The AIMS trial is a type 2 hybrid trial comparing two sepsis packs—one within 3 hours and one within 1 hour—and their impact on mortality and health outcomes in emergency departments. Implementation strategies included collaborative learning, educational materials, audit and feedback reports, local knowledge sharing and technical assistance. In the implementation phase, 24 semi-structured interviews were conducted with two champions (nurse and doctor) from 18 sites and 19 satisfaction surveys of learning collaborative participants. Implementation strategies were executed as planned, respondents were satisfied, monthly collaborations facilitated networking and learning, materials served for registration and references, reports helped quantify progress. Barriers were identified as the need to simplify contact points and materials, support networking and increase knowledge. Based on this, 15 modifications (7 content, 4 contextual, 2 assessment, 1 training, 1 multi-purpose) were made to improve acceptability, feasibility, fidelity and adoption of the packages. The summative evaluation will assess the impact of the modifications. Registration NCT05491941 at ClinicalTrials.gov.