Bacteremia and septic shock after solid-organ transplantation

Background. Bacteremia and septic shock remain important causes of morbidity and mortality after solid-organ transplantation. The aim of this study was to assess the characteristics and risk factors for mortality among patients with bloodstream infections and shock. Methods. From January 1991 to December 2000, all episodes of bloodstream infection were prospectively examined, considering bacteremia or fungemia as significant according to the CDC criteria. Septic shock was diagnosed in a patient with systemic inflammatory response syndrome and persistent dysfunction of at least one organ caused by hypoperfusion despite hemodynamic support. Results. There were 466 episodes of bacteremia in 382 patients, with 66 of them developing septic shock. Risk factors for developing shock were age > 50 (P =.006), liver transplant (P =.029), nosocomial infection (P =.034), pulmonary focus (P =.0001), P. aeruginosa infection (P =.001), and polymicrobial etiology (P =.039). On multivariate analysis, only age, nosocomial infection, and pulmonary source were significant. Among 66 shock patients, bacteremia was due to gram-negative bacteria in 53%, gram-positive bacteria in 24%, fungal in 7.5%, and polymicrobial in 12% of patients. The most frequent source was the lung (26%). Empiric antimicrobial therapy was correctly chosen in 79%; however, 36 patients died (54%), including 27 despite correct therapy. Urinary tract infections had less mortality than other foci. Conclusions. Risk factors for developing septic shock in bacteremia were age more than 50 years, nosocomial acquisition, and pulmonary focus. Despite adequate empiric antibiotic therapy, the mortality remained high.