Final submission for Master of Medicine in Emergency Medicine

Abstract

Introduction: CRP is a widely used biomarker for detecting infection and inflammation, and it may aid in antimicrobial stewardship. Rapid point-of-care (POC) CRP testing can support timely decisions in resource- constrained, high-acuity environments, such as critical care. Methods: This prospective, single-centre study was conducted in the ICU of Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) from September 2023 to April 2024. A total of 110 adult patients were enrolled through convenience sampling. Paired central or arterial blood samples were tested using both the AfinionTM 2 POC device and standard laboratory methods (Roche CobasTM). Data collected included CRP levels and relevant clinical variables. Ethics approval was obtained. Results: Sixty-two valid POC CRP results were analysed. The median CRP was 90 mg/l (POC) vs. to 120 mg/l (laboratory). The POC test demonstrated 100% sensitivity for CRP >10 mg/l, and 100% sensitivity with 92.5% specificity for CRP >100 mg/l. A strong correlation was observed between POC and laboratory results (r = 0.97; 95% CI: 0.96–0.97; p < 0.0001). Bland-Altman analysis showed acceptable mean differences (–25.4 to 33.9 mg/l). The median time to result was significantly shorter for POC (4 minutes) compared to laboratory testing (5.5 hours; p < 0.001). Conclusion: The Afinion 2 POC CRP test provides reliable and rapid results, supporting its integration into critical care workflows to improve clinical decision-making and promote responsible antimicrobial use. Contribution: The study substantiates the clinical utility of the Afinion™ 2 POC CRP test as a dependable, swift, and pragmatic instrument for application in critical care. It emphasises the potential of POC CRP testing to improve patient outcomes, optimise workflows, and encourage judicious antibiotic utilisation, all of which are essential for the advancement of healthcare delivery.