Lung Ultrasound Profiles From the BLUE Protocol – “BLUE-Protocol and FALLS-Protocol: Two Applications of Lung Ultrasound in the Critically Ill”

This post discusses the Lung Ultrasound Profiles of the BLUE protocol from BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill [PubMed Abstract] [Full Text HTML] [Full Text PDF]. Chest. 2015 Jun;147(6):1659-70. doi: 10.1378/chest.14-1313.

The Lung Ultrasound Profiles are used in the decision tree from the article:


The interpretation of lung ultrasound in acute respiratory failure requires the mastery of ten lung ultrasound signs [See post Lung Ultrasound Signs]:

  1. Normal lung surface
    1. bat sign
    2. lung sliding
    3. A-lines
  2. Pleural effusion
    1. Quad sign
    2. Sinusoid sign
  3. Lung consolidation
    1. Fractal sign (also called the shred sign)
    2. Tissue-like sign
  4. Interstitial syndrome
    1. Lung rockets
  5. Pneumothorax
    1. Stratosphere sign
    2. lung point sign

These lung signs are determined at standard points on the chest (Ref 4 below):


There are eight lung profiles discussed in the article:

  1. A-profile
    1. Anterior A-lines present with lung sliding
  2. A’-profile
    1. Anterior A lines present with absent lung sliding
  3. B-profile
    1. Lung sliding with lung rockets
  4. B’-profile
    1. Absent lung sliding with lung rockets
  5. A/B-profile
    1. Unilateral lung rockets
  6. C-profile – See fig 4 below from Reference 4
    1. “Anterior lung consolidation regardless of number and size up to simply a thick irregular pleural line”
  7. Posterior consolidations are seen in hemodynamic pulmonary edema or pulmonary embolism
  8. “PLAPS” profiles*: “At the posterior chest wall, lung consolidations and pleural effusions are assessed together for simplicity because both disorders usually come together, hence the practical term “PLAPS”
    1. “The A-no-V-PLAPS-profile is connected with pneumonia.”
    2. “The A-profile with no DVT and no PLAPS (ie, nude profile) is linked with asthma and COPD (two bronchial diseases with similar therapy combined for simplification.”

Lung Consolidation from Reference 4:


The following are excerpts from the above article:

. . .  all acute, life-threatening [lung] disorders are superficial. This allows to standardize the field ( Table 1 ).


The BLUE-protocol was developed based on the study of 300 consecutive adults with acute respiratory failure who were admitted to our ICU and given a diagnosis. The most frequent cause of respiratory failure was:

  • pneumonia (32%)
  • followed by acute hemodynamic pulmonary edema (24%);
  • exacerbated COPD (18%);
  • severe asthma (13%);
  • pulmonary embolism (8%);
  • pneumothorax (4%);
  • and countless rare causes, including easy-to-diagnose ones, such as massive pleural eff usion (3%).
  • We excluded rare, unknown, and multiple diagnoses because they generate methodologic issues.

The BLUE-protocol is integrated within the control of acute respiratory failure, which requires an understanding of anatomy, physiology, pathophysiology, clinical signs, traditional imaging, and the biology of dyspnea. Th e BLUE-protocol is fully based on pathophysiology.

Additional Resources:

(1) BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill [PubMed Abstract] [Full Text HTML] [Full Text PDF]. Chest. 2015 Jun;147(6):1659-70. doi: 10.1378/chest.14-1313.

(2) Lung Ultrasound in the Critically Ill Neonate [PubMed Abstract] [Full Text HTML] [Full Text PDF]. Curr Pediatr Rev. 2012 Aug;8(3):217-223.

(3) Clinically integrated multi-organ point-of-care ultrasound for undifferentiated respiratory difficulty, chest pain, or shock: a critical analytic review  ([PubMed Abstract] [Full Text HTML] [Full Text PDF]. J Intensive Care. 2016 Aug 15;4:54. doi: 10.1186/s40560-016-0172-1. eCollection 2016.)

(4) Lung ultrasound in the critically ill. Ann Intensive Care. 2014 Jan 9;4(1):1. doi: 10.1186/2110-5820-4-1. [PubMed Abstract] [Full Text HTML] [Full Text PDF]


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