Abstract & Commentary
Source: Stiell IG, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349:2510-2518.
Each year in North America more than 13 million patients at risk for cervical spine fracture after trauma are assessed in emergency departments (ED). Despite the fact that very few of these patients have a cervical spine fracture, most undergo cervical-spine radiography, a low-cost procedure that because of the high volume of its use adds substantially to health care costs. A current standard of care recommended for use by ED physicians is based on the National Emergency X-Radiology Utilization Study (NEXUS) Low-Risk Criteria (NLC)1 The NLC rule requires cervical spine radiography for patients with trauma unless they meet all 5 of the low-risk criteria: no midline cervical spine tenderness, no evidence of intoxication, normal level of alertness, no focal neurologic deficit, and no painful distracting injuries. Studies conducted to validate these criteria indicate that the NLC rule has a high sensitivity (99.6%) but a low specificity (12.9%) for cervical spine injury.2
Stiell and associates, convinced that the NLC rule leads to unnecessary testing and delayed triage of patients in the ED, developed the Canadian C-Spine Rule (CCR) to assess alert, stable patients for traumatic cervical spine injury.3 The CCR is more complex than the NLC and is based on: 1) 3 high-risk criteria (older than 65 years, dangerous mechanism of trauma, and paresthesias in extremities); 2) 5 low-risk criteria (simple rear-end motor vehicle collision, sitting position in the emergency department, ambulatory at any time, delayed onset of neck pain, absence of midline cervical spine tenderness); and 3) the ability of patients to rotate their necks.
In their current report, Stiell et al conducted a prospective cohort study in 9 EDs in Canada comparing the CCR and NLC as applied to alert patients with trauma who were in stable condition. The CCR and the NLC were interpreted by 394 physicians for patients before radiography. The purpose of the study was to prospectively evaluate the accuracy, reliability, clinical acceptability, and potential effect of the CCR and NLC on the use of ED resources. The study enrolled more than 8000 alert patients with trauma who were stable. The primary outcome measure was chosen to be any clinically important cervical spine injury. Cervical spine injury was defined as any fracture, dislocation, or ligamentous instability demonstrated by radiologic imaging. Patients who did not undergo radiologic testing in the ED were evaluated with the use of a proxy outcome assessment tool. In such patients, a study nurse contacted them by telephone and classified them as having no cervical spine injury if they met the following criteria at 2 weeks: mild or no neck pain, mild or no restriction of neck movement, neck collar not used, and a return to usual occupational activities. Patients who did not fulfill these criteria were recalled for cervical spine radiography.
Stiell et al found that only 169 patients (2%) out of 8283 had clinically important cervical spine injuries. In 845 (10.2%) of the patients, physicians did not evaluate range of motion as required by the CCR algorithm. In an analysis that excluded such patients, the CCR was more sensitive than the NCL (99.4% vs 90.7%; P < .0001) and more specific (45.1% vs 36.8%; P < .001%) for injury. In addition, use of the CCR vs the NLC resulted in lower rates of radiographic testing (55.9% vs 66.7%; P < .001). Physicians using the CCR missed one patient, but when using the NCL they missed 16 patients with important cervical spine injuries.
This study validates the high sensitivity, reliability, and clinical acceptability of the CCR. Therefore, the CCR has the potential to replace the NLC as a new standard for assessment of cervical spine injury in stable, alert patients after trauma. Use of this rule would optimize the use of radiology resources in the ED and decrease the time spent by patients in the emergency room. As Stiell et al point out, patients with possible cervical spine injuries usually are immobilized on a back board and may spend several hours awaiting radiologic testing, the delay leading to considerable discomfort and unnecessary use of space in an already crowded ED.
Stiell et al are to be congratulated for their continued efforts to standardize practice and improve the efficiency of diagnostic procedures in the ED. They previously have provided the medical community with the Canadian CT rule for patients with minor head injury.4 The only problem with the CCR compared with the NLC appears to be the former’s complexity. As Stiell et al noted, the physicians in their study appeared slightly less comfortable using the CCR compared with the NLC and, most importantly, were reluctant to assess range of motion of the neck in patients with possible cervical spine injury. Therefore, and unfortunately, it seems likely that in clinical practice, ED physicians will continue to use the simpler NLC and opt for more radiographic studies rather than for more physical examination of the patient. — John J. Caronna and Igor Ougorets
Dr. Caronna, Vice-Chairman, Department of Neurology, Cornell University Medical Center; Professor of Clinical Neurology, New York Hospital, is Associate Editor of Neurology Alert. Igor Ougorets is Director, Neuroscience Intensive Care Unit, New York Presbyterian Hospital, Weill Cornell Medical Center.
1. Hoffman JR, et al. Ann Emerg Med. 1992;21: 1454-1460.
2. Hoffman JR. N Engl J Med. 2000;343:94-99.
3. Stiell IG, et al. JAMA. 2001;286:1841-1848.
4. Stiell IG, et al. Lancet. 2001;357:1391-1396.