CT Head Rules
There is strong evidence that physicians should not order CT head scans for patients with minor head injury unless validated clinical decision rules suggest otherwise (i.e., Canadian CT head rule for adults, and CATCH or PECARN rules for children). Despite their validity, these rules are never 100% sensitive and are meant to assist and not replace, clinical judgement - Choosing Wisely Canada
image by: US Air Force
HWN Suggests
The ED Guide to Neuroimaging: Part 2
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.
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In the adult ED patient presenting with minor head injury, are there clinical decision tools to identify patients who do not require a head CT?
Level A Recommendations - Use the Canadian CT Head Rule (CCHR) to provide decision support and improve head CT utilization in adults with a minor head injury.
Pediatric Head Injury in the ED: Is Imaging Necessary?
Bottom line: in children presenting to the ED with minor head injuries, use a clinical decision making tool in addition to clinical judgment when deciding if CT is warranted.
Articles of Interest
SGEM#412: I Can't Choose…from all the Head Injury Prediction Rules
How about we call these “tools” instead. They are there to help guide decision making but should not be taken as dogma.
Australian and New Zealand Guideline for Mild to Moderate Head Injuries in Children
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.
Blunt Head Trauma Imaging Clinical Decision Rules
Hoping to reduce the utilization of scarce medical resources, yet protect the health of your distinguished colleagues, you look to the recent medical literature to help you decide who to send for CT scanning.
Curb unnecessary computed tomography scans for pediatric concussions
The use of clinical head injury rules can help clinicians appropriately order CT scans for head injuries and reduce the number of unnecessary CT scans in the pediatric age group.
Evaluation of Three Clinical Decision Rules in Pediatric Patients with Minor Head Injury: PECARN, CHALICE and CATCH
ciTBI risk prediction models will assist in clinical decision making and establish an accurate neuroimaging strategy. According to the results of our study, all three clinical decision rules can be safely used in the management of pediatric minor head trauma patients.
Head CT for Minor Head Injury Presenting to the Emergency Department in the Era of Choosing Wisely
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.
Improving Head CT Scan Decisions for Pediatric Minor Head Trauma in General Emergency Departments:
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 unnecessary radiation.
Mild Traumatic Brain Injury
The guideline is intended for adults with blunt head injury (Q1/Q2), or adults diagnosed with mild traumatic brain injury or concussion (Q3).
PECARN algorithms for minor head trauma: Risk stratification estimates from a prospective PREDICT cohort study
The risk estimates of ciTBI for each of the PECARN algorithms risk group were consistent with the original PECARN study
Pediatric Minor Head Injury and Concussion
Our experts recommend using PECARN in patients with GCS 14-15 in whom your gestalt is that they do not require a CT scan and using CATCH2 in patients with a GCS of 13 in whom your gestalt is that they do require a CT scan.
Ten Things Physicians and Patients Should Question
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).
To CT or Not to CT – PECARN, CHALICE, and CATCH Algorithms
In this 16-minute lecture from Rebellion in EM 2021, Dr. Hilary Fairbrother focuses on the description of PECARN, CHALICE, and CATCH algorithms with best practices for use in pediatric patients with head trauma.
Resources
Canadian CT Head Injury/Trauma Rule
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.
New Orleans/Charity Head Trauma/Injury Rule
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).
NEXUS Head CT Instrument
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.
PECARN Pediatric Head Injury/Trauma Algorithm
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%!
CATCH (Canadian Assessment of Tomography for Childhood Head injury) Rule
Predicts clinically significant head injuries in children. Less sensitive than the PECARN Algorithm.
Ottawa Subarachnoid Hemorrhage (SAH) Rule for Headache Evaluation
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.
Glasgow Coma Scale/Score (GCS)
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).
Pediatric Glasgow Coma Scale (pGCS)
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).
