3 lung and thorax

Lung & thorax SAH & RNSH 2011Critical Care Ultrasound Course Thanks to: Dr Paul Atkinson Dr Bishr Faheem Dr Daniel Lichtenstein

Scanning the lung• Why scan the lung?• Probe & scanner settings• Technique• Landmarks• US findings• Terminology: the lung profiles• Matching the findings to the disease• Sticking needles & tubes in the lung 2

Why scan the lung?• Diagnosis • Air in pleura: PTX • Fluid in pleura: blood, pus • Fluid in lung tissue: APO/ pneumonia / ARDS • Consolidated lung tissue: pneumonia / contusion / infarct (PE) / cancer• Procedures 3

Why bother?• Lung US is more accurate than CXR for: • PTX (>95% versus 50%) • Pleural fluid (20ml versus 200ml) • APO sens 97%, spec 94%, acc 95% • PE?? Sens 74% … 81% if add DVT• It’s also • Faster (2 min versus 19 min) • Safer • Repeatable 4

The Technique 5

Patient position! No need to sit patient up (eg trauma)! In fact, accuracy for PTX is improved if lying ﬂat… just harder to get round the back for pleural ﬂuid! Air rises! Fluid sinks 6

Probe! Ideally the curved probe! Linear array no anatomical info! Phased array poor image quality 7

Preset! Abdo / FAST! Not the commercial ‘lung’ settings! Turn off ﬁlters ! Multibeam / compounding ! Tissue harmonics! Why? You are looking for artefacts 8

Depth! Close up consolidation? = 5cm! Just sliding / A / B lines? = 10cm! Base of lung / diaphragm? = 15cm! Making sure rockets are rockets? = 15cm 9

Probe position! Sagittal! Right angles to the ribs! Makes sure that the landmarks (rib shadows) stay in view 10

Find those ribs ‘RIB’ ‘RIB’ 11

Look between the ribs RIB RIB PLEURAL LINE (WHERE THE ACTION IS) 12

So:! Curved probe! FAST / abdo preset! 10-15cm depth! Turn off fancy ﬁlters! Sagittal / long axis of patient 13

Where will I scan? Depends on clinical context 14

The basic principle! Air rises " scan highest point of the chest! Fluid sinks " scan lowest point! Some diseases are patchy (eg pneumonia, ARDS) " scan as much of the lung as possible (at least look at each lobe) 15

Where will I scan?! Cardiac arrest: highest point on each side! Shock: 2 anterior (BLUE) points on each side! Breathless: 3 points on each side ! Add 1 posterior (PLAPS) point! Thorough look: as much of each lung as possible (improves accuracy) 16

BLUE points & PLAPS points 17

BLUE points & PLAPS points! What the %$#% ???! Daniel Lichtenstein’s BLUE protocol! BLUE is not an acronym! PLAPS is, though 18

BLUE points & PLAPS points! Upper BLUE point = upper lobe! Lower BLUE point = middle lobe / lingula! PLAPS point = lower lobe 19

Lichtenstein’s BLUE points 20

Lichtenstein’s BLUE points in theory 21

Lichtenstein’s BLUE points in practice 22

Lichtenstein’s PLAPS point 23

PLAPS point! ‘Postero- Lateral Alveolar / Pleural Syndrome’! What the %$#% ???! Posterolateral = round the back! Alveolar syndrome = consolidation! Pleural syndrome = pleural ﬂuid 24

PLAPS point! The PLAPS point is the lowest point of the lung! The Morisons Pouch of the thorax’ (thanks to Dr Chris Wong)! So this is where you find pleural fluid! If there’s no fluid here, there’s no fluid anywhere in the thorax! 25

How to ﬁnd the PLAPS point! It’s the posterior continuation of the lower BLUE point (as far around as you can get the probe) 26

How to ﬁnd the PLAPS point 27

Tip: watch out for the abdomen!! If you scan the liver / spleen & think you’re still above the diaphragm, it will resemble consolidation! ESP if you are using linear probe 28

Tip: Get round as far back as you can! wrong right 29

Normal lung 30

NB: ‘normal lung’! Pleural line looks like a ‘curtain’ sliding back & forth! Sparkle = scatter from air in lung! You don’t really seeing normal lung at all! If it looks like liver: ! mirror ! hepatization 31

What am I looking for? 32

What am I looking for?! Pleural ﬂuid! Pleural sliding! A lines: reverb artefact from pleural line! B lines: hyperechoic reverberation effect from air/water interface! C: consolidation 33

Pleural ﬂuid 34

Pleural ﬂuid! Site: dependent regions! Appearance: ! black = anechoic (fresh blood, transudate/ exudate) ! echogenic / stuff = blood, exudate! Amount: as little as 20ml! Sensitivity >97%, speciﬁcity 99-100% (Sisley et al, J Trauma 1998) 35

Pleural ﬂuid 36

Pleural ﬂuid 37

Pleural fluid: caveats! Pleural vs pericardial fluid (pericardial = delimited by descending aorta)! Peritoneal fluid (where’s the diaphragm?)! Small traces of fluid: easy to miss 38

Pleural or pericardial ﬂuid? 39

Duh! Just look all over the thorax

A, B & Z lines 41

A, B & Z lines! A lines = horizontal & static = reverberation artefact from pleura! B lines = vertical & move with resps (prev ‘comet tails’) = thick vertical lines which reach to edge of screen & obliterate A lines! Z lines = vertical, fade quickly, don’t move with resps 42

A lines 43

A lines 44

A linesHorizontal artefacts Only air is presentPresent in dry lungs Present in PTX 45

B-line B line 46

B lines Vertical artefacts Air/ﬂuid mix in interlobular septa Equivalent of Kerley B lines Not seen in PTXEven 1 B line rules out PTX at that site 47

B lines Vertical Bright Obliterate A lines Don’t fade!Reach all the way to the edge of the screen! 1 or 2 per lung ﬁeld is OK 3 or more = ‘rockets’ 48

Z-lines(Note: A line maintained) 49

Z lines! ill deﬁned! DON’T move with respiration! DON’T erase the A lines 50

Lung rockets‘When several B lines are visible in a single scan, the pattern evokes a rocket at lift-off, and we have adopted the term ‘lung rockets’’ (Lichtenstein p106) 51

Lung rockets3 or more B lines per lung ﬁeld = ‘rockets’ 52

Not ‘comets’International consensus dropped the term (terminology is confusing enough already) 53

Rockets 54

Top TipUp to 1/3 normal patients have rockets in dependent regions So if you see rockets in PLAPS points, it doesn’t matter! 55

Lung rockets = wet lungs! Just in the bases = normal! In all windows = cardiogenic oedema! Patchy, with spared areas = non cardiogenic oedema / widespread pneumonia! Localised = pneumonia / chronic interstitial diseases eg ﬁbrosis 56

TestRemember: 1 or 2 B lines are OK. Lung is still dry at that point! 57

A, B or Z lines? Dry or wet? 58

Applications of lung rockets! Diagnosis ! Is it his CCF or COPD playing up today?! Fluid status ! is this guy with a crap LV overloaded today?! Guiding ﬂuid resuscitation ! Fill him up until the rockets appear ! Dialyse him until the rockets disappear 62

Validation! Volpicelli et al, Am J Emerg Med 2006 (24): 689-696 ! N=300 (75 had AIS) ! Combined gold standard incl 1 month follow up ! sens spec ! Rockets 85.7% 97.7% 63

Just remember ! Not all vertical lines are B lines ! Z lines = puny ! pseudo-rockets with subcut emphysema (don’t move with respiration, & can’t see normal rib shadow above them) ! Not all rockets = ﬂuid ! widespread pneumonia ! widespread ﬁbrosis! rockets can be normal in lowest intercostal space! Posterior lung rockets can be normal in supine patients 64

Lung sliding 65

Lung sliding! Visceral pleura glides on parietal pleura! Why is it important?! A lines + sliding = dry lung = A profile! A lines without sliding = PTX = A’ profile! Rockets + sliding = APO = B profile! Rockets without sliding = ARDS / pneumonia = B’ profile 66

Lots of things can prevent lung sliding! CAL! Apices! Failure to ventilate ! eg R main stem intubation (L lung doesn’t move) ! Eg pain (chest splinting)! Pneumothorax! Pneumonia & ARDS 67

Lots of things can prevent lung sliding! CAL! Apices! Failure to ventilate ! eg R main stem intubation (L lung doesn’t move) ! Eg pain (chest splinting)! Pneumothorax! Pneumonia & ARDS … ??? 68

How the hell do pneumonia / ARDS reduce lung sliding? 69

Here’s how: ARDS/ disseminated APO: pneumonia: Transudate Exudate Lung sliding is Proteinaceous preserved, smooth ‘sticky’ pleural lineReduced / absent lung B proﬁle sliding, irregular pleural line B’ proﬁle

Is sliding preserved?

So how do I diagnose PTX? 74

Diagnosis of PTX1. No lung sliding2. No B lines3. Ideally, a lung point 75

1. a o lung sliding N 76

Which side is the PTX?

Tip 1: compare sides 78

Tip 2: M-mode can help! Sliding = seashore sign! No sliding = stratosphere sign! But beware ‘false seashore’ with chest wall movement! 79

Normal: seashore sign 80

PTX: stratosphere sign 81

Stratosphere sign! M-mode = motion mode! If something isn’t moving, it’s a straight line 82

2. No B lines• i.e. the A’ proﬁle (air is dry)• Even a single B line rules out PTX• Because B lines = air/ﬂuid interface• Absent sliding + B line = LUNG • EG not ventilating • EG pneumonia 83

3. The lung point sign! Speciﬁc to PTX! the site where normal lung gives way to PTX! on one side of the image sliding is present! on the other side it is absent. 84

Lung point sign 85

What if there’s no lung point sign?there might still be a massive PTX which has collapsed the entire lung. Go back to the clinical picture & decide whether you need to go ahead & decompress the chest. 86

Can I trust lung US for PTX? If you are just starting out: ! If you want to ﬁnd all PTX: get a CT ! Stable patient, Negative CXR, positive EFAST: get a CT … or ask a friend to scan ! Unstable patient, Negative CXR, positive EFAST: decompress the chest ! Rushing to OT/ chopper, neg CXR, pos EFAST: warn anaesthetist or insert ICC 87

Test 88

Sliding or not? 89

Sliding or not? 90

Sliding or not? 91

Sliding or not? 92

Consolidationa.k.a. the C proﬁle 93

Alveolar consolidation! If you can see lung tissue, it ain’t normal!! It ain’t aerated ! Collapse ! Consolidation ! Atelectasis ! Contusion ! Infarction (PE) 94

Alveolar consolidation 95

Putting it all together 96

Terminology• A profile = A lines (or no lines), sliding preserved• A’ profile = A lines (or no lines), sliding absent• B profile = lung rockets in all windows, sliding preserved• B’ profile = lung rockets in all windows, sliding reduced / absent• A/B profile = patchy rockets alternate with normal areas• C profile = areas of consolidation• PLAPS positive = consolidation / effusion at bases• PLAPS negative = anything else at bases (A lines / B lines / rockets)

A word of advice about the A profile• All A lines = A profile• No lines seen? Still = A profile• Up to 2 B lines per window are OK! Still = A profile• Z lines? Still = A profile

Test 99

A, A’, B, B’ or C?

A, A’, B, B’ or C? (NB trick question)

PLAPS: positive or negative?

Normal lungs• A proﬁle• Up to 2 B lines per window are OK• PLAPS negative

Pneumothorax• A’ proﬁle = A lines (or no lines), sliding absent• There are no B lines at all on that side• There will be a lung point unless lung is completely collapsed

Acute cardiogenic pulmonary oedema (APO)• B proﬁle = • lung rockets in all windows • lung sliding preserved

ARDS or pneumoniaB’ profile =• lung rockets in all windows• lung sliding reduced / absent• And pleural line may be irregularA/B profileC profileA profile anteriorly, PLAPS positive

Pulmonary embolus A proﬁle anteriorly, PLAPS positive or negative i.e.lungs can look normal Sometimes C proﬁle (pulmonary infarcts)

Asthma / COPD lungs look ‘normal’• A proﬁle• PLAPS negative

Sticking needles in thorax 11 6

Chest drains/ thoracocentesis! Same rationale as central line placement! Ensures you don’t stick ICC in the liver! Tricks: ! Get patient to take maximal inspiration & expiration ! Scan in 2 planes ! Scan in same position you’ll insert ICC ! Use real time US 11 7

Let’s wrap this up 11 8

Lung US: top tips! Curved probe / FAST preset! At right angles to the ribs! Is there sliding? Tip: compare sides! A or B or C?! PLAPS or no PLAPS? 11 9

Any questions?

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3 lung and thorax

by nswhems on Aug 06, 2011

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3 lung and thorax Presentation Transcript