Lung ultrasound in internal medicine: training and clinical practice

Lung ultrasound (LUS) represents an emerging technique for bedside chest imaging in different clinical settings. A standardized approach allows the diagnosis, the quantification, and the follow-up of different conditions for which acute respiratory failure is the main clinical presentation. The aim of this study was to test what skill targets could be achieved in LUS, with a short-training course offered to 19 Medical Doctors attending the certification board school in Internal Medicine at the University of Verona, Italy.

The training course (theoretical and practical) consisted of 9 h subdivided in 4 days. Each trainee examined three healthy volunteers during the first day that was also the day of the theoretical lessons. Moreover, they examined nine patients per day (a total of 27 patients). Trainees were tested in the recognition of the basic signs in LUS, the managing of the Bedside Lung Ultrasound Evaluation (the BLUE protocol), and the recognition of the broad clinical scenarios recognized by the LUS. Kappa statistic was used to calculate the inter-observer agreement (trainees/tutor).

Twenty-seven patients were examined by the 19 trainees (ten trainees had previous limited experience in general ultrasound). The agreement among the trainees and the tutor in the recognition of the LUS basic signs and in the recognition of the BLUE protocol profiles ranged from "fair" to "excellent". In particular, the agreement among the trainees and the tutor in the final LUS diagnosis was "excellent" for the recognition of the interstitial syndrome and the pleural effusion, "substantial" for the recognition of the normal lung, and "moderate" for the recognition of consolidation and pneumothorax. LUS outcome gave useful information and drove change in therapy in 16 patients. It affected immediate management in nine patients. The concordance between the previous X chest ray and LUS was observed in 21 patients.

A short training in LUS provided good proficiency in the recognition only of the main signs of the BLUE protocol, but allowed a correct LUS diagnosis in the Internal Medicine most frequent clinical settings of acute respiratory failure. This study supports incorporating LUS into Internal Medicine fellowship training programs.