Infections caused by carbapenemase-producing organisms have become a major problem during the treatment of secondary bloodstream infection in patients with severe intra-abdominal infection (sIAI). Early detection and identification of potential carbapenemases by colloidal gold immunochromatography assay kit can provide information about the susceptibility of pathogenic bacteria before conventional microbial testing results are obtained. This study aims to evaluate the effects of rapid carbapenemase detection-guided antibiotic therapy on patients with sIAI.

The RAPID study is a multicentre, single-blinded, randomised controlled trial. All patients with intra-abdominal infection will be screened for eligibility on any given day that the first gram-negative bacilli-positive blood culture is detected. In total, 640 eligible study participants assigned informed consent will be randomised to either carbapenemase detection-directed antimicrobial treatment or the conventional group, receiving antimicrobial agents based on different bacterial identification and susceptibility tests. Patients will be followed until discharge or death within a follow-up 28 days after randomisation. The primary outcome is all-cause 28-day mortality. Secondary outcomes include antibiotic duration, length of stay in the hospital and intensive care unit and bacterial clearance. The desirability of outcome ranking and response adjusted for duration of antibiotic risk will also be used to comprehensively assess treatment effectiveness at 28 days.

The study has been approved by the Ethics Committee of Jinling Hospital (2023DZKY-069–01) and all participating centres. Written informed consent will be obtained from all participants or their legal representatives. The results of this trial will be disseminated through peer-reviewed publications and presented at national and international scientific conferences.

ChiCTR2300076159.