Clinical variables predicting the risk of a hospital stay for longer than 7 days in patients with severe acute exacerbations of chronic obstructive pulmonary disease: a prospective study

BackgroundChronic obstructive pulmonary disease (COPD) patients may experience an acute exacerbation (AECOPD) that requires hospitalisation. The length of hospital stay (LHS) has a great economic impact on the health-care system. Knowing the predictors of prolonged LHS could help to identify possible interventions.MethodsWe performed a prospective study to identify the clinical predictors of prolonged LHS in patients hospitalised for AECOPD. We divided the study sample by LHS into normal (7days) and prolonged LHS (>7days) groups. Outcomes were the need for non-invasive and invasive mechanical ventilation (NIMV and IMV), intensive care unit (ICU) admission, and the 3-year mortality.ResultsWe enrolled 437 patients, of which 213 and 224 had normal LHS and prolonged LHS, respectively. Patients with a prolonged LHS had more prior hospitalisations for AECOPD, a worse mMRC (modified Medical Research Council) dyspnoea score, a higher prevalence of long-term oxygen therapy and a higher rate of congestive heart disease. During the current admission, this group also tended to require NIMV, IMV and ICU admission and the mortality risks at 6months, 1year and 3years were higher. In the multivariate regression analysis, an mMRC dyspnoea score2 (odds ratio-OR 2.24; 95% confidence interval-CI 1.34 to 3.74; p=0.002) and the presence of acute respiratory acidosis (OR 2.75; 95% CI 1.49 to 5.05; p=0.001) predicted a prolonged LHS at admission.ConclusionsThe presence of an mMRC 2 and acute respiratory acidosis at admission independently increased the risk of a prolonged LHS for AECOPD.