Mapping the Evidence on Midline Catheter Tip Location, Confirmation Methods and Associated Characteristics: A Scoping Review

BACKGROUND: Midline catheters (MCs) are increasingly utilized as an alternative to peripheral and central venous catheters. However, the lack of standardized protocols for tip location and confirmation methods remains a significant barrier to patient safety and clinical decision-making. AIM: This scoping review aimed to systematically map the current evidence and evolving clinical practices regarding MC tip placement, specifically exploring tip location standards, confirmation methods and associated clinical characteristics. DESIGN: Scoping review. REVIEW METHODS: The scoping review was conducted following the Arksey and O'Malley framework and PRISMA-ScR reporting guidelines. Two independent reviewers conducted screening and data extraction, with descriptive methods used for synthesis. DATA SOURCES: Eleven databases (platforms) were searched from inception to 31 August 2026: the Cochrane Library, PubMed, EMBASE, Web of Science, Scopus, ProQuest, CINAHL, CNKI, Wanfang Data, SinoMed and VIP databases. RESULTS: Out of 762 initial records, 41 publications met eligibility criteria. North American guidelines strictly restrict MC tips to the peripheral axilla, whereas European consensus advocates for deeper placement into the thoracic axillary or subclavian veins. Tip confirmation practices are heterogeneous. Methods range from external anatomical measurement to ultrasound guidance and post-procedural radiography. A significant limitation identified is the reduced reliability of ultrasound for tip visualization in patients with morbid obesity, often necessitating alternative confirmation or resulting in indeterminate placement. The quality and comparability of outcome data across studies were limited by inconsistent tip location definitions, heterogeneous patient populations and variable follow-up durations. CONCLUSION: This review highlights substantial heterogeneity in clinical practice and guideline recommendations. The association between tip position and catheter-related complications is multifactorial. This scoping review identifies that current evidence is inadequate to support a clear preference for any single midline catheter tip-positioning strategy. These findings set an agenda for future research to inform standardized, evidence-based midline catheter practice guidelines. IMPLICATIONS FOR THE PROFESSION: Clinical nurses and vascular access specialists should be aware of divergent international guideline suggestions for midline catheter tip positioning. Consensus-based definitions for implantation depth and target veins, together with consistent anatomical terminology, are needed to support cross-study comparison. Optimized multimodal tip-confirmation workflows may reduce unnecessary X-ray use and improve safety, supported by targeted education and interprofessional collaboration. Future prospective cohort studies and comparative trials are needed to evaluate the relationship between tip location, confirmation strategies and patient-important clinical outcomes. IMPACT: This scoping review synthesizes existing international literature on midline catheter tip-related practices and exposes inconsistencies across guideline documents. It draws attention to key unresolved clinical questions and provides clear directions for subsequent primary research. The findings may support the development of future consensus statements and help reduce practice variation in midline catheter care. REPORTING METHOD: PRISMA-ScR. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution. REVIEW PROTOCOL REGISTRATION: https://osf.io/fn8vz/overview.