1. HG U/S Course Prep #2: Lung Ultrasound
Dr. Caroline Walker
March 23, 2018

2. Practice Changing

3. Intro to lung ultrasound
How to get started
Pneumothorax
Pulmonary edema
Pleural effusion

4. Why do lung ultrasound? Technically easy
Superior diagnostic tool to CXR in majority of instances
Integrate with other ultrasound skills (IVC/echo/FAST) to systematically evaluate undifferentiated sick patients
Target resuscitation
Save lives!
Let your x-ray tech sleep…

5. Probes of choice: Pros and Cons
Phased Array
Small footprint = Visualize in rib space (matters more for cardiac views)
Low Hx; Deep penetration ideal for lung artefact
Curvilinear Array
Low Hz; Deep penetration
Easy transition from FAST to e-FAST and advantage of single probe
Linear Array
Higher Hz = better near field resolution
Good for assessing pleura

6. Non-Anatomic Images

7. Lung ultrasound = mostly artifact
In a healthy lung you do not see the anatomy due to air scatter
“A” lines - normal horizontal lines that represent reverberation artifact from the pleural line
“A” lines = air filled lung

8. Technique Probe in long axis Indicator to patient head
Perpendicular to chest wall
Pleural lines will be as close to near field as possible
Will see either A line or B line pattern

9. Pneumothorax POCUS Better test than a chest x-ray!
Comparing POCUS vs supine CXR in traumatic pneumothorax
Sensitivity for u/s: 98% (CXR: 28-75%)
Specificity for u/s: % (CXR: 100%)

10. Primary Question: Is there lung sliding?
If there is lung sliding there is no pneumothorax at that location
Excellent RULE OUT test
NO lung sliding can mean:
Pneumothorax
COPD blebs
Pleurodesis/other pleural conditions
Post pneumonectomy
Mainstem intubation
Dense pneumonia (consolidated lung not inflating)
Apnea
Technique:
Check most non-dependent areas (air rises)

11. The “sea shore” sign = lung sliding present

12. The “stratosphere” or “bar code” sign = lung sliding absent

13. The Lung Point = Pathognomonic for PTX

14. Pneumothorax

15. Lung point = Rule IN PTX (100% specific)

16. Be sure you are looking at the pleural line!
Subcutaneous emphysema
- Irregular (not like pleural line)
- Too superficial to be pleural line

17. B-lines A fluid-air artifact
’B’ lines = Something going on in the alveoli and interstitium (edema, fibrosis)

18. B-line Characteristics
Arises from the pleural line
Well defined and laser-like
Hyperechoic
Long, spreading out without fading to the edge of the screen
Erases the A-lines
Moves with lung-sliding (if present)

19. Technique Phased or curvilinear array Increase depth to 15 cm
Probe perpendicular to chest wall
Scan in 4 regions (supine patient)

20. All about the B-lines
Originates from fluid/fibrosis of interlobular septae
Isolated B-lines in dependent area is normal finding
3 or more B-lines in one lung region is abnormal
Distribution helps your diagnosis
RULES OUT pneumothorax in that area

21. B-line pattern: stuff in the alveoli/interlobular septae
Diffuse B-lines
Pulmonary edema
Pulmonary fibrosis
Focal B-lines
Pneumonia
ARDS
Pulmonary contusion
Pulmonary hemorrhage

22. B-lines to guide resuscitation
Undifferentiated hypotensive patient, can use lung US to guide resus
A line pattern: no pulmonary edema, consider more fluid
Correlates with low pulmonary artery wedge pressure
B line pattern: be cautious about more fluid, consider transition to pressors

23. Pleural Effusion POCUS
Much more sensitive than CXR, as good as CT
Assists thoracentesis (much safer!)
RUQ and LUQ FAST scan locations then move superiorly
Generally see hypoechoic fluid (obvious); not always (clot, pus)
May cause compressive atelectasis
“The Spine Sign” – fluid transmits sound, will generate image of vertebrae through the lung (not normal)

26. “Jellyfish sign”

27. Integration: BLUE Protocol (Lichtenstein) Acute Dyspnea NYD

28. Summary A-lines: normal parenchyma B-lines: stuff in the interstitium
Lung sliding: Rule OUT pneumothorax, Lung point rule IN
Pleural effusion: Spine sign
Can guide Dx and resuscitation
THANK YOU!