Résumé
Lung ultrasound is a simple tool, mainly based on the study of artifacts, quick to learn, available in real time and at bedside. It allows the diagnosis of 5 major pleuropulmonary syndromes: pleural effusion and pneumothorax, normal parenchyma, interstitial syndrome and alveolar consolidation. Lung ultrasound should always be interpreted according to the clinical context. Its association with other ultrasound examinations and its incorporation into management protocols improve its diagnostic performance and could improve prognosis in critically ill patients. Lung ultrasound is mainly used for patients in acute respiratory failure in association with cardiac or even venous ultrasound. It is also increasingly used in the fields of emergency medicine, but also cardiology and nephrology. It then allows an evaluation of extravascular pulmonary water, an important prognostic element for the management of acute and chronic patients. Its performance remains improvable for the diagnosis of pneumothorax, the discrimination between pulmonary and lesional oedema, and especially for the detection of alveolar overdistension. The use of new technologies such as Speckle Tracking or artificial intelligence could ultimately improve its performance and facilitate its large-scale use.