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

Background: Pseudomonas aeruginosa bacteremia is a serious and possibly fat al condition in patients with cancer. Objectives: To ascertain the frequency, demographics, and predisposing fact ors for P aeruginosa bacteremia in patients with cancer and to determine th e efficacy of various therapeutic regimens. Subjects and Methods: Patient records of the Clinical Microbiology Laborato ry, The University of Texas, M. D. Anderson Cancer Center, Houston, were re viewed. From January 1, 1991, through December 31, 1995, 245 eligible cases of P aeruginosa bacteremia were identified. We examined the patient record s for the underlying malignant neoplasm and its management, symptoms and si gns of infection, culture results of appropriate specimens, antibiotic ther apy, and outcome. We also compared our present experience with a previous a nalysis from this institution covering the period from January 1, 1972, to December 31,1981. Results: The incidence of P aeruginosa bacteremia has decreased compared wi th the previous study (2.8 vs 4.7 cases per 1000 admissions). It was most c ommon in patients with acute leukemia (55 of 1000 registrations), and the f requency 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 combinatio n 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 acu te leukemia. Antibiotic regimens for empirical therapy of neutropenic patie nts and especially patients with acute leukemia should still provide covera ge against P aeruginosa.