Procalcitonin as a diagnostic marker of ventilator‑associated pneumonia in cardiac surgery patients

Abstract

The aim of the present study was to assess whether procalcitonin (PCT) can be used as a diagnostic marker for ventilator‑associated pneumonia (VAP) in cardiac surgery patients. Between January 2012 and June 2013, a total of 92 patients were recruited and divided into non‑VAP (59 patients) and VAP (33 patients) groups. The preoperative and postoperative characteristics of the patients were recorded. Serum levels of PCT, interleukin (IL)‑6 and C‑reactive protein (CRP) were measured using an electrochemiluminescence immunoassay. Subsequently, receiver operating characteristic curves of the PCT, IL‑6 and CRP levels were constructed. In addition, associations between the sequential organ failure assessment (SOFA) scores and the serum levels of PCT, IL‑6 and CRP in the VAP patients were analyzed. No statistically significant difference was observed between the non‑VAP and VAP patients in the occurrence of postoperative complications. However, the SOFA scores (days 1 and 7), the duration of stay in the intensive care unit and the mechanical ventilation time were all significantly higher in the VAP group when compared with the non‑VAP group (P<0.05). The optimum PCT cut‑off value for VAP diagnosis on day 1 was 5.0 ng/ml, with a sensitivity of 91% and a specificity of 71%. The serum PCT levels on days 1 and 7 were found to correlate positively with the SOFA scores (r=0.54 and r=0.66 for days 1 and 7, respectively). Therefore, the results suggested that serum PCT may be used as diagnostic marker for VAP in patients following cardiac surgery.