patients with obstructive disease (62.9+11.9y, 27.7+4.9 BMI). Across this heterogeneous population we found TLCMiniBox=1.01TLCPLETH, r=0.91 (Pearson), CI: 0.922-0.88 (Fig.1). The coefficient of variation (CV) for repeated trials was 5.1%. These results establish a robust new method for accurate, rapid, and reproducible determination of TLC not only in healthy subjects but also in patients with a range of obstructive and restrictive disorders. Because it is compact, rapid, and accurate, this method is suitable for use in a physician office.This work was sponsored by PulmOne Ltd., Ra’anana, Israel.