Utility of procalcitonin in a medical intensive care unit in Croatia

Aims To investigate the clinical benefit of routine procalcitonin (PCT) measurement in the medical intensive care unit (ICU) of a tertiary referral hospital. Methods Adult patients with suspected infections were included. White blood cells, C-reactive protein (CRP), and PCT were measured. Results In this study 129 patients of median age 64 years (interquartile range 39-89years) were prospectively included. The Acute Physiology And Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were 21 +/- 14 and 7 +/- 6, respectively. Intensive care unit (ICU) mortality was 22.5%. Immunocompromised patients constituted 39.5%. A significant correlation was observed between PCT and APACHE II (Spearman's rho 0.461, p< 0.01), PCT and SOFA (Spearman's rho 0.494, p< 0.01) and PCT and CRP (Spearman's rho 0.403, p< 0.01). Most patients (n= 83, 64.3%) received antibiotics before admission. No difference in PCT (1.56 +/- 8 mu g/L vs. 1.44 +/- 13 mu g/L, p= 0.6) was observed with respect to previous antibiotic therapy. Levels of PCT and CRP were significantly increased in patients with positive blood cultures, the infection caused by Gram-negative microorganism regardless of disease severity and pneumonia with complications. PCT did not differ among patients with positive vs negative urine culture (4.6 +/- 16 mu g/L vs. 1.76 +/- 11.9 mu g/L) or positive vs. negative endotracheal aspirate (1.93 +/- 11.4 mu g/L vs. 1.76 +/- 1.11 mu g/L). PCT-guided stewardship was applied in 36 patients (28%). Conclusion Increased initial PCT levels might point to the development of more severe disease caused by Gram-negative bacteria, regardless of previous antibiotic treatment. The results pertain to immunocompetent and immunocompromised patients. Implementation of PCT-guided stewardship in those patients is possible and relies on experience as well as knowledge of reference change value for a marker within the specific setting.