Sensitivity of serum C-reactive protein (CRP) levels compared to white blood cell count (WBC) as a predictor of surgical site infection in patients undergoing major surgery

Abstract

Early diagnosis and treatment of infections is essential in the care of the surgical patients. Rapid
and appropriate diagnosis for an infection can prevent irrational use of antibiotics in the surgical
care. A blood culture is a standard method to detect and identify bacteria causing the infections.
However, it is time-consuming to confirm the results. Therefore, an alternative method that
sensitive and specific to reduce the time necessary to confirm the laboratory report is urgently
needed. The aim of this study was to compare the sensitivity and specificity of C-reactive
protein (CRP) with white blood cell (WBC) count as a predictor of surgical site infection (SSI) in
patients who underwent major surgery. This was a descriptive analytical study with a prospective
observational design involving patients who underwent major surgery in Department of Surgery,
Dr. Sardjito General Hospital, Yogyakarta between Octobers until December 2011. On the third
day post operative surgery, serum CRP level and WBC were measured. In addition, bacterial
culture from the surgical wound of patients who suffered SSI, according to Centers for Disease
Control (CDC) criteria, was performed. Among 49 patients who involved in this study, 16
patients (32.7%) suffered from SSI consisting 12 cases of superficial SSIs and 4 cases of deep
SSIs. Among 9 patients who had an abnormal WBC count, 6 patients experienced SSI, while
among 9 patients who had CRP serum levels above 8 mg/dL, 7 patients suffered from SSI. The
sensitivity and specificity of serum CRP levels in predicting SSI was 43.75% and 93.93%,
respectively. Whereas the sensitivity and specificity of WBC was 31.25% and 87.87%,
respectively. In conclusion, CRP is more sensitive and specific than WBC in predicting SSI in
patients who underwent major surgery.