Lowering P With Noninvasive Ventilation Is Associated With Improved Survival in Chronic Hypercapnic Respiratory Failure.

Background: Chronic hypercapnic respiratory failure is associated with high mortality. Although previous work has demonstrated a mortality improvement with high-intensity noninvasive ventilation in COPD, it is unclear whether a P reduction strategy is associated with improved outcomes in other populations of chronic hypercapnia.

Methods: The objective of this study was to investigate the association between P reduction (by using transcutaneous P as an estimate for P and survival in a broad population of individuals treated with noninvasive ventilation for chronic hypercapnia. We hypothesized that reductions in P would be associated with improved survival. Therefore, we performed a cohort study of all the subjects evaluated from February 2012 to January 2021 for noninvasive ventilation initiation and/or optimization due to chronic hypercapnia at a home ventilation clinic in an academic center. We used multivariable Cox proportional hazard models with time-varying coefficients and P as a time-varying covariate to test the association between P and all-cause mortality and when adjusting for known cofounders.

Results: The mean ± SD age of 337 subjects was 57 ± 16 years, 37% women, and 85% white. In a univariate analysis, survival probability increased with reductions in P to < 50 mm Hg after 90 d, and these remained significant after adjusting for age, sex, race, body mass index, diagnosis, Charlson comorbidity index, and baseline P . In the multivariable analysis, the subjects who had a P < 50 mm Hg had a reduced mortality risk of 94% between 90 and 179 d (hazard ratio [HR] 0.06, 95% CI 0.01-0.50), 69% between 180 and 364 d (HR 0.31, 95% CI 0.12-0.79), and 73% for 365-730 d (HR 0.27, 95% CI 0.13-0.56).

Conclusions: Reduction in P from baseline for subjects with chronic hypercapnia treated with noninvasive ventilation was associated with improved survival. Management strategies should target the greatest attainable reductions in P .