Sputum purulence-guided antibiotic use in hospitalised patients with exacerbations of COPD

In patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) needing hospitalisation, sputum purulence is associated with bacteria in the lower respiratory tract. We performed a prospective non-randomised interventional pilot study applying a sputum purulence-guided strategy of antibiotic treatment and investigating the relationship between sputum purulence and biomarkers. In hospitalised patients with acute exacerbation of COPD antibiotics were restricted to those with purulent sputum. The primary end-point was rate of therapeutic failure during hospitalisation. Secondary end-points were parameters reflecting short- and long-term outcomes. We included 73 patients, 34 with non-purulent sputum. No differences were observed on therapeutic failure criteria (9% non-purulent versus 10% purulent (p=0.51)). Serum C-reactive protein (CRP) was significantly increased in the purulent group at admission (11.6 versus 5.3, p=0.006) and at day 3 (2.7 versus 1.2, p=0.01). Serum procalcitonin (PCT) was similar between the groups. No differences were found in short-term outcomes. The exacerbation rate at 180 days was higher in the purulent group. These results support the hypothesis of performing a randomised trial using a sputum purulence-guided antibiotic treatment strategy in patients with acute exacerbations of COPD. CRP, but not PCT, may be a useful parameter to increase confidence of the absence of bacterial bronchial infection.