Background Chronic

obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction due to chronic bronchitis or emphysema.1,2 In Canada, its estimated prevalence is 5.7%.3 Among the five most common diseases, its morbidity and mortality are the only ones that continue to rise4, and are expected to rise further. For these reasons, the importance of managing COPD will increase. The natural course of COPD is that of repeated acute exacerbations (AEs) which are defined as changes in purulence, viscosity or volume of sputum production and/or an increase in dyspnea5, and may be associated with other symptoms such as increased cough or wheeze, for at least two consecutive days.6 The mean frequency of AEs in patients with severe COPD is one to four per year.6-8 Three to 16 % require hospitalization6,9 and in severe AEs, mortality is up to 10%.10,11 Although increased inflammatory activity and worsened airway obstruction are found during AEs12, infections (viral, bacterial or a combination of the two) account for up to 80%.13-17 The recommended treatments are based on anti-inflammatory and anti-microbial mechanisms. Diagnosis of Acute Exacerbations of COPD Diagnosis of an AE is made using the history and physical examination and must rule out other potential causes for illness.18 General laboratory work is not recommended except for arterial blood gases19 which help determine the need for assisted ventilation in patients presenting with low oxygen saturation.18,20 Sputum studies should be obtained in patients with “very poor lung function, frequent AEs or who have been on antibiotics in the previous three months ” to optimize antibiotic treatment and minimize drug resistance.18 Additionally, chest x-rays are recommended for patients presenting with severe AEs, to rule out other pathology, as an estimated 16 to 21 % of those arriving at acute care settings have x-ray findings requiring adjustments to treatment.20,21 As spirometry is difficult to obtain during AE, it is not recommended for patients with known respiratory disease. Otherwise, spirometry may be indicated with full PFTs recommended once the patient is stable.18,2