Traumatic Pneumothorax; Roadside to Resus
Highlights
- Episode AI notes
- Traumatic pneumothoraces are common in multi-trauma patients and can also occur in those with isolated chest injury.
- Tension pneumothorax can occur in traumatic pneumothorax, but it can be confusing due to differing definitions in the literature.
- When evaluating a chest x-ray for pneumothorax, look for the lung edge separated from the thoracic cage and measure the distance from the lung edge to the thoracic wall to approximate its size.
- Decompressing a patient with a needle can be done in the second intercostal space in the midclavicular line, but this may not always be effective due to chest wall thickness.
- Choosing the right chest wall decompression device is crucial, and if not available, the fourth or fifth intercostal space in the mid-axillary line can be an alternative site.
- The decision to perform an open thoracostomy in a trauma patient should consider the patient's unique characteristics and available resources.
- If the patient doesn't improve after the first attempt at decompression, consider changing the decompression site or kit. (View Highlight)
- The Different Types of Neumithoraxes
Key takeaways:
- A Neumithorax is a collection of air outside of the lung, but within the intraplural space.
- Traumatic Neumithorases are present in about a fifth of multitrauma patients.
- They can occur in those with isolated chest injury too.
Transcript:
Speaker 1
Right, now, I won't bore you with the detailed anatomy that underlies a Neumithorax. James is far too much of an expert in doing that for me to attempt. Take from that what you will, whether or not it's the bore or the detail. At the base level, a Neumithorax is a collection of air outside of the lung, but within the intra-plural space. Now being a high-level evidence-based podcast, it's fair to say that air in the wrong place in the chest isn't great and can lead to some bad stuff. Fortunately though, there are some great treatments for Neumithorases, but those treatments can also be pretty invasive and to complicate matters further, not all Neumithorases need intervention. So as we'll cover, there are lots of ways you can categorize Neumithorases, but in order to maintain any attention, we'll be focusing on traumatic Neumithorases here and we'll come on to atromatic or spontaneous ones in another episode. Now traumatic Neumithorases are present in about a fifth of multi-trauma patients, so it's not infrequent to come across them, and they can obviously occur in those with isolated chest injury too. (Time 0:01:35)
- Tension Pneumothorax: What It Is and How to Treat It
Key takeaways:
- A tension pneumothorax can occur in a traumatic pneumothorax, and it can be difficult to understand because the literature surrounding it is confusing.
- It is an excusable flaw, because the definitions of a tension pneumothorax are different.
Transcript:
Speaker 1
But whether the patient is breathing spontaneously or whether they are being ventilated is a really important point that we need to consider. And don't worry, we'll be coming back on to that in a bit. We will, but we've got something very exciting to think about now. And that's tension pneumothoruses, which can occur in a traumatic pneumothorax as well. And I know you'll find this difficult to believe, but it's actually taken me quite a long time to get my head around this because... No. No. Oh, no. I won't hear you say that about yourself, mate. No. No, it's all right. It's because the literature that surrounds it is actually very confusing. So it's an excusable flaw. Because when you look up what a tension pneumothorax is, there are loads of different definitions. So some definitions talk about a pneumothorax being under tension when the pressure has got so great that the mediastinal structures have been displaced. Some talk about a pneumothorax being under tension when you get cardiovascular collapse. Some talk about it being a retrospective diagnosis, my favorite to make, when pressure is released and physiological improvement occurs after decompression. And some are anatomical and talk about the valve being one way. So the more I think you read about this, or certainly from my perspective, the more I got confused. (Time 0:09:48)
- Pneumothorax: What to Look For on a Chest X-Ray
Key takeaways:
- A pneumothorax is an air pocket in the lungs, and can be caused by a number of things, including trauma or a spontaneous pneumothorax.
- If you see a pneumothorax on a chest xray, it's important to determine its size and whether it needs to be treated.
- There is a way to approximate the size of a pneumothorax on a chest xray, and this is done by measuring the distance from the lung edge to the thoracic wall at the level of the highlum.
Transcript:
Speaker 1
He's going to have a go. Here you go. Let me just clear my throat. When you've got that chest x-ray in front of you, you are looking for that visceral pleura, so that lung edge, and you're looking for it being separated from the thoracic cage with no visible lung marking between the two. So that's just a little bit there for someone who doesn't look at these regular. From someone who doesn't look at them regularly. It's a catastrophic couple of errors going there. Well, I think when you do look at them, there are a couple of potential mimics which you need to be made aware of though. And as a recap, there is the border of the scapula. So that is a big one, as is the outline of the oxygen tubing. So those are the two things you're looking out for. And if you have got artifact potentially mimicking a pneumothorax, there's no real harm in repeating the chest x-ray after you've removed what that artifact might be. Now, if you see a pneumothorax, this is really interesting when I'll have to read into this. There is a way to approximate its size on a chest x-ray, and I know we are doing spontaneous pneumothorax next month, so I'm sort of feeling myself being dragged away from this topic. But the British Theratic Society say that we should be measuring the distance from the lung edge to the thoracic wall at the level of the highlum when it comes to assessing for size. So it's not the distance from the apex, it's the level of the highlum. And this is done differently around the world, but bear with me. So if that distance at the highlum is less than two centimeters, that is what's classed as a small pneumothorax. If that distance is more than two centimeters, then it's classed as a large pneumothorax. And the reason that two centimeters is the key figure here is that this is approximately the point at which half of the lung volume has been lost. So it's a really small measurement when you look at it on the screen, but that's a key factor that you're looking at here. (Time 0:22:48)
- How to Decompress a Patient with a Needle
Key takeaways:
- Prehospital clinicians should use a needle to decompress patients if they are showing signs of respiratory or cardiovascular compromise.
- This can be done using the second intercostal space in the midclavicular line, just over the top of the third rib. However, this can lead to failure of decompression in a significant percentage of patients.
Transcript:
Speaker 2
Then when we've temporized the patient, if they're showing signs of respiratory or cardiovascular compromise, as we've said, so increasing hypoxia, severe respiratory distress or hypotension, then we're going to want to decompress that tension. And for the vast majority of pre-hospital clinicians, that means using a needle. Now, I could talk about this all day long, but you and I have got much better things to do. We have, yes, we have. And we do need to save some topics for future episodes. You know, we wouldn't want to run out or anything. So let's summarize the key points around needle decompression. So the classically taught area for insertion is the second intercostal space in the mid-clavicular line, just over the top of the third rib. But we know from multiple studies that this can lead to failure of decompression, particularly when an IV cannula is used. And that's because the chest wall thickness at that point is on average about 42 millimeters. The 14 gauge cannula, well, that's about 45 millimeters. So that means that there's a significant percentage of patients that won't have their plural cavity penetrated by an IV cannula. So I guess there's two ways to overcome that issue, either you use a longer needle or you change your decompression site. So let's go with the long needle to start with. (Time 0:33:04)
- The Advantages of Chest Wall Decompression Devices
Key takeaways:
- There are different types of decompression devices, and it is important to choose the right one for the patient.
- The fourth or fifth intercostal space is a good place to insert a needle if you don't have a decompression device.
- It is important to be careful when inserting the needle, and to feel for a loss of resistance when going deeper into the tissue.
Transcript:
Speaker 2
Firstly, it's got that longer needle, but also the catheter around it is thicker and is less prone to kinking. That's another problem with your cannulas. But with those commercial devices, we do need to be more careful about our insertion technique because the risk of eye at trigenic injury with that much bigger needle is higher, particularly when we think about the needles being up to about eight centimeters long. Now some devices have got a built-in indicator at the top which moves when the plural cavity has been punctured, that's really handy, but if they don't then some have got depth markers on the side. That's pretty useful. You could then start to become really cautious as you progress beyond about five centimeters and try and feel for a loss of resistance. Or you can just go for that old school method of attaching a syringe half filled with saline onto the end of your needle and then just aspirate as you push the needle through the tissue. And I think actually of all of the options is probably one of the best actually. However, if you haven't got a specific needle decompression device, or even if you have, an alternative site for decompression is the fourth or the fifth intercostal space in the mid-acillary line. Now a systematic review and meta-analysis in injury reported that the chest wall thickness at that point in the mid-acillary line was 39 millimeters. And therefore, if we insert our needle into there, even with a cannula which was 45 millimeters, then it would result in a reduced failure rate. (Time 0:34:32)
- The Decision to Perform an Open Thoracostomy in a Trauma Patient
Key takeaways:
- Chest wall thickness at the midacillary line is a factor in determining the success of chest decompression.
- Decompression in the midacillary line is preferable to decompression at other points in the chest if the expertise is available.
- If the patient fails to improve after decompression in the midacillary line, the decompression site or kit may need to be changed.
Transcript:
Speaker 2
Now a systematic review and meta-analysis in injury reported that the chest wall thickness at that point in the mid-acillary line was 39 millimeters. And therefore, if we insert our needle into there, even with a cannula which was 45 millimeters, then it would result in a reduced failure rate. But each patient is unique and those chest wall thickness differences really aren't that great plus decompressing in that mid-acillary line does bring some challenges in the pre-hospital setting, particularly around packaging the patient. So I think I'm going to sort of summarize like Rob did and say, look at the patient in front of you and make the decision based on the kit that you've got and the patient in front of you. But it's worth saying that if the patient fails to improve after your first attempt at decompression, then you need to have a really low threshold for changing either the decompression sites or the kit that you've got if that is feasible for you.
Speaker 1
James, we all know that strapped beside your ultrasound on your leg, you've got the knife and you've failed to mention what you're going to be doing with that. So what about an open thoracostomy, though? Because you haven't mentioned that yet.
Speaker 2
I haven't, though. Thank you, Simon. And well, you're absolutely right. And interestingly, the nice guidelines on major trauma do actually suggest that open thoracostomy should be used preferentially if the expertise is available. So why is that then? (Time 0:35:38)