• Adult
• Humans
• Male
• Middle Aged
• Aged
• Female
• Prospective Studies
• Critical Illness
• Ultrasonography/methods
• Lung/diagnostic imaging
• Italy

• Artificial intelligence
• COVID-19
• Critically ill; Handheld ultrasound devices
• Point of care
• Ultrasound

• critical care
• medical education
• ultrasound

• Emergencies
• Humans
• Reproducibility of Results
• Thoracic Diseases/diagnosis
• Thorax/diagnostic imaging
• Ultrasonography/methods

• commentary
• lung
• ultrasound

This review article shows the potential of lung ultrasound in the critically ill (LUCI) to study lung sliding and describes the optimal equipment for its assessment. Then, it analyses the integration of lung sliding within lung ultrasound then whole body critical ultrasound. It describes the place of lung sliding in the BLUE-protocol (bedside lung ultrasound in emergency) (lung and venous ultrasound for diagnosing acute respiratory failure), the FALLS-protocol (fluid administration limited by lung sonography) (the role of lung sliding in circulatory failure), and the SESAME-protocol (sequential assessment of sonography assessing mechanism or origin of severe shock of indistinct cause) (whole body ultrasound in cardiac arrest). In the LUCIFLR project (LUCI favoring limitation of radiations), the consideration of lung sliding allows drastic reduction in irradiation and costs. In conclusion, lung sliding is proposed as a gold standard for indicating the presence of the lung at the chest wall and its correct expansion.

• BLUE-protocol
• acute respiratory failure
• critical ultrasound
• lung sliding
• lung ultrasound
• pneumothorax

• Echocardiography
• Heart failure
• Intensive care unit
• Pleural effusion
• Pneumothorax
• Thoracic ultrasound

Lung ultrasound is a basic application of critical ultrasound, defined as a loop associating urgent diagnoses with immediate therapeutic decisions. It requires the mastery of ten signs: the bat sign (pleural line), lung sliding (yielding seashore sign), the A-line (horizontal artifact), the quad sign, and sinusoid sign indicating pleural effusion, the fractal, and tissue-like sign indicating lung consolidation, the B-line, and lung rockets indicating interstitial syndrome, abolished lung sliding with the stratosphere sign suggesting pneumothorax, and the lung point indicating pneumothorax. Two more signs, the lung pulse and the dynamic air bronchogram, are used to distinguish atelectasis from pneumonia. All of these disorders were assessed using CT as the “gold standard” with sensitivity and specificity ranging from 90% to 100%, allowing ultrasound to be considered as a reasonable bedside “gold standard” in the critically ill. The BLUE-protocol is a fast protocol (<3 minutes), which allows diagnosis of acute respiratory failure. It includes a venous analysis done in appropriate cases. Pulmonary edema, pulmonary embolism, pneumonia, chronic obstructive pulmonary disease, asthma, and pneumothorax yield specific profiles. Pulmonary edema, e.g., yields anterior lung rockets associated with lung sliding, making the “B-profile.” The FALLS-protocol adapts the BLUE-protocol to acute circulatory failure. It makes sequential search for obstructive, cardiogenic, hypovolemic, and distributive shock using simple real-time echocardiography (right ventricle dilatation, pericardial effusion), then lung ultrasound for assessing a direct parameter of clinical volemia: the apparition of B-lines, schematically, is considered as the endpoint for fluid therapy. Other aims of lung ultrasound are decreasing medical irradiation: the LUCIFLR program (most CTs in ARDS or trauma can be postponed), a use in traumatology, intensive care unit, neonates (the signs are the same than in adults), many disciplines (pulmonology, cardiology…), austere countries, and a help in any procedure (thoracentesis). A 1992, cost-effective gray-scale unit, without Doppler, and a microconvex probe are efficient. Lung ultrasound is a holistic discipline for many reasons (e.g., one probe, perfect for the lung, is able to scan the whole-body). Its integration can provide a new definition of priorities. The BLUE-protocol and FALLS-protocol allow simplification of expert echocardiography, a clear advantage when correct cardiac windows are missing.

• Acute Disease
• Critical Illness
• Equipment Design
• Humans
• Lung/diagnostic imaging
• Point-of-Care Systems
• Predictive Value of Tests
• Respiratory Tract Diseases/diagnostic imaging
• Ultrasonography/instrumentation

• Critical Care
• Humans
• Intubation, Intratracheal/methods
• Lung/diagnostic imaging
• Lung Diseases/diagnostic imaging
• Pleural Diseases/diagnostic imaging
• Ultrasonography/instrumentation
• Ultrasonography/methods

• Humans
• Lung Diseases/diagnostic imaging
• Time Factors
• Ultrasonography