Tag Archives: clearance

Imaging

Best of EAST #3: Spine MRI Usage After EAST Guidelines

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In 2015, EAST published their practice guidelines for spine clearance in the obtunded blunt trauma patient. Click here to view them. They stated that a high-quality CT scan can be used to remove (clear) the cervical collar in these patients. This avoids the use of the expensive and personnel-intensive MRI clearance.

The group at UCSF used the NTDB to review the use of MRI in such patients over an 11 year period. They focused on comatose patients (GCS < 8) with an AIS head > 3 and intubation for more than 72 hours. They used logistic regression to equalize confounders while examining the use of MRI over time, before and after the guidelines were published.

Here are the factoids:

  • More than 75,000 patients from 530 trauma centers were included
  • Patients who were older, Hispanic, uninsured, or involved in a car crash were less likely to undergo spinal MRI
  • Level I centers were more likely to use MRI for clearance than Level II centers
  • Patients evaluated after release of the practice guidelines were 1.7x more likely to undergo MRI for spine clearance (!!)

The authors concluded that spinal MRI use has been increasing since 2007 despite publication of the EAST guideline.

My comments: To me, this indicates one of the following:

  1. Nobody reads the EAST guidelines, or
  2. Trauma programs believe that they alone are able to figure out what is right, and everyone else is wrong

I suspect that it is #2. For some reason, trauma programs insist on doing it their own way despite what decent evidence shows. I think that this represents a defense mechanism to minimize the cognitive dissonance that comes with defying what is published in the literature.

I always encourage programs to borrow/steal what is already out there when crafting their own practice guidelines. Someone else has already done the work, why not take advantage of it? Typically, it’s just an excuse to continue doing things the way they’ve always been done.

This incessant reinventing the wheel becomes tiresome. And for once, I don’t have many questions or suggestions for the authors. Their evidence is pretty well laid out. 

My questions for the author / presenter are:

  1. Do you use MRI for spine clearance in your obtunded blunt trauma patients? And if so, WHY?
  2. Why do you think there are demographic and trauma center level disparities? Is it the teaching environment? Something else?

To everyone else, I say “get over yourself and read the literature!”

Reference: Assessing the e3ffect of the EAST guideline on utilization of spinal MRI in the obtunded adult blunt trauma patient over time. EAST 2021, Paper 7.

Imaging

Best of AAST #2: Cervical Spine Clearance And Distracting Injuries

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Debate has forever swirled around how to clear the cervical spine. Clear clinically? CT scan plus exam? CT only? Flexion/extension views? Distracting injury?

This last one has been problematic for a long time. What is a distracting injury? Is there a difference between lower extremity wounds vs upper chest/shoulder wounds from a distraction standpoint? Is it possible to clinically clear the cervical spine if one of these injuries exist?

Finally, a multi-institutional trial was performed that strives to answer this question. Seven Level I US trauma centers participated in this 3.5 year long study. All patients with GCS > 14 underwent a standard clinical exam regardless of whether a possible distracting injury was present. Then all underwent CT evaluation of the entire cervical spine.

Here are the factoids:

  • Distracting injuries were classified into three regions: head, torso, and extremities, but no further analysis was presented in the abstract
  • Nearly 3,000 patients were enrolled and 70% had a potential distracting injury
  • A total of 233 patients (8%) had a cervical spine injury identified by CT
  • 136 patients had a cervical injury AND distracting injury, and 14 were missed by clinical exam (10%)
  • 87 patients had a cervical injury BUT NO distracting injury, and 10 were missed by clinical exam (13%)
  • Only one injury missed by clinical exam required operation

Bottom line: This study shows the usual prevalence of cervical spine injury after blunt trauma, but adds some interesting information regarding distracting injury. Basically, clinical examination will miss about 1% of patients with a negative exam, regardless of distracting injury status. Therefore, the study suggests that clinical clearance should be attempted on all patients first, regardless of “distracting injury.”

Reference: Clearing the cervical spine for patients with distracting injuries: an AAST multi-institutional trial. Session I Paper 3, AAST 2018.

Abstracts

EAST 2018 #11: Prehospital Cervical Spine Clearance

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More and more often, I am receiving trauma activation patients after blunt trauma with no cervical collar in place. Up until a year ago or so, literally everyone with even a hint of blunt trauma had one in place. Now, it is becoming a rarity. It seems that there has been a shift in the philosophy and practice of prehospital providers and the guidelines they follow. 

The group at SUNY Stony Brook reviewed their experience with prehospital spine clearance (meaning non-placement of a collar by EMS) over a 6 year period. They analyzed trends in prehospital spine immobilization during this period.

Here are the factoids:

  • Over 5,000 patients were analyzed, and the incidence of cervical spine injury remained constant at 9% over the study period
  • Placement of prehospital cervical immobilization decreased from 54% to 35%
  • The incidence of spine injury in patients without immobilization  increased from 4% to 6%
  • Of those without immobilization, 15% had a major spine injury (AIS > 3), and 19% had multisystem injuries
  • Factors significantly associated with “inappropriate” prehospital clearance included fall mechanism, elderly, functional dependence, dementia, and presence of comorbidities

Bottom line: This study is intriguing, but I worry that the study population is a bit too small to draw the best conclusions. I say this because the incidence of cervical injury is significantly higher in this study that in a larger one with 34,000 patients. This may indicate either a small sample size or some type of sample bias. I’m unclear about what data the prehospital agencies used to relax the immobilization criteria, and whether or not the criteria are being applied appropriately. It does appear, however, that the elderly are at higher risk for having an injury and not being immobilized.

Here are some questions for the authors to consider before their presentation:

  • How did you define cervical injury, and why is the incidence in your study so much higher?
  • Do the prehospital agencies delivering patients to your center utilize the same clearance guidelines?
  • Big picture question: What should we do to make sure that cervical immobilization is applied appropriately?

Reference: EAST 2018 Podium abstract #34.

Guidelines

A New Proposed Practice Guideline For Cervical Spine Clearance

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In my last post, I reviewed a very recent prospective study on using CT scan alone for  cervical spine clearance in intoxicated patients. I believe that this is the final piece in the spine clearance puzzle to allow us to perform this task intelligently.

We’ve been accumulating more and more data that supports the use of CT scan in patients who fail clinical clearance. This failure can be due to the patient being obtunded or intoxicated, bearing a “distracting” injury, or being just plain uncooperative. Because of this, and our fear of missing a potentially devastating injury (typically because of rare anecdotal cases or urban legends), we have resorted to a significant degree of overkill. This has included, over the years, prolonged immobilization in a rigid collar, flexion/extension imaging (plain x-ray or fluoro), and MRI.

I’ve synthesized the available literature, and have drafted a simple, one sheet practice guideline for discussion. In order to use it, you must have the following:

  • A decent CT scanner – minimum 64 slice
  • A well-defined scan setup protocol – 3mm collimation, skull base to T2, 2-D reconstruction in sagittal and coronal planes (get a copy of our protocol below)
  • A skilled radiologist – neuroradiologist required

An image of the protocol can be found at the bottom of this post. I’m interested in your comments, and your comfort or discomfort with adopting something like this. Please leave comments here or on twitter.

Links: 

Reference: Cervical spine evaluation and clearance in the intoxicated patient: A prospective Western Trauma Association Multi-Institutional Trial and Survey. J Trauma 83(6):1032-1040, 2017.

Guidelines

It’s Time To Simplify Cervical Spine Clearance!

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Cervical spine clearance is another one of those tasks that everyone seems to do their own way. Most trauma centers have an algorithm for clearance, or even two, like my center. But anytime different clinicians or centers do the same thing in different ways, it means we don’t really know what we’re doing. 

It basically means that the hard data is not there to dictate what we truly should do. So there are two alternatives:

  1. Wait for good data to become available. Unfortunately, this can take forever.
  2. Extrapolate from any existing data, and fill in the gaps with our clinical experience to come up with something that works and causes no harm.

The protocols in use at Regions Hospital are based on #2, and have been in place for over a decade. But now, we have a good example of #1 to work with.

Fortunately for us, cervical spine clearance has been evolving for decades. And as technology has improved, so has our ability to miss fewer and fewer “significant” injuries. A multi-center trial published this month provides one of the final puzzle pieces to help us settle upon a uniform cervical spine clearance guideline. It was a prospective look at intoxicated patients after blunt trauma, who can’t always participate in the process of clinical cervical spine clearance.

This three year study took place at 17 centers and specifically looked at the combination of clinical and radiographic clearance in alcohol and drug intoxicated patients. Over 10,000 patients participated in the study. There are some limitations, of course, when so many centers participate. But the pros massively outweigh the cons.

Here are the factoids:

  • The overall incidence of cervical spine injury was 10.6% (!)
  • 30% of patients were intoxicated (19% etoh, 6% drugs, 5% both (also !)
  • Intoxicated patients had a significantly lower incidence of cervical injury (8% vs 12%). (Don’t get any ideas about the old adage about being relaxed when they crash. This probably represents lower speeds involved.)
  • For intoxicated patients, sensitivity of CT scan was 94%, specificity was 99.5%, and the negative predictive value (NPV) was 99.5%
  • The NPV for clinically significant injuries in intoxicated patients was 99.9%, and no unstable injuries were missed by CT  (100% NPV) (!!)
  • When CT was negative, being intoxicated led to longer time in a collar (8 hrs vs 2 hrs)

Bottom line: Fear of clearing the cervical spine without a clinical exam, or in obtunded or intoxicated patients, is primarily due to old anecdotal reports. And much of it is not first-hand experience, but rumors of others’. What is finally becoming clear is that it is okay to clear based upon radiographic findings alone. 

Tomorrow, I’ll provide my version of a new, unified clearance protocol based on this work.

Reference: Cervical spine evaluation and clearance in the intoxicated patient: A prospective Western Trauma Association Multi-Institutional Trial and Survey. J Trauma 83(6):1032-1040, 2017.