X: Manage eXacerbations

X: Manage eXacerbations


Evidence level


 


III-2


II


I


I


II


 


I


 


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 2012) [evidence level II] often require hospital admission for treatment of respiratory failure. A record linkage study in WA (Geelhoed 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 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  2007).

Exacerbations become more frequent as severity of COPD worsens (Hoogendoorn 2010a). In the 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 2010). ECLIPSE data also showed that a history of prior hospitalisation for COPD is the strongest predictor of subsequent hospitalisation. This data also confirmed 12 month mortality rates were significantly higher in patients hospitalised for COPD (15%) compared to those without hospitalisation (5%) (P<0.001) (Mullerova 2015). In a Spanish cohort of (predominantly male) patients prospectively followed, Guerrero et al demonstrated that re-admission to hospital within 30 days following discharge for an acute exacerbation of COPD increased 12 month mortality rates (37% in readmitted vs 17% in non-readmitted patients, p=0.001) and was an independent risk factor for mortality at one year (HR 2.48 CI 1.1-5.59) (Guerrero 2016).

Studies have confirmed that although the prognosis of exacerbations is poor, the prognosis post-exacerbation is improving. Hoogendoorn et al (Hoogendoorn 2010b) 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 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].

Soltani et al (Soltani 2015) prospectively evaluated a cohort of 150 severe COPD patients admitted with AECOPD at an Australian tertiary hospital and reported a 28% readmission rate at three months and a 12 month mortality rate of 24.5%. It should be noted that patients requiring invasive or non-invasive ventilation were excluded from this study.

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 1993, Smith 1980, Soler 1998, Wilson 1998, Stockley 2000, Walsh 1999, Mogulkoc 1999, Murphy 1999, Miravitlles 1999). Exacer­bations can also be caused by viral infection (Seemungal 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 2011) [evidence level II]. Chest trauma and inappropriate use of sedatives can lead to sputum retention and hypoventilation. A systematic review found one of four COPD patients who require hospitalisation for an acute exacerbation may have pulmonary embolism (Rizkallah 2009) [evidence level I]. In a small study, approximately 1 in 5 patients hospitalised with a COPD exacerbation were found to have pulmonary embolism on CTPA (Shapira-Rootman 2015). Similarly, a Turkish group performed a CT pulmonary angiogram on 138 consecutive patients admitted with an exacerbation of COPD and found pulmonary embolism in 14% of patients (Gunen 2010).

Early diagnosis and treatment of exacerbations may prevent admission (Wilkinson 2004) [evidence level III-2].

Prolonged COPD exacerbations are associated with worse health status and the exacerbation that follows occurs sooner. A failure of airway function to return to pre-exacerbation levels is associated with symptoms of cold and sore throat (viral infections), and patients who have these events have a faster decline in FEV1. Patients with non-recovered exacerbations showed a 10.8 ml/yr (p=001) faster decline in FEV1 (Donaldson 2015).

Early diagnosis and prompt management of exacerbations of COPD may prevent progressive functional deterioration and reduce hospital admissions (Lorig 1999Shepperd 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://lungfoundation.com.au/health-professionals/clinical-resources/copd/copd-action-plan/. This plan might indicate which medications to take, including antibiotics and oral corticosteroids. The plan should also require patients to contact their GPs or community nurses to allow rapid assessment (see section D).

Statins have been shown to reduce rates of hospitalization (for COPD or any other reason), lung-function decline, the need for mechanical ventilation, and all-cause mortality in observational studies of COPD patients. The Prospective Randomized Placebo-Controlled Trial of Simvastatin in the Prevention of COPD Exacerbations (STATCOPE) examined the effect of daily treatment with simvastatin in patients with moderate-to-severe COPD who were at high risk for exacerbations and had no other indications for statin treatment. Simvastatin at a daily dose of 40 mg for at least 12 months did not affect exacerbation rates or the time to a first exacerbation (Criner 2014) [evidence level II].