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LUNG ULTRASOUND FOR PULMONARY OEDEMA
Kylie Baker
Ipswich Hospital, Qld
Ultrasound is not for everyone, but everyone can understand the terminology, recognise a good scan from a poor one, and understand its error rate.
DISCLAIMER
This talk:-
Background Rationale- screening tool vs definitive. Acquisition Interpretation Tweaks
Background
The Comet-tail Artifact
An Ultrasound Sign of Alveolar-Interstitial SyndromeDANIEL LICHTENSTEIN, GILBERT MEZIERE, PHILIPPE BIDERMAN, AGNES GEPNER, and OLIVIER BARRE
Service de Reanimation Medicale and Service de Radiologie, Hopital Ambroise-Pare, Boulogne (Paris), and Service de Reanimation Polyvalente, Centre Hospitalier General, Saint-Cloud (Paris), France
AM J RESPIR CRIT CARE MED 1997;156:1640–1646.
International evidence-based recommendations for point-of-care lung ultrasound
Intensive Care MedDOI 10.1007/s00134-012-2513-4 Giovanni Volpicelli Mahmoud Elbarbary Michael BlaivasDaniel A. Lichtenstein Gebhard Mathis Andrew W. Kirkpatrick Lawrence Melniker Luna Gargani
Vicki E. Noble Gabriele Via Anthony Dean James W. Tsung Gino Soldati Roberto Copetti Belaid Bouhemad Angelika Reissig Eustachio Agricola Jean-Jacques Rouby Charlotte Arbelot Andrew Liteplo Ashot Sargsyan Fernando Silva Richard Hoppmann Raoul Breitkreutz Armin Seibel
Luca NeriEnrico StortiTomislav PetrovicInternational Liaison Committee on Lung Ultrasound (ILC-LUS) for the InternationalConsensus Conference on Lung Ultrasound (ICC-LUS)
CONFERENCE REPORTS AND EXPERT PANEL
International evidence-based recommendations for point-of-care lung ultrasound Published online March 2012
“This pattern was present all over the lung surface in 86 of 92 patients with diffuse alveolar-interstitial syndrome (sensitivity of 93.4%). It was absent or confined to the last lateral intercostal space in 120 of 129 patients with normal chest X-ray (specific- ity of 93.0%).”
Rationale
Approaches to Lung scanning1. Screening tool - ED
2 - 8 views (3 minutes)
2. Blue Protocol –ICU
(multisystem views)
3. Detailed inspection –
Resp Physicians
28 views(30 minutes)
4. Endobronchial/Contrast studies.
LUS as a screening tool
Resp/Med equivalent of FAST Tells you that there is extra-vascular
lung water/thickening( >400ml ) Tells you distribution Tells you rough quantity Does NOT tell you what sort Does NOT tell you how old
Limits of the SCREENING TOOL
DOES NOT interrogate post/basal CAN NOT interrogate hilum Does not consider asymmetry You still have to ‘be a doctor’
(quoting Justin Bowra for the umpteenth time)
Diagnostic accuracy 85%
Doctor + CXR > diagnostic accuracy 72%
STEPPING STONE
SAFE for novices Dichotomous question Feasible/storable/auditable
Experience informs interpretation MANY extra signs In expert hands, better than CXR
(Zanobetti M 2011, Xirouchaki N 2011)
AIM for today
Acquisition of standard protocol Interpretation using basic terminology Tweak the protocol Introduce the extra signs
Volpicelli G et al International evidence-based recommendations for point-of-care lung ultrasound, Intensive care med, 2012; 38: 577-591.
Acquisition
Focused exam – 8 views
Sagittal or coronal views RIB SHADOWS confirm position and guide you to pleura.
THE BAT VIEW
Rib shadow
Rib shadow
Chest wall
Pleural line
Rock the probe slightly side to side until the pleura is in sharp focus
Pleura not at right angles to probe so indistinct
Correct angle =
sharpest edge.
SIZE MATTERS (and focus)
SAME SPACE, SAME TIME, SAME PATIENT……….
F>
F>
F>
F>
The Regions
1 2
3
4
Volpicelli et al, Am J Emerg Med 2006; 24: 689-696
Region 2 is usually above the nipple
Interpretation
NORMAL LUNG
A = AIR , ASTHMA……
A lines = default normal Horizontal echo
reflection at exact multiples of intervals from surface to bright reflector.
Dry lung OR PNTX Decay with depth Obliterated by B
pleura A
A
A
A
A
A
B = BAD, BUBBLY
B lines = fluid in alveolus or interstitium
Originates from pleural line
Reaches base of screen OR ALMOST
MORE THAN 2 at once is abnormal
EXCEPT in lung base
Remember as ‘Kerley Bs’
Not exactly the same.
RIB RIB
B B B BB
B Lines = Crackles
Confluent B lines = Bad Bad ‘White’ or ‘shining’
lung Means increased
severity Probably indicates
thicker fluid in alveoli eg protein or inflammatory cells
% space / 10
C = COMPLICATED, CRINKLY, CRUD…..
CARDIAC……………..
C = Pleural line abnormalities
Acute inflammation Old fibrosis.
Indicates abnormal interstitium
Resistant to APO APO not excluded
RIB C
C can be grossly abnormal
If CCF is clinically likely, need to cross
check with heart or IVC
view.RIB
PLEURAL LINE ABNORMALITIES
OBVIOUS SUBTLE
B x 3 x 2 x 2 = CCF
Makes assumption that ‘globally’ wet lungs are most likely to be CCF
PER V
IEW
ZONES
SIDES
12
CASE A. RIGHT LUNG
CASE A. LEFT LUNG
XRAY A
Case B RIGHT LUNG
Case B LEFT LUNG
XRAY B
False Positive False negative Global fibrosis Bilateral
pneumonitis ARDS
Resolving CCF (pleural effusions)
Low focus Dual diagnosis
Tweaks
‘DRY’ BY PROTOCOL
POSSIBLE PE, LOOK FOR SUBPLEURAL ABNORMALITIES
?RESOLVING APO, LOOK FOR PLEURAL EFFUSIONS
‘WET’ BY PROTOCOL
RIGHT HEART LARGER THAN LEFT > ?FIBROSIS
LOOK FOR COLLAPSING IVC > ? pneumonia
View IVC for fluid tolerance
EXTRA SIGNS….
SUB-PLEURAL ABNORMALITIES
CONSOLIDATION OR COLLAPSE
SUB PLEURAL FLUID
Pneumonia with air bronchograms
..pneumonias, PE, mets….
HEPATISATION VS COLLAPSE
SOLID, NO CHANGE WITH RESPIRATION
COLLAPSE – CONCAVE EDGES, CHANGE WITH RESPIRATION
PLEURAL EFFUSIONS
VERY BIG MEDIUM
Pneumothorax
Normal Lung Pneumothorax
M-mode for sliding - normal
straight
speckled
No sliding – PNTX or Adhesion
straight
straight
No sliding- PNTX or adhesion
VERY SENSITIVE, LESS SPECIFIC
WALL MOTIONARTIFACT
PLEURA
straight
speckled
Additional PNTX signs
LUNG PULSE
NO PNTX
LUNG POINT
PNTX OR ADHESION
Sliding traps
BREATH HOLD NO BREATH HOLD
Recap
Terminology?
= 12 B lines Good scan?
= Rib shadow, sharp pleura and high focus Errors?
=15% with pre-existing fibrosis, dual pathology or resolving APO.
Summary
Lung scanning is easy Cheap/quick/safe/portable International acceptance
8 views/12 B lines Not infallible : 85% DA Better than auscultation + CXR