Complicated urinary tract infections.

A complicated urinary tract infection is that which occurs in a patient with an anatomically abnormal urinary tract or significant medical or surgical comorbidities. Whereas this definition may not cover each and every situation, it does serve to encompass the great majority of these patients and guide their care. The definition is necessarily broad, to assure that these potentially complex patients are appropriately managed. Thus, complicated urinary tract infection describes a group of patients that usually need a prolonged course of antimicrobial therapy, with all its attendant morbidities, costs, and outcome differences.