Objective: Predictors of the need to initiate noninvasive ventilation (NIV) in stable COPD outpatients with acute exacerbation of chronic obstructive pulmonary disease (COPD-AE) are insufficiently defined. The objective of this study was to investigate predictors of the need to initiate NIV in stable COPD-AE outpatients.
Methods: A total of 140 consecutive stable COPD outpatients who were hospitalized for COPD-AE for the first time were retrospectively examined. Demographic and clinical parameters measured in the stable state were evaluated, including data for arterial blood gases, the pulmonary function, body mass index and dyspnea scores.
Results: Of the 140 patients included, NIV was used in 32 (23%) patients. In a univariate Cox proportional hazards analysis, the baseline partial pressure of arterial carbon dioxide (PaCO2) (hazard ratio (HR), 1.14 per mmHg; 95% confidence interval (CI), 1.08-1.21) and forced expiratory volume in one second (FEV1)% predicted (HR, 1.03 per %; 95% CI, 1.01-1.05) were identified to be significant predictors. A multivariate logistic regression analysis showed only the PaCO2 (HR, 1.18 per mmHg; 95% CI, 1.12-1.26) to be a significant predictor.
Conclusion: Our results suggest that the PaCO2 measured in the stable state is an independent significant predictor of the need to initiate NIV in COPD-AE patients who are hospitalized for the first time.