POCUS Thoracic
General notes —
Must include at minimum 2 views (anterior lung and lung base on left and right), although 4 points is better.
Must designate LEFT and RIGHT lung via annotations, can shorten to L/R as long as labels present.
Can use linear probe, although phased array or curvilinear preferred, especially for lung bases.
Linear probe is good if definitively trying to evaluate for lung sliding or evaluating for lung point.
Must demonstrate rib shadows (at least two rib shadows, or more, with lung sliding in between).
Visualize diaphragm when evaluating lung base.
Four points on each side of the thorax including base.
Normal lung —
Lung sliding present
A-lines (horizontal reverberation artifacts)
May have some comet tail artifacts (vertical reverberation artifacts that fade with time).
Must show two rib shadows
A-lines —
Reverberation artifact — ultrasound waves reflecting off of air returning echoes.
Horizontal lines eventually fading out.
Normal lung base —
Diaphragm visualized
Can see spine below diaphragm, but no spine sign above diaphragm.
May see “curtain” sign — aerated lung preventing visualization of lung base.
B-lines —
Vertical ring-down artifacts arising from the pleural line that erase A-lines.
Do not fade with depth unlike comet tail artifacts.
BLUE Protocol
Lichtenstein BLUE Protocol — the goal of this protocol is not to provide a definite diagnosis, but to approach a 90.5% accuracy when using LUS.