POEMs Research Summaries
Is it possible to identify exacerbations of mild to moderate chronic obstructive pulmonary disease that do not require antibiotic treatment?
Among patients with an exacerbation of mild to moderate chronic obstructive pulmonary disease (COPD), those with a C-reactive protein (CRP) level greater than 40 mg/L and those with sputum purulence are at increased risk for treatment failure without antibiotics. Other patients are unlikely to benefit from antibiotics and would be candidates for symptomatic therapy and close follow-up. (LOE = 1b)
A recent randomized controlled trial compared amoxicillin/clavulanate with placebo in 310 patients with an exacerbation of mild to moderate COPD (Am J Respir Crit Care Med 2012; 186: 716-23). Clinical failure was defined as incomplete resolution, persistence, or worsening of symptoms on days 9 to 11 that required additional treatment. In that trial, 19% in the placebo group and 10% in the antibiotic group were classified as clinical failures (number needed to treat = 9). In this study, the authors looked only at those who had received placebo (n = 152), all of whom had experienced either increased dyspnea, increased sputum volume, and/or increased sputum purulence as inclusion criteria for the study. Patients with increased dyspnea and/or sputum volume had a 5.6% failure rate, those with sputum purulence alone or sputum purulence with increased dyspnea or sputum volume had a 20.3% failure rate, and those with all 3 symptoms had a 33% failure rate. Patients with a CRP level of less than 40 mg/L had a 12.4% failure rate, compared with a 65% failure rate for those with CRP levels of 40 mg/L or higher. A multivariate analysis found that CRP levels equal to or greater than 40 mg/L (odds ratio [OR] = 13.4; 95% CI, 4.6 – 39) and increased sputum purulence (OR = 6.1; 1.5 – 25) were independent predictors of treatment failure.