Assessing the effects of fluids and antibiotics in an acute murine model of sepsis: study protocol for the National Preclinical Sepsis Platform-01 (NPSP-01) Study

Background: Sepsis remains a leading cause of mortality in critical care. Despite extensive preclinical research on sepsis pathophysiology, the development of effective novel therapies has been largely unsuccessful. Key obstacles include limited construct validity of animal models (e.g. standard therapies not incorporated in model), insufficient methodological rigor (e.g., absence of randomization and blinding), and the lack of collaborative frameworks akin to clinical trials. These issues plague not only preclinical sepsis research, but preclinical research in general. The National Preclinical Sepsis Platform (NPSP), an interdisciplinary network under Sepsis Canada, addresses these challenges in sepsis research through multilaboratory, randomized, controlled preclinical studies. NPSP-01, the platform’s inaugural study, will establish baseline conditions for future investigations using an acute fecal-induced peritonitis model of sepsis.Methods: This randomized, controlled study will evaluate the effect of standard sepsis therapy (antibiotics and fluids) in a mouse model of sepsis across six centres (laboratories). In addition, interlaboratory variability and the interaction of biological sex on outcomes will also be examined. C57BL/6 mice of both sexes will be centrally randomized into sham (healthy control), sepsis, or sepsis + treatment groups (allocation ratio of 0.5:1:1). Sepsis will be induced via intraperitoneal injection of fecal slurry, while sham mice will receive vehicle control. Blinded personnel will administer all procedures. Treatment groups will receive imipenem-cilastatin and Ringer’s lactate at 4 hours post-induction. Mice will be euthanized 8 hours post-induction for analysis. The primary outcome is plasma interleukin-6. Secondary outcomes include biological (blood gas, chemistry, white blood cell count, bacterial load) and clinical (body weight, core temperature, sepsis score, surrogate mortality) measures.Discussion: NPSP-01 will be the first multilaboratory study of sepsis and represents a paradigm shift in preclinical sepsis research, mirroring the rigor of clinical multicenter trials through harmonized protocols and collaborative study designs. By addressing procedural standardization, interlaboratory variability, and sex-based differences, this study aims to enhance the reliability and translational relevance of preclinical findings. The outcomes of NPSP-01 will establish foundational data for future investigations and provide a roadmap for rigorous, collaborative preclinical studies to accelerate the evaluation of novel sepsis therapies.