Tag Archives: clearance

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.

Cervical Spine MRI After Negative CT

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There are multiple ways to clear a cervical spine! Most centers use a combination of clinical decision tools and CT scan in adults. The gold standard tie breaker, warranted or not, seems to be MRI. This tool is only used in select cases where conventional imaging is in doubt, or the clinical exam is puzzling.

Some centers clear based on CT only as long as imaging is indicated. Some use MRI in cases where patients continue to complain of midline neck pain or tenderness after negative CT. A multi-center trial encompassing 8 Level I and II centers prospectively performed MRI on patients who could not be clinically evaluated, or had persistent midline cervical pain after normal CT.

A total of 767 patients were seen over a 30 month period. Besides looking at the usual data points, the authors were interested in new diagnoses and changes in management based on the MRI results.

Here are the factoids:

  • Neck pain and inability to evaluate occurred with equal frequency, about 45%; the remaining 10% had both
  • 23% of MRIs were abnormal, with 17% ligament injury, 4% swelling, 1% disk injury, and 1% dural hematomas.
  • Patients with normal and abnormal MRI had neurologic anomalies about equally (15-19%). [Why are these patients included? Were they initially not evaluable?]
  • The cervical collar was removed in 88% of patients with normal MRI (??), and in 13% with abnormal MRI
  • After (presumably) positive MRI, 14 (2%) underwent spine surgery; 8 of these had neurologic signs or symptoms

Bottom line: I’m a bit confused. If the authors were really trying to figure out the rate of abnormal MRI after negative CT, they should have excluded the patients with known neurologic findings. These patients should nearly always have an abnormal MRI. And why did they not take the collar off of the 12% of patients with both normal CT and MRI??

Hopefully, details in the presentation next week will help explain all this. I suspect that the study will show that there are cases where CT is normal but MRI is not. The abstract does not clearly describe how many of these are clinically significant.

I admit, I’m not very comfortable clearing the cervical spine in a patient with negative CT (even if read by a neuroradiologist) and obvious midline neck pain/tenderness. I hope this study helps clarify this issue. We shall see…

Reference: Cervical spine MRI in patients with negative CT: a prospective, multicenter study of the research consortium of New England centers for trauma (ReCONECT). AAST 2016, Paper 61.