Focused thoracic ultrasound
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Transcript of Focused thoracic ultrasound
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Focused Thoracic Ultrasound
Sonographic appearances of the normal thorax
Dr Andrew Ferguson
Consultant in Intensive Care Medicine & Anaesthesia
+A shot in the dark…
simply a hopeful
attempt to hit an enemy
that you can't see
+Why Use Thoracic Ultrasound?
Increasingly “standard of care” issue
Stop “shooting in the dark”
Both for Seldinger and conventional “surgical” drains
Really informative – negative findings also important
Interesting and challenging
Enjoyable!
+Objectives
Level 1 sono-anatomy
Right and left hemidiaphragm
Ribs and intercostal spaces
Lungs
Heart
Liver, spleen, kidneys
+Diaphragm
Double or triple line
Easily seen in presence of effusion from mid-axillary line
Abdominal surface visible with ascites
Curves upwards except with large effusions
Closely applied to liver/spleen – used as acoustic windows
Functional assessment feasible
+Diaphragm
Boussuges A et al. Chest 2009;135:391-400
C
+Diaphragm (trans-organ)
RIGHT through liver LEFT through spleen
+Diaphragm Function (M-Mode)
RIGHT
LEFT
Towards probe
+Diaphragm Function (2-D)
Normal diaphragm thickens on inspiration
End-inspiratory thickness 20% or more above baseline
+Heart
+Liver
Note texture (remember for consolidated lung images)
Artifacts e.g. mirror-image (implies aerated lung above)
Liver
Mirror-image
Liver
Diaphragm
Kidney
Hepato-renal recess
+Spleen
Diaphragm
Spleen
Kidney
Spleno-renal recess
+Intercostal space
Pleura
+Lungs – normal static findings
Normal lung considered “invisible” to ultrasonographer
Artefacts can be used to infer normality or abnormality
A lines
horizontal reverberation artifacts from pleural line
the only finding in 2/3 of normal lung US
B lines
vertical narrow bands from pleural line to edge of screen
obliterate the A line
multiple B lines = Ultrasound Lung Rockets = interstitial oedema
Abnormal lung has characteristics that are clinically useful
+Lungs – normal static findings
Rib
B line
Wipe out A lines as they pass
A lines
“Bat sign”
Rib Rib
+Lungs – normal dynamic findings 1
Pleural sliding (lung sliding sign)
Pleural line “shimmers” with respiration
Presence of lung sliding rules out pneumothorax
Lung sliding greatest in lower thorax (greatest expansion)
Absence of lung sliding has a number of causes
Pneumothorax
Apnoea
Pleural adhesions
Mainstem bronchial intubation or occlusion
Critical parenchymal lung disease e.g. ARDS, contusion
+Lung sliding
+Lungs – normal dynamic findings 2
M-mode “seashore sign”
Structures superficial to pleural line are static
= Horizontal lines on M-mode (motion against time) = WAVES
Motion of pleural line is “reflected” deep to it
= Granular pattern reflecting motion = SAND
+M-Mode seashore sign
Pleural line
Static structures
horizontal lines (waves)
Pleural line reverberations
dynamic – granular (sand)
+Lungs – normal dynamic findings 3
“Lung pulse” sign
Cardiac pulsations transmitted via lung to pleura
When seen in the absence of sliding…
Normal if breath-hold
Abnormal in other conditions with no sliding
Presence of lung pulse excludes pneumothorax
+Lung Pulse Sign
+
Focused Thoracic Ultrasound
Sonographic appearances of the abnormal thorax
Dr Andrew Ferguson
Consultant in Intensive Care Medicine & Anaesthesia
+Objectives – Level 1
1. Pleural effusion
2. Pleural thickening
3. Consolidated lung
4. Paralysed hemidiaphragm
5. Pericardial effusion
6. Pneumothorax
7. Interstitial syndrome
8. Guided thoracocentesis and drain placement
+Pleural effusion
Characteristics
Anechoic (transudate or exudate)
Echoic
Homogeneously echogenic
Complex non-septated (exudate)
Complex septated (exudate)
Size
Depth on 2-D
Estimates of volume
Inversion of diaphragm if very large
+Pleural effusion - anechoic
+Pleural effusion, complex, non-septated
Plankton sign –
mobile swirling
elements in
effusion
+Pleural effusion, complex, septated
+Pleural effusion, inverted diaphragm
+Effusion with atelectasis
+Clotted haemothorax
Clot
Lung with peripheral
consolidation
(contusion)
+Organised Haemothorax
+Pleural effusion - colour doppler
Fluid colour sign – can be used to differentiate small
effusion from pleural thickening
+Fluid colour sign
Kalokairinou-Motogna M, et al. Medical
Ultrasonography 2010, Vol. 12, no. 1, 12-16
+Pleural thickening
Hypo-echoic pleural plaque
+Malignant pleural thickening
+Lung consolidation
Tissue pattern
loss of air barrier leading to a “real” tissue image akin to liver i.e.
hepatisation
Boundary or shred line
ragged boundary between consolidated and normal lung
Air bronchograms
Non-mobile linear or punctate hyper-echoic features
Fluid bronchograms
May be partially fluid-filled with material motion visible with breathing
+Lung consolidation
+Lung tail (atelectasis and consolidation)
Note normal thickening of diaphragm with inspiration
+Lung consolidation
Note material within effusion
+Severe consolidation - hepatisation
Hepatised lung
Fluid bronchograms
+Pneumothorax
Absent lung sliding
Absent lung pulse
Absent lung rockets
M-Mode – barcode or stratosphere sign
Lung-point sign
+Pneumothorax – stratosphere sign
+Pneumothorax – lung point sign
+Pneumothorax – lung point sign
1) Transient normal
pattern as lung
reaches chest wall
at peak inflation or
2) transition zone
where lung is sitting
on chest wall
+Lung point on 2D US
+Interstitial/alveolar syndrome
Interlobular septal thickening/oedema
> 3 lung rockets spaced around 7mm apart (B7 lines)
Alveolar filling/oedema
> 3 lung rockets spaced around 3mm apart (B3 lines)
Lichtenstein DA, et al. Chest 2009;136:1014-1020
B7 B3Normal
+Diaphragm Dysfunction (M-Mode)
Towards probe
Normal Paralysis
+Diaphragm Dysfunction (2-D)
Towards probe
NO thickening
McCool FD, Tzelepis GE. Dysfunction of the Diaphragm. N Engl J Med 2012; 366:932-942
+Pericardial effusion
Combined pleural and pericardial effusions
Pericardial effusion
+Pneumothorax US algorithm
Lung
sliding
YES
No pneumothorax
NO
B-lines
YES
NO
Lung
point
Lung
pulse
NO
YES
YES
NO
Pneumothorax