Lung Ultrasonography - SD

Introduction

Hello, my name is Dr. Paul Mayo.
I'm the director of the MICU at Long Island Jewish Medical Center in New York City.
I'm a professor of clinical medicine at Albert Einstein College of Medicine.
I'll be talking today about critical care lung ultrasonography.
Lung ultrasonography is of great interest to any critical care physician as well as our colleagues in the emergency medicine world.
What's nice about lung ultrasonography is that it's very, very easy to learn.
It gives you immediate, very important diagnostic information and allows you to establish management strategy based upon this information very quickly at the bedside of the patient who's critically ill.

General References

Here are some general references that might be of interest.
Nice clinical review here.
And I mention up front, Dr. Lichtenstein.
He has a review in recent critical care medicine journal, but it's very important if you develop some interest in this field to read his original articles.
He did all of the basic work in this field and he has an extensive article list from the 1990s.
If you go to PubMed, you'll be able to pull his chest and his blue journal, as well as intensive care medicine articles, and they formed the basis of the cognitive component of the field based on his work, which was in the 1990s that really established the field.
You'll find, if you look into the literature, that it's been completely, really thoroughly validated by some Italian groups as well as some North American investigators now.
So I would suggest that, if you really want to get a good feel of the general subject, take a look at his articles as well as this review article.
The other resource would be recently that cargo brought out a book titled chest Ultrasonography, I think, and there's an article there, there's some other forthcoming stuff as well that you can keep your eye out for.

Utility Compared to Standard Chest Radiography

Lung ultrasonography has a lot of utility in the critical care unit when compared to standard chest radiography.
The reason for this is that any of you and the audience who work in ICUs know that there's the ritual of the daily chest film.
It's supine, it's rotated, it's under over penetrated.
We puzzle over these films.
We squint at them, they're useless for most purposes.
Maybe we check an endotracheal tube position, but otherwise they're filled with non-specific opacity patterns, summation artifact, and you're left wondering what's really going on with the patient.
Lung ultrasonography offers you a imaging modality that is far superior to supine portable chest radiographs for detection of pneumothorax, normal aeration pattern alveolar interstitial pattern consolidation, pleural effusion.
Really the bread and butter of what you wanna know is going on with your patient.
Dr. Lichtenstein has compared lung ultrasonography and it's yield for the things we look for in the ICU and in the ED with the gold standard of chest ct.
Very interesting article in anesthesiology in 2004, and he showed I think unequivocally that compared to not just chest radiography, but to CT scan, lung ultrasound has excellent performance characteristics when compared to CT scan.

Major Advantages of Lung Ultrasonography

The major advantages of lung ultrasonography are that it's immediately available at the bedside with a good quality portable unit.
You have it there at the bedside of the critically ill patient in a minute or two.
If you're well equipped and ready to use it, then it can be repeated whenever you like.
It's very effective if you have a specific question to answer.
For example, does the patient have a pneumothorax?
You wanna know that immediately.
It's a directed application.
It's a major advantage of the technique.
It saves money because you're not imaging in other ways, and I don't have to tell you that.
The reduction in radiation exposure is of major concern when you compare ultrasonography to the radiation exposure that accrues with a chest CT chest CT scans every time an adult receives a body scan.
Our expert advice from the American Journal of Radiology and from the New England Journal of Medicine indicates that you have an incremental increase of cancer later in that person's life.
About 0.1%.
It doesn't seem like too much unless you're the person who gets the cancer.
And we have a patient population who have chronic lung disease who can be subjected to far more than one chest CT scan.
So, our colleagues, the radiology side are predicting an epidemic of cancer related to the unfettered use of CAT scanning.
Anybody who has a bit of shortness of breath where there's any ambiguity at all right away, pack 'em into a CAT scanner for A-C-T-P-A.
If that's a younger patient, how many times will that they go through that if they have chronic lung disease?
That's a major issue of risk if you look at large population exposure.
So one of the major advantages of lung ultrasonography is with proficiency, the clinician can avoid unnecessary CAT scans.

Basic Findings in Lung Ultrasonography

The basic findings of lung ultrasonography are, again, the bread and butter of what the intensivist looks for.
They have pneumothorax.
Is that an ambiguous chest film merely a underpenetrated film?
Do you have a normal aeration pattern?
Do you have a infiltrative process in the lung parenchyma a something in the interstitial or in the alveolar compartment, we'll call that generally alveolar interstitial, or do you have frank consolidation?
Is there a pleural effusion?
We have to understand that lung ultrasonography is not effective in detecting certain types of lung diseases.
For example, you cannot image a mass, a pulmonary nodule, solitary pulmonary nodule that's surrounded by lung completely.
You just can't see that with a lung ultrasonography.
But in the ED and in the critical care unit, that is the last thing we're worried about.
We're worried about the big stuff, the stuff that you hope to find on chest film, but you're never really sure it's there that you see on CT scan, but you don't wanna pack the patient who's unstable down to the CT scanner repeatedly when you have a question like this.
So the advantage of lung ultrasound is that you look for the things that you're interested for in as an intensivist.

Equipment Requirements

The equipment requirements are very, very simple.
You need an ultrasound machine.
Obviously doppler is not required.
Cardiac transducers have major advantage because they have a small footprint.
So just like when you scan the heart, you wanna be able to fit the probe between the narrow intercostal spaces.
So cardiac transducers work very, very well.
Dr. Lichtenstein described the entire field with a 1991 Hitachi machine, just a 2D machine, very simple device.
He still uses it so that the older machines actually sometimes give better quality lung imaging because some of the newer machines, there's an obsession by the manufacturers in sort of smoothing the image so it's pleasing to the eye or specifically to their eye.
And these overly processed images sometimes have poor near field resolution and they sometimes don't clearly resolve the pleural interface, whereas the older machines that sort of give a raw unprocessed image are good for near field stuff as well as for picking up some of the air artifacts that are important with lung ultrasonography.

Scanning Technique

I'm sorry, I don't have a video of lung ultrasonography, but you can imagine how it's done.
The orientation marker is always of course, to the right of the screen and by common sort of international standard, the image is done in longitudinal plane.
The transducer is held perpendicular to the skin surface and simply images through the inter spaces.
Pulmonary clinicians have major advantage because they can scan the entire thorax anterior, lateral posterior with the patient seated.
Sometimes the examiner will have the patient hold their arms up on their head, for example, and you can throw a whole bunch of scan lines on the patient longitudinal orientation, multiple intercostal spaces very easily.
Unfortunately, in the ICU and the ed, our patients are frequently supine so that we have good access to the anterior and lateral thorax.
But if you really wanna do a full posterior examination of the lung with ultrasound, you have to roll 'em over in a lateral decubitus and you know, that gets to be sometimes difficult when patients are very unstable.
They have endotracheal tube in body habitus may make it difficult, but at least we can image the anterior and lateral compartment quite effectively in the patient who's supine.
The scanning technique, as I said, is standard abdominal thoracic vascular orientation of the marker on left of screen hold the transducer in longitudinal orientation with the marker obviously pointed in the cephalad position.
The transducer is pressed into the intercostal space, moving it off of the rib shadows, and then not looking for a static image, which the so characteristic of CT or chest radiography, the transducer is moved over the thorax as needed.
The best way to do it is to use a logical scan line approach so that the transducer is applied, say to the anterior chest, and then is drawn down across the chest and then moved a few centimeters over to the side and drawn down another scan line, scan line after scan line.
And the experienced examiner will use this multiple scan line technique to develop a three dimensional image of the thorax through multiple 2D images.
It's really a dynamic scanning technique so that historically, radiologists have very little interest in this field.
It's unique in that characteristic because there's very little radiology literature about it.
The reason for that is very simple, that it has to be done at the bedside of the patient.
It's a dynamic scanning technique, rough and ready right there in the front line in the trenches.
It's not for static image interpretation.
So it's a field that has been developed by ED and em people rather than radiology.
A few points to remember, of course, is that free flowing pleural effusion will always, by gravitational effect, be dependent in the thorax, whereas the air-filled lung floats above the effusion.
And then if there's a pneumothorax, unless it's rarely ated, the pneumothorax will assume the most non-dependent position.
IE the anterior.
In a supine patient, it's important to identify rib shadows and keep them out of your primary area of focus, and therefore to orientate the rib shadows on either side of the image, lateral parts of the image, and really maintain the look through the interspace deep into the lung, keeping the ribs off to the side.

Lung Sliding

For the basic lung ultrasonographer, there are several very, very simple basic findings that you would wanna learn upfront.
The transducer is placed in the intercostal space.
The rib shadows are orientated so that they're lateral on the screen.
And if you look carefully, you'll see just below the periosteal level, the pleural line.
The pleural line is an essential anatomic feature because if you see that there's a shimmering quality, a sliding quality to this interface, this ultrasound interface, that means that at that point of examination, the visceral and parietal pleura are fully opposed.
Here we have sliding lung with my indicator.
I show you the rib shadow here, the rib shadow here.
Here's the chest wall.
And we have here a mobile interface and that represents the visceral and parietal pleura.
And if I see that mobility, it means they're sliding one across the other.
And it means that at that point of examination, there is no pneumothorax, none.
The predictive value of that is 100%.
This is a very important basic finding of lung ultrasonography.
That's sliding movement.
Sliding lung, IE the pleural and visceral lines moving against each other is synchronous with the respiratory cycle.
As the lung inflates, it slides the parietal against the visceral pleura.
You'll notice that it's most obvious that the lung base, and that's because of the big pump of the system, the diaphragm, the piston moves the lung more at the base.
So it's somewhat attenuated at the apex, but you can see it.
And the nice thing about sliding lung is that you can be rapidly observed at multiple sites on the thorax.
So I showed you one, one second.
Later I can look in adjacent intercostal space.
Another one, another one, another one, another one.
So you can examine the entire anterior thorax in a matter of 10 or 15 seconds in a tight clinical situation.
Once again, the presence of sliding lung rules out pneumothorax with, I repeat 100% certainty, but only at the site of the transducer examination.
However, in 10 or 15 seconds, you can look at the entire anterior thorax and that's where air in the pneumothorax space will accumulate.
So you rule it out, not waiting for a chest film to show up 30 minutes too late.
So it allows very rapid exclusion of pneumothorax.

Absent Lung Sliding

The absent lung sliding. Here we have the interface.
I have a rib shadow, rib shadow.
And notice, here's the chest wall, here's the air artifact.
Notice that there is no movement at the very end of the slide.
That's my transducer moving a little bit, okay, don't worry about that here.
It's absent compared to the previous.
Sliding And absent lung sliding is useful.
It's a key finding. Let's review these and notice the mobility of the line.
Notice the immobility, the silence of the line, except when I disturb it by pro movement.
That's a key finding.
I'm throwing this in because I wanna remind everyone that the machine, you're at the mercy of your machine so that if you over gain, for example, you're gonna have a hard time finding the pleural interface.
So please control your machine.
Lung sliding or its absence means simply that the parietal and visceral pleura are not moving against each other.
Now of course that occurs with pneumothorax.
Unfortunately, it also occurs with some other conditions.
For example, if the patient is apneic if's no lung movement.
So temporarily doing AP during apnea, there'll be absence of lung sliding.
Let's say that someone has intubated the patient and they've put the endotracheal tube down into the main stem, inflated the cuff and blocked off air entry into the left main stem on that lung, the left, you'll ha lack lung sliding a big mucus plug in a mainstem bronchus.
You lose it. Say the patient had a essis, they have a pleural synthesis from scarring.
You won't see lung sliding in that patient.
And a patient who has really, really severe parenchymal lung disease where the lung barely can be inflated, may cause loss of lung sliding.
So the presence of lung sliding is absolute no pneumo.
The absence means there's the possibility of a pneumothorax and clinical correlation is required.

Lung Pulse

There are two related findings, Whereas the heart beats it is thrown against the lung and it causes the lung to move.
So cardiac movement is transmitted through the lung to the pleural surface.
So if you look carefully, you'll see lung sliding synchronous with respiratory movement.
But also if you look carefully, you'll see jiggling movement of the pleural surface that occurs with each cardiac pulsation, especially on the left side.
So obviously if you see lung sliding, there's no pneumo, but if you see lung pulse, it also means that the two pleural surfaces are touching each other.
Something we'll talk about in a moment are beelines and their presence excludes pneumothorax more about this later.
And it, you know, as an aside, the lung pulse is sort of interesting because if you do a main stem intubation with an over enthusiastic fellow who's put the endotracheal tube down to 26 centimeters, you'll lose lung sliding in the on the left side.
But you'll still have lung pulse as you pull the endotracheal tube back so that it's able to pass air into both mainstem, then the lung sliding will return.
Here's an example of lung pulse using a 3.5 megahertz probe.
Cardiac probe. You notice here it's pulsing and if you had a stopwatch, you'd be able to count the patient's heartbeat. It's clearly not synchronous with respiratory function 'cause I hope the patient is not breathing at 60 times a minute.
Some Italian sonographers are branching into using higher frequency transducers to look at the pleural surface.
Here's an example, using a vascular transducer of lung pulse.
Once more we have the muscle and the soft tissue of the chest wall.
The rib, the rib.
And we have here lung pulse which has the same meaning as lung sliding full opposition of the two pleural surfaces.
Hence no pneumothorax.
Remember, lung sliding means no pneumothorax.
The absence of lung sliding means possible pneumothorax.
By the way, the loss of lung sliding following a procedure is strong evidence for pneumothorax providing lung sliding was documented before the procedure.
So the worried clinician will always check for lung sliding before they insert the IJ or the subclavian line or before performing the thoracentesis because if you detect loss of lung sliding when it was there before you got a pneumothorax on that patient, obviously.

Lung Point

An advanced level finding is called lung point.
Think of a typical pneumothorax space.
Unless the lung is 100% collapsed, part of that lung is going to be touching the inside of the chest wall.
If the patient is supine, the lung falls, the pneumothorax, lung falls posterior, but part of the lung, unless it's a hundred percent collapsed, will be opposed to the lateral chest wall.
The experienced ultrasonographer can find this point of contact.
It represents that point, which is called the lung point, intermittent lung sliding as the partially collapsed lung moves in and out of the scanning plane.
You'll see the lung slide in and out.
That point is where the pneumothorax space begins.
This is not for beginners.
It's hard to find at first, but the skilled ultrasonographer who finds it, that is 100% accurate for the diagnosis of pneumothorax.
The problem is it's hard to find sometimes.
Here's an example of lung point.
The transducer is over in the lateral lung zone scanning.
Here's a rib, here's a rib.
And you notice the flickering of the partially collapsed lung as it enters the space again and again.
Okay, that's lung point.
Once you see it a few times you become, you'll become quite proficient at finding it.
It's a nice finding because it's diagnostic.
Here's a lung point.
I see the absent lung sliding over here.
This is a 7.5 vascular transducer.
We're doing this Italian style And you see here in and out actually coming under a rib shadow, we see the lung sliding in and out.
That is diagnostic for pneumothorax by the way.
It also allows you to target SafePoint for chest tube or you know, insertion.

Clinical Utility of Lung Sliding

The clinical utility of lung sliding is for the urgent evaluation of the acutely DYS patient.
It's great to exclude procedure related pneumothorax.
And in particular it's great for the urgent evaluation of the acutely decompensated ventilator patient.
In my unit, we generally have 16 to 20 people who are really, really sick.
We're very, very busy.
Half of them are very ill on ventilators, a lot of peep, et cetera, et cetera.
And on a regular basis, daily, many times a week we're called by the nursing staff.
The patient is suddenly hypotensive indoor hypoxemic.
And we go over to the bedside quickly and the first thing we think in that situation, have they dropped a lung?
These are people on not a lot of peep a pneumothorax on a patient who's on ventilatory support with severe A-R-D-S-A sepsis syndrome can rapidly develop tension effect and the clinician is faced with a tough challenge.
What's going on? They have a pneumothorax that could be very dangerous.
Let's call for a stat chest film. If you're lucky.
The film would be there in 20 minutes, half an hour, maybe in a well organized unit.
10 minutes, that's too late.
Might as well send the chest radiograph machine down to the morgue.
If the patient has a true tension.
Blind evacuation is ill-advised because if you're wrong, if it's some other mechanism for hypoxemia, the patient will end up with a pneumothorax instead.
Let's bring over the ultrasound machine, which every MICU should have in my opinion is standard equipment.
And let's look for sliding lung.
And if you see it, you see it quickly unequivocally that patient does not have a pneumothorax and you can move on to other causes of acute desaturation on ventilator.

A-Lines

The second basic finding that you want to have in your imaging armar are a lines.
These are simply defined as one or more horizontal lines seen below the pleural line.
You'll notice that a lines are equidistant from each other if there are multiple ones and they're equidistant to the distance between the pleural line and the skin surface.
This is because they represent a reverberation artifact.
And if you see a lines at that point of examination, it means that there's a lot of air where you're looking.
And unfortunately pneumothorax space is a lot of air.
So pneumothorax of course gives a lines but much more commonly a normally aerated lung Will give a lines.
The difference obviously is that the pneumothorax space lacks sliding lung, but the normal aeration pattern would be sliding lung with a lines.
That means the parenchymal compartment is well aerated at that point of examination.
Let's take a look at some A lines. Here they are.
We have rib, rib muscle soft tissue, the pleural line with a nice lung sliding.
And here we have a line one, a line two, you call 'em a ones A twos.
This represents normal aeration pattern.
And if you did a CAT scan of this patient and looked at that site that corresponded to the exam on the CAT scan, you would see normal aeration pattern.
You can have a whole lot of a lines.
Here's an A, 1, 2, 3, 4.
The magnification or depth is obviously adjusted here.
Here is a spleen and the world's smallest pleural effusion.
Once again, if you see this pattern at that site of ultrasound exam, that's gonna be normal aeration on CT scan or on chest film A lines.
Then if they're associated with sliding lung, that's normal aeration pattern.
If you have a lines in the absence of sliding lung, it indicates the possibility of pneumothorax.
I emphasize the possibility for the reasons that we spoke about just a few moments ago.
What are the clinical utility of a lines?
Well if you find 'em all over the place, say you scan a couple of scan lines anterior and the lateral chest bilaterally, if you do a chest film on that patient, it's gonna be normal.
If you do a CT scan, that parenchyma is gonna have normal aeration pattern.
So in a sense it gives you the same information from a clinical point of view as would a normal chest film.

B-Lines

On the other hand, the third basic finding are beelines.
Beelines have a very specific definition.
Let's go through them. They're vertical ray like lines that originate at the pleural interface.
They extend to the bottom of your screen.
If you've set your machine properly with gain because they originate at the pleural interface at the visceral, pleural interface, they move with lung sliding, they move with the pleural line.
They will generally efface a lines where they intersect them.
And all of us who are normal have a few B lines way down in the lateral thorax.
So keep that in mind. If they're found in bunches, they're called lung rockets, some people call them comet tails, whatever you like.
But here they are Once again they start at the pleural surface.
They move with the pleural surface.
They extend ray like to the bottom of the screen.
I don't have any A lines but that's 'cause they face A lines generally beware.
B lines, you wanna satisfy these criteria.
There are some mimics of beelines, they're called by the experts Z and eyelines, but they just don't look like this.
Make sure they're mobile. They extend down ray like they face a lines and they start at the pleural surface.
Let's look at 'em together, how different they are.
Horizontal lines with lung sliding normal aeration pattern.
These are B lines. Completely different.
A key finding. And what are the clinical utility of beelines?
Well where you find beelines on your scan, if you compare that to a CT scan, you're either gonna see interstitial pattern or a ground glass appearance on your CT scan.
Therefore generalized beelines indicate quote unquote a wet lung.
The patient has CHF or they have pulmonary edema, some A RDS or they have some sort of interstitial lung disease.
Say you know, the fibrosing diseases, the infiltrative diseases, lymphangitic carcinoma will give you B lines.
So like any radiographic finding, they don't give you a diagnosis, they tell you there's an abnormality.
And in this case the clinician has to decide why the patient has the equivalent of interstitial or granular or ground glass appearance on other radiographic technique.
Therefore they're very useful for the immediate evaluation of respiratory failure.
And to clarify the ambiguous chest film, the summation artifact, the difficult to read supine ICU film that requires ultrasonography to straighten out what's going on.
If you face off against a patient who's acutely dyspneic say on a rapid response team run or down in the ed, you can get a chest film eventually.
But why not take out the equivalent of a portable chest film, which is your ultrasound machine.
See do they have wet lungs?
If they have a lot of diffuse beelines, then go right to cardiac quick screening echo to see is it likely to be from CHF or are we talking about pulmonary?
It tells you something is seriously wrong with that lung.
You the clinician render diagnosis.

Alveolar Consolidation

The next basic finding is alveolar consolidation air that is filled with pus or that has become airless on another basis.
It appears as a tissue density structure.
None of these air artifacts you see tissue density, Consolidated lung therefore looks like liver and some of us would call it sonographic hepatization of the lung.
I'll ask you to use standard nomenclature when you see tissue density lung simply call it alveolar consolidation.
But I want to emphasize that if you call alveolar consolidation on lung ultrasound, that is purely descriptive.
It does not imply a specific diagnosis such as pneumonia.
So just as the radiologist who looks at a CT scan and sees radio density with air bronchograms, they'll say aha alveo consolidation.
They're not telling you that's a pneumonia.
They're telling you that there's an abnormality that may be a pneumonia, it may be something else.
So in calling alveolar consolidation, you're a radiologist.
When you're using your ultrasound machine as a clinician, you're going to decide why it's there.
Alveolar consolidation on ultrasonography of the lung occurs with standard pneumonia or any other alveolar filling process.
It also occurs with Any feature that causes airless lung or atelectatic lung.
For example, a compressive atelectasis from pleural effusion.
The pleural effusion being under positive pressure literally squeezes the air out of the lung or a bronchial block with resorptive atelectasis.
That lung will appear to be tissue density.
It's not necessarily pneumonia.
And if you look carefully at alveo consolidation, consolidation pattern among ultrasonography, you'll see that there may be punctate white specs in it.
Those represent air left in the bronchi.
If you see those, it means at least that the bronchus is probably open that supplies that segment or lobe.
Whereas if you can see none of those, you have to be concerned that the bronchus is blocked supplying that region.
Here we have a nice example of alveolar consolidation.
Obviously I'm over on the left side.
I am probably in the mid axillary line looking here and I see a rather odd short axis view of the mitral valve opening and closing.
We can see this because the tissue density lung has given us an ultrasound window.
So there's an unusual way to look at the heart.
So here we see part of the diaphragm, another small pleural effusion, but notice we have tissue density with a few little punctate white dots there.
This is a lower lobe alveolar consolidation pattern on lung ultrasound.
Is this a pneumonia? Yes, it might be, might be something else.
But now you know it's there.
It's no longer a mysterious summation artifact seen on a supine chest film.
You see it with your eyes.
Here we have another example of alveolar consolidation the diaphragm.
We have a pleural effusion that surrounds a miniaturized lower lobe.
When I say miniaturized, it's compressed by the pleural effusion.
It's very common to see these.
This sort of miniaturized lung with a big pleural effusion.
I see that the bronchus is open 'cause I see evidence of sonographic air, bronchograms.
And if you were going to ask, oh, alveolar consolidation, is this a pneumonia or is this simple?
Compressive atelectasis?
The clinician will have to answer that question, but I'll tell you this probably is simple compressive atelectasis just by the company that it keeps diaphragm underlying liver over here.
Here's a great big lower lobe alveolar consolidation pattern.
See how it looks like the liver? Here's a liver down here.
It's punctate air bubbles in the bronchi.
So the bronchus is open here.
There's no pleural effusion beyond a little tiny one here.
I wouldn't be surprised if this patient had a tempa 1 0 4 with a lot of purulent sputum being coughed up 'cause this would be more characteristic of a alveo consolidation on ultrasound.
That actually is a pneumonia. There's no loss of volume here we have something that's a little more complex here.
I'm throwing a scan line as the ribs pass through the screen.
We call that like a bicycle there. The bicycle spokes.
I'm moving my transducer up the chest wall, likely lateral in position.
I start here with the diaphragm, the liver underneath.
Notice the liver is rather similar to the lung.
I obviously have a pleural effusion here and we have a alveolar consolidation pattern.
Probably from compressive effect.
However, further higher up I see some holes in the lung.
Uh oh. Here, here, here, here.
This represented a necrotizing pneumonia with multiple abscesses within the lung.
The CAT scan on this patient of course showed homogeneous consolidation pattern.
Lung ultrasonography beats out cat scan any day for looking at lung parenchyma in terms of necrosis or lung abscess.
So, that's characteristic of complex con consolidation pattern.
Let's call it that. Here's another nice example in frozen view, I believe.
Yeah, chest wall.
We have here an entire lobe which is alveo consolidation pattern, but very likely to be from compressive atelectasis.
A few little nubbins of air there.
Nice outline of the diaphragm with some sub phrenic ascites.
A little bump here on the liver. I wonder about that.
Just another example of alveolar consolidation but likely from compressive atelectasis.

Clinical Utility of Alveolar Consolidation

What's a clinical utility?
Well, it confirms a diagnosis and once again it's useful for immediate evaluation of respiratory failure To clarify ambiguous chess film.

Other Findings

For those of you who are interested, there are many other lines to look at.
C-D-E-I-M-O-S-W I'm sure you're curious about w lines.
A hunter is in the forest 10 or 15 years ago and their good friend mistakes the hunter for a deer.
The friend fires at a distance, a load of buckshot into the hunter's chest.
There are 20 or 30 pellets non-lethal 'cause it's at a distance.
These are hard to pick out surgically.
So they're generally left there and they give w lines, which are multiple sort of comet tail artifacts that are very different than the e lines that are found with subq emphysema.
B threes, B seven lung points. We went over that.
I'll refer you to Dr. Lichtenstein's masterful articles.
By the way, lung ultrasonography allows you to identify a lung mass, lung abscess and also air fluid levels in abscess cavities.
And of course a close relative of lung ultrasonography is pleural ultrasound, which we may discuss in a moment.
Here's a complex pleural effusion.
Here's some pleural hardware.
It's useful for that application.
For those of you who are more inclined in the direction of pulmonary medicine.
This is an example of a lung mass rib shadow, rib shadow standard longitudinal scanning position with a cardiac probe.
And I see here an interface between air artifact and a rather large hyperechoic structure, which is adjacent to the chest wall.
This is what a tumor looks like and it would be child's play obviously to target this under ultrasound control for transthoracic needle aspiration and biopsy, that should be a routine application of lung ultrasonography for the pulmonary specialist.
Unfortunately, if the mass is surrounded entirely by air, it will be invisible on lung ultrasound.
And then obviously bronchoscopy or CT guided needle insertion is going to be the indicated procedure, but any mass that is adjacent to the chest wall can generally be imaged with ultrasound and accessed very conveniently under ultrasound control.
Here's a little tiny lung mass up there.
I'm scanning trying to look for it. There it is right there.
Eh, that's a small one.
That's gonna be a two or three centimeter lung mass here.
So before you go after these little ones, you wanna develop a steady hand with the big one that I showed you before.
But these smaller ones are accessible in the non neophyte scanner.
Here's a lung mass once more for the specialist.
We have an adjacent beeline that probably has come up at the interface here of the pleura and normal lung.
You'd want to go after this one with a very steady hand 'cause I noticed it's close proximity to the heart.
So if you went more than a few centimeters into this at a poor angle, you might have some cardiac injury.
So again, if you're going to become interested in transthoracic ultrasound needle or biopsy work, you wanna be very cognizant of adjacent anatomy.

Summary

In summary, general application of lung ultrasonography.
It's a great bedside tool.
Fast, simple, flexible, very important clinical information In a sense.
It's as if you're carrying a chest x-ray machine with you.
You can answer very specific questions and it can be used in an algorithmic approach in the urgent assessment of respiratory failure if it's tied to urgent or goal directed echocardiography and leg study for DVT.
That then sort of brings into a general approach of general body ultrasonography of the critically ill and lung ultrasonography is a key component of that approach.
It's great to clarify these x-rays that torture us every morning.
It just tells you what's going on as opposed to just guessing.
Pneumothoraces, although relatively rare in a well-run ICU are problematic because there's a clear literature that they can be missed on supine chest film to shocking extent.
So, where there's ambiguity, the ultrasound really is helpful 'cause it can rule them out.
Just take out the transducer and you get a lot more information with lung ultrasonography from than from standard low quality chest films very specifically.
I'll emphasize that before and after every procedure where there's risk of pneumothorax.
Just scan the patient in your terms of a standard safety approach, both before and after.
Anybody who has acutely dyspneic, One of the first things to rule out is do they have a pneumothorax?
Generally it's ruled out, but it gives the clinician the assurance that that's off the table immediately.
If the patient's on a ventilator and they have unexplained abrupt decompensation, that's gonna be first on the list.
And you can even either say, I'll wait for the chest film or I guess it's not a pneumothorax.
Just take out the ultrasound and just rule it out right then and there.
It's off the table. And then the thoracic surgeons, the traumatologists ed people have now written a couple of nice articles about using lung ultrasonography and the trauma room for immediate rule out or rule in of pneumothorax.
They of course, have shown that it's far superior to chest films equal in the yield, generally speaking to a CT scan.
But you can get it the answer immediately In my hospital, we use it for rapid response team function, take it with us to an RRT run.
And instead of sort of just guessing what's going on with the acutely DYS patient can do a lung ultrasound one or two minutes, combine it with goal directed echo and a two point DVT study, and it then becomes part of the ultrasound creed.
You're heavy, you have in your hand a portable diagnostic powerhouse.
Never leave the ICU without it.
I'll refer you to a very nice article about a year ago in Chest by Lichtenstein.
He gives a nice algorithmic approach to lung ultrasound use of your lung ultrasonography for acute dyspnea goes without saying that if you scan a person who's coly di acutely dyspneic and they have a lines all over the place with sliding lung, their dyspnea derives from airway disease, a pulmonary embolism bicarb four with metabolic dyspnea or neuro failure with dyspnea on that respiratory failure in that basis.
On the other hand, if you see bilateral beelines all over the place, you're dealing with CHF or pulmonary edema.
Take a look at the heart immediately.
If you have unilateral beelines with or without consolidation, you're dealing probably with a pneumonia.
Look for lung point, look for lung sliding.
And of course, sometimes patients are severely dyspneic of a large pleural effusion.