Clinical Significance of On-Admission Fibrinogen Levels in Patients With Blunt Traumatic Brain Injury: A Retrospective Observational Study.

Abstract

Traumatic brain injury (TBI) is a major cause of morbidity and disability, which may be complicated by coagulation disturbances that exacerbate intracranial bleeding and worsen patient outcomes. Fibrinogen is a critical coagulation factor that is often depleted early following severe TBI. We aimed to explore the relationship between admission serum fibrinogen levels in patients with traumatic brain injury (TBI) and mortality. A retrospective analysis was conducted for patients with TBI admitted between 2016 and 2021. Comparative analyses based on on-admission serum fibrinogen levels (< 1.0 (critical low), 1.0-1.5 (low), and > 1.5 g/L) were performed. A multivariable regression analysis was carried out to predict mortality. A total of 804 patients were included. Most patients were young males and were involved in motor vehicle crashes (60%) or falls (24%). The median fibrinogen level was 2.3 (IQR 1.8-2.9) and 1.9 (IQR 1.5-2.5) g/L in isolated (23%) and polytrauma TBI (77%), respectively. Fibrinogen therapy was administrated to 145 patients (in patients with fibrinogen levels ≤ 1.5). The most prevalent TBI lesions were subarachnoid hemorrhage (43%) and subdural hematoma (35%). The median Injury Severity Score (ISS) was 27 (interquartile range 19-34) and 75.7% had severe TBI. Hypofibrinogenemia was found in 26.5% of cases and was correlated with MTP and the severity of TBI. Fibrinogen therapy was given in 18% of the cohort (88% and 61% of the critical low and low fibrinogen group, respectively). The overall mortality rate was 21.8%. Mortality rates begin to rise at fibrinogen levels below 1.5 g/L, increasing by 263% at levels 1.0-1.5 g/L and by 630% at levels lower than 1.0 g/L (p < 0.05). The critical low level was an independent predictor of mortality (odds ratio 4.03 and 95% confidence interval 1.44-11.27) after adjustment for age, GCS, shock index, Injury Severity Score, fibrinogen therapy, serum lactate, and positive Focused Assessment with Sonography in Trauma. This study demonstrates an association between admission serum fibrinogen levels and mortality in blunt polytrauma patients with TBI.