The lung pulse sign refers to the sonographic finding of apparent oscillations of the pleural line occurring secondary to transmitted vibrations from cardiac contractile activity 1.
Typically obscured by the more apparent “lung sliding” as a result of ventilated lung expanding and contracting throughout a normal respiratory cycle, it may become evident when regional pulmonary ventilation is impaired in conditions such as:
endobronchial obstruction with obstructive atelectasis
apnea
-
pleural adhesions, which may be secondary to
iatrogenic pleurodesis
fibrosis
-
inflammation
empyema
pneumonia
acute respiratory distress syndrome
contralateral endobronchial intubation
The presence of a visible lung pulse implies contact between the visceral and parietal pleura, thereby ruling out a pneumothorax in the visualized sonographic field 2.