Lung ultrasound (LUS) is accurate for diagnosing pneumonia in the emergency department (ED), but standard training is time-intensive, limiting its widespread implementation. We evaluated LUS proficiency for pneumonia diagnosis and perceived adoption barriers after a short training programme.

This study was conducted in the frame of the PLUS-IS-LESS trial (Procalcitonin and Lung UltraSonography-based antibiotherapy in patients with Lower rESpiratory tract infection in Swiss Emergency Departments) (NCT05463406), a pragmatic stepped-wedge cluster-randomised clinical trial evaluating a clinical management algorithm combining LUS and procalcitonin to guide antibiotic use for lower respiratory tract infections (LRTIs) in 10 Swiss EDs.

All medical supervisors (senior registrars and senior physicians) from the participating EDs were invited to go through the PLUS-IS-LESS LUS training programme and all those who completed the training programme were included in this study.

The training programme included an e-learning course, followed by a half-day on-site training session with theory and hands-on practice. For proficiency evaluation, a validated structured assessment of LUS skills (LUS-OSAUS) was adapted into a 32-question online quiz and five bedside LUS examinations. Success was defined as achieving a score ≥80% on both the online quiz and supervised practical assessment. Success rates were compared between physicians according to their characteristics (age, sex, medical experience, previous use of ultrasound or LUS, linguistic region of work and type of hospital) using a ² test. A 6-month follow-up survey identified factors associated with non-certification and barriers to the clinical use of LUS for managing LRTIs.

Of 122 trained physicians, 83 (68 %) completed both quiz and supervised LUS and 61 (50%) achieved certification. The most challenging items were pleural line assessment (83% success), recognition of consolidations (83%) and decision-making based on LUS findings (72%). Physicians <40 years had a higher success rate (p=0.009). Among those without complete certification, limited access to an ultrasound machine and low perceived added value of LUS were the main identified reasons. Lack of time was the most frequently reported barrier overall to LUS integration into ED workflows (77%).

After receiving short training and focused proficiency testing, only half of physicians achieved certification, underscoring the challenges of broad LUS implementation. Limited time, equipment access and low perceived clinical value were key barriers, and integrating LUS findings into decision-making remained difficult. Ongoing support, supervision and protected time may be needed to enhance LUS adoption in EDs.

NCT05463406.