Clinical features, outcomes and predictors of drug resistance and complications in patients admitted with pyelonephritis.

Drug resistance and the presence of structural complications have significant implications for the treatment of acute pyelonephritis. We aimed to examine the predictors of drug resistance and complications in a retrospective cohort of patients admitted with pyelonephritis. 188 patients were included in this study. Patients who had had a urinary catheterization in the previous month and who lived outside the district in which the hospital was located were more likely to have ESBL infections. Carbapenem resistance was associated with recent urinary catheterization, a positive urine nitrate test, hypotension requiring vasopressors and the need for intensive care. A history of flank pain, urea level >13.3 mmol/L, a differential neutrophil count >75% and a urinalysis with >1000 leucocytes per high power field was associated with an increased risk of complications. A score derived from these variables to predict structural complications of infection had a sensitivity of 77.8% and a specificity of 67.1.