ObjectiveTo evaluate the value of serum procalcitonin (PCT) level after conventional intravenous antibiotic treatment to predict the risk of re-exacerbation, and vertify the feasiblity of an additional course of oral antibiotics after discharge to reduce the risk of re-exacerbation. MethodsThe patients who hospitalized in West China Hospital from October 2012 to October 2013 because of infectious acute exacerbation of chronic obstructive pulmonary disease (AECOPD) were recruited. The concentrations of PCT and C-reactive protein (CRP), the number of white blood cell (WBC) and neutrophil percentage at the end of intravenous antibiotic therapy were recorded. The information about additional course of antibiotics was collected according to the medical instruction and visit. The subjects were followed up for 1 year.The time to the first re-exacerbation and frequencies of exacerbations were recorded. The Cox regression model was used to estimate the hazard rations (HR). ResultsOne hundred and thirty-eight eligible patients were included totally. The HRs in PCT≥0.11μg/L and neutrophil percentage≥70% were 1.462 (P=0.035) and 1.673 (P=0.005) respectively, suggesting higher risk of re-exacerbation. There was no relationship of CRP (P=0.330) or WBC (P=0.432) with the risk of re-exacerbation. Generally an additional course of antibiotics had no effects on re-exacerbation (P=0.231) but this therapy could reduce the risk of re-exacerbation in high PCT level group (HR=2.29, P=0.004). ConclusionsSerum PCT concentrations and neutrophil percentage after conventional intravenous antibiotic treatment can predict the risk of re-exacerbations in the future. An additional course of antibiotics in the patients with high PCT level can reduce the risk of re-exacerbation.