Different Bacteriology and Prognosis of Thoracic Empyemas Between Patients With Chronic and End-Stage Renal Disease

BackgroundBacterial infections are a well-documented complication in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). However, there are no previous studies of the empyemas that can develop in these patients.MethodsThis retrospective study investigated the bacteriology and outcomes of empyema in stage 4 CKD (predialysis) and ESRD patients receiving long-term dialysis and treated in a tertiary university hospital from January 2001 to March 2006.ResultsEighty-four stage 4 CKD patients and 40 ESRD patients had empyemas. Most empyemas (n = 77, 62%) were secondary to pneumonia. Empyema culture findings were positive in 102 patients (82%): 87 microorganism were isolated in pleural fluid from 67 stage 4 CKD patients, and 39 microorganisms were isolated in pleural fluid from 35 ESRD patients. Aerobic Gram-negative organisms (n = 58, 67%), especially Klebsiella pneumoniae (n = 20, 34%), were the predominant pathogens in stage 4 CKD patients; aerobic Gram-positive organisms (n = 21, 54%), especially Staphylococcus aureus (n = 14, 67%), were the main pathogens in ESRD patients. Compared to stage 4 CKD patients, ESRD patients had a significantly higher percentage of catheter infections (p = 0.002) and aerobic Gram-positive organism bacteremia (p = 0.001), as well as a lower aerobic Gram-negative organism infection rate (p < 0.001) and a lower infection-related mortality rate (p = 0.022).ConclusionStage 4 CKD patients and ESRD patients with empyema have different causative pathogens and outcomes. In ESRD patients, the dialysis catheter or the dialysis process appear to alter the microbiological flora responsible for empyema. This finding has clinical implications that clinicians need to consider.