Tag Archives: clearance

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

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.

EAST 2018 #11: Prehospital Cervical Spine Clearance

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.

A New Proposed Practice Guideline For Cervical Spine Clearance

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.

It’s Time To Simplify Cervical Spine Clearance!

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.

Physical Exam And Thoracolumbar Spine Fractures

The physical exam is an important part of the initial evaluation of trauma patients. Sometimes it actually makes the diagnosis, but much of the time it focuses further studies like x-rays or lab tests. But we can also use it as a tool to avoid further imaging. For example, consider clinical clearance of the cervical spine. A negative exam in a reliable patient allows us to remove the cervical collar.

Can we apply the same thinking to the thoracic and lumbar spines? Many of us do. No pain or tenderness equates to no imaging or log-roll precautions.

The trauma group at LAC+USC looked at this one a few years ago. They studied every blunt trauma patient over a 6-month period, and first determined if they were “evaluable.” This meant not intoxicated, head injured (GCS<15), and no distracting injury (determined very subjectively). All underwent a standard exam of the TL spine by a resident or attending surgeon.

Here are the factoids:

  • 886 patients were enrolled, and 218 (25%) were not evaluable using the criteria above
  • 11% of the non-evaluable patients were found to have a TL spine fracture by CT, whereas only 8% of the evaluable group did
  • Of the evaluable patients, half (29) had no signs or symptoms of fracture
  • Of those 29 without signs or symptoms, two had a “clinically significant” fracture. Both were younger (20 and 59). One had a T7 compression and a transverse process fracture, the other a T9 compression fracture. Both were treated with a TLSO brace.
  • Of the 27 who could not be examined, 11 had “clinically significant” fractures; 8 were treated with TLSO and 6 with surgery (obviously some overlap there)

Bottom line: So physical exam of the thoracic and lumbar spine sucks, right? Not quite so fast! First, this is a small-ish study, but with enough patients to be intriguing. The biggest issue is that we don’t really know what is “clinically significant.” Treatment of stable fractures of the spine is controversial, and our friendly neighborhood neurosurgeons vary tremendously in how they do it. Ask five neurosurgeons and you’ll get six different answers.

Braces are expensive, and the optimal choice is not clear yet. At my hospital, we are treating select ones with a binder for comfort or a simple backpack brace. The fancier ones like the TLSO easily cost over $1000!

At this point, I recommend that you use a good blunt imaging practice guideline like the one below, coupled with a good physical exam. If the patient has sufficient mechanism to break something (which decreases with patient age), then image them. If they don’t, but have an abnormal exam, image them anyway. And we’ll wait for the next bigger/better study!

Related posts:

Reference: Clinical examination is insufficient to rule out thoracolumbar spine injuries. J Trauma 70(1):174-179, 2011.