Fibrinogen: a predictor of injury severity and short-term outcomes among young and middle-aged adults with traumatic brain injury.

Abstract

Introduction: Fibrinogen levels drop quicker than any other factors in severe trauma such as Traumatic Brain Injury (TBI). Contemporaneous studies show that fibrinogen concentrations < 2 g/L are strongly related to mortality. However, little is known regarding fibrinogen levels and TBI severity as well as short-term outcomes in sub-Saharan Africa. We therefore set out to study whether fibrinogen levels can be used to detect TBI severity and predict outcomes over 7 days Objectives: To determine the sensitivity and specificity of fibrinogen levels in predicting severity of traumatic brain injuries. To determine the association between fibrinogen and short-term outcomes among TBI patients presenting to the ER Mulago Hospital. Methods: We prospectively studied 213 randomly selected patients with TBI aged between 13 to 60 years of age presenting within 24hrs of injury. Patients with pre-existing coagulopathy, concurrent use of anticoagulant or antiplatelet agents, pre-existing hepatic insufficiency, diabetes mellitus and pregnant participants were excluded. Fibrinogen levels were determined using the Clauss fibrinogen assay. Results: Among the study participants, 101 patients (47.4%) had severe TBI. Majority were male (88.7%) and nearly half were aged 30 or less (48.8%). Fibrinogen levels less than 2g/L were observed in 74 (35.1%) of the patients while levels above 4.5 g/L were observed in 30(14.2%) of the patients. The average time spent in the study was 3.7 ± 2.4 days. The sensitivity and specificity using fibrinogen <2g/L was 56.5% and 72.9%. (p < 0.001). Fibrinogen levels predict TBI severity with an AUC = 0.656 (95% CI 0.580-0.731: p=0.000) Fibrinogen levels <2g/L (hypofibrinogenemia) were independently associated with severe TBI. (AOR 2.869 CI,1.341-6.139: p=0.007). Levels above 4.5g/L were also independently associated with injury severity (AOR 2.89, CI 1.117-7.479: p<0.05) Fibrinogen levels more than 4.5g/L were independently associated with mortality (OR 4.5, CI;1.472-13.607, p<0.05). Conclusions: We established that fibrinogen was a useful tool in predicting severity including mortality of TBI. We suggest the routine use of fibrinogen levels in TBI patient evaluation as levels below 2g/L and levels above 4.5g/L are associated with severe injuries and poorer outcomes.