S100B serum protein cannot predict secondary intracranial haemorrhage after mild head injury in patients with low-dose acetylsalicylic acid prophylaxis

AbstractIntroduction: The goal of this study was to investigate if S100B serum protein could predict secondary intracranial haemorrhagic events (SIHEs) after mild head injury (mHI) in patients taking low-dose acetylsalicylic acid (LDA), making routinely repeated head computed tomography (RRHCT) scans unnecessary.Methods: Three hundred and eight-two patients with mHI, older than 60 years and taking LDA prophylaxis were enrolled. Primary head CT and RRHCT scans within 3 and 48 hours to trauma were performed. Additionally, S100B serum protein levels were evaluated at admission and predictive power for SIHEs was analysed.Results: Fifty-nine per cent were female and the mean age of all included patients was 81.8 ± 8.9 years. In four patients SIHEs were diagnosed. Sensitivity and the negative predictive value of S100B serum protein (cut-off value 0.10 µg l−1) were 75.0% and 98.6%, respectively. Specificity was 19.0% and the positive predictive value 1.0% (306 false positive values). In patients without bleeding...