The aim of the study was to evaluate the role of procalcitonin (PCT), C-reactive protein (CRP) and white blood cells (WBC) in the differential diagnosis between sepsis and systemic inflammatory response syndrome (SIRS).
We retrospectively analysed 2834 consecutive patients after cardiac surgery operated between January 2012 and December 2017. From the whole cohort we identified two groups based on the postoperative characteristics: patients with sepsis (44 patients) and patients with a diagnosis of SIRS (40 patients). From the two groups were excluded patients with endocarditis, patients treated preoperatively with corticosteroid, those who developed an infection in the ward and patients who died in the first 48 hours. Measurements of PCT, CRP and WBC were analysed for the first five postoperative days.
The mean values of PCT in patients with sepsis and SIRS were not statistically different at any time-point. CRP values were consistently higher in patients with sepsis from the third to the fifth postoperative day (p = 0.05, p = 0.00064 and p < 0.0001, respectively). In patients with sepsis, WBC mean values were lower in the first postoperative day (p = 0.0044), but higher in the fifth (p = 0.01).
CRP is a reliable value in the challenging diagnosis between sepsis and SIRS after cardiac surgery, especially after the second postoperative day. On the contrary, preliminary results suggest that PCT and WBC are less useful to this differential diagnosis.
1Department of Cardiac Surgery, Stadtspital Triemli, Allianz Herzchirurgie Zürich Zurigo
2Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich Zurigo