The Trauma Professional's Blog

Oct 21

Tech: Bandage Indicates Wound Tissue Oxygen Concentration

Tissue oxygenation is critical to wound healing. But unfortunately, there is no easy way to “see” how healthy the wound is just by looking at it. A research team at the Massachusetts General Hospital is developing a spray-on “smart” bandage that determine, at a glance, shows a map of tissue oxygen levels.

Now, of course, the researchers had to get clever and come up with a lame acronym. So here it is: sensing, monitoring and release of therapeutics (SMART). Get it? SMART bandage. 

Here’s what it looks like:

Okay, so how does it work? There are three components: a sensor molecule that glows over a useful range of oxygenation values, a bandage material to bind it to, and an imaging device for capturing useful images.

The sensor molecule is a phospor derivative that glows longer and brighter as tissue oxygen decreases. The bandage is a viscous liquid that is painted on the skin and dries as a solid film within a minute (think NewSkin). It contains the sensor molecule. In order to keep room air from seeping into the bandage and interfering with the readings, a transparent barrier is placed over it (think Tegaderm). 

Finally, the detector is … a smartphone or camera! No need for other expensive equipment. The flash stimulates the phosphors as the image is recorded. The image can then be analyzed for brightness and color of the phosphors. 

What is this good for? Trauma professionals deal with soft tissue wounds on a regular basis. Some of the more complicated ones require skin grafts or flaps, and maintaining their health is very important. Imagine begin able to identify oxygenation problems early in the edges of a flap or from a small seroma under a skin graft. This could lead to earlier correction of any problems and an increase in graft salvage. And it may allow us to better predict which burns are getting worse or may need grafting. Here are images of burn vs normal skin:

Bottom line: Yet another cool (and probably inexpensive) tool in expanding our senses to appreciate factors that help wound healing. Once the kinks are worked out, expect this to move into clinical care fairly quickly.

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Reference: Non-invasive transdermal two-dimensional mapping of cutaneous oxygenation with a rapid-drying liquid bandage. Biomedical Optics Express 5(11):3748-3764, 2014.

Oct 17

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.

image

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.

image

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. 

Oct 15

The Value of Protocols in Trauma

Most trauma centers have a book of practice protocols or guideleines. Actually, it is required by the American College of Surgeons verification standards. All centers must have a massive trauma protocol. Many have pain management or alcohol withdrawal or a number of other protocols. The question sometimes arises: why do we need another protocol? Can we show some benefit to using a protocol?

I’ve looked at the literature, and unfortunately there’s not a lot to go on. Here are my thoughts on the value of protocols.

In my view, there are a number of reasons why protocols need to be developed for commonly encountered issues. 

A number of years ago, we implemented a solid organ injury protocol here at Regions Hospital. I noted that there were large variations in simple things like time at bedrest, frequency of blood draws, how long the patient was kept without food and whether angiography should be considered. Once we implemented the protocol, patients were treated much more consistently and we found that costs were reduced by over $1000 per patient. Since we treat about 200 of these patients per year, the hospital saved quite a bit of money! And our blunt trauma radiographic imaging protocol has significantly reduced patient exposure to radiation.

Bottom line: Although the proof is not necessarily apparent in the literature, protocol development is important for trauma programs for the reasons outlined above. But don’t develop them for their own sake. Identify common problems that can benefit from consistency. It will turn out to be a very positive exercise and reap the benefits listed above.

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Oct 14

… And The Ultimate Retained Foreign Bodies

Sponges are unfortunately one of the most common retained foreign bodies. This is due to their small, flimsy nature. The surgeon usually looks at the obviously visible areas of the abdomen or other body cavity before closing. She can also feel around in the “nooks and crannies”, but sponges feel very similar to the other organs surrounding it.

But what about more substantial items, like surgical instruments? Surely these are so obvious as to not leave behind?

Unfortunately, not so. Take a look at these items. This is a large pari of surgical forceps.

This is a malleable retractor, a long, thin sheet of pliable metal that can be bent to any desired shape.

And finally, a pair of Metzenbaum scissor, a common surgical instrument for cutting tissue.

Bottom line: It doesn’t matter how small or large, anything can and will be left behind in emergent and trauma cases. Recognizing that this can occur, no matter how confident you are that it has not, is the key. Always count, but followup with an x-ray that covers all areas of the surgical field before closing.

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