COPD Case 1 Lung Pulse

This clip demonstrates the sign known as lung pulse.

• With severe hyperexpansion tidal volume is minimal and so lung sliding is markedly reduced.
• Cardiac pulsation and the associated rhythmic mediastinal movement remain and are transmitted to lung.
• Lung pulse confirms the absence of pneumothorax and alerts the clinician to poor ventilation.
• The emphysematous lung creates a smoother more reflective pleural surface than normal lung. This means A-lines are more prominent.
• Tidal volumes are smaller and lung sliding is subsequently less.

This is an ultrasound of a patient with severe COPD; there is no pneumothorax.

Ultrasound appearance of COPD may be confused with pneumothorax for several reasons:

1. The normal interstitial markings are fewer. It is the interstitial tissue that creates the slightly irregular lung surface, and the occasional B-lines and comet tail artefacts that characterise normal lung.
2. The emphysematous lung creates a smoother more reflective pleural surface than normal lung. This means the horizontal reverberation artefact lines (A-lines) are more prominent.
3. Tidal volumes are smaller and lung sliding is subsequently less.

This slide is a histological section of mildly emphysematous lung magnified 10 times.

Air-spaces are enlarged with loss of alveolar walls and pulmonary interstitial tissue.

This explains why in emphysema the ultrasound appearance is often more like pneumothorax than normal lung.