Recent experience with Pseudomonas aeruginosa bacteremia in patients with cancer -: Retrospective analysis of 245 episodes

Background: Pseudomonas aeruginosa bacteremia is a serious and possibly fatal condition in patients with cancer. Objectives: To ascertain the frequency, demographics, and predisposing factors for P aeruginosa bacteremia in patients with cancer and to determine the efficacy of various therapeutic regimens. Subjects and Methods: Patient records of the Clinical Microbiology Laboratory, The University of Texas, M. D. Anderson Cancer Center, Houston, were reviewed. From January 1, 1991, through December 31, 1995, 245 eligible cases of P aeruginosa bacteremia were identified. We examined the patient records for the underlying malignant neoplasm and its management, symptoms and signs of infection, culture results of appropriate specimens, antibiotic therapy, and outcome. We also compared our present experience with a previous analysis from this institution covering the period from January 1, 1972, to December 31,1981. Results: The incidence of P aeruginosa bacteremia has decreased compared with the previous study (2.8 vs 4.7 cases per 1000 admissions). It was most common in patients with acute leukemia (55 of 1000 registrations), and the frequency in this disease has not changed. Half of the patients were not in the hospital when they developed their infection. The overall cure rate was 80%, which was a significant (P<.001) increase compared with the 62% cure rate in the previous study. In this study, no significant difference in the cure rates was observed between monotherapy with a p-lactam and combination therapy overall (P = .72), and in patients with shock (P = 1.0) and those with pneumonia (P = .60). The patients' initial neutrophil counts were not of prognostic value; however, the cure rate depended on subsequent changes in neutrophil count during therapy. Conclusions: The frequency rate of P aeruginosa bacteremia has decreased in patients with solid tumors but has remained unchanged in patients with acute leukemia. Antibiotic regimens for empirical therapy of neutropenic patients and especially patients with acute leukemia should still provide coverage against P aeruginosa.