Clinical validation of S100B in the management of a mild traumatic brain injury: issues from an interventional cohort of 1449 adult patients.

BACKGROUND: This study's primary objective was to validate the routine use of S100B via a prospective study. The aim was a reduction of cranial computed tomography (CCT) scans by 30%. The secondary goal was to investigate the influence of age and associated risk factors on the reduction of CCT. METHODS: S100B (sampling within 3 h postinjury) was used for patients with mild traumatic brain injury (mTBIs) presenting a medium risk of complications and requiring a CCT scan. Patients with negative S100B (S100B-) were discharged without a CCT scan. RESULTS: Of the 1449 patients included in this study, 468 (32.3%) had S100B- with a sensitivity of 96.4% (95% CI: 87.5%-99.6%), a specificity of 33.4% (95% CI: 31%-36%) and a negative predictive value of 99.6% (95% CI: 98.5%-99.9%). No significant difference in serum levels or the S100B+ rate was observed if patients had retrograde amnesia (0.16 µg/L; 63.8%), loss of consciousness (0.13; 63.6%) or antiplatelet therapy (0.20; 77.9%). Significant differences were found between the S100B concentrations and S100B positivity rates in patients >65 years old and all the groups with patients <55 years old (18-25, 26-35, 36-45 and 46-55). From 18 to 65 years old (n=874), the specificity is 39.3% (95% CI: 36%-42.6%) compared to 18.7% (95% CI: 15.3%-22.3%) for patients >65 years old (n=504). CONCLUSIONS: The clinical use of S100B in mTBI management reduces the use of CCTs by approximately one-third; furthermore, the percentage of CCTs reduction is influenced by the age of the patient.

Predictive factors of intracranial bleeding in head trauma patients receiving antiplatelet therapy admitted to an emergency department.

BACKGROUND: In head trauma cases involving antiplatelet agent treatment, the French Society of Emergency Medicine recommends performing computed tomography (CT) scans to detect brain lesions, 90% of which are normal. The value of CT is still debatable given the scarce number of studies and controversial results. METHODS: We used the RATED registry (Registry of patient with Antithrombotic agents admitted to an Emergency Department, NCT02706080) to assess factors of cerebral bleeding related to antiplatelet agents following head trauma. RESULTS: From January 2014 to December 2015, 993 patients receiving antiplatelet agents were recruited, 293 (29.5%) of whom underwent CT scans for brain trauma. Intracranial bleeding was found in 26 (8.9%). Multivariate analysis revealed these patients more likely to have a history of severe hemorrhage (odds ratio [OR]: 8.47, 95% confidence interval [CI]: 1.56-45.82), dual antiplatelet therapy (OR: 6.46, 95%CI:1.46-28.44), headache or vomiting (OR: 4.27, 95%CI: 1.44-2.60), and abnormal Glasgow coma scale (OR: 8.60; 95%CI: 2.85-25.99) compared to those without intracranial bleeding. The predictive model derived from these variables achieved 98.9% specificity and a negative predictive value of 92%. The area under the ROC curve (AUROC) was 0.85 (95%CI: 0.77-0.93). CONCLUSIONS: Our study demonstrated that the absence of history of severe hemorrhage, dual antiplatelet therapy, headache or vomiting, and abnormal Glasgow coma scale score appears to predict normal CT scan following traumatic brain injury in patients taking antiplatelets. This finding requires confirmation by prospective studies. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT02706080 .