Summary
Usage Head trauma complaints in the outpatient setting (emergency department, urgent care and primary care) are common. However, the majority of patients have minor head trauma that will not require specialized treatment or neurosurgical intervention. Yet, rates of CT imaging of the head have more than doubled starting in the early 1990s. The Canadian CT Head Rule (CCHR) is a well-validated clinical decision aid that assists clinicians in determining which minor head injury patients need head CT imaging. Thus, safely ruling out the presence of intracranial injuries that would require neurosurgical intervention or admission. In the validation trial (Stiell, 2005), the CCHR was 100% sensitive for both clinically important brain injuries and injuries that require neurosurgical intervention. Specificity was 76.3% for clinically important brain injuries and 50.6% for injuries that required neurosurgical intervention. It is 70% sensitive for clinically important brain injury in patients with alcohol intoxication (Easter, 2013). In most studies 7-10% of patients had positive CT's considered to be clinically important brain injuries, but < 2% required neurosurgical intervention. The rule excludes patients on blood thinners, > 16 years old and with seizure after injury. Providers often consider applying the Canadian CT Head Rule (CCHR) for head trauma in addition to the New Orleans/Charity Rule (NOC). Both the CCHR and the NOC have demonstrated 100% sensitivity for ruling out intracranial injuries that would require neurosurgical intervention. One trial found the NOC more sensitive for detecting clinically significant intracranial injuries (99.4% versus 87.3%) but a decreased specificity (5.6% versus 39.7%) compared to the CCHR. The NOC is less complex than the CCHR but much less specific than the CCHR in all settings. The decrease in specificity can be attributed to the NOC's broad questions, such as "Any trauma above the clavicles.". Summary The Canadian CT Head Rule (CCHR) is a well-validated clinical decision aid that assists clinicians in determining which minor head injury patients need head CT imaging. The criteria allow clinicians to safely rule out the presence of clinically important traumatic brain injuries among adult head injury patients without the need for CT imaging. Consider the PECARN Pediatric Head Injury/Trauma Algorithm for patients < 19 years old. Recommendations & Criteria RecommendationCriteria CCHR FindingsExclusion criteria met: Not eligible for ScoringAny of the following trueAge < 16 yearsPatient on blood thinnerSeizure after injury Consider CT: High riskAny of the following trueGCS < 15 at 2 hours post-injurySuspected open or depressed skull fractureAny sign of basilar skull fracture¹≥ 2 episodes of vomitingAge ≥ 65 years Cannot rule out need for imaging due to presence of one or more high risk criteria that may need neurosurgical intervention.High risk means 5 out of 100 patients will need treatment by a neurosurgeon, but the risk could be higher or lower based on clinician judgement and patient risk factors.Consider CT: Medium risk Any of the following trueRetrograde amnesia to the event ≥ 30 minutesDangerous mechanism²Cannot rule out need for imaging due to presence of one or more medium risk criteria that may put the patient at risk for a "clinically important" brain injury defined as a positive CT that typically requires admission. CT UnnecessaryAll criteria are falseThe Canadian Head CT Rule suggests a head CT is not necessary.Sensitivity 83-100% for all intracranial findingsSensitivity 100% for findings requiring neurosurgical intervention ¹Signs of basilar skull fractureHemotympanumRacoon eyesBattle's signCSF otorrhea or rhinorrhea ²Dangerous mechanismPedestrian struck by motor vehicle Occupant ejected from motor vehicleFall > 3 feet or > 5 stairs Management ConsiderationsIf CT is negative and patient is referred for outpatient follow-up, consider the following recommendations:Provide reassurance, education and strict return precautions. CDC patient handout: Mild Traumatic Brain Injury and Concussion Discuss post-concussive symptoms and clinical course. HeadacheBalance problems or dizzinessSound and light sensitivityFeeling agitated or irritableConfusion, concentration or memory problemsDiscuss brain bleed symptoms. Go to the ED if you experience any of these symptoms:Drowsiness or inability to wake upWorsening headacheSlurred speech, weakness, numbness, or decreased coordinationRepeated vomiting or seizuresUnusual behaviorFollow-up with primary care, sports medicine or neurologist as indicated. Provider ResourcesConcussion awareness, diagnosis and treatment (AAFP).