BLUE protocol

The BLUE protocol  

One of the most useful concepts about bedside ultrasound is the ability to make rapid and accurate assessments in the critically ill patient. There are two protocols that have been adapted when utilizing POCUS at the bedside in this population, the BLUE protocol and the FALLS protocol. We will focus on the BLUE module this block.

BLUE protocol

-Used to assess acute respiratory failure. This protocol is a simple, goal directed lung examination

-Main diagnoses of patients admitted and performance of US compared with CT:

• Pleural effusion Sn: 94% Sp: 97%
• Alveolar consolidation Sn: 90% Sp: 98%
• Interstitial syndrome Sn: 100% Sp: 100%
• Complete pneumothorax Sn: 100% Sp: 96%
• Occult pneumothorax  Sn: 79% Sp: 100%

-Established profiles associated with locations

This may seem complicated to some, so where to start?

Start with your locations – called “BLUE” points:

1.) Determine initial locations – can use hands as landmark points

2.) Determine lateral portion of lower lobe – phrenic point

3.) Find “PLAPS” point

PLAPS point can be used to evaluate etiology of the posterior lower lobe, namely effusion and consolidation. PLAPS is the most dependent portion of the lungs

 

In order to understand the profiles, you need to know how to interpret basic ultrasound images. Always start your algorithm evaluating for unilateral or bilateral lung sliding

Lung sliding:

Seen with normal pleura. If absent, search for PTX and attempt to ID lung point
Some use “M-mode” to assist with identification –“seashore sign”- normal, “barcode sign”-ptx

Then evaluate for A lines or B lines

A lines:

Reverberation artifact. Consists of horizontal lines parallel to the pleural line
Seen in normal aerated lung parenchyma
A lines without lung sliding? – search for pneumothorax.

B lines:

“Comet tail” artifact
Extend to the bottom of the screen
Closely spaced B lines (<3mm apart) –intra-alveolar process, ie. pulmonary edema/ARDS
Largely spaced B lines (>7mm apart) –intra-septal process, ie. Interstitial fibrosis

 

 

EXAMPLES:

Predominant bilateral A lines plus lung sliding

“A profile”
-scan legs for DVT
DVT positive = PE
DVT negative= Look for PLAPS
PLAPS positive = Pneumonia
PLAPS negative= COPD or Asthma (MUST STILL CONSIDER PE (MODIFIED BLUE PROTOCOL)

 

Predominant bilateral B lines plus lung sliding
“B profile”
-pulmonary edema –cardiogenic vs ARDS

 

One lung not sliding
“A’ profile” or “B’ profile”
If A line predominant, look for lung point and assess for PTX
If B line predominant, look for pneumonia

 

Anterior predominant B lines on one side and A lines on another
“A/B profile”
-pneumonia

 

Any anterior consolidation and/or thick, irregular pleural line
“C-profile”
-pneumonia

 

REFERENCES

1.) BLUE-Protocol and FALLS-Protocol Lichtenstein, Daniel A.CHEST , Volume 147 , Issue 6 , 1659 – 1670

2.) Ultrasonography Fundamentals in Critical Care: lung ultrasound, pleural ultrasound, other potential utilities of ultrasound from Bassel Ericsoussi, MD. Extracted 12/27/17 from  https://www.slideshare.net/basselericsoussi/ultrasonography-fundamentals-in-critical-care-lung-ultrasound-pleural-ultrasound-other-potetial-utilities-of-ultrasound

3.)http://www.nuemblog.com/blog/diagnosing-pneumothorax-ultrasound