TY - JOUR T1 - The importance of stabilizing PaCO<sub>2</sub> during long-term non-invasive ventilation in patients with COPD JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P453 AU - Tomomasa Tsuboi AU - Toru Oga AU - Kensuke Sumi AU - Kazuko Machida AU - Motoharu Ohi AU - Kazuo Chin Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P453.abstract N2 - Background: In subjects with COPD, the importance of changes in PaCO2 during long-term non-invasive ventilation (NIV) on continuation remains uncertain. We intended to elucidate whether stabilizing PaCO2 during NPPV had an advantageous prognostic effect.Methods: Data from 54 subjects with COPD and who received long-term NIV were studied retrospectively. The annual change in PaCO2 during NPPV was determined using a simple linear regression method for each subject who had at least two six-month intervals of PaCO2 data. Annual changes in PaCO2 during long-term NIV and probable confounders were analysed with discontinuation of long-term NIV as the principal consequence.Results: Thirty seven subjects who had more than two six-month intervals of PaCO2 data were involved in this study. PaCO2 during long-term NIV increased slightly in 19 subjects (group 1; less than 2 mmHg/y), and increased greatly in 18 subjects (group 2; more than 2 mmHg/y). In multivariate modality model, lesser annual changes in PaCO2 (P = 0.009) and lesser PaCO2 six months after the start of long-term NIV (P = 0.03) were associated with a significantly higher probability of continuing NPPV. The two- and five-year probabilities of continuing NIV for group-1 were 89% and 66%, respectively, while those for group-2 were 78% and 32%, respectively.Conclusion: A decrease in not only the PaCO2 six months after the start of long-term NIV but the annual change of PaCO2 during long-term NIV was shown to be a significantly prognostic variable. ER -