Risk factors for bacteremia in urinary tract infections attended in the emergency department

Urinary tract infections (UTI) are common in emergency departments (ED), and at least 15% of them are bacteremic. However, there are few data on how to predict which patients are at high risk of developing bacteremic UTI (b-UTI). We performed a retrospective observational cohort study including patients diagnosed with UTI who were admitted to the ED of a tertiary-care hospital in Spain. We included only those patients in whom blood cultures were performed. A nomogram for b-UTI was developed as visualizations of a logistic regression model. Two hundred and thirteen patients with UTI were finally included, 108 of them developed b-UTI (50.7%). The mean age was 60.5 ± 21.4 years. A previous urologic disease was present in 45.5%, 12 out of 213 patients (5.6%) had a urologic tumor (10.2% in b-UTI group vs. 1% in non b-UTI, p = 0.003), and 4.2% were kidney transplant recipients. In a multivariate analysis, variables associated with b-UTI were: solid organ malignancy (OR 3.19; CI 95% 1.01–10.03, p = 0.04), elevated neutrophil count (more than 80% of neutrophils) (OR 5.84; CI 95% 2.13–15.99, p = 0.0006), elevated C reactive protein (OR 1.046; CI 95% 1.006–1.087, p = 0.022), and pyuria (presence of ≥50 white cells per high-power field of urine) (OR 4.43; CI 95% 1.94–10.11, p = 0.0004). The presence of solid tumor, elevated neutrophil count, elevated C reactive protein, and pyuria are independent risk factors that could be useful in anticipating the development of bacteremia in patients with UTI seen in the ED.