Acute pyelonephritis in adults: prediction of mortality and failure of treatment.

BACKGROUND To formulate a classification tool for early recognition of patients admitted with acute pyelonephritis (AP) who are at high risk for failure of treatment or for death. METHODS A retrospective chart review of 225 patients (102 men) admitted with AP. We considered 13 potential risk factors in a multivariate analysis. RESULTS Recent hospitalization, previous use of antibiotics, and immunosuppression were found to be independent correlates of the prevalence of resistant pathogens in both sexes. Additional predictors included nephrolithiasis in women and a history of recurrent AP in men. Prolonged hospitalization should be expected for a man with diabetes and long-term catheterization who is older than 65 years or for a woman of any age with the same characteristics, when the initial treatment was changed according to the results of urine culture. For mortality prediction, we derived an integer-based scoring system with 6 points for shock, 4 for bedridden status, 4 for age greater than 65 years, and 3 for previous antibiotic treatment for men and 6 points for shock, 4 for bedridden status, 4 for age greater than 65 years, and 3 for immunosuppression for women. Among patients with at least 11 points, the risk for in-hospital death was 100% for men and 91% for women. CONCLUSIONS Simple variables available at presentation can be used for risk stratification of patients with AP. The additional identification of certain risk factors by means of a carefully obtained history could contribute to early recognition of patients infected by resistant bacteria and optimize the selection of antimicrobial agents.