Sterile pyuria in patients admitted to the hospital with infections outside of the urinary tract.

OBJECTIVES: The objective of this study was to determine the incidence, associations, evaluation, and management of pyuria in patients admitted to the hospital with nonurinary infections.

METHODS: This study abstracted inpatient records of consecutive patients hospitalized for pneumonia, intra-abdominal infections, female genital tract infections (GYN infections), bacterial septicemia, and enteritis in the pediatric and adult medical and surgical units at an academic medical center.

RESULTS: The study population included 210 patients (66 children; 144 adults). Nearly one-third had ≥5 white blood cells (WBCs) per high-power field (pyuria). Pyuria was more common in women (P < .001) and in patients with GYN infections (P = .001) and less common in patients with pneumonia (P < .001). Cultures were performed on 18 of 19 children (94.7%) and 26 of 43 adults (60.5%) with pyuria. Of those, 11.1% of children and 42.1% of adults had a positive culture, and all but one of those met criteria for a urinary tract infection. Excluding patients with GYN infections, only 18.8% of patients with pyuria had a positive culture. Of the 44 patients with pyuria who were cultured, a positive culture was associated with having a GYN infection (P = .01), moderate or large amounts of bacteria in the urine (P = .005), and a positive urine nitrite (P = .004). The absolute number of WBCs or red blood cells in the urine and the presence of casts, proteinuria, and leukocyte esterase were not associated with positive culture or urinary tract infection. Neither pyuria nor a positive culture was related to temperature, systemic WBC count, or serum albumin, blood urea nitrogen, or creatinine.

CONCLUSIONS: Sterile pyuria of uncertain cause is common in patients admitted to the hospital with acute nonurinary infections.