A Negative Urinalysis Rules Out Catheter-Associated Urinary Tract Infection in Trauma Patients in the Intensive Care Unit

BackgroundUrinary tract infection (UTI) in trauma patients is associated with increased mortality. Whether the urinalysis (UA) is an adequate test for a urinary source of fever in the ICU trauma patient has not been demonstrated. We hypothesized that the UA is a valuable screen for UTI in the febrile, critically ill trauma patient.Study DesignAll trauma ICU patients in our surgical ICU who had a fever (temperature >38.0°C), urinary catheter, UA, and a urine culture between January 1, 2011 and December 13, 2011 were reviewed. A positive UA was defined as positive leukocyte esterase, positive nitrite, WBC > 10/high power field, or presence of bacteria. A positive urine culture was defined as growth of ≥105 colony forming units (cfu) of an organism irrespective of the UA result or ≥103 cfu in the setting of a positive UA. A UTI was defined as positive urine culture without an alternative cause of the fever.ResultsThere were 232 UAs from 112 patients that met criteria. The majority (75%) of patients were men; the mean age was 40 (±16) years. Of the 232 UAs, 90 (38.7%) were positive. There were 14 UTIs. The sensitivity, specificity, positive predictive value, and negative predictive value of the UA for UTI were 100%, 65.1%, 15.5%, and 100%, respectively.ConclusionsA negative UA reliably excludes a catheter-associated UTI in the febrile, trauma ICU patient with a 100% negative predictive value, and it can rapidly direct the clinician toward more likely sources of fever and reduce unnecessary urine cultures.