The changing pathogens of complicated parapneumonic effusions or empyemas in a medical intensive care unit.

OBJECTIVES: To assess the incidence, pathogens, and outcome of complicated parapneumonic effusions or empyemas in a medical intensive care unit (MICU) patients with pleural effusions.

DESIGN AND SETTING: Prospective study of febrile MICU patients with pleural effusion carried out in a tertiary care hospital between April 2001 and September 2003.

PATIENTS: The study included 175 patients with a temperature above 38 degrees for more than 8 h with evidence of pleural effusion confirmed by chest radiography and ultrasound.

INTERVENTION: Routine thoracentesis and effusion cultures.

RESULTS: The prevalence of complicated parapneumonic effusions or thoracic empyemas in febrile MICU patients with pleural effusions was 45% (78/175). A total of 78 micro-organisms were isolated from the pleural fluid of 58 patients (positive microbiological culture 74%) including aerobic Gram-negative (n=45), aerobic Gram-positive (n=23), anaerobic (n=5), Myobacterium tuberculosis (n=3), and Candida (n=2). The infection-related mortality rate of complicated parapneumonic effusions or empyemic patients in the MICU was 41% (32/78).

CONCLUSION: The development of complicated parapneumonic effusions or thoracic empyemas in MICU patients is a high-mortality disease. The increasing incidence of aerobic Gram-negative pathogens in empyema has become a more urgent problem.