All posts by TheTraumaPro

Misleading Abstract Alert: Injuries Identified By Chest CT

Here is another one of those papers that have this nicely done abstract that arrives at what seems to be a reasonable conclusion. But then you sit back and think about it. And it’s no longer so reasonable.

This study seems like it should be a good one! It’s a multi-center trial involving data from ten level I trauma centers. The research infrastructure used to collect the data and the statistical analyses for this retrospective review were sound.

Here are the factoids:

  • Of nearly 15,000 patients with blunt chest trauma, about 6,000 (40%) underwent both chest x-ray and CT
  • 25% (1,454) of these patient had new injuries discovered by the CT
  • 954 were truly occult, only being found on the CT; the remaining 500 scans found more injuries than seen on chest x-ray
  • 202 patients had major interventions (chest tube, ventilator, surgery)
  • 343 had minor interventions (admission, extended observation)
  • Chest x-ray was not very good at detecting aortic or diaphragm injury (surprise)
  • 76% of the major interventions were chest tube insertions
  • 32% of of patients with new fractures seen were hospitalized for pain control
  • None of the odds ratios reported were statistically significant

Bottom line: What could possibly go wrong? Ten trauma centers. Six thousand patients. Lots of data points. There are two major issues. First, the primary outcome was a major intervention based on the chest CT. The problem with having so many participating centers is that it is hard to figure out why they performed the interventions. Are they saying that a pneumothorax or hemothorax that was invisible on chest x-ray required a chest tube? Based on whose judgment? Unfortunately, that is a big variable. The authors admit that they did not know whether “interventions based on chest CT were truly necessary or beneficial because we did not study patient outcomes” and that the decisions for intervention “were largely made by residents (usually) or fellows.”

And the secondary outcome was admission or extended observation based on the chest CT. Yet these admissions were primarily for pain management in patients with fractures. Did the patients develop additional pain due to irradiation, or was it there all along?

So adding a chest CT greatly increases the likelihood of doing additional procedures. And it is difficult to tell (from this study) if those procedures were truly necessary. But we know that they can certainly be dangerous. If you back out all of the potentially unnecessary chest tubes and the admissions for pain that should have been admitted anyway, this study demonstrates very little additional value from CT.

A well-crafted imaging guideline will help determine which patients really need CT to identify patients with those occult injuries that are dangerous enough that they can’t be missed. The authors even conclude that “a validated decision instrument to support clinical judgment is needed.”

Related posts:

Reference: Prevalence and clinical import of thoracic injury identified by chest computed tomography but not chesty radiography in blunt trauma: multicenter prospective cohort study. Annals Emerg Med 66(6):589-600, 2015.

The Contaminated Patient

In my last post, I presented the issue of dealing with a surprise patient who was both in arrest and contaminated with gasoline. They are brought into your resuscitation room without warning of the potential hazard. Now that they are here, what do you do?

Thanks for the many online and email responses. This is a tough question, because there are so many variables to think about. And you have to make decisions very quickly. Here’s a rundown on my thought processes.

First, if you get an indication that there might be any type of contamination, insist that your prehospital providers hold the patient outside the ED. Have part of your trauma team waiting at the ambulance dock to do a quick assessment there. Another minute or two of Lucas CPR will not make a difference. Use your best judgment as to how much of a hazard is posed by the fuel/mystery liquid/white powder. But err on the side of being conservative so you don’t end up shutting your entire ED down due to contamination. If in doubt, immediately move to your decontamination area.

If the patient ends up deep in your ED before anyone recognizes that there might be a contamination problem, you must heed three overarching principles:

  • Limit contamination to the rest of your facility. Close the doors to the resuscitation room. Notify security and your hazardous materials team so they can start working on containment and safety issues outside the room. Failure to do this can take your entire hospital offline. If the situation turns out to be a multiple or mass casualty event and your hospital was the only one able to respond, you’ve just created a catastrophe and delayed treatment for the other patients.
  • Ensure the safety of your team. This is a great reason to require and enforce that everyone on the team dress up completely for every resuscitation. You never know where your patients have been, and when one of these will sneak in.
  • Continuously assess the risk:benefit ratio. Is the contamination a minor irritant? What is the danger to the team? The ED/hospital? How likely are your efforts to save the patient to succeed? As soon as the ratio goes bad, rethink the options and act accordingly.

Bottom line: In situations like this, think fast and think globally. Don’t just consider the patient. There may be many more lives at stake, and this can and should factor into your decisions about where and how long to continue resuscitation.

In this case, we were certain it was only gasoline. We closed the doors and quickly stripped the patient, bagging the clothes tightly. We tried not to generate any sparks, but we are surrounded by all kinds of electrical equipment. Defibrillation was out of the question. After the event was finished, it was time to wash everything down and start thinking about what would have happened if this had been something more toxic than fuel!

Related post:

What Would You Do? The Contaminated Patient

Here’s some food for thought. Read through the scenario below, as well as the questions under it. I’m interested in some comments from prehospital providers, physicians and nurses in the ED on what you would do in this situation.

Scenario: Paramedics call ahead to activate your trauma team for a young male who was ejected from his car during a motor vehicle crash. He was quickly extricated and was found to be in pulseless electrical activity (PEA) arrest. IVs were inserted and the Lucas automated CPR device was attached. The patient is immobilized and will arrive at your hospital in 5 minutes.

You assemble your trauma team and are patiently awaiting when the medics arrive. The patient / Lucas / backboard are rapidly transferred over to the ED stretcher and mechanical CPR continues. At that point, you are overwhelmed by the odor of gasoline, and you note that the patient’s clothing is saturated with liquid.

What would you do?

Here are my questions for you:

  • Do you move the patient or keep him in your trauma bay?
  • What if your decontamination area is a short/moderate/longer distance from your ED?
  • What if this situation involved a farmer in arrest who smelled strongly of pesticide? Any different?
  • Or someone covered with mysterious white powder?
  • How do you balance patient survival and team safety?
  • What kind of performance improvement activities will be needed with regard to the team? The prehospital providers?

Tweet or comment away! More tomorrow.

What Is: The LisFranc Injury?

Medicine is full of conditions with eponyms. Trauma is no exception. There’s the Mattox maneuver and the Cushing response, to name two. Many times, the name is just a kind of vanity plate for the discoverer of the condition. But in the case of the LisFranc injury (or fracture), it makes some sense. This injury is tough to describe in a sentence or two, let alone a few words.

Jacques LisFranc de St. Martin was a French surgeon and gynecologist (!) who described this condition in about 1815. It entails the fracture of the heads of the metatarsal bones and possible dislocation from the tarsals (the cuboid, navicular, and three cuneiform bones). This area is known as the LisFranc joint complex.

The injury can involve any or all of the metatarsals. The typical mechanism applies high energy across the midfoot, which can often be seen in head-on motor vehicle crashes. Crush injury to the proximal foot can also do this, such as running the foot over with a car. Occasionally, this injury pattern is produced with lower energy during sports play. In this case, the top of the foot is typically contacting the ground, plantar flexing it. At the same time, another player steps on the heel, grinding the foot into the ground (ouch). Interestingly, LisFranc did not describe the injury pattern or mechanism. His name is associated with the joint complex, and it is an injury to his joint complex.

Most of the time, the injury is obvious. There is usually notable pain and swelling of the foot. X-ray findings are generally not subtle. However, lower energy mechanisms may not cause much displacement, and initial imaging may not show the injury. If your patient starts to complain of pain in the midfoot when they begin to ambulate, think of LisFranc.

Treatment depends on the degree of displacement and the amount of disruption of the tarso-metatarsal joints. If minimal, a trial of nonoperative, non-weight bearing may be sufficient. But frequently, surgical reconstruction is required.

Single Incision Fasciotomy?

The concept of performing 4-compartment leg fasciotomy using only one incision is not a new one. Techniques using a lateral approach, either with or without fibulectomy, have been described as early as 1967.

A new paper describes a single-incision technique for compartment syndrome using a medial approach. The authors believe that going through the anterior compartment to release the deep posterior is quicker, uses a smaller flap, and avoids injury to the peroneal nerve. They reviewed their own experience over a 5 year period.

Here are the factoids:

  • 180 fasciotomies were performed for compartment syndrome, of which 30 were single-incision
  • 27 had associated fractures, 2 were due to soft tissue injury and 1 was spontaneous
  • There was a single wound infection, nerve injury, and patient with persistent pain. There were several tethered tendons and scars.
  • The number and types of complications were similar to traditional fasciotomy

Traditional 4 compartment fasciotomy with 2 incisions. Source: gog.net.nz

Bottom line: Sounds great, right? Yes, it’s a small study, and statistically there is not enough power to show that it’s “better.” So if it’s not worse, and there is just one smaller incision, what’s wrong with it?

For me, the problem is that there is too much opportunity to perform an incomplete fasciotomy. The learning curve for single incision fasciotomy, either this one or the more traditional lateral approach, is steep. Seriously impaired patients who need fasciotomy are frequently not going to be awake any time soon, leaving the surgeon with no neurologic or pain exam.

My recommendation: read papers like this and smile. Then do the classic 2 incision operation, making sure that all compartments are completely released.

Related post:

Reference: A single incision fasciotomy for compartment syndrome of the lower leg. J Ortho Trauma, Publish ahead of print, January 21, 2016.