Prognostic Marker for Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease: Analysis of Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) and Forced Expiratory Volume in One Second (FEV1)

Background: It is important to assess the prognosis and classify patients in chronic obstructive pulmonary disease (COPD) and acute exacerbation of COPD (AECOPD) treatment. Recently, it was suggested that diffusing capacity of the lung for carbon monoxide (D LCO ) should be added to multidimensional tools for assessing COPD. This study aimed to compare the D LCO and forced expiratory volume in one second (FEV 1 ) to identify better prognostic factors for admitted patients with AECOPD. Methods: : We retrospectively analyzed 342 patients with AECOPD receiving inpatient treatment. We classified 342 severe AECOPD events using D LCO and FEV 1 . We defined the prognostic factors of severe AECOPD as the length of hospital stay, mortality in hospital, experience of mechanical ventilation, and experience of intensive care unit (ICU) care. We analyzed the prognostic factors by multivariate analysis using logistic regression. In addition, we conducted a correlation analysis and receiver operating characteristic (ROC) curve analysis. Results: : In univariate and multivariate analyses, D LCO was shown to predict mortality rate (odds ratio = 4.408; 95% confidence interval, 1.070–18.167; P = 0.040), experience of ventilator (odds ratio = 2.855; 95% confidence interval, 1.216–6.704; P = 0.016) and ICU (odds ratios = 2.685; 95% confidence interval, 1.290–5.590; P = 0.008). However, there was no statistically significant difference in mortality rate when using FEV 1 classification ( P = 0.075). In the correlation analysis, both D LCO and FEV 1 showed a negative correlation with length of hospital stay. The correlation rate was more pronounced in the D LCO (D LCO ; B = -0.103, P < 0.001) (FEV 1 ; B = -0.075, P = 0.007). In addition, D LCO showed better predictive ability than FEV 1 in ROC curve analysis. The area under the curve (AUC) of D LCO was greater than 0.68 for all prognostic factors, and in contrast, the AUC of FEV 1 was less than 0.68. Conclusion: D LCO was likely to be as good as or better prognostic marker than FEV 1 in severe AECOPD.