Validation of a Barriers Scale for Local Anesthesia in Arterial Blood Sampling

BACKGROUND: Arterial blood gas (ABG) sampling is a common and painful procedure. Despite strong evidence supporting the use of local anesthesia to reduce pain, its use in clinical practice remains limited. AIM: To develop and validate a scale assessing nurses' perceived barriers to the use of infiltrated local anesthesia prior to ABG sampling. DESIGN: Instrument development and psychometric validation study. METHODS: A two-stage design was conducted between October 2024 and June 2025. In Stage 1, items were generated from a literature review and refined through a four-round Delphi process with expert nurses. Content validity was assessed using the item-level Content Validity Index, Aiken's V and modified kappa. In Stage 2, a cross-sectional online survey of 558 registered nurses across Spain was performed. Construct validity was evaluated using Rasch analysis, and reliability was assessed through internal consistency and test-retest reliability. RESULTS: The Delphi process resulted in an initial 34-item scale. Psychometric evaluation led to a final 30-item version with good fit indices and no relevant differential item functioning by gender, professional experience, specialty, academic level or type of institution. Internal consistency was high (ω = 0.898 [95% CI: 0.886-0.910]; α = 0.892 [95% CI: 0.879-0.904]) and test-retest reliability was excellent (ICC = 0.912 [95% CI: 0.863-0.971]). Higher scores were observed for barriers related to training, knowledge and organizational factors. CONCLUSION: The ABG-LA Barriers Scale is a valid and reliable instrument (with excellent internal consistency and test-retest reliability) to assess nurses' perceived barriers to the use of local anesthesia prior to ABG sampling. Its use may support clinical decision-making and development of strategies to improve pain management and patient experience in practice.