6. The Blue Protocol

Blue Protocol

Researchers have created protocols to streamline the use of pulmonary ultrasound in clinical practice. The most widely used protocol has been the BLUE protocol created by Lichenstein and colleagues and is used by many practitioners to diagnose the cause of acute respiratory failure. Pulmonary edema, pulmonary embolism, pneumonia, chronic obstructive pulmonary disease, asthma, and pneumothorax yield specific profiles predicted by the BLUE protocol.

This protocol classifies A-lines and B-lines into various profiles. Though quite simple, they can be confusing if you are not first familiar with them.

  • “A-profile” has A-lines with lung sliding and describes normal lungs
  • “B-profile” has B-lines and lung sliding
  • “B’ profile” has B-lines with impaired lung sliding
  • “A’ profile” has A-lines with impaired lung sliding
  • A/B profile has one lung with A-lines and the other with B-lines.
Figure 8