So for the eFAST, you would just do here for the pulmonary views, you would just do the R1 view here looking for pneumothoraces. But I'm going to talk about a complete pulmonary ultrasound evaluation as well, so we know how to do that as well. So for the first view is this mid-clavicular line at the second intercostal space, you want to have your probe up and down in orientation. And like Dr. Pickett was saying, the linear probe would be best for this because you're looking for pneumothoraces, which is a pretty superficial view. However, in the sake of time, if you're doing a FAST exam, you can do this with the curvilinear as well as a phase array probe as well. So this would be the view here, obviously on both sides. The next would be the mid-axillary line around the sixth or seventh intercostal space, and the purpose here is to kind of evaluate those lateral lung fields. And then the last view is the intersection of the posterior axillary line in a rib space between the 10th and 12th ribs, depending on which side you're on. So here's the right side, this little gif here, and you're looking at the liver with some lung sliding above. So you want to see the kind of the diaphragm and then everything above, because this is usually where the pleural effusions sit, and then a lot of times you can see those consolidations, which could represent as isolated B-lines just in this lung view. And if there was a pleural effusion, you'd see hypoechoic above the diaphragm as opposed to below the diaphragm. You worry about an intra-abdominal injury would be above the diaphragm, which you don't see here. This is normal. So here's a normal lung ultrasound. This would be in that first position, that second intercostal space, that mid-clavicular line. And you can see here, this is a rib here, and then we don't see the other rib over here. It's a little cut off, but you can see some good lung sliding here. Some people describe it as ants marching on a log, if you want to think about it that way. And then this is our patient here. So these are real, real ultrasound views. So here's a rib here, here's a rib here, and you can see here there's absolutely no lung sliding there, consistent with a pneumothorax. And you can see his muscles moving, but no actual lung sliding. And then here is another view of our patient. So this is another rib space, and you can see actually a transition point. So you can see lung sliding in half this rib space, but the other half, there is absolutely no lung sliding. So this is consistent with the transition point here. You can see the lines coming down of the lung sliding as well. And Dr. Ferry will talk about that a little bit later. So the other thing, if you're unsure, if you can't see it with the naked eye, you can always do M-mode on the ultrasound and drop that line right through the middle of that lung. Here you can see a normal seashore sign, and you can see kind of the waves crashing down on the beach here. And then if there was a pneumothorax and there was no lung sliding, you would get this barcode or stratosphere sign. As you can see, it kind of looks like a barcode. So I'm going to kick this next part to Dr. Ferry to talk about a little bit of the stats behind these ultrasound evaluations and to bring us home. All right. Thanks, Eric. So just to recap kind of a few of the things that we're looking for here as part of our comprehensive pulmonary evaluation. So first, we're looking for the presence or absence of lung slide. In addition to that, we're looking for the presence or absence of B-line. So even in the absence of lung slide, if you see a B-line, that effectively rules out the diagnosis of pneumothorax. Additionally, like Eric highlighted, we're using M-mode for additional evaluation, looking for that expected normal seashore sign. And if that's absent, if we're seeing the stratosphere or barcode sign, another indicator for pneumothorax. And then finally, the transition point, which we were able to identify in our specific patient. So that's a focal transition point where there's an absence of lung sliding. We're not seeing B-lines with it. We're not seeing kind of the comet tail sign going along with that. Various studies have looked at this. Overall, the sensitivity is good. And the specificity is even better, closer to 100%. So you see this study from 2000. They gave a sensitivity of 100% for lung slide. And then from 2000, they gave a sensitivity of 67% associated with identification of a transition point and the specificity of near 100%. Additionally, kind of looking through the literature, there's kind of various or a range of different sensitivities and specificities. Across the board, sensitivity probably is ranging somewhere from the 60 to 70% range, up to 80 to 90% for identification of a pneumothorax. From a specificity standpoint, again, it's even higher, usually 95 plus percent. If you're identifying absence of lung slide, a specific transition point, no B-lines with it, that's very specific for pneumothorax. And a couple of things, you know, it's not a perfect test. So a couple of things that you would want to consider. If you do see absence of lung slide, these are less likely to be identified in kind of a young, otherwise healthy athletic population. But things to keep in mind, nonetheless, if the patient has a history of prior thoracic surgery, the presence of pulmonary blebs, the presence of significant atelectasis or lower consolidation, if there was a large parenchymal tumor, or if this was a more massive, a larger scale injury associated with total lung collapse, those could all be alternative reasons that you're not going to see lung slide outside of just pneumothorax. So one of the other common modalities that we use to evaluate for pneumothorax is a chest x-ray. You can see here the sensitivity from this specific study is wide ranging, you know, somewhere between the order of 28 and 75 percent. Specificity is high again, but comparing between ultrasound evaluation and chest x-ray, usually your sensitivity is actually a little bit higher with ultrasound evaluation. So particularly at the point of care, usually we're going to have a little more ready access to that, particularly in our training room setting. So I think a nice modality to use.

2nd Edition, CASE 41

2nd Edition

Pulmonary

pulmonary ultrasound

pneumothorax detection

lung slide assessment

seashore sign

point-of-care tool