Point-of-care ultrasound in emergency department sepsis and septic shock: a pragmatic framework for source-oriented assessment and physiologic reassessment.

In emergency department (ED) sepsis and septic shock, early management is often dominated by two bedside uncertainties: identifying a clinically plausible infection source and determining whether additional fluid is likely to improve perfusion or worsen pulmonary or systemic congestion. Point-of-care ultrasound (POCUS) may contribute to both questions when it is used as a trigger-based, time-boxed adjunct rather than as a comprehensive screening test or stand-alone diagnostic adjudicator. This article presents a pragmatic narrative review of multiorgan POCUS in adult ED sepsis and septic shock, based on a focused, non-systematic search of major databases and a synthesis of sepsis guidelines, landmark resuscitation trials, and clinically relevant reviews and representative studies addressing source-oriented assessment, shock phenotyping, fluid responsiveness, and congestion assessment. Particular attention was given to separating diagnostic capability and physiologic plausibility from demonstrated clinical utility and patient-centered outcome benefit. Priority was given to adult ED literature; intensive care unit (ICU), perioperative, and physiologic studies were used only when ED-specific evidence was limited and the underlying principles were clinically transferable. The proposed framework is organized around two linked arms. First, a source-oriented scan may support pneumonia or pleural complication as a working source and may identify biliary disease, obstructive urinary infection, urinary retention, or drainable soft-tissue infection when clinical features make these sources plausible. Its intended role is to trigger formal imaging, drainage planning, specialist consultation, or source-control pathways, not to prove the source at the bedside. Second, physiologic reassessment can use focused cardiac ultrasound (FoCUS), dynamic flow-based assessment such as passive leg raise with left ventricular outflow tract velocity-time integral (PLR-LVOT VTI), and serial lung ultrasound to provide context for fluid and vasopressor decisions after the initial resuscitation step. Venous Doppler and the venous excess ultrasound (VExUS) framework are discussed as optional advanced congestion assessments, not as routine ED requirements, because ED sepsis-specific evidence remains limited. Overall, current evidence supports POCUS mainly as an adjunct for bedside clarification, escalation support, and physiologic reassessment; direct evidence that POCUS-guided ED sepsis pathways improve patient-centered outcomes remains limited. POCUS should therefore be used as a decision-support tool, not a stand-alone adjudicator or a reason to delay antimicrobials, CT, formal imaging, or specialist involvement.