Distribution of Infections in Patients with Renal Failure Followed in the Intensive Care Unit and the Role of Procalcitonin in Infection Follow-Up

Background: In this study, the aim was to assess the association between procalcitonin levels and culture positivity in patients with acute renal failure (ARF) admitted to the intensive care unit due to Type 1 and Type 2 respiratory failure. Methods: About 128 patients with ARF were restrospectively included between January 2022 and December 2023. Based on admission culture results, patients were grouped as infection-positive (n=40) or infection negative (n=88). Laboratory parameters, particularly procalcitonin levels, were compared. Results: Platelet levels were significantly higher in patients with positive culture results (P=.03), while procalcitonin levels did not differ between groups (P=.33). Escherichia coli was the most frequently isolated microorganism (25%), with the urinary tract being the most common site of growth. In culture- positive patients, procalcitonin levels exhibited a stronger negative correlation with glomerular filtration rate (GFR) (R=-0.355, P= .02) and a positive correlation with creatinine (R=0.385, P= .01), highlighting the impact of renal function. Additionally, procalcitonin levels were positively correlated with C-reactive protein (CRP) (R=0.586, P < .001) and negatively correlated with serum sodium (R=-0.39, P=.01) in patients with culture growth. As a secondary observation, platelet levels were elevated in patients with positive cultures. Conclusion: Although procalcitonin is a recognized marker for infection and sepsis, its diagnostic reliability appears limited in critically ill patients with ARF due to its association with renal dysfunction. Additionally, defining infection based solely on culture positivity has inherent limitations, and further research including comprehensive clinical and laboratory parameters is warranted.