What Is the Appropriate Use of Antibiotics In Acute Exacerbations of COPD?

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Chest X-ray of enlarged, hyperinflated lungs, typical of patients with chronic obstructive pulmonary disease (COPD).

Case

A 58-year-old male smoker with moderate chronic obstructive pulmonary disease (COPD) (FEV1 56% predicted) is admitted with an acute exacerbation of COPD for the second time this year. He presented to the ED with increased productive cough and shortness of breath, similar to prior exacerbations. He denies fevers, myalgias, or upper-respiratory symptoms. Physical exam is notable for bilateral inspiratory and expiratory wheezing. His sputum is purulent. He is given continuous nebulizer therapy and one dose of oral prednisone, but his dyspnea and wheezing persist. Chest X-ray does not reveal an infiltrate.

Should this patient be treated with antibiotics and, if so, what regimen is most appropriate?

Overview

Acute exacerbations of COPD (AECOPD) present a major health burden, accounting for more than 2.4% of all hospital admissions and causing significant morbidity, mortality, and costs.¹ During 2006 and 2007, COPD mortality in the United States topped 39 deaths per 100,000 people, and more recently, hospital costs related to COPD were expected to exceed $13 billion annually.² Patients with AECOPD also experience decreased quality of life and faster decline in pulmonary function, further highlighting the need for timely and appropriate treatment.¹

Several guidelines have proposed treatment strategies now considered standard of care in AECOPD management.^3,4,5,6 These include the use of corticosteroids, bronchodilator agents, and, in select cases, antibiotics. While there is well-established evidence for the use of steroids and bronchodilators in AECOPD, the debate continues over the appropriate use of antibiotics in the treatment of acute exacerbations. There are multiple potential factors leading to AECOPD, including viruses, bacteria, and common pollutants; as such, antibiotic treatment may not be indicated for all patients presenting with exacerbations. Further, the risks of antibiotic treatment—including adverse drug events, selection for drug-resistant bacteria, and associated costs—are not insignificant.

However, bacterial infections do play a role in approximately 50% of patients with AECOPD and, for this population, use of antibiotics may confer important benefits.⁷

Interestingly, a retrospective cohort study of 84,621 patients admitted for AECOPD demonstrated that 85% of patients received antibiotics at some point during hospitalization.⁸

Support for Antibiotics

Several randomized trials have compared clinical outcomes in patients with AECOPD who have received antibiotics versus those who received placebos. Most of these had small sample sizes and studied only ββ-lactam and tetracycline antibiotics in an outpatient setting; there are limited data involving inpatients and newer drugs. Nevertheless, antibiotic treatment has been associated with decreased risk of adverse outcomes in AECOPD.

One meta-analysis demonstrated that antibiotics reduced treatment failures by 66% and in-hospital mortality by 78% in the subset of trials involving hospitalized patients.⁸ Similarly, analysis of a large retrospective cohort of patients hospitalized for AECOPD found a significantly lower risk of treatment failure in antibiotic-treated versus untreated patients.⁹ Specifically, treated patients had lower rates of in-hospital mortality and readmission for AECOPD and a lower likelihood of requiring subsequent mechanical ventilation during the index hospitalization.