X: Manage eXacerbations

An exacerbation is an event in the natural course of the disease characterised by a change in the patient’s baseline dyspnoea, cough, and/or sputum that is beyond normal day-to-day variations, is acute in onset, and may warrant a change in regular medication in a patient with underlying COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD), 2006)

Acute exacerbations of COPD which are more frequent in the winter months in temperate climates(Jenkins et al., 2012) [evidence level II] often require hospital admission for treatment of respiratory failure. A record linkage study in WA (Geelhoed et al., 2007) demonstrated that the rate of hospital admission for COPD has been declining. The risk of readmission was highest within three months of discharge and more than half of all patients were readmitted within 12 months. About 10% of patients with a primary diagnosis of COPD died either during admission or within the same year. Median survival from first admission was five years in men and eight years in women. The poorest survival was among older patients with recognised emphysema. In one study of more than 1000 patients admitted to several hospitals with an acute exacerbation of severe COPD, about 50% were admitted with a respiratory infec­tion, 25% with congestive cardiac failure, and 30% with no known cause for the exacerbation. (Connors et al., 1996) A study of 173 patients with COPD reported an average of 1.3 (range 0–9.6) exacerbations annually. An ecological study of hospital admissions for COPD in Victoria found higher rates of admission in rural and remote areas with greater socioeconomic disadvantage and higher rates of smoking. (Ansari et al., 2007)

Exacerbations become more frequent as severity of COPD worsens. (Hoogendoorn et al., 2010a) In the recently reported study by the ECLIPSE investigators, exacerbation rate increased with increasing GOLD stage, such that 22% of patients with GOLD stage 2 disease had two or more exacerbations during one year of follow-up, whereas 47% of patients with GOLD stage 4 disease had frequent exacerbations over the same period. The single best predictor of exacerbations across all GOLD stages was prior exacerbations. Other predictors included a history of heartburn , poorer quality of life and elevated white cell count (Hurst et al., 2010). Recent studies have confirmed that although the prognosis of exacerbations is poor, it is improving. Hoogendoorn et al (Hoogendoorn et al., 2010c) identified six cohort studies that followed the survival of COPD patients for at least 1.5 years after a severe exacerbation resulting in hospitalisation. A meta-analysis resulted in a weighted average case-fatality rate of 15.6% (95%CI 10.9-20.3). The excess risk of mortality continued after discharge from hospital. Almagro et al (Almagro et al., 2010) prospectively examined three year mortality after a severe exacerbation resulting in hospitalisation in two well matched cohorts seven years apart (1996/97 and 2003/04). The 1996/97 three year survival rate was 53% and the 2003/4 three year survival rate was significantly improved at 61% ( log rank p = 0.017). The 2003/4 cohort had increased usage of tiotropium, long acting beta₂ agonists, angiotensin receptor blockers, statins and anti-platelet therapy. The authors speculated that the increased survival may be due to improved treatment options for COPD and co-morbidities including cardiac disease. [evidence level III-2]

In patients with COPD the normally sterile lower airway is frequently colonised by Haemophilus influenzae, Streptococ­cus pneumoniae and Moraxella catarrhalis. While the number of organisms may increase during exacerbations of COPD, the role of bacterial infection is controversial. (Macfarlane et al., 1993, Smith et al., 1980, Soler et al., 1998, Wilson, 1998, Stockley et al., 2000, Walsh et al., 1999, Mogulkoc et al., 1999, Murphy et al., 1999, Miravitlles et al., 1999) Exacer­bations can also be caused by viral infection (Seemungal et al., 2001) other causes include left ventricular failure and pulmonary embolus. A panel study of patients with moderate to severe COPD demonstrated that exacerbations could also be triggered by urban air pollutants such as PM10, black smoke and NO2(Peacock et al., 2011)[evidence level II]. Chest trauma and inappropriate use of sedatives can lead to sputum retention and hypoventilation. A diagnosis of pulmonary embolism should be considered in patients with an intermediate to high pretest probability of pulmonary embolism. A systematic review found one of four COPD patients who require hospitalisation for an acute exacerbation may have pulmonary embolism (Rizkallah et al., 2009) [evidence level I].

Early diagnosis and treatment may prevent admission (Wilkinson et al., 2004) [evidence level III-2]

Early diagnosis and prompt management of exacerbations of COPD may prevent progressive functional deterioration and reduce hospital admissions. (Lorig et al., 1999),(Shepperd et al., 1998) Education of the patient, carers, other support people and family may aid in the early detection of exacerbations. A self-management plan devel­oped in conjunction with the patient’s GP and specialist to indicate how to step-up treatment may be useful (see examples at http://www.lungfoundation.com.au/professional-resources/general-practice/copd-action-plan. This plan might indicate which medications to take, including antibiotics and oral glucocorticoids. The plan should also require patients to contact their GPs or community nurses to allow rapid assessment (see section D).