Clinical question: Which criteria identify ambulatory patients with exacerbations of mild to moderate COPD who do not need antibiotics?
Background: The Anthonisen criteria (increased dyspnea, sputum volume, sputum purulence) are commonly used to identify which patients with COPD exacerbations would benefit from antibiotics. These criteria, however, were derived in patients with severe COPD. It is unknown whether these criteria are predictive in patients with mild to moderate COPD.
Study design: Multivariate logistic regression analysis of placebo group of a double-blinded RCT.
Setting: Multicenter, ambulatory, primary care clinics in Spain.
Synopsis: The original RCT enrolled 310 ambulatory patients with exacerbations of mild to moderate COPD and tested the efficacy of amoxicillin/clavulanate. Clinical failure without antibiotics was 19.9% compared to 9.5% with antibiotics (P=0.022). Here they analyzed the 152 patients from the placebo group to identify factors associated with increased risk of clinical failure. Only increased sputum purulence (OR 6.1, CI 1.5-25; P=0.005) or C-reactive protein (CRP) >40 mg/L (OR 13.4, CI 4.5-38.8, P<0.001) were independently associated with increased risk of failure. Presence of both predicted a 63.7% failure without antibiotics.
The study did not define “increased sputum purulence,” but this is similar to real-life clinical practice. Placebo effect cannot be ruled out, but correlation of the objective measures with the clinical assessments suggests that the clinical assessments were accurate. The study did not have a protocol for administering co-medications such as steroids and inhalers. Despite these limitations, the criteria of increased sputum purulence and CRP >40 mg/L identified COPD patients likely to have a clinical failure without antibiotics.
Bottom line: Patients with exacerbations of mild to moderate COPD who do not have increased sputum purulence or CRP >40 mg/L can be safely managed without antibiotics.
Citation: Maravitlles M, Moravas A, Hernandez S, Bayona C, Llor C. Is it possible to identify exacerbations of mild to moderate COPD that do not require antibiotic treatment? Chest. 2013;144(5):1571-1577.
