Lung Ultrasound as a Physiotherapy Assessment Tool. Lung assessment using ultrasound is a topic of growing interest in the assessment of critically ill patients. The lung ultrasound (USP) technique is based on the fact that all acute aggressions reduce aeration in the lungs, altering their surface and generating predictable and distinct patterns, which allows diagnoses to be made and therapeutic interventions to be monitored. The intensive care physiotherapist has an overview of the patient and has the task of continuously assessing a patient’s physiological functions in real time, with the aim of guiding the therapy to be applied and observing the response to treatment. Thus, the purpose of this study was to analyse the clinical application of lung ultrasound in the day-to-day work of hospital physiotherapists.