BackgroundTraumatic brain injury is a common ED presentation. CT-head utilisation is escalating, exacerbating resource pressure in the ED. The biomarker S100B could assist clinicians with CT-head decisions by excluding intracranial pathology. Diagnostic performance of S100B was assessed in patients meeting National Institute of Health and Clinical Excellence Head Injury Guideline (NICE HIG) criteria for CT-head within 6 and 24 hours of injury.MethodsThis multicentre prospective observational study included adult patients presenting to the ED with head injuries between May 2020 and June 2021. Informed consent was obtained from patients meeting NICE HIG CT-head criteria. A venous blood sample was collected and serum was tested for S100B using a Cobas Elecsys-S100 module; >0.1 µg/mL was the threshold used to indicate a positive test. Intracranial pathology reported on CT-head scan by the duty radiologist was used as the reference standard to review diagnostic performance.ResultsThis study included 265 patients of whom 35 (13.2%) had positive CT-head findings. Within 6 hours of injury, sensitivity of S100B was 93.8% (95% CI 69.8% to 99.8%) and specificity was 30.8% (22.6% to 40.0%). Negative predictive value (NPV) was 97.3% (95% CI 84.2% to 99.6%) and area under the curve (AUC) was 0.73 (95% CI 0.61 to 0.85; p=0.003). Within 24 hours of injury, sensitivity was 82.9% (95% CI 66.4% to 93.44%) and specificity was 43.0% (95% CI 36.6% to 49.7%). NPV was 94.29% (95% CI 88.7% to 97.2%) and AUC was 0.65 (95% CI 0.56 to 0.74; p=0.046). Theoretically, use of S100B as a rule-out test would have reduced CT-head scans by 27.1% (95% CI 18.9% to 36.8%) within 6 hours and 37.4% (95% CI 32.0% to 47.2%) within 24 hours. The risk of missing a significant injury with this approach would have been 0.75% (95% CI 0.0% to 2.2%) within 6 hours and 2.3% (95% CI 0.5% to 4.1%) within 24 hours.ConclusionWithin 6 hours of injury, S100B performed well as a diagnostic test to exclude significant intracranial pathology in low-risk patients presenting with head injury. In theory, if used in addition to NICE HIGs, CT-head rates could reduce by one-quarter with a potential miss rate of <1%.

Background: Traumatic brain injury (TBI) is a common Emergency Department (ED) presentation. CT-head utilisation is escalating, exacerbating resource pressure in ED. The biomarker S100B could assist clinicians with CT-head decisions by excluding intracranial pathology. Diagnostic performance of S100B was assessed in patients meeting NICE CT-head criteria within 6 and 24-hours of injury. Methods: This multi-centre prospective observational study included adult patients presenting to ED with mild TBI who were able to give their own informed consent and had a CT-head scan performed as part of standard care. Patients were recruited using consecutive sampling methods. Informed consent was obtained prior to blood sampling. Serum was tested for S100B using a Cobas Elecsys S100 module; >0.1ug/ml is the validated threshold indicating a positive test. Diagnostic performance was assessed using ROC analysis as well as sensitivity, specificity, NPV and PPV calculations. Results: There were 265 included patients, and 35 (13.2%) had a positive CT-head. The sensitivity of S100B when performed within 24 hours of injury was 82.9% (95%CI 66.4-93.44) and specificity was 43.0% (95%CI 36.6–49.7%). NPV was 94.29% (95%CI 88.7–97.2). Within 6 hours sensitivity was 93.8% (95%CI 69.8–99.8%) and specificity was 30.8% (22.6–40.0%). NPV was 97.3% (95%CI 84.2–99.6%). Theoretically, use of S100B as a rule out test would have reduced CT scans by 37.4% within 24 hours and 27.1% within 6-hours. The risk of missing a significant injury with this approach would have been 2.3% within 24 hours and 0.75% within 6-hours. Conclusion Within 6-hours of injury, S100B performed well as a diagnostic test to exclude significant intracranial pathology in patients presenting with mild head injuries, with low risk of missed injury. In theory, if used in addition to NICE CT-head guidelines, CT-head request rates could reduce by one quarter and one fifth of patients could be discharged earlier from ED. What is already known on this topic S100B has shown promise diagnostically as an objective marker that can rule out intracranial injuries in head injured patients. S100B has a validated platform that could potentially be used to reduce CT head demand in ED. However, evidence testing the added value of biomarkers to existing clinical guidelines are limited. What this study adds This study demonstrates that S100B could theoretically reduce CT-head demand and enable earlier ED discharge in low-risk patients meeting NICE CT-head criteria. The included population were GCS 15, had no post traumatic amnesia and were able to consent for themselves. This low-risk population have a low yield of traumatic CT abnormalities and could be a suitable population to target biomarker use. How this study might affect research, practice or policy S100B has the potential to reduce CT-head demand, thereby benefitting EDs by reducing overcrowding, resource burden and healthcare costs; and from the patients’ perspective, enable shorter waits, earlier intervention and earlier discharge. Further research should focus on optimising the performance of S100B within the NICE CT-head guidelines in low-risk patients, and review real-time economic benefits.

Objective Concussion is a common ED complaint, but diagnosis is challenging as there are no validated objective measures. Use of concussion tools derived from sports medicine is common, but these tools are not well validated in ED settings. The aim of this study was to assess the ability of the Sport Concussion Assessment Tool 5th Edition (SCAT5) to identify concussion in ED patients presenting following head injury. Methods We conducted a prospective observational study of head‐injured adult patients presenting to ED between March and July 2021. ED diagnosis of concussion was used as the diagnostic standard, and we assessed the diagnostic performance of the SCAT5 test and its three subsections (Standardised Assessment of Concussion (SAC), Post‐Concussion Symptom Scale (PCSS) and Modified Balance Error Scoring System (mBESS)) against this. Results Thirty‐two head‐injured participants were enrolled, 19 of whom had a discharge diagnosis of concussion, alongside 17 controls. Median time for SCAT5 testing was 21 (interquartile range 16–27) min. Fifteen (30.6%) participants were interrupted during testing. Area under the curve (AUC) (95% confidence interval) for the SAC, PCSS and mBESS were 0.51 (0.34–0.68), 0.92 (0.84–0.99) and 0.66 (0.47–0.85), respectively. Sensitivity and specificity of sections were as follows: entire SCAT5 (100.0%, 20.0%), SAC (48.1%, 60.0%), PCSS (89.7%, 85.0%) and mBESS (83.3%, 58.8%). Using PCSS alone would have identified 17 of 19 concussions. Conclusion The SCAT5 test had a low specificity, was long and was frequently interrupted. We suggest it is not an ideal assessment to use in ED. The PCSS score performed well and was easy to complete. It may be useful as a standalone tool to simplify ED concussion identification.