The lung ‘microbiome’ is likely to be one of the factors involved in exacerbation risk; the more pathogens present in the lower airways, the worse the COPD outcome. Patients with COPD may have lower airways colonised by bacteria including Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Pseudomonas aeruginosa and Staphylococcus aureus may colonise airways of patients with severe airflow obstruction, and appear associated with more frequent exacerbations and worse outcomes. Identification of these patients may highlight a higher exacerbation risk (and also direct antibiotic management when needed). Other causes of exacerbations include left ventricular failure, pulmonary embolus and urban air pollutants.
Exacerbations may be triggered by respiratory tract infections, either viral or bacterial. In a recent retrospective study in Australian hospitals, the most common viruses isolated in patients presenting with COPD exacerbations were influenza virus, rhinovirus and respiratory syncytial virus A/B.11 Patients who do not receive influenza vaccination are at higher risk.
Optimising baseline COPD management
Ensuring that each patient’s usual COPD management is effective and appropriate will help in reducing both exacerbations and the impact of exacerbations. The Australian and New Zealand COPD guidelines are regularly updated. The current version is available online through the Lung Foundation Australia website (https://copdx.org.au).10 These guidelines are known as the COPD-X plan, from:
C – confirm diagnosis
O – optimise function
P – prevent deterioration
D – develop a self-management plan and manage
X – exacerbations.
An approach to the management of patients with COPD based on these guidelines is discussed in this article.
Referral of patients
Referral of patients to a respiratory physician should be considered if their COPD is moderate to severe, the diagnosis is unclear or complications such as cor pulmonale are present (Box 2).10
Management strategies in patients with COPD focus on the relief of symptoms, the prevention of disease progression, and the prevention and treatment of exacerbations and complications, with the aims of improving exercise tolerance and health status, and reducing mortality. The extents to which these goals can be realised vary with each patient, and some treatments will produce benefits in more than one area. Treatments include both pharmacological and nonpharmacological therapies.
In addition, patients with COPD are often elderly and frequently have comorbidities such as cardiac failure, diabetes and gastro- oesophageal reflux disease. These issues may be worsened by COPD medications, and the comorbidities themselves may aggravate symptoms of COPD such as dyspnoea. Osteoporosis risk should be specifically assessed as it is common in this patient group, and may be worsened by corticosteroid use.