Acute Dyspnea

This multicentre, cluster-randomised, stepped-wedge clinical trial aims to assess whether an intervention designed to implement an ultrasound-guided pre-hospital care pathway for the management of acute dyspnea would improve the effectiveness and efficiency of the mobile emergency medical service (SMUR) compared with standard care. The order in which centres switch to the intervention (use of ultrasound) will be randomized. The study will begin with an initial 2-month period during which no centre will use ultrasound (standard care). Thereafter, two centers will switch to the intervention phase, and every two months, a further two centres will in turn move into the intervention phase. By the end of the study, all centres will have used ultrasound for at least 2 months. A total of 800 adults patients treated for acute dyspnea by the SMUR and meeting the inclusion criteria will be enrolled. Each patient's management will be determined by the study phase in effect at their centre at the time of enrolment (control phase without ultrasound or intervention phase with ultrasound). The appropriateness of treatments administered during SMUR interventions will be compared between the period with ultrasound (intervention phase) and the period without ultrasound (control pahse).

Acute dyspnea is a common cause of emergency department admissions among elderly patients. Acute respiratory failure is often multifactorial and requires rapid and reliable evaluation. Currently, management relies on clinical, biological, and radiological assessments, but diaphragmatic ultrasound could provide an additional tool for real-time respiratory function evaluation. This study aims to integrate this non-invasive technology into the initial assessment of patients to improve care pathways. Hypothesis : Diaphragmatic ultrasound enables reliable assessment of respiratory function and can predict the need for mechanical ventilation.

Patients presenting to the emergency department with acute dyspnea undergo arterial blood gas measurement and monitoring of transcutaneous capnography using the TCM5 monitor. The aim of this study is to determine whether GapCO2, the difference between transcutaneous and arterial pCO2 (PaCO2 - PtcCO2), is correlated with the congestive or non-congestive origin of dyspnea.

This observational retrospective multi-center study focuses on patients treated for acute dyspnea by emergency medical teams. The primary objective is to identify factors associated with the risk of mortality and rehospitalization in these patients. This evaluation will be conducted both overall and within specific subgroups of interest, including gender (men/women), age categories, mode of admission, and comorbidities.