To analyze the clinical characteristics and distribution of pathogens in adult acute empyema.

Adult patients with acute empyema were divided into the control group (patients with community-acquired empyema) and the treatment group (patients with hospital-acquired empyema) according to cohort method. The general data, clinical manifestations, laboratory examinations, imaging data, antimicrobial drugs use, invasive treatment and outcomes of the two groups were collected and compared.

There were 59 cases in the treatment group and 102 cases in the control group. Compared with the control group, the proportion of lung abscess in the treatment group was lower (1.69% vs 10.78%, P<0.05), the proportion of pneumothorax, positive rates of pus culture and mixed infection were higher (47.46% vs 18.63%, 55.93% vs 24.51%, 27.12% vs 1.96%, all P<0.05). In the control group, 27 strains of pathogens were isolated, predominantly Gram-positive cocci (74.07%), with Streptococcus anginosus group being the most common (44.44%). In the treatment group, 52 strains were isolated, predominantly Gram-negative bacilli (67.31%), with Pseudomonas aeruginosa being the most common (21.15%). Streptococcus anginosus group was sensitive to penicilins and cephalosporins, while the multidrug resistance rate of Gram-negative bacilli was high, with Pseudomonas aeruginosa showing a 69.23% resistance to meropenem. Six patients in total died, all from the treatment group and receiving non-surgical treatment, due to malignant tumors or hospital-acquired pneumonia.

In adult acute empyema, non-parapneumonic empyema is common, and there were significant differences in the pathogenic distribution between community-acquired empyema and hospital-acquired empyema.