BackgroundThe health issues experienced by older people can often be severe and complex, and an increasing number are using residential aged care services to meet their care needs. High-quality nursing care is fundamental to the health and safety of aged care residents and is contingent on nurses’ accurate assessment, informed decision-making, and delivery of timely interventions. However, the role of the aged care nurse is often challenging, impeded by factors such as understaffing, high workloads, and a lack of access to clinical infrastructure and resources. When these challenges mount, residents are put at greater risk of adverse outcomes, such as avoidable clinical deterioration and hospital transfers. This study describes the adaptation and implementation of the emergency nursing framework, HIRAID® (History including Infection risk, Red Flags, Assessment, Interventions, Diagnostics, reassessment, communication and plan)—a tool to assist nurses’ assessment, decision-making and care in residential aged care.MethodsThe HIRAID® framework will be adapted for residential aged care using a real-time Delphi and panel of aged care and nursing experts. The co-designed HIRAID® Aged Care framework will be trialled in 23 residential aged care homes in Sydney, Australia, in a modified stepped-wedge cluster randomised controlled trial design. All homes will be randomised into one of four clusters. Outcomes of interest include the rate of clinical deterioration events resulting from nurses’ actions, the rate of hospital transfers determined to be inappropriate, performance against the national mandatory aged care quality indicators, resident satisfaction with care, nurse and medical staff satisfaction with communication, and the quality of nursing documentation. These outcomes will be evaluated using a combination of qualitative and quantitative analysis of routinely collected resident data, expert assessments of facility documentation events against validated criteria, and pre- and post-intervention surveys of residents, family carers, nurses, and medical staff.DiscussionThis protocol describes a pragmatic trial that aims to translate an evidence-based framework from the emergency care context into residential aged care. The adapted HIRAID® Aged Care framework will be the first of its kind to standardise and guide holistic nursing assessment, decision-making, and documentation in residential aged care in Australia.Ethics and disseminationThis research has been approved by the Western Sydney Local Health District Human Research Ethics Committee: 2023/ETH00523. A waiver of consent has been approved to access resident health data and nursing documentation at each participating site.Trial registrationAustralian and New Zealand Clinical Trial Registry, ACTRN12623000481673. Registered 12 May 2023.Protocol versionVersion 1.0 6 February 2024.