Category Archives: General

A New Way To Repair Damaged Muscle?

February 29, 2016 The Trauma Pro Leave a comment

For patients with severely damaged skeletal muscles, the best way to heal them is a combination of splinting and physical therapy, right? These serve to increase the size of existing muscle fibers. And a few cellular therapies are also available involving stem cells or stimulating their production, which may actually add new muscle. But what about something cheaper and less complicated?

Researchers at the engineering school at Harvard are working on a new approach, mechanotherapy. They tried two therapeutic interventions in mice with hindleg muscle damage and ischemia.

The first was implantation of a magnetic gel pack directly in contact with the muscle. A magnet placed on the other side of the muscle was pulsed to repeatedly squeeze the muscle gently.

The second group had a small pneumatic cuff placed which encircled the leg (a tiny mouse BP cuff?). If was inflated cyclically to massage the muscle.

Both therapies resulted in a 2.5x increase in muscle regeneration and less scarring and fibrosis, compared to control animals that had neither therapy.

Left image: control animal. Right image: mechanotherapy. Note the increased muscle cell density.

Bottom line: Unfortunately, we typically think about medicine from a chemical standpoint. That’s why we are so reliant on drugs for just about everything. But this study suggests that merely squeezing the muscle regularly and early after injury may greatly improve healing. There are significant implications for trauma patients, of course. Might it also be possible to help decrease muscle mass loss in denervated muscles, as in para- and quadriplegics? And we may find that if we combine this with some of the biologics already in use, the results may be even better. Stay tuned for developments.

Related post:

Regrowing new muscle with pig bladders?

Reference: Biologic-free mechanically induced muscle regeneration. Proc Natl Acad Sci USA 113(6):1534-1539, 2016.

General

Comparison of Cervical Spine Stabilization

February 24, 2016 The Trauma Pro Leave a comment

A reader recently asked what the optimal method for inline stabilization is. We’ve been pondering this question for nearly 30 years. In 1983, trauma surgeons at UCLA looked at a number of devices available at that time and tested them on normal volunteers. They measured neck motion to see which was “best.”

Here’s what they found:

Soft collar – In general, this decreased rotation by 8 degrees but insignificantly protected against flexion and extension. Basically, this keeps your neck warm and little else.
Hard collars – A variety of collars available in that era were tested. They all allowed about 8% flexion, 18% lateral movement, and 2% rotation. The Philadelphia collar allowed the least extension.
Sandbags and tape – Surprisingly, this was the best. It allowed no flexion and only a few percent movement in any other direction.

The Mayo clinic compared four specific hard collars in 2007 (Miami J, Miami J with Occian back, Aspen, Philadelphia). They found that the Miami J and Philadelphia collars reduced neck movement the best. The Miami J with or without the Occian back provided the best relief from pressure. The Aspen allowed more movement in all axes.

And finally, the halo vest is the gold standard. These tend to be used rarely and in very special circumstances.

Bottom line:

For EMS: Rigid collar per your protocol is the standard. In a pinch you can use good old tape and sandbags with excellent results.
For physicians: The Miami J provides the most limitation of movement. If the collar will be needed for more than a short time, consider the well-padded Occian back Miami J (see below).

References:

Efficacy of cervical spine immobilization methods. J Trauma 23(6):461-465, 1983.
Range-of-motion restriction and craniofacial tissue-interface pressure from four cervical collars. J Trauma 63(5):1120, 1126, 2007.

General

Falls vs Abuse In Kids: Differences In Injury Patterns

February 23, 2016 The Trauma Pro Leave a comment

Nonaccidental trauma (NAT) in children, a.k.a. child abuse, is a problem that trauma professionals see all too frequently. Much of the time, the abuse is obvious. Sometimes, it is more insidious and occult, and we can be misdirected by the history given by the caregivers. The most frequent story used to cover up obvious injuries child abuse is that the child fell. Unfortunately, the injuries observed from abuse may be very similar to those seen from shaking, grabbing, lifting, and throwing.

A paper that is currently in press from the University of Colorado at Aurora seeks to clarify this a bit, trying to tease out nuances in common injury patterns that may help us distinguish NAT from falls. They performed a retrospective database review at both Denver Health and Children’s Health Colorado over a 15 year period. They specifically looked at children with blunt abdominal trauma. Unfortunately, they chose the age group < 18 years as “children”, which muddies the picture somewhat.

Here are the factoids:

Of the 1,005 blunt abdominal trauma cases identified, 65 were confirmed to be due to NAT, and 115 were actually from falls
63 of the 65 NAT victims were less than 5 years old, but only 35 of the falls were
Average ISS for the NAT kids was 20, vs only 12 for falls
There were more hollow viscus injuries in NAT kids (25 vs 2), and more pancreatic injuries (16 vs 2)
If a head injury was present, it was more severe with NAT
Hospital LOS was longer after NAT, which makes sense given the ISS and head info above

Bottom line: Unfortunately, the authors could accumulate only a small amount of data over 15 years, but it paints a clear picture. Injured children presenting with a history of falls, particularly young children who can’t engage in the high energy pursuits of adolescents, should arouse suspicion. If multiple injuries are found, especially visceral or deep solid organ abdominal injury (pancreas), suspect foul play. Similarly, if the head injury is more severe, be suspicious. All trauma professionals need to keep the possibility of NAT in the back of their minds on every injured child they see!

Related posts:

Reference: Pediatric abdominal injury patterns caused by “falls”: A comparison between nonaccidental and accidental trauma. J Ped Surg, in press, Feb 2, 2016.

General

Impact Of Arm Position On Torso CT Scan

February 22, 2016 The Trauma Pro Leave a comment

CT scan is a valuable tool for initial screening and diagnosis of trauma patients. However, more attention is being paid to radiation exposure and dosing. Besides selecting patients carefully and striving for ALARA radiation dosing (as low as reasonably achievable) by adjusting technique, what else can be done? Obviously, shielding parts of the body that do not need imaging is simple and effective. But what about simply changing body position?

One simple item to consider is arm positioning in torso scanning. There are no consistent recommendations for use in trauma scanning. Patients with arm and shoulder injuries generally keep the affected upper extremity at their side. Radiologists prefer to have the arms up if possible to reduce scatter and provide clearer imaging.

A retrospective review of 710 patients used dose information computed by the CT software and displayed on the console. Radiation exposure was estimated using this data and was stratified by arm positioning. Even though there are some issues with study design, the results were impressive.

There was no difference in scanning time for any arm position. Here are the factoids for radiation dose:

Both arms up: 19 mSv (p<0.0000001)
Left arm up: 23 mSv
Right arm up: 24 mSv
Arms down: 25 mSv

Bottom line: Do everything you can to reduce radiation exposure:

Be selective with your imaging. Do you really need it?
Work with your radiologists and physicists to use techniques that reduce dose yet retain image quality
Shield everything that’s not being imaged.
Think hard about getting CT scans in children. They probably don’t need it!
Raise both arms up during torso scanning unless injuries preclude it.

There is a commercial product now available that helps position the arms without tape, paper clips, or other office supply items. It doubles as a pillow for the patient and is held in place by their weight

Courtesy of http://accessoryaccommodations.com/

Related posts:

Reference: Influence of arm positioning on radiation dose for whole body computed tomography in trauma patients. J Trauma 70(4):900-905, 2011.

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