Role of Procalcitonin Versus C-Reactive Protein in Guiding Antibiotic Therapy for Surgical Infections: A Structured Narrative Review

Abstract

Background: Surgical and postoperative infections require timely antimicrobial treatment, but physiological inflammation after surgery can resemble bacterial infection and complicate decisions regarding antibiotic duration. Procalcitonin and C-reactive protein are commonly evaluated as adjunctive biomarkers, although their comparative clinical roles remain uncertain. Objective: To critically compare the biological characteristics, postoperative kinetics, diagnostic utility, and antimicrobial-stewardship applications of PCT and CRP in surgical and postoperative infections through a structured narrative review. Methods: A focused review of peer-reviewed biomedical literature was undertaken using terms related to PCT, CRP, surgical infection, postoperative infection, surgical-site infection, antibiotic duration, and antimicrobial stewardship. Foundational biomarker studies, diagnostic investigations, randomized trials, systematic reviews, meta-analyses, and clinically relevant cohort studies were synthesized thematically. Evidence was interpreted according to study design, population, directness of surgical relevance, biomarker timing, and reported clinical application. Results: CRP was consistently identified as a sensitive, widely available marker of inflammatory activity, but its frequent elevation after uncomplicated surgery limited its specificity for bacterial infection. PCT demonstrated comparatively greater association with systemic bacterial activity and generally declined more rapidly after effective infection control. Randomized evidence from heterogeneous critically ill populations supported PCT-guided strategies for reducing antibiotic exposure without compromising clinical safety, although direct evidence from exclusively surgical populations remained limited. Neither biomarker reliably distinguished all postoperative infections from sterile inflammation, and no universal threshold was supported across surgical procedures. Conclusion: PCT has greater potential than CRP as an adjunct to antibiotic-discontinuation decisions, whereas CRP remains useful for monitoring general inflammatory trends. Both biomarkers should be interpreted serially and integrated with clinical assessment, microbiological findings, imaging, and confirmation of adequate source control