Ultrasound: Lungs: Difference between revisions
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==Technique== | ==Technique== | ||
*Use | [[File:Lung and diaphragm.jpg|thumb|Lobes of the lung with related anatomy.]] | ||
**Can use curvilinear or | *Use linear probe | ||
**Can use curvilinear or phased array probe, but will need to decrease depth | |||
*Place the probe vertically (marker toward head) over the 2nd intercostal space at the midclavicular line | *Place the probe vertically (marker toward head) over the 2nd intercostal space at the midclavicular line | ||
*Adjust your view in order to see a rib on each side of the screen (designated by rib shadow) | *Adjust your view in order to see a rib on each side of the screen (designated by rib shadow) | ||
| Line 8: | Line 9: | ||
*Can continue to evaluate each intercostal space for sliding if needed | *Can continue to evaluate each intercostal space for sliding if needed | ||
== | ==Specific Indications== | ||
{{BLUE Protocol}} | |||
{{Lung ultrasound pneumothorax}} | |||
{{Lung ultrasound pulmonary edema}} | |||
==Further Reading== | ==Further Reading== | ||
Latest revision as of 22:08, 13 December 2023
Technique
- Use linear probe
- Can use curvilinear or phased array probe, but will need to decrease depth
- Place the probe vertically (marker toward head) over the 2nd intercostal space at the midclavicular line
- Adjust your view in order to see a rib on each side of the screen (designated by rib shadow)
- Look between the ribs for "lung sliding"
- To document sliding on a single image, use M mode ("waves on a beach")
- Can continue to evaluate each intercostal space for sliding if needed
Specific Indications
Bedside Lung Ultrasound in Emergency (BLUE) Protocol[1]
- Landmark study by a French intensivist that described various profiles of specific pulmonary disease found on US[2]
- Ultrasound approaches include anterior zones and PLAPS (posterior or lateral alveolar and/or pleural syndrome) point, which is located at the posterior axillary line similar to FAST view
- Predominant A lines anteriorly + lung sliding = Asthma/COPD
- Multiple predominant B lines anteriorly + lung sliding = Pulmonary Edema
- Predominant A lines anteriorly + lung sliding + positive DVT = PE
- Absent anterior lung sliding + anterior A lines + positive lung point = Pneumothorax (PTX)
- PLAPS findings +/- A or B lines +/- abolished lung sliding = Pneumonia
- PLAPS describes changes at the PLAPS point, usually related to consolidations and pleural effusions[3]
- Consolidations may include lung hepatization, shred sign, air bronchograms
- Note that mirroring (normal) may appear similar to hepatization, but mirroring only shows in specific spots due to specific echogenic windows
- Pleural effusions are visualized as anechoic/hypoechoic areas with possible spine sign or floating lung sign (sinusoid sign on M-mode)
- A suggested BLUE protocol guides diagnosis of dyspnea; this should be modified as needed based on clinical presentation
- Check lung sliding in anterior lung fields ---> check for A and B lines ---> check for PLAPS findings
Lung ultrasound of pneumothorax
- No lung sliding seen (not specific for pneumothorax)
- May also identify "lung point": distinct point where you no longer see lung sliding (pathognomonic)
- Absence of lung sliding WITHOUT lung point could represent apnea or right mainstem intubation
- Evaluate other intercostal spaces because pneumothorax may only be seen in least dependent area of thorax
- NO comet tail artifact
- Bar Code appearance/"Stratosphere" sign on M-mode (absence of "seashore" waves)
- Ultrasound has greater sensitivity than chest x-ray for pneumothorax in trauma patients [4]
Lung ultrasound of pulmonary edema
- A lines and B lines
- A lines:
- Appear as horizontal lines
- Indicate dry interlobular septa.
- Predominance of A lines has 90% sensitivity, 67% specificity for pulmonary artery wedge pressure <= 13mm Hg
- A line predominance suggests that intravenous fluids may be safely given without concern for pulmonary edema
- B lines ("comets"):
- White lines from the pleura to the bottom of the screen
- Highly sensitive for pulmonary edema, but can be present at low wedge pressures
- A lines:
Further Reading
References
- ↑ http://ccm.anest.ufl.edu/files/2012/08/BLUELung.pdf Relevance of Lung Ultrasound in the Diagnosis of Acute Respiratory Failure - The BLUE Protocol
- ↑ Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008 Jul;134(1):117-25. doi: 10.1378/chest.07-2800. Epub 2008 Apr 10. Erratum in: Chest. 2013 Aug;144(2):721. PMID: 18403664; PMCID: PMC3734893.
- ↑ Lichtenstein DA. Lung ultrasound in the critically ill. Ann Intensive Care. 2014 Jan 9;4(1):1. doi: 10.1186/2110-5820-4-1. PMID: 24401163; PMCID: PMC3895677.
- ↑ Nagarsheth K, Kurek S. Ultrasound detection of pneumothorax compared with chest X-ray and computed tomography scan. Am Surg. 2011 Apr;77(4):480-4. PMID: 21679560.