Background: Capillary refill time (CRT) has re-emerged as a clinically relevant marker of peripheral perfusion and a potential target for hemodynamic resuscitation in patients with circulatory shock. Recent randomized trials have highlighted its feasibility and potential clinical value, leading to guideline recommendations for its use. However, substantial heterogeneity may exist in how CRT is measured, interpreted, and applied across studies, which may limit comparability and hinder evidence synthesis. Objectives: This scoping review aims to systematically describe and visualize heterogeneity in the measurement, interpretation, and clinical application of CRT in adult patients with shock. Secondary objectives include categorizing measurement techniques, summarizing interpretation strategies, classifying clinical purposes, and identifying methodological gaps. Methods: We will conduct a systematic scoping review following PRISMA-ScR guidelines. Eligible studies will include randomized controlled trials, interventional studies, and observational studies involving adult critically ill patients with shock in whom CRT is measured. MEDLINE, Embase, and CENTRAL will be searched from inception. Six reviewers will independently perform study selection, and data will be extracted using a standardized form. Extracted variables will include study characteristics, CRT measurement methods (e.g., site, compression technique, timing), interpretation approaches (e.g., thresholds, dynamic changes), and clinical applications (e.g., prognostic marker, therapeutic target). Results will be summarized descriptively and visualized using figures such as heatmaps and alluvial plots. Conclusions: This review will provide a comprehensive mapping of how CRT is operationalized in the literature. By identifying heterogeneity and knowledge gaps, the findings are expected to inform future consensus development, trial design, and clinical decision-making in shock management.
Kotani et al. (Thu,) studied this question.