Diagnostic algorithm for urgent causes of dyspnea based on lung auscultation and ultrasound: The CLINIC-LUS Prospective Study

OBJECTIVE: Dyspnea is a frequent reason for consultation in emergency departments (EDs). Ultrasound artifacts generated within lung tissue can be interpreted for diagnostic purposes. The primary endpoint of this study was to provide evidence on the feasibility and applicability of the CLINIC-LUS algorithm, based on lung auscultation and lung ultrasound, for diagnosing causes of acute dyspnea in adult patients presenting to hospital. METHODS: We conducted a prospective, multicenter feasibility study in patients evaluated for acute dyspnea in EDs. Lung auscultation and lung ultrasound patterns were assessed using a 12-point ultrasound protocol. Feasibility was evaluated by the time (in minutes) required to perform lung ultrasound and by the investigator's perception. Diagnostic accuracy (percentage of correct diagnoses) and the Cohen kappa coefficient for agreement of the algorithm were calculated. RESULTS: A total of 95 patients with acute dyspnea presenting to EDs from January 2024 through June 2025 were included and eventually analyzed. The time required to perform lung ultrasound [median (range)] was 12 (9 16) minutes. Investigators unanimously reported that use of the CLINIC-LUS algorithm was straightforward and did not pose difficulties in clinical practice. Diagnostic accuracy was 78.1% (95% CI, 67.5-86.4). The kappa coefficient was 0.73 (95% CI, 0.52-0.82). CONCLUSIONS: Integrating physical examination with lung ultrasound into a single algorithm for diagnosing causes of acute dyspnea in the ED is feasible in clinical practice.