Reliability of lung ultrasound in adult patients in emergency and intensive care settings: a systematic review protocol

OBJECTIVE: This review aims to assess the intrarater and interrater reliability of lung ultrasound (LUS) in adult patients in emergency and intensive care settings, and to understand the associated influencing factors. INTRODUCTION: LUS is an increasingly important tool for diagnosis and monitoring of diseases of the respiratory system, especially in emergency and intensive care settings. LUS findings, however, are largely dependent on operator technique and expertise to identify and interpret images, thus concerns remain about its reliability across different examiners and clinical settings. A comprehensive review of reliability, specifically intrarater and interrater, is needed to ensure the accuracy and reproducibility of LUS findings in clinical practice. ELIGIBILITY CRITERIA: The review will include eligible studies of LUS examinations on adult patients (>18 years) receiving care in emergency or intensive care settings for the investigation of any signs, symptoms, or conditions suggestive of alteration of the respiratory system. Studies published from the 1990s to the present will be considered for inclusion, without restriction on language or methodological quality. METHODS: The review will follow Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) for systematic reviews. The search will be conducted in MEDLINE (Ovid), Embase (Ovid), Web of Science, CINAHL (EBSCOhost), Scopus, and gray literature sources. Two independent reviewers will assess studies against predefined criteria and the COSMIN Risk of Bias tool. Intrarater and interrater reliability of relevant LUS findings will be extracted and synthesized, with meta-analyses and subgroup analysis, where relevant. REVIEW REGISTRATION: PROSPERO CRD420251081274.