ABSTRACT
Objective To investigate the feature of the microorganisms colonization of the thoracic catheter-related infection and evaluate the clinical significance of prophylactic antibiotics administration in patients with pneumothorax treated with closed thoracic drainage. Method A total of 120 patients with pneumothorax treated with closed thoracic dramage in emergency department wore enrolled. The patients were randomized (random number) into group A (n =60) and group B (n =60). In group A, the patients received levofloxacin mesylate injection and in group B, patients received physiological saline injection instead after closed thoracic drainage. The tip of catheter was cut off to get a 2-cm long segment after catheter removal and this segment was dipped into a bottle filled with liquid culture medium for microorganism culture. Statistical analysis carried out by using χ2 test or Fisher exact test. Results Of all 120 patients, microorganisms were found in 49 segments of catheter and 57 strains of microorganisms were found. The four most common microorganisms were Coagulase-negative staphylococci (57.9%), Candida albicans (10. 5%),Staphylococcus aureus (7%) and Acinetobacter baumanii (7%). All of them were highly drug-resistant to β-1actam antibiotics. The difference in the positive rate of microorganism culture was distinct in pneumothorax patients with underlying diseases (50%) in comparison to the patients without underlying diseases (31%) (P ＜ 0.05). The positive rate of microorganism culture increased significantly as the duration of drainage was longer than 14 days (P ＜ 0.01). The positive rate of culture in group A was lower than that in group B if the duration of drainage was less than 7 days (8.3% vs 52.9%, P ＜ 0.01). The positive rate of culture after drainage for 7 days was 21.4% in group A and 68.8% in group B (P ＜0.05), and that after drainage for over 14 days was 70% in both groups (P ＞ 0.05). There were no significant differences in outcome and days of hospital stay between two groups (P ＞ 0. 05). Conclusions The common colonized microorganisms of thoracic catheter-related infection are conditional pathogens and highly resistant to antibiotics. Lengthening the duration of drainage and having underlying diseases increase the risk of infection. Although prophylactic antibiotics administration is beneficial to decrease the risk of thoracic catheter-related infection, it has no effects on shortening hospital stay and outcome of disease.