Developing a comprehensive haemodynamic ultrasound assessment for critical care: Rationale and methodology from the FUSIC programme.

Haemodynamic ultrasound is central to bedside assessment of circulatory failure in critical care. The Focused UltraSound in Intensive Care HaemoDynamics (FUSIC HD) programme was originally designed to provide a structured national framework for physiologically focused ultrasound assessment, distinct from comprehensive diagnostic echocardiography. Since publication of the original framework, experience from training cohorts, logbook review, and centralised summative assessment has shown that a broader range of haemodynamic parameters can be acquired and interpreted in routine practice. This article outlines the rationale, development process, and methodological principles underpinning the recent revision of the FUSIC HD dataset. The updated framework incorporates additional assessment of left ventricular performance, right ventricular function, and pulmonary vascular loading, together with a refined approach to estimating left atrial pressure while maintaining emphasis on physiological coherence, bedside feasibility, and avoidance of unnecessary diagnostic complexity. The aim is not to expand diagnostic echocardiography capability, but to support more integrated haemodynamic interpretation in critically ill patients within an established training and governance structure.