Clinical and physiologic factors associated with early hypofibrinogenemia in trauma

Fibrinogen plays a critical role in hemostasis and may be depleted early during trauma resuscitation. Although balanced resuscitation strategies have improved trauma care, early identification of trauma patients who are hypofibrinogenemic remains challenging in many real-world settings. We aimed to identify clinical and physiologic characteristics associated with early hypofibrinogenemia in trauma patients.

We conducted a health records review of adult trauma patients (≥ 18 years) who triggered a trauma team activation at a single trauma center between 2016 and 2021. Patients who died prior to blood sampling or had no usable initial fibrinogen measurement were excluded. The primary outcome was hypofibrinogenemia defined as the initial fibrinogen level collected in the trauma bay below 1.5 g/L. A multivariable logistic regression model was used to explore factors associated with early hypofibrinogenemia. This was an exploratory association analysis.

Among 4,936 included patients, 155 (3%) had early hypofibrinogenemia. Patients with early hypofibrinogenemia experienced high in-hospital mortality (51%). In adjusted analyses, the odds of early hypofibrinogenemia increased with greater blood component transfusion in trauma bay (OR 1.2 per unit, 95% CI 1.09-1.24), reflecting resuscitation intensity, and systolic blood pressure < 90 mmHg (OR 2.5, 95% CI 1.04-5.84). The odds decreased with higher (less negative) base excess (OR 0.84 per mmol/L, 95% CI 0.81-0.87) and with penetrating injury compared with non-penetrating injury (OR 0.43, 95% CI 0.21-0.83). Time from injury to presentation had an increased odds of hypofibrinogenemia (OR 1.03 per hour, 95% CI 0.99-1.07).

Early hypofibrinogenemia occurred in a small subset of trauma patients but was associated with marked physiologic derangement and high mortality. These hypothesis-generating findings contribute to understanding the physiologic context of fibrinogen deficiency in trauma and provide a foundation for future prospective validation studies.