The “lung pulse”: an early ultrasound sign of complete atelectasis
Complete atelectasis can be immediately generated by selective intubation. A dynamic lung ultrasound sign can be described as the association of absent lung sliding with the perception of heart activity at the pleural line, a sign which was called “lung pulse.” We examined whether this sign be used promptly to confirm complete atelectasis due to selective intubation.
Design and setting
Prospective study in the medical intensive care unit of a university-affiliated teaching hospital.
Consecutive patients with no history of respiratory disorders and needing intubation were enrolled. Fifteen patients with selective intubation of the right lung were compared with 30 patients with nonselective intubation and 15 healthy volunteers.
The “lung pulse” was sought at the left anterolateral chest wall in intubated patients. Healthy subjects were studied during breathing and apnea.
A left “lung pulse” was immediately present in 14 of 15 patients with right selective intubation, and absent, with normal lung sliding, in all 30 correctly intubated patients and in all 15 healthy subjects during breathing. All healthy subjects exhibited a “lung pulse” in apnea. The “lung pulse” had a sensitivity of 93% and a specificity of 100% for the diagnosis of complete atelectasis following selective intubation in patients without previous respiratory disorders.
The “lung pulse” is a sign of complete atelectasis which is observable immediately before radiological changes. Its absence which is correlated with the absence of selective intubation and of conserved lung inflation can eliminate the need for confirmation radiography.
KeywordsAtelectasisUltrasound diagnosisIntensive care unitLung, ultrasound diagnosisThorax, ultrasound diagnosis
Clip video 1: Normal lung sliding Ventilated patient with pulmonary edema. The presence of lung rockets (B lines) makes easier the recognition of lung sliding (excursion around 20 mm).
Clip video 2: Example of “lung pulse” Recent atelectasis in a ventilated patient. Lung sliding is abolished, but millimetric movements of the lung rockets in rhythm with the heart rate can be noted.
Clip video 3: Pneumothorax Complete absence of lung sliding and complete absence of lung rockets, with exclusive A lines.