Lung: BLUE Protocol

1. 1

   Select linear probe for pleural line detail or curvilinear for deeper pathology.

2. 2

   Identify the Upper BLUE point (hand placed on chest, upper hand = upper zone) bilaterally.

3. 3

   Assess Lower BLUE point (lower hand on chest) bilaterally. Note A-lines (horizontal, normal) vs. B-lines (vertical, comet-tail).

4. 4

   ≥3 B-lines per zone is significant. Bilateral B-lines = interstitial syndrome (CHF, pneumonia).

5. 5

   Check for lung sliding at each point — absence = pneumothorax until proven otherwise.

6. 6

   Assess PLAPS point (postero-lateral alveolar/pleural syndrome): probe in posterior axillary line above diaphragm. Look for effusion or consolidation.

7. 7

   Integrate findings: A+A bilateral = normal/PE/asthma; B+B bilateral = CHF/pneumonia; A+B = pneumonia; C = consolidation.

• Upper BLUE Point (bilateral)
• Lower BLUE Point (bilateral)
• PLAPS Point (bilateral)

• A-lines (air, normal/PTX)
• B-lines (fluid, interstitial)
• Lung sliding
• Pleural effusion
• Lung consolidation

• 3+ B-lines per zone required to be significant
• Z-lines vs. B-lines (Z-lines don't reach far field)

Use high-frequency linear probe for pleural line detail. Low-frequency for deeper pathology.