@article {Tsuboi1671, author = {Tomomasa Tsuboi and Toru Oga and Kensuke Sumi and Kazuko Machida and Motoharu Ohi and Kazuo Chin}, title = {The Importance of Controlling PaCO2 Throughout Long-Term Noninvasive Ventilation}, volume = {59}, number = {11}, pages = {1671--1678}, year = {2014}, doi = {10.4187/respcare.02829}, publisher = {Respiratory Care}, abstract = {BACKGROUND: The significance of changes in PaCO2 during long-term noninvasive ventilation (NIV) on prognosis remains unclear. We aimed to clarify whether stabilizing PaCO2 during NIV had a favorable prognostic effect. METHODS: Data from 190 subjects with restrictive thoracic disease and who received long-term NIV were studied retrospectively. The annual change in PaCO2 during NIV was determined using a simple linear regression method for each subject who had at least 4 6-month intervals of PaCO2 data. Annual changes in PaCO2 during long-term NIV and possible confounders were analyzed with discontinuation of long-term NIV as the main outcome. RESULTS: One hundred and twenty-five subjects who had \> 4 6-month intervals of PaCO2 data were included in the study. PaCO2 during long-term NIV decreased in 41 subjects (group 1; \< 0 mm Hg/y), increased slightly in 42 subjects (group 2; between 0 and 1.85 mm Hg/y), and increased significantly in 42 subjects (group 3; \> 1.85 mm Hg/y). Smaller annual changes in PaCO2 (P \< .001) and a control ventilator mode (P = .008) were associated with a significantly higher probability of continuing NIV, compared with decreased PaCO2 3{\textendash}6 months after the start of long-term NIV (P = .11). The 10-y probability of continuing NIV was 69\% in group 1, 39\% in group 2, and 12\% in group 3. CONCLUSIONS: A decrease in the annual change of PaCO2 during long-term NIV was shown to be a significantly prognostically favorable factor. Efforts to reduce PaCO2 should be made if PaCO2 increases at a greater rate during long-term NIV.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/59/11/1671}, eprint = {https://rc.rcjournal.com/content/59/11/1671.full.pdf}, journal = {Respiratory Care} }