BravoCalc

Canadian C-Spine Rule Calculator

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High-Risk Factors

Age ≥ 65 years?

Dangerous mechanism of injury?

Fall from ≥3 feet/5 stairs, axial load to head, high-speed MVC (>100km/h, rollover, ejection), motorized recreational vehicle accident, bicycle collision

Paresthesias in extremities?

What is the Canadian C-Spine Rule?

The Canadian C-Spine Rule is a clinical decision tool developed to help clinicians determine which trauma patients require cervical spine imaging. It was designed to reduce unnecessary radiography while maintaining high sensitivity for clinically important cervical spine injuries.

This rule applies to alert (GCS 15) and stable trauma patients where cervical spine injury is a concern. It is one of the most widely validated clinical decision rules in emergency medicine.

Clinical Significance

Cervical spine injuries occur in approximately 2-3% of patients with blunt trauma. However, over 98% of cervical spine radiographs are negative for injury. The Canadian C-Spine Rule helps identify patients at very low risk of clinically significant injury, reducing unnecessary imaging, radiation exposure, and healthcare costs.

Studies have shown that proper application of the Canadian C-Spine Rule can reduce imaging rates by 15-20% without missing clinically important injuries.

How to Use the Calculator

The Canadian C-Spine Rule follows a stepwise approach:

  1. First, determine if any high-risk factors are present that mandate radiography
  2. If no high-risk factors, check if any low-risk factors are present that allow safe assessment of range of motion
  3. Finally, assess if the patient can actively rotate their neck 45° to the left and right

The calculator will guide you through these steps and provide a recommendation based on your inputs.

Limitations

The Canadian C-Spine Rule should not be applied to patients who:

  • Are under 16 years of age
  • Have unstable vital signs
  • Have a GCS score less than 15
  • Have acute paralysis
  • Have known vertebral disease (e.g., ankylosing spondylitis, rheumatoid arthritis)
  • Have had previous cervical spine surgery

Clinical judgment should always be used alongside this decision tool. When in doubt, imaging is recommended.

Evidence and Validation

The Canadian C-Spine Rule was derived from a study of 8,924 patients and validated in a study of 8,283 patients. It has demonstrated a sensitivity of 99-100% for clinically important cervical spine injuries and a specificity of 42-44%.

Multiple external validation studies have confirmed its safety and efficacy in various clinical settings.

References

  1. Stiell IG, Wells GA, Vandemheen KL, et al. The Canadian C-spine rule for radiography in alert and stable trauma patients. JAMA. 2001;286(15):1841-1848.
  2. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510-2518.
  3. Michaleff ZA, Maher CG, Verhagen AP, Rebbeck T, Lin CW. Accuracy of the Canadian C-spine rule and NEXUS to screen for clinically important cervical spine injury in patients following blunt trauma: a systematic review. CMAJ. 2012;184(16):E867-E876.