Interventional radiology (IR) can be a very helpful adjunct to the evaluation and management of trauma patients. I’m going to talk specifically about using it for blunt trauma today because the use in penetrating trauma can be a little more nuanced.
For blunt trauma, IR is used primarily to stop bleeding. In a smaller subset of patients, this tool is used to evaluate pulse deficits. There are two basic principles that apply in either case, and I’ve wrapped them up into a single concept: the 30:60 rule for interventional radiology.
Of course, the second law of trauma still applies: hypotensive patients cannot leave the ED to go anywhere but the OR. Once you make sure you are not violating that one, you can start the process of going to IR.
The two portions of the rule are times: the time for the IR team to arrive to start the evaluation, and the maximum time allowed for them to succeed, hence the 30:60 numbers.
The maximum acceptable time for the patient to wait until the IR team is ready for them is typically 30 minutes. US trauma center verification requires a reasonable arrival time frame, and the vast majority of hospitals have a 30 minute expectation if the team is not already in place. This response time needs to be monitored by the trauma performance improvement program (PI) and addressed if it ever exceeds the limit.
The second number is the maximum time the radiologist is given to be successful. Like other physicians, radiologists like to do a good job and finish the work they start. If they find a particularly tortuous splenic artery to navigate, they will persist at trying to get through it in order to do a selective embolization and kill the smallest piece of spleen possible. Unfortunately, this takes time and radiation (lots). And a bleeding patient is running out of time.
The good thing is that there are surgical alternatives to most of the tasks the radiologist is working on. True, some are much more difficult surgically, like managing a shattered liver or dealing with a bleeding pelvis. In those cases, I may let the interventionalist work a little longer while I keep up with blood transfusions and monitor patient status.
- Expect a 30 minute response time from the IR team
- Let the radiologist know they have about 60 minutes to succeed. If it looks like they can’t make that, have them go to plan B (e.g. main splenic artery embolization instead of selective)
- Make sure an experienced trauma physician is watching the patient for decompensation and is managing fluids and blood products (no pressors!)
- If the patient decompensates at any point, they are done in IR and must proceed to OR
So you’re faced with a chest tube that “someone else” inserted, and the followup chest xray shows that the last drain hole is outside the chest. What to do?
Well, as I mentioned, there is very little written on this topic, just dogma. So here are some practical tips on avoiding or fixing this problem:
- Don’t let it happen to you! When inserting the tube, make sure that it’s done right! I don’t recommend making large skin incisions just to inspect your work. Most tubes can be inserted through a 2cm incision, but you can’t see into the depths of the wound. There are two tricks:
- In adults with a reasonable BMI, the last hole is in when the tube markings show 12cm (bigger people need bigger numbers, though)
- After insertion, get into the habit of running a finger down the radiopaque stripe on the tube all the way to the chest wall. If you don’t feel a hole (which is punched through the stripe), this will confirm that the it is inside, and that the tube actually goes into the chest. You may laugh, but I’ve seen them placed under the scapula. This even looks normal on chest xray!
- Patient with a high BMI may not need anything done. The soft tissue will probably keep the hole occluded. If there is no air leak, just watch it.
- If the tube was just put in and the wound has just been prepped and dressed, and the hole is barely outside the rib line, you might consider repositioning it a centimeter or two. Infection is a real concern, so if in doubt, go to the next step.
- Replace the tube, using a new site. Yes, it’s a nuisance and requires more anesthetic and possibly sedation, but it’s better than treating an empyema in a few days.
Here’s a neat trick for finding hard to see rib fractures on standard chest x-rays.
First, this is not for use with CT scans. Although chest CT is the “gold standard” for finding every possible rib fracture present, it should never be used for this. Rib fractures are generally diagnosed clinically, and they are managed clinically. There is little difference in the management principles of 1 vs 7 rib fractures. Pain management and pulmonary toilet are the mainstays, and having an exact count doesn’t matter. That’s why we don’t get rib detail x-rays any more. We really don’t care. Would you deny these treatments in someone with focal chest wall pain and tenderness with no fractures seen on imaging studies? No. It’s still a fracture, even if you can’t see it.
So most rib fractures are identified using plain old chest xray. Sometimes they are obvious, as in the image of a flail chest below.
But sometimes, there are only a few and they are hard to distinguish, especially if the are located laterally. Have a look at this image:
There are rib fractures on the left side side on the posterolateral aspects of the 4th and 5th ribs. Unfortunately, these can get lost with all the other ribs, scapula, lung markings, etc.
Here’s the trick. Our eyes follow arches (think McDonald’s) better than all these crazy lines and curves on the standard chest x-ray. So tip the x-ray on its side and make those curves into nice arches, then let your eyes follow them naturally:
Much more obvious! In the old days, we could just manually flip the film to either side. Now you have to use the rotate buttons to properly position the digital image.
Final exam: click here to view a large digital image of a nearly normal chest xray. There is one subtle rib fracture. See if you can pick it out with this trick. You’ll have to save it so you can manipulate it with your own jpg viewer. If you find it, tweet it out to me! Let’s see who gets it first!
This tip is for all trauma professionals: prehospital, doctors, nurses, etc. Anyone who touches a trauma patient. You’ve probably seen this phenomenon in action. A patient sustains a very disfiguring injury. It could be a mangled extremity, a shotgun blast to the torso, or some really severe facial trauma. People cluster around the injured part and say “Dang! That looks really bad!”
It’s just human nature. We are drawn to extremes, and that goes for trauma care as well. And it doesn’t matter what your level of training or expertise, we are all susceptible to it. The problem is that we get so engrossed (!) in the disfiguring injury that we ignore the fact that the patient is turning blue. Or bleeding to death from a small puncture wound somewhere else. We forget to focus on the other life threatening things that may be going on.
How do we avoid this common pitfall? It takes a little forethought and mental preparation. Here’s what to do:
- If you know in advance that one of these injuries is present, prepare your crew or team. Tell them what to expect so they can guard against this phenomenon.
- Quickly assess to see if it is life threatening. If it bleeds or sucks, it needs immediate attention. Take care of it immediately.
- If it’s not life threatening, cover it and focus on the usual priorities (a la ATLS, for example).
- When it’s time to address the injury in the usual order of things, uncover, assess and treat.
Don’t get caught off guard! Just being aware of this common pitfall can save you and your patient!
Clearance of the cervical spine can often be done using clinical criteria alone (see this video at http://youtu.be/NhjF9kDOcjE). If this is not possible, a combination of radiologic and clinical evaluation is usually carried out.
In some cases, radiographic studies (usually CT) are normal, but there is pain on clinical exam. Our next step is to send the patient to xray for flexion and extension views. This exam is performed by removing the collar while the patient is sitting, so the thoracic and lumbar spines must be clear before ordering this. The patient then gently flexes and extends the neck to their limits of comfort. Images are then obtained at the limits of flexion and extension. The premise is that a normal, awake patient cannot and will not move their neck beyond their comfort level to the point where they could cause themselves neurologic injury.
It is very important that you look at the images yourself. The radiologist may review the images and will report that “there is no evidence of subluxation at the limits of flexion and extension.” But the patient may have barely moved their neck!
The question is: how much flexion and extension do you need to have to clear the spine?
The answer is not easy to find, and is buried in literature from the 1980s and 90s. According to the EAST guidelines, the ideal amount is 30 degrees from neutral for both flexion and extension. This is not always achievable in elderly patients, so in those cases you must use your judgment. Talk to the patient to find out if they stopped moving their neck forward or backward due to pain, or because they just can’t move it that far.
Trouble signs to look for are:
- Subluxation of more that 2mm at any level
- Angulation of more than 11 degrees
Any abnormality should prompt a spine consult.
If the study is not abnormal but the amount of flexion and/or extension is not adequate, there are two options. First, just leave the collar in place and try again in a week or so and try again. This will allow any soft tissue injuries to get better and may allow a successful repeat study. The alternative is a more costly and less well-tolerated MRI.
- EAST Practice Guidelines, Identifying Cervical Spine Injuries Following Trauma – Update (2000).
- Defining radiographic criteria for flexion-extension studies of the cervical spine. Robert Knopp et al. Ann Emerg Med. 2001 Jul;38(1):31-5.