Combining PCT with CRP is better than separate testing for patients with bacteriuria in the intensive care unit: a retrospective study.

Background: Previous studies on PCT for urinary tract infections (UTI) have focused primarily on minors. This study investigated the predictive value of the neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP) level and procalcitonin (PCT) level in adult patients with bacteriuria in IUC.

Methods: This case‒control study included 85 patients with bacteriuria (PB) in the ICU from March 2021 to Jan 2024 based on positive urine culture results and a control group (n = 136) from Jan 2024 to March 2024. Patient data were collected using a hospital information management system. ROC curves of the NLR, CRP and PCT were use to predict the PB.

Results: The AUCs of the NLR, CRP and PCT for the prediction of PB in ICU were 0.711 (95% CI 0.644-0.772), 0.855 (95% CI 0.800-0.900), and 0.884 (95% CI 0.832-0.924), respectively; the optimal thresholds were 8.02, 18.52 mg/L, and 0.215 ng/mL, respectively; the sensitivities were 69.0 (95% CI 56.9-79.5), 90.1 (95% CI 80.7-95.9), and 83.1 (95% CI 72.3-91.0), respectively; and the specificities were 67.6 (95% CI 59.1-75.4), 68.4 (95% CI 59.9-76.1), and 80.9 (95% CI 73.3-87.1), respectively. The negative predictive value (NPV) of CRP is greater than that of PCT. In bacteriuria caused by Candida infections, CRP and PCT have higher sensitivity and NPV.

Conclusions: Combined CRP and PCT testing is more helpful for diagnosing bacteriuria. CRP and PCT have higher sensitivity and NPV in diagnosing bacteriuria caused by Candida infection.