Using a well validated decision instrument, such as the Canadian CT Head Rule in adults or the PECARN rule in children, reduces the frequency of unnecessary imaging and decreases length of stay while increasing the diagnostic yield (frequency of positive tests) amongst those patients that are imaged. With this in mind, integration of these rules into clinical practice is a key component of appropriate resource utilization, and is recommended by multiple clinical practice guidelines. However, the use of decision instruments cannot completely replace clinical gestalt, defined as the impression of the patient derived from the clinical evaluation.
The guideline is intended for adults with blunt head injury (Q1/Q2), or adults diagnosed with mild traumatic brain injury or concussion (Q3).
Pediatric head injury decision rules were developed to decrease
CT utilization and radiation effects of CT. In counselling parents,
comparison to background radiation dose may be helpful: in
comparison to a CXR which has a similar radiation dose to ~10 days of background radiation for a child, a CT head has a similar
radiation dose to ~8 months of background radiation.
Clears head injury without imaging. While there is only one US validation study for the CCHR, it was 100% sensitive for clinically important injuries and injuries requiring neurosurgery.
Criteria for which patients are unlikely to require imaging after head trauma. Use ONLY in patients with head injury and loss of consciousness (LOC) who are neurologically normal (i.e., GCS 15 and normal brief neurological exam).
Predicts need for head CT after blunt head injury. Use in patients ≥18 years old who have sustained blunt head trauma within the past 24 hours and in whom head CT is being considered.
Predicts need for brain imaging after pediatric head injury. Although the largest trial of its kind, the PECARN study had low rates of TBI on Head CT (5.2%) and even lower rates of ciTBI (0.9%) – this suggests overall TBI in children is rare!
Head CTs were obtained in approximately 35% of patients, lower than the average estimate of 50%!
Predicts clinically significant head injuries in children. Less sensitive than the PECARN Algorithm.
Rules out SAH in patients with headache. Specificity is low (15%), and so it should not be used to diagnose SAH, even in patients in whom all criteria are positive. As with other rule-out decision aids, just because a patient fails the rule does not require that all patients are then evaluated for SAH, given its very low specificity.
Coma severity based on Eye (4), Verbal (5), and Motor (6) criteria. Note that this calculator has been updated as of May 2019 in order to add more supporting references and to distinguish between the Glasgow Coma Score (total score, only applicable when all three components are testable) and the Glasgow Coma Scale (component scores, applicable if any of three components is not testable).
Assesses impaired consciousness and coma in pediatric patients. Use for children 2 years and younger only. For older children, use the standard Glasgow Coma Scale (GCS). Note the difference between the Glasgow Coma Score (total score, only applicable when all three components are testable) and the Glasgow Coma Scale (component scores, applicable if any of three components is not testable).
Children frequently present with head injuries to acute care settings. Led by PREDICT (Paediatric Research in Emergency Departments International Collaborative), a multidisciplinary working group developed the first Australian and New Zealand guideline for mild to moderate head injuries in children. Addressing 33 key clinical questions, it contains 71 recommendations, and an imaging/observation algorithm. The Guideline provides evidence-based, locally applicable, practical clinical guidance for the care of children with mild to moderate head injuries presenting to acute care settings.
The Choosing Wisely campaign currently recommends avoiding computed tomography (CT) of the head in low-risk emergency department (ED) patients with minor head injury, based on validated decision rules. However, the degree of adherence to this guideline in clinical practice is unknown.
Although CT scans in high-risk groups are a necessary
diagnostic tool, CT scans in the low-risk groups yield
little diagnostic benefit and expose children to
The risk estimates of ciTBI for each of the PECARN algorithms risk group
were consistent with the original PECARN study
Don’t order CT head scans in adults and children who have suffered minor head injuries (unless positive for a validated head injury clinical decision rule).
Part two of this series examines the literature regarding the appropriate use of the head CT in blunt head trauma, a common clinical grey zone in emergency medicine.
The Canadian Head CT Rule (Canadian), New Orleans Criteria (New Orleans), NEXUS II Head CT Rule (NEXUS), and PECARN Pediatric Head Injury Algorithm (PECARN) are four major decision rules designed to assist clinicians with this often difficult decision.