Recovery Following Acute Exacerbations of Chronic Obstructive Pulmonary Disease - A Review

Acute exacerbations are associated with disease progression, hospital admission and death in people with chronic obstructive pulmonary disease (COPD). The detrimental outcomes associated with acute exacerbations highlights a need to understand the time course of recovery following acute exacerbation of COPD (AECOPD) so that effective and timely interventions can be provided. The aim of this narrative review was to describe the natural recovery in physiology, symptoms and function following AECOPD. Substantial recovery of lung function and airway inflammation occurs in the first week after onset of an AECOPD, whilst systemic inflammatory markers may take up to two weeks to recover. Symptoms generally improve over the first 14 days, however marked variation is evident between studies and individuals. There are limited data regarding the time course of recovery for functional capacity, quality of life and strength. In a small number of patients (<10%) recovery of lung function and symptoms has not occurred by three months. Features of patients at risk of a prolonged recovery following AECOPD include older age, more severe lung disease, presence of chronic bronchitis, lower body mass index and more chronic dyspnoea. Exacerbation features associated with prolonged recovery are symptoms of the common cold at exacerbation onset, evidence of viral infection, more severe dyspnoea during the exacerbation and persistent systemic inflammation. In clinical practice efforts should be made to recognise prolonged recovery, which puts patients at risk of poor outcomes, and to address the consequences of AECOPD including physical inactivity and skeletal muscle weakness. Whether delivery of specific interventions at distinct time points in the recovery process can enhance recovery remains to be determined.