PSEUDOMONAS-AERUGINOSA BACTEREMIA - IS PANCREATICOBILIARY DISEASE A RISK FACTOR

Objective: To review changes in the epidemiology, course, and outcome of bacteraemia caused by Pseudomonas aeruginosa. Design and setting: A retrospective, descriptive study of consecutive cases of P. aeruginos a bacteraemia occurring at a university teaching hospital. Patients an d methods: Between January 1980 and December 1989,164 patients were ad mitted to Westmead Hospital with P. aeruginosa bacteraemia. Patients i n whom there was no clinical evidence of sepsis were excluded from ana lysis leaving a cohort of 152 patients. Hospital records were reviewed and details of demography, clinical features, therapy, and outcome we re recorded. Results: One hundred and fifty-five episodes of P. aerugi nosa bacteraemia were recorded at an average rate of 0.39 per 1000 adm issions per year. The respiratory and pancreatobiliary tracts were the most common sources of the bacteraemia. Pancreatobiliary disease, ind ependent of an underlying malignancy or immunosuppression, emerged as a previously undescribed risk factor for pseudomonal bacteraemia (inci dence of 3.0 episodes per 1000 hospital admissions for patients with t his disease). The crude mortality rate was 52%; 35% was attributable t o pseudomonal bacteraemia. Factors identified as being independently a ssociated with an increased mortality included hypotension, age of 60 years or older, and the presence of an underlying malignancy. Combinat ion therapy with an antipseudomonal penicillin and an aminoglycoside c onfers a significant survival advantage independent of underlying neut ropenia. Conclusions: Bacteraemia caused by P. aeruginosa remains an i mportant cause of morbidity and mortality. Pancreatobiliary disease re presents a new risk factor for P. aeruginosa bacteraemia, independent of an underlying malignancy or immunosuppression. It may be prudent to consider P. aeruginosa as a cause of sepsis in these circumstances, e specially if there has been instrumentation of the biliary tree. Hypot ension, age of 60 years or older, and the presence of an underlying ma lignancy were independently associated with significantly increased mo rtality. Appropriate antibiotic therapy consisting of an antipseudomon al beta-lactam in addition to an aminoglycoside resulted in a signific ant decrease in mortality compared with the use of an aminoglycoside a lone, not only in the study population as a whole, but also in patient s without neutropenia.