[Prognosis following acute exacerbation of COPD treated with non-invasive mechanical ventilation]

Abstract

Introduction: Patients with chronic obstructive pulmonary disease (COPD) who survived an acute exacerbation with acute respiratory failure that required non-invasive mechanical ventilation (NIMV) are a group with a poor medium-term prognosis.

Objective: To identify re-admission and mortality rates within one year from discharge and to analyse factors associated with both events in a consecutive series of COPD patients treated with NIMV.

Methods: A cohort of 93 COPD patients who survived an acute exacerbation and who required NIMV was followed up after discharge. Re-admissions due to respiratory causes and survival were measured and the outcomes were analysed against possible factors associated to such events using multivariate Cox proportional risk regression analysis.

Results: Over the year following discharge, 61 patients (66%) had to be re-admitted into hospital due to respiratory complications. Upon multivariate analysis, a low FEV(1) value in stable phase and a high average length of stay were associated independently with a high risk of hospital readmission. The probability of survival at 1 year was 0.695. Age, PaCO(2) prior to initiation of NIMV and the number of hospitalisation days in the previous year were associated independently with a high mortality risk.

Conclusions: This group of COPD patients has a high mortality rate and need for re-hospitalisation in the ensuing year following discharge. The variables relating to the severity of the baseline disease and the actual exacerbation have been shown to be associated with these events, and could be applied to this subgroup of patients in specific follow-up programs.