point of care ultrasound ucsf continuing medical …• basic principles of lung ultrasound • key...
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October 21-22, 2018
Point of Care Ultrasound UCSF Continuing Medical Education
Disclosure
I have no relevant financial relationships with any companies related to the content of this course.
Lung Ultrasound and Thoracentesis
Stephanie Conner, MD UCSF Medical Center at Parnassus Heights
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Objectives
• Basic principles of lung ultrasound • Key findings with lung ultrasound • Overview of thoracentesis
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Probe Selection
Linear10-15 MHz25 mm CurvilinearPhased Array
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Patient Position
Chest. 2011;140(5):1332-1341. doi:10.1378/chest.11-0348
Hospitalized Patient Technique
• Interstitial findings• Anterior: A or B lines • Lateral Bases: normal to
have some B-lines
• Look for effusions
• Probe orientation• Vertical (longitudinal) • Midclavicular line !
posterior axillary line
Used with permission from Arun Nagdev
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Findings on lung ultrasound
• Normal Lung • Alveolar and interstitial changes (pulmonary
edema, fibrosis, etc.) • Consolidation • Pleural Effusion • Pneumothorax
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Findings, continuedA-Lines B-lines
Effusions Consolidations
Pneumothorax
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A Lines and B Lines• Curvilinear or Phased Array Probe • Increase Gain • Depth 12-16cm
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Normal Lung
• Normal aerated lung scatters ultrasound waves, can’t be seen
• A-lines are horizontal hyper echoic lines representing artifact: reverberations between the highly reflective pleura and transducer
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A lines = non-thickened interstitial septa
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Alveolar Interstitial Changes
• Widening of the interlobular septa allows for propagation of ultrasound waves and the formation of b-lines.
• Seen in pulmonary edema, PNA, ARDS, ILD
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Rib RibTissue
Air/WaterInterface
“B” Lines
16Acute Interstitial Syndrome
Arise from the pleural line
Well-defined
Move with lung sliding
3 per rib space
Reach screen edgeB lines = interstitial syndrome
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Lung US: Dynamic Monitoring
Liteplo et al. Real-time resolution of sonographic B-lines in a patient with pulmonary edema on CPAP. AJEM (2010)
• Case: Hx CHF, ESRD, dyspnea, orthopnea
• Initial US: Diffuse B-lines • After CPAP x 3.5hrs: A-lines
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Review
A-lines vs B-lines
Curvilinear or Phased Array Which Probe?
Scan Where? Anterior Midclavicular
What are B-lines? Interstitial SyndromeCHFPNAARDS
FibrosisAre B-lines pathologic in lateral zones?NO!
A-Lines B-Lines
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Alveolar Consolidation
• “Hepatization of lung”
• 98.5% PNAs abut pleura
• US vs CT: (Lichtenstein 2007)
• Sens: 0.91 • Spec: 0.98
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Case: 50 y/o male with cough & fever
Liver
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Pleural Effusion
• Identification of a hypoechoic or echo-free space surrounded by typical anatomic boundaries:
• diaphragm (and abdominal organs) • chest wall • Ribs • visceral pleura • normal/consolidated/atelectatic lung
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PositioningStart South then Go North
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RUQ/Perihepatic view: Normal
Morison’s Pouch
Costophrenic Recess
Diaphragm
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Pleural Effusion
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Pleural Effusion
• US more sensitive than XR or exam:
• Exam > 300mL • CXR >200mL • US > 20 mL
• Scan dependent zones
• Fluid is hypoechoic (black) • Large effusions generally
more symptomatic
Effusion
Lung
Liver
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Simple vs complex effusions
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Consolidation and Effusion Summary
• More sensitive than physical exam or X-ray • Faster to acquire than CXR • Less radiation
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Pneumothorax
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Probe Selection
Linear10-15 MHz25 mm Curvilinear
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Rib
Alveoli
RibShadow
Normal Lung: Sliding Visceral Pleura
Slide used with permission of Arun Nagdev
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Is Pleural Sliding
Present?
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Is Pleural Sliding
Present?
Pneumothorax
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SoftTissue
NormalLung Beach
Ocean
Normal M-mode of Lung
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SoftTissue
AbnormalLung
Ocean / Barcode
Abnormal Lung M-mode: PNEUMOTHORAX
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OVERVIEWConfirm: M-Mode
PneumothoraxNo Pneumothorax
Ocean + Beach Ocean
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The Lung Point
• Sensitivity: 0.66• Specificity: 1.00(Lichtenstein 233 ICU pts vs CT)
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US: Pneumothorax
• Outperforms CXR in supine patients • Much higher sensitivity, similar specificity • Lower specificity critically ill ICU patients • False positives with pulmonary scarring,
TB, ARDS (specificity 60-91%) • Lung Point: 100% specificity
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Lung US Review
• A-Lines: R/O CHF. Likely COPD/PE/Normal • B-Lines: Diffuse: CHF, ARDS, PNAs. • B-Lines: Focal: PNA • Hepatization likely consolidation • Effusions: scan posterior and lateral bases. Find
the diaphragm! • Pneumothorax: absence of lung sliding, lung
point highly specific
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Thoracentesis
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US Guidance in Thoracentesis
• Find fluid on ultrasound • Establish landmarks for safe needle insertion
with adequate depth • Usually not done under direct US guidance • Check for lung sliding after the procedure
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Safe for thoracentesis?
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Safe for thoracentesis?