TY - JOUR T1 - The effect of reducing breath holding time to assess diffusion capacity JF - European Respiratory Journal JO - Eur Respir J VL - 40 IS - Suppl 56 SP - P3220 AU - Elsa Magro AU - Barry Kenedy AU - Sophie Crinion AU - Orla Cotter AU - David Curran AU - Terry O'Connor Y1 - 2012/09/01 UR - http://erj.ersjournals.com/content/40/Suppl_56/P3220.abstract N2 - The single breath method to measure diffusion capacity requires a subject to inspire a gas mixture followed by a 10 ± 2 second breath hold. However, dyspnoea may preclude measurement in patients with advanced pulmonary disease. We sought to determine if breath hold time reduction had a significant effect on measured DLCO values.Forced spirometry and CO-diffusion by the single breath method were performed in duplicate with breath-holding for 10 ± 2 seconds, 8 ± 2 seconds and 6 ± 2 seconds in 30 controls (FEV1 107 ± 12.04% predicted), 30 severe COPD patients (FEV1 37.2 ± 7.92% predicted), and 30 patients with interstitial lung disease (ILD) (FEV1 69.5 ± 17.61% predicted).There was no significant difference between DLCO(SB) and DLCO(VA) measured at 10, 8 and 6 seconds in the control (p=0.4431) and ILD groups (p=0.5915). However, there was a significant difference between DLCO(SB) (p=0.0003) and DLCO(VA) (p=0.0183) measured at 10, 8 and 6 seconds in the COPD group.In the presence of severe airway obstruction the DLCO decreases with breath hold time reduction. However, in healthy controls and patients with ILD, there was no significant change in the DLCO when breath hold time is reduced from 10 to 6 seconds. This could allow for a reduction in breath hold time when measuring the DLCO in patients with advanced ILD who are unable to breath hold for 10 seconds. ER -