Lung ultrasound in children: What does it give us?

Lung ultrasound (LUS), a non-invasive non-ionizing radiation tool, has become essential at the bedside in both adults and children, particularly in the critically ill. This manuscript reviews normal LUS patterns and the most important pathologies that LUS allows to diagnose. Normal LUS is represented by the pleural line, the lung-sliding and the A-lines and B-lines. These two last findings are artifacts derived from the pleural line. Pleural effusion appears as an anechoic collection. Pneumothorax is suspected when only A-lines are present, without lung-sliding and B-lines. Alveolo-interstitial syndrome is characterized by different degrees of confluent B-lines and can be present in different pathologies such as pulmonary edema and acute respiratory distress syndrome. The distribution of B-lines helps to differentiate between them. LUS is useful to evaluate the response to lung recruitment in pathologies such as acute respiratory distress syndrome or acute chest syndrome. The distribution of B-lines also appears to be useful to monitor the response to antibiotics in pneumonia. However, further studies are needed to further ascertain this evidence. LUS is also useful to guide thoracocentesis.