Canadian C-spine Rule for Clinical Clearance

November 18, 2017

On the Shoulders of Giants

Spoon Feed
The Canadian C-spine rule has high sensitivity for c-spine injury and higher specificity than the NEXUS rule.  It allows clinical clearance of more people.

Why does this matter?
C-spine imaging is costly, time consuming for patients, and exposes them to radiation. If we could clear the c-spine clinically using the history and exam, and this was a safe practice, it would be better than getting an x-ray or CT.  We covered NEXUS, which came out in 2000.  This rule came out the following year, with lead author Ian Stiell (aka @EMO_Daddy), and seemed to have better performance.  Then, just as in hockey, Canada took on the US and won when the Canadian and NEXUS rules were compared head to head.

O Canada! Our home and native land!
There are a lot of exclamation points in that song!  This was a prospective convenience sample of 8924 adult patients with blunt trauma who were slated to undergo c-spine imaging.  This was the derivation study, which came up with the following 3 questions with 100% sensitivity and 42.5% specificity for clinically important c-spine injuries.  They are quoted here:

• (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)?
• (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)?
• (3) is the patient able to actively rotate neck 45 degrees to the left and right?

This study derived the rule.  It was subsequently validated by this group and others.  Also, actual implementation in practice has been studied.

Source
The Canadian C-spine rule for radiography in alert and stable trauma patients.  JAMA. 2001 Oct 17;286(15):1841-8.