All posts by The Trauma Pro

CNS

GCS At 40: The Original GCS

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The Glasgow Coma Score (GCS) has been in use for more than 40 years. Since that 40th anniversary a few years back, there has been talk of updating this tried and true system. But where did this scale come from? How was it devised? And why are we looking to update it now? I’ll dig into this topic over my next several posts.

The original paper describing the GCS was published in 1974 by Graham Teasdale and Bryan Jennett. They were neurosurgeons at the Institute of Neurologic Sciences in Glasgow, Scotland (of course) and were based in the Southern General Hospital. Until this paper was published, each report in the literature described its own assessment of level of consciousness. Most divided the spectrum into various steps noted between fully alert and comatose. Unfortunately, these systems were confusing, and they varied from 3-17 steps! There was just no consensus. Some relied on a comprehensive neurologic exam, including brainstem function tests. However, none of these were really designed for repeated bedside assessment.

Teasdale and Jennett settled on three simple areas to examine: eye-opening, motor response, and verbal response. They selected easily observable responses for each of these components. Here is a copy of the original scale:

Notice that this differs from the current-day score. The motor response did not have a “withdrawal” option, so the maximum score was only 14! But that didn’t matter much at the time; the individual components were graphed out over time for inspection. A total score was not generally calculated.

Teasdale and Jennett found that inter-rater reliability for this system was excellent, compared to a 25% discrepancy for other less objective systems in use at the time. This led to its rapid adoption over the coming years.

In my next post, I’ll describe how GCS came to be used over the ensuing years.

Imaging

Radiation Exposure From Imaging At Adult vs Pediatric Trauma Centers

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Anyone who reads this blog already knows I am a big believer in well-crafted and focused practice guidelines. And by focused I mean directed toward a clinical problem that typically sees a lot of variability between care providers. Use of imaging is one of these clinical problems. A surgeon may order a certain set of studies for a major blunt trauma patient, and their emergency medicine colleague might order a somewhat different set for someone with the exact same history, physical exam, and injury pattern. Who is right? Neither!

And the variability is even greater when we throw a pediatric patient into the mix. Trauma professionals tend to be even more “generous” when ordering studies on children because they are afraid they might miss something. Unfortunately, this has the potential for overuse of imaging and exposure to unnecessary radiation.

Avery Nathens and a consortium of pediatric trauma centers used the Trauma Quality Improvement Database (TQIP) to review CT imaging practices on children age < 18 over a four year period. Only blunt trauma patients were studied, and the Abbreviated Injury Scale had to be at least 2 for a minimum of one organ system. Transfer patients were excluded because there is no data on imaging for the referring hospital in the TQIP database for them. Comparisons were made between practices at adult trauma centers treating children (ATC), mixed adult/pediatric centers (MTC) and pediatric only trauma centers (PCT).

Here are the factoids:

  • Over 59,000 pediatric trauma patients were identified in the data, and about half (31,081) received at least one CT scan
  • The distribution among the three types of trauma centers was even, with roughly a third seen at each
  • Of the study group 46% had a head CT, 17% a chest CT, and 26% underwent abdominal CT
  • Injured children were more likely to undergo CT if they were older, had a higher ISS, lower motor GCS, were involved in a car crash, or had severe injuries to head or torso
  • Overall CT rates were about the same across the three types of centers (56% ATC, 57% MTC, 43% PTC)
  • Chest CT was performed 8x as much at ATC/MTC vs PTC (!)
  • Abdominal CT was performed 2x as much at ATC/MTC vs PTC
  • Lesser injured children received relatively more CT scans at ATC/MTC when compared to PTC
  • Using standard estimates of cancer risk from all CT scans received, children treated at adult or mixed trauma centers received enough radiation to cause 17 additional lifetime cancers per 100,000 patients
  • About 35 additional lifetime cancers per 100,000 would be caused by the chest and abdominal scans performed at the ATC/MTC centers when compared to pediatric-only centers

Bottom line: This is yet another reason to adopt a well-designed pediatric imaging guideline. Not only are adult centers using CT scanning much more that pediatric-only centers, but they are unnecessarily adding to the lifetime risk for cancer of our children!

As I always recommend, find a well-designed imaging guideline from an established pediatric center and “borrow” it. Sure, it may need a few minor tweaks to fit well with your hospital. That’s okay. Just get it done so your team can begin to order the initial imaging studies consistently and intelligently.

Reference: Computed tomography rates and estimated radiation-associated cancer risk among injured children treated at different trauma center types. Injury 2018, in press.  https://doi.org/10.1016/j.injury.2018.09.036

Complications

Bullet In The Disk Space: Big Deal Or Not?

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In an earlier post, I reviewed the problems with lead poisoning that can occur if a bullet remains in contact with a joint space / synovial fluid, or ends up in the GI tract. But what about if it comes to rest in an intervertebral joint space? They’re dry, right?

The first case report I could find dates back to 1981. A male presented to Parkland Memorial Hospital 12 years after a gunshot to the abdomen in which the bullet lodged in a disk space. He was treated for a GI bleed, but was also noted to have many signs and symptoms of high lead levels. These included irritability, anemia, headache, lethargy, muscle weakness and confusion. A blue line was noted on the gums. X-ray of the lumbar spine showed the bullet fragment in the center of the disk space, and a cystic mass in the prevertebral area that appeared radiodense as well. Blood lead levels were elevated. The patient underwent diskectomy, resection of the mass, chelation therapy, and recovered.

Another case report from 2010 was similar in many ways. The patient was young, had a gunshot 5 years previously, and presented with symptoms of lead poisoning. The appearance of the bullet in the disk space was similar to the last case, in that the bullet could be seen within it, and there appeared to be additional radiopaque material surrounding it. It almost looked like lead was flowing out of the bullet into the disk. This case was also treated with surgical removal and chelation with a successful result.

A literature review was conducted 15 years ago that examined other case reports of bullets in the spine. Over a 25-year period 238 patients were identified with this injury. Only 12 had bullets or fragments in the disk space. All were tested for plumbism, and only one was positive. He underwent diskectomy and resection with resolution of the high lead levels.

Bottom line: We know that a bullet in contact with synovial fluid is bad, with rapid leaching of lead into the circulation. There are also suggestions that lead in contact with CSF can cause a similar problem. However, the intervertebral disk space is usually considered to be “dry” and doesn’t usually cause a problem.

However, patients with a bullet in this location should be cautioned that they do have a small risk of developing lead poisoning. They should be tested about six months post-injury to see if lead levels are on the rise. They should also be cautioned to report the development of new back pain. Structural disruption by the bullet may slowly lead to anatomic changes that result in chronic pain. And be very suspicious if there is radiopaque material in the disk space in addition to the bullet itself!

References:

  1. Acute lead intoxication from a bullet in the intervertebral disk space. JBJS 63A(7):1180-1182, 1981.
  2. Lead Poisoning by Intradiscal Firearm Bullet. Spine 35(4):E140-E143, 2010.
  3. Long-Term Clinical Manifestations of Retained Bullet
    Fragments Within the Intervertebral Disk Space. J Spinal Disord Tech 17(2):108-111, 2004.

 

Imaging

Pan Scanning for Elderly Falls?

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The last abstract for the Clinical Congress of the American College of Surgeons that I will review deals with doing a so-called “pan-scan” for ground level falls. Apparently, patients at this center have been pan-scanned for years, and they wanted to determine if it was appropriate.

This was a retrospective trauma registry review of 9 years worth of ground level falls. Patients were divided into young (18-54 years) and old (55+ years) groups. They were included in the study if they received a pan-scan.

Here are the factoids:

  • Hospital admission rates (95%) and ICU admission rates (48%) were the same for young and old
  • ISS was a little higher in the older group (9 vs 12)
  • Here are the incidence and type of injuries detected:
Young (n=328) Old (n=257)
TBI 35% 40%
C-spine 2% 2%
Blunt Cereb-vasc inj * 20% 31%
Pneumothorax 14% 15%
Abdominal injury 4% 2%
Mortality * 3% 11%

 * = statistically significant

Bottom line: There is an ongoing argument, still, regarding pan-scan vs selective scanning. The pan-scanners argue that the increased risk (much of which is delayed or intangible) is worth the extra information. This study shows that the authors did not find much difference in injury diagnosis in young vs elderly patients, with the exception of blunt cerebrovascular injury.

Most elderly patients who fall sustain injuries to the head, spine (all of it), extremities and hips. The torso is largely spared, with the exception of ribs. In my opinion, chest CT is only for identification of aortic injury, which just can’t happen from falling over. Or even down stairs. And solid organ injury is also rare in this group.

Although the future risk from radiation in an elderly patient is probably low, the risk from the IV contrast needed to see the aorta or solid organs is significant in this group. And keep in mind the dangers of screening for a low probability diagnosis. You may find something that prompts invasive and potentially more dangerous investigations of something that may never have caused a problem!

I recommend selective scanning of the head and cervical spine (if not clinically clearable), and selective conventional imaging of any other suspicious areas. If additional detail of the thoracic and/or lumbar spine are needed, specific spine CT imaging should be used without contrast.

Related posts:

Reference: Pan-scanning for ground level falls in the elderly: really? ACS Surgical Forum, trauma abstracts, 2016.

General

Can Lead Poisoning Occur After A Gunshot?

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This is a fairly common question from victims of gunshots and their families. As you know, bullets are routinely left in place unless they are superficial. It may cause more damage to try to extract one, especially if it has come to rest in a deep location. But is there danger in leaving the bullet alone?

One of the classic papers on this topic was published in 1982 by Erwin Thal at Parkland Hospital in Dallas. The paper recounted a series of 16 patients who had developed signs and symptoms of lead poisoning (plumbism) after a gunshot or shotgun injury. The common thread in these cases was that the injury involved a joint or bursa near a joint. In some cases the missile passed through the joint/bursa but came to rest nearby, and a synovial pseudocyst formed which included the piece of lead. The joint fluid bathing the projectile caused lead to leach into the circulation.

The patients in the Parkland paper developed symptoms anywhere from 3 days to 40 years after injury. As is the case with plumbism, symptoms were variable and nonspecific. Patients presented with abdominal pain, anemia, cognitive problems, renal dysfunction and seizures to name a few.

Bottom line: Any patient with a bullet or lead shot that is located in or near a joint or bursa should have the missile(s) promptly and surgically removed. Any lead that has come to rest within the GI tract (particularly the stomach) must be removed as well. If a patient presents with odd symptoms and has a history of a retained bullet, obtain a toxicology consult and begin a workup for lead poisoning. If levels are elevated, the missile must be extracted. Chelation therapy should be started preop because manipulation of the site may further increase lead levels. The missile and any stained tissues or pseudocyst must be removed in their entirety.

Reference: Lead poisoning from retained bullets. Ann Surg 195(3):305-313, 1982.