Lung and cardiac ultrasound for respiratory distress in the elderly: study protocol of the LUC REED stepped-wedge cluster randomised trial.

Abstract

Dyspnea is a common chief complaint leading to emergency department (ED) visits. Multiple conditions may cause or be associated with dyspnoea, including bacterial pneumonia, acute heart failure (AHF), exacerbation of chronic obstructive pulmonary disease (COPD) or asthma and pulmonary embolism. Each of these diagnoses has a specific treatment recommended by international guidelines. Inappropriate treatment in the ED is more frequent among elderly patients and is independently associated with in-hospital mortality. Point-of-care ultrasound is immediately available at the bedside. Lung and cardiac ultrasound (LuCUS) offers excellent diagnostic accuracy for bacterial pneumonia, AHF and COPD exacerbations, even in elderly patients. The primary objective of the LUC REED trial is to evaluate the impact of a LuCUS-guided strategy versus standard care on reducing inappropriate treatment of dyspnoea in elderly ED patients. The LUC REED trial is a prospective, interventional, multicentre, stepped-wedge randomised controlled trial designed to assess the superiority of a LuCUS-guided strategy over standard care in ensuring treatment appropriateness for dyspnoea in elderly ED patients. The study will include 504 patients over 2 years. Patients aged >65 years presenting with acute dyspnoea and signs of severity (respiratory rate ≥22 or SpO₂ <92% on room air) will be enrolled. Each ED (cluster) will start with a control phase. Every 3 months, one centre will transition to the intervention phase (LuCUS-guided strategy). The primary outcome is treatment inappropriateness within the first hour after inclusion, assessed by comparing administered treatment to the final diagnosis adjudicated by two experts. Ethics final approval was obtained from the Institutional Review Board of France-Est IV on 4 April 2025 (2024-A01678-39). Results will be published in peer-reviewed international journals. NCT06807983.