Procalcitonin versus C-Reactive Protein: Usefulness as a Biomarker of Sepsis in    Surgical Patients

Objective: To determine the diagnostic accuracy of serum procalcitonin and C-Reactive Protein in the detection of sepsis, using the American College of Chest Physicians criteria for sepsis as gold standard. Study Design: Cross-sectional validation study. Place and Duration of Study: Department of General Surgery, Combined Military Hospital, Quetta Pakistan, Nov 2021 to Apr 2022. Methodology: A total of 102 patients with suspected sepsis following major surgery were included in our study. Patients who suffered from immune-deficiency states, neoplastic disease or were on immunosuppressive drugs within the past one month, or had samples that were hemolyzed, icteric or lipaemic were excluded. Patients were assessed for the presence of sepsis using the American College of Chest Physicians criteria 24-hours post-admission. At the same time, patients were tested for serum procalcitonin and C-Reactive Protein levels. Results: The mean age of our sample was 49.20±11.48 years, with 57(55.9%) female patients. Serum procalcitonin levels, with a using a cut-off level of greater than 2.0 ng/mL in determining the presence of sepsis had a sensitivity of 82.2%, a specificity of 30.0% and a diagnostic accuracy of 61.8%, in this regard. Using a cut-off level of 50 mg/L for detecting the presence of sepsis with C-Reactive Protein levels carried a sensitivity of 74.2%, a specificity of 22.5% and an identical diagnostic accuracy of 53.9%. Conclusion: Both serum procalcitonin and C-Reactive Protein levels showed a reasonable degree of accuracy in predicting the presence of sepsis, however, neither was accurate enough to be used in isolation.