Comparison of Preoperative and Postoperative Inflammatory Markers as Predictors of Surgical-Site Infection in Elective General Surgery

Abstract

Background: Surgical-site infection is a significant postoperative complication in general surgery and is associated with delayed recovery, readmission, reoperation, and higher health care costs. Clinically, early detection of patients at higher risk is important. Some inflammatory markers like C-reactive protein, total leukocyte count, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio may be helpful in understanding the development of a postoperative infection.

Objective: To compare preoperative and postoperative inflammatory markers and assess their value in predicting surgical-site infection among patients undergoing elective general surgery.

Methods: The study was a prospective observational study of 88 patients who were undergoing elective general surgical procedures from September 2025 to February 2026 at the Department of General Surgery, Jakarta State University, Indonesia. Preoperative and early postoperative inflammatory markers (total leukocyte count, neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and C-reactive protein) were taken. Surgical-site infection (SSI) was followed in patients. Patients with and without SSIs were compared and receiver operating characteristic curve analysis was used to assess the predictive capacity of individual inflammatory markers.

Results: Surgical-site infection developed in 16 of 88 patients (18.2%). Postoperative inflammatory markers were significantly higher than their corresponding preoperative values. Patients who developed SSI had substantially higher postoperative CRP, NLR, WBC, and PLR compared with patients without infection. Postoperative CRP demonstrated the highest predictive performance, with an AUC of 0.86, followed by postoperative NLR with an AUC of 0.82 and postoperative WBC with an AUC of 0.79. Multivariable analysis showed that elevated postoperative CRP, elevated postoperative NLR, and prolonged operative duration were independently associated with SSI.

Conclusion: Postoperative inflammatory markers, particularly CRP and NLR, appear to be more useful than preoperative measurements for predicting surgical-site infection after elective general surgery. Their routine assessment may assist in early identification of high-risk patients and support closer postoperative surveillance.