Advanced nursing practice (APN) is grounded in critical thinking and a comprehensive understanding of the relevant theoretical foundations [1]. The APN is a recognized healthcare provider who delivers high-quality care across diverse global contexts [2]. In 2020, the International Council of Nurses (ICN) defined the APN as a generalist or specialist nurse who, through advanced graduate education (typically at the master’s level) has acquired an expert knowledge base, sophisticated clinical decision-making abilities, and advanced competencies [3]. These attributes are shaped by the specific healthcare context in which the nurse is authorized to practice. The two most prevalent APN roles internationally are the Clinical Nurse Specialist (CNS) and the Nurse Practitioner (NP) [2].

APN roles have developed through distinct historical phases across regions. Early development was most prominent in North America, where nurse practitioner roles were established to improve access to care and respond to workforce needs [4]. Over subsequent decades, APN expanded internationally, but with substantial cross-country variation in titles, educational preparation, scope of practice, and regulatory authority [4]. This variability has been particularly evident across European systems, where implementation has progressed unevenly and is shaped by national governance and professional regulation [5]. In the Asia-Pacific region, advanced practice roles have expanded more visibly in recent years, driven by rising demand for complex care, emergency and critical pressures, and system redesign initiatives [6].

Early evidence provides important context for understanding the evolution of APN effectiveness in emergency departments (EDs) and intensive care units (ICUs). In EDs, comparative studies evaluated nurse practitioner-led care for minor injuries, demonstrating comparable clinical outcomes, high patient satisfaction, and potential service efficiencies when compared with physician-led models [7], [8]. In ICUs, early evidence-based review identified promising contributions of APN to patient management, while also highlighting the limited availability of high-level experimental studies in ICUs [9].

These foundational findings informed subsequent expansion of advanced practice roles, while underscoring the need for more rigorous designs in later research. Fig. 1 summarizes major international milestones in APN development from 1960s, with focus on EDs and ICUs, and provide historical context for the present scoping review.

As healthcare systems face increasing pressures from aging populations, complex comorbidities, physician shortages, and the residual impact of the COVID-19 pandemic, the demand for advanced, safe, and efficient critical and emergency care delivery has intensified [6], [10]. In this context, APNs such as NPs and CNSs, have emerged as a strategic solution to bolster workforce capacity and enhance quality of care in acute settings [2], [6], [10].

It has been demonstrated that APNs practicing in EDs and ICUs can provide patient care comparable or superior to physician-led models [11], [12]. Studies have consistently reported benefits including reduced length of stay, shorter wait times, improved adherence to clinical guidelines, patient satisfaction, and operational efficiencies [13], [14], [15], [16]. Nonetheless, findings on cost-effectiveness remain mixed, underscoring the need for updated synthesis of evidence considering recent workforce and policy changes.

Despite the growing global use and evolving roles of APNs, several key challenges persist [2], [17]. Variability in educational preparation, competencies, legal recognition, and scope of practice across regions (especially in critical and emergency care) has hindered standardization of roles and the ability to generalize outcomes across systems [18], [19]. Moreover, prior reviews often included literature only up to 2020, leaving a gap in capturing more recent developments, especially following the COVID-19 pandemic [6], [14], [20], [21].

A number of scoping reviews and systematic reviews have highlighted these gaps. For example, a recent a scoping of APN competencies identified seven core domains, but specific competencies in emergency and ICU settings remain under-described, pointing out the need for further studies regarding the role of APN in emergency and critical care settings [18]. Another scoping review focused on models of APN deployment in emergency departments pinpointed diverse role configurations (for example fast-track clinics, minor injury units), yet evidence about integration and outcomes in critical care remains patchy [14]. A seminal review on APN roles in ICUs categorized their functions into direct clinical practice, leadership, education, collaboration, and research domains, which highlight their potential yet noting low global consistency in policy support and standardization [22].

Terminology for advanced practice roles varies internationally and is a major source of conceptual and regulatory inconsistency. In this review, we use APN as an umbrella term consistent with ICN guidance, wherein the two most common APN role types are NPs and CNSs [3]. In some jurisdictions, particularly the United Kingdom and parts of Europe, the multi-professional title Advanced Clinical Practitioner (ACP) is widely used and may encompass nurses as well as other health professions; therefore, ACP is not necessarily synonymous with nursing-specific APN roles [23], [24]. To minimize ambiguity for international readers, this review focuses on nursing-specific advanced practice roles (APN/NP/CNS; and where used, ANP is treated as a nursing advanced practice designation aligned to APN rather than the broader multi-professional ACP construct).

Prior evidence synthesis of APN in emergency and critical care settings have frequently not extended beyond 2020, limiting their ability to capture evolving role expectations, regulatory responses, and service redesigns following the COVID-19 pandemic. Consistent with this gap, the present scoping review provides an updated synthesis of the 2015–2025 literature, ensuring that post-2020 evidence (including pandemic and post-pandemic developments) is incorporated into the mapping of roles, competencies, outcomes, and implementation issues.

Therefore, the current scoping review aims to address these knowledge gaps by synthesizing recent global evidence on APN roles, competencies, and impacts specifically within emergency and critical care settings. This effort will identify role definitions, educational preparation, outcome evidence, implementation challenges, as well as regional and policy-related variations. Ultimately, the goal is to support standard-setting, inform workforce planning, and guide future research in integrating APNs effectively into these high-acuity environments. By synthesizing international evidence on role scope, education, regulation, and reported outcomes, this review will provide a practical evidence map that can inform workforce planning, support role standardization and governance, and guide policy reform for advanced practice nursing in EDs and ICUs.