Normally the parietal and visceral pleura slide against each other

  • Look at the pleural line just under the rib
  • Shimmer of the surfaces sliding (Video 1)
  • Line of pearls

A pneumothorax will allow air between the pleural surfaces

  • No sliding (Video 2)
  • Loss of signal after parietal pleura
  • Will still see the white line of parietal pleura but no shimmer
  • Compare to other side to see normal lung sliding
  • Can be harder to diagnose with bilateral pneumothorax

Look for lung point

  • Unless complete collapse there will be a lung point
  • Transition where pleural surfaces separate
  • See change from sliding to no-sliding (Video 3 and 4)

M-mode can confirm pneumothorax

  • Normal M-mode-Seashore (Figure 1)
  • Abnormal loss of signal, sometimes called Barcode sign (Figure 2)

Figures and Clips

Figure 1 - Normal M-mode (Seashore)

Figure 2 - Abnormal M-mode (Barcode)

Clip 1 - Normal Lung Sliding

Clip 2 - Abnormal Lung Lack of Sliding

Clip 3 - Lung Point

Clip 4 - Lung Point


Lichtenstein, Daniel A. “Lung ultrasound in the critically ill.” Annals of intensive care 4.1 (2014): 1.