Editing Urinary Tract Infections (section)

==== Renal Abscess ====
* A collection of purulent material confined to the renal parenchyma

===== Pathogens =====
* '''Majority caused by gram-negative organisms'''

===== Pathogenesis =====
* '''Ascending infection associated with tubular obstruction from prior infections or calculi appears to be the primary pathway for the establishment of gram-negative abscesses.'''

===== Diagnosis and Evaluation =====
* '''May present with fever, chills, abdominal or flank pain, and occasionally weight loss and malaise. The patient typically has marked leukocytosis.'''
* '''CT is the diagnostic procedure of choice''' because it provides excellent delineation of the tissue.
* CT- or US-guided needle aspiration may be necessary to differentiate an abscess from a hypervascular tumor.

===== Management =====
* '''<span style="color:#ff0000">Size</span>''' 
**'''<span style="color:#ff0000"><3-5 cm: IV antibiotics are appropriate in clinically stable patient</span>'''
*** Antibiotics, if begun early enough in the course of the process, may obviate surgical procedures.
** '''<span style="color:#ff0000">≥5 cm: percutaneous drainage</span>'''
* '''Patients should have serial examinations with US or CT until the abscess resolves'''