Tag Archives: new technology

New Technology: Blood Type In 30 Seconds!

This one is really exciting! Blood banks typically keep a significant number of units of O- “universal donor” blood available. These units can be given immediately when a trauma patient in need arrives, since it contains no antigens to the common blood types. It takes anywhere from 5-15 minutes for the blood bank to determine the blood type from the patient’s blood. Then and only then can they begin delivering “type specific” blood that matches the patient’s blood type.

Researchers at the Third Military Medical University in China have developed a paper-based test to determine the ABO type as well as the Rh type (D). Indicators for A, B, and D antigens turn a blue color when they are present, allowing the clinician or blood bank to accurately determine the blood type in 30 seconds. 

Why is this important? O- is an uncommon blood type, with only about 6% of the US population carrying it. Yet blood banks have to keep an inordinate amount in stock “just in case.” Using a blood type test like this could significantly cut down on unnecessary use of this rare O- blood. Unfortunately, it will be 1-2 years before the test is commercially available. I’m sure our nation’s blood bankers can’t wait!

Here’s a brief video that demonstrates how it works.

Reference: A dye-assisted paper-based point-of-care assay for fast and reliable blood grouping. Science Translational Medicine 15 Mar 2017:
Vol. 9, Issue 381, eaaf9209.

A Scan That Can Find Clots Anywhere In The Body

Our current technology for identifying venous thromboembolism (VTE) / deep venous thrombosis (DVT) consists of duplex ultrasonography, and sometimes, CT angiography. Both are relatively noninvasive and painless (unlike the old-fashioned venography of days gone by.

Researchers at the Massachusetts General Hospital have been working with different chemical probes that could adhere to clot and allow it to be identified on a PET scan. After experimenting with a number of fibrin-targeting peptides they settled upon one called copper fibrin-binding peptide 8 (Cu-FBP8). It was found to have a high affinity for clot, remain stable, and clear quickly from the animal.

A series of rats were subject to a surgically induced thrombus in the carotid or femoral arteries, or a sham operation. The animals were then imaged by CT/PET scan after injection with the Cu-FBP8 probe. The authors found that the probe worked as expected, identifying clot immediately. They were also able to follow resolution over the days following induction. 

Here is a whole-body fused CT/PET scan of one of the animals with both carotid artery (yellow arrow) and femoral artery (blue arrows) clot.

Bottom line: This is a potentially exciting tool that could make it much easier for us to identify DVT and VTE. It could also help us understand the etiology and incidence of PE as well. But as with all animal studies, it remains to be seen whether this will translate into a useful test for humans. Stay tuned, as it will probably take about 3 years to find out the answer.

Reference: 

Multisite Thrombus Imaging and Fibrin Content Estimation With a Single Whole-Body PET Scan in Rats. Arterioscler, Thromb, Vasc Biol 35(10):2114-2121, 2015.

Interesting Concept: The Abdominal Aortic & Junctional Tourniquet

Tourniquets for extremity bleeding are definitely back in vogue. Our military experience over the past 20 years has shown us what a life saver this simple tool can be. It’s now carried by many prehospital trauma professionals for use in the civilian population. But what about bleeding from the nether regions? You know what I’m talking about, the so-called junctional zones. Those are the areas that are too proximal (or too dangerous) to put on a tourniquet, like the groin, perineum, axilla, and neck.

Traditionally, junctional zone injury could only be treated in the field with direct pressure, clamps, or in some cases a balloon (think 30Fr Foley catheter inserted and blown up as large as possible, see link below). In the old days, we could try blowing up the MAST trousers to try to get a little control, but those are getting hard to find. 

An Alabama company (Compression Works) developed a very novel concept to try to help, the Abdominal Aortic and Junctional Tourniquet (AAJT). Think of it as a pelvic compression device that you purposely apply too high.

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Note the cool warning sticker at the bottom of the device!

The developers performed a small trial on 16 volunteer soldiers after doing a preliminary test on themselves (!). The device was placed around the abdomen, above the pelvis, and inflated to a maximum of 250 torr. Here are the factoids:

  • All subjects tolerated the device, and no complications occurred
  • Flow through the common femoral artery stopped in 15 of the 16 subjects
  • The subject in whom it did not work exceeded the BMI and abdominal girth parameters of the device
  • Average pain score after application was 6-7 (i.e. hurts like hell!)

Here’s a list of the criteria that preclude use of this device:

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Bottom line: This would seem to be a very useful device for controlling hemorrhage from pesky areas below the waist.

BUT! Realistically, it will enjoy only limited use in the civilian population for now. Take a closer look at the exclusion criteria above. Half of the population is ineligible right off the bat (women). And among civilians, more than a third are obese in the US. Toss in a smattering of the other criteria, and the unlikelihood of penetrating trauma to that area in civilians, it won’t make financial sense for your average prehospital agency to carry it. Maybe in high violence urban areas, but not anywhere else.

The company has received approval for use in pelvic and axillary hemorrhage control, so we’ll see how it works when more and larger studies are released (on more and larger people). 

Related post:

Reference: The evaluation of an abdominal aortic tourniquet for the control of pelvic and lower abdominal hemorrhage. Military Med 178(11):1196-1201, 2013.

Thanks to David Beversluis for bringing this product to my attention. I have no financial interest in Compression Works.

Newest Cool Device: XStat Dressing

This new investigational device has made quite a splash during the past week. Manufactured by an Oregon company, it is designed to control bleeding, and is for use by combat medics and first responders.

Inspired by the old Fix-A-Flat expanding foam tire patch system, the XStat looks like a big syringe, and is filled with small 1cm sponges that expand rapidly when they get wet. It’s designed to stop hemorrhage in small wounds and wound tracts. Just pull back the plunger (which comes fully inserted to save space), push the unit into the wound, then hold the plunger while pulling the syringe out. This serves to leave the load of sponges in the tract and achieve rapid hemostasis.

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It would seem that leaving a lot of tiny sponges in a wound could cause problems, especially if they are not removed at the time of definitive surgical management. However, each one is tagged with a radiopaque marker so they can be identified with xray or fluoro.

Preclinical trials have claimed to be successful, and an application has been submitted to the FDA for human use. This has the potential to save lives when bleeding gunshot wounds are encountered, especially in combat situations.

I have no financial interest in RevMedx, the manufacturer of this device.

More info: 

New Technology: The Bruise Suit

Here’s an interesting new product. It’s called the “bruise suit”, and it was designed by some students at the Imperial College of London. The purpose of the suit is to visually indicate that enough force has been applied to potentially cause injuries.

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It was initially designed to help Paralympic athletes detect when they’ve encountered enough force to cause injuries that they are unable to feel. It uses a pressure-sensitive industrial film developed by Fuji that changes color based on the compressive force applied. It gets darker as the force increases. 

This product is currently in the concept phase, meaning that it will be some time before it hits the market. However, it’s a great idea that has implications for athletes playing contact sports and rescue professionals, to name a few. We’ll see how it develops!