Objectives: More effective management of chronic obstructive pulmonary disease (COPD) and improved survival of COPD patients requires a better understanding of the risk factors for exacerbation. The aim of this study was to identify factors related to readmission in patients with moderate-to-severe COPD.
Patients and methods: Ninety patients with moderate-to-severe COPD hospitalized consecutively for acute exacerbation were studied prospectively. At discharge, the following potential predictors were assessed: clinical and spirometric variables, arterial blood gases, and respiratory muscle strength determined noninvasively. The patients were followed for a period of 3 months. Readmission for exacerbation and time intervals free of hospitalization were recorded.
Results: Univariate analysis showed that the presence of cor pulmonale (P<.05), long-term oxygen therapy (P<.05), hypercapnia (P<.05), and high inspiratory load--mean inspiratory airway pressure measured at the mouth exceeding 0.40 cm H2O and a pressure-time index greater than 0.25 (P<.05 for both variables)--increased the risk of hospitalization for exacerbation. Multivariate analysis showed that only cor pulmonale (P<.05) and a high pressure-time index (>0.25, P<.05) were independently related to risk of readmission.
Conclusions: Cor pulmonale and a high pressure-time index are independent risk factors for hospitalization for exacerbation of moderate-to-severe COPD.