[Thinking, evaluating, and replenishing the fibrinogen hemostatic strategy in neurosurgery]

Hemostatic control in neurosurgery represents a major clinical challenge, in which even small variations in blood loss can critically alter intracranial pressure and neurological prognosis. Fibrinogen, the first coagulation factor to be depleted during hemorrhage, is also an early marker of coagulopathy and a key determinant of clot stability. This narrative review analyzed the scientific literature published between 2020 and 2025 in PubMed, Scopus, and the Cochrane Library, with emphasis on studies evaluating the pathophysiology, diagnosis, and targeted replacement of fibrinogen in neurosurgical patients. Through critical analysis and systematic integration of the selected studies, convergent evidence was identified demonstrating that low fibrinogen levels are associated with greater blood loss, an increased risk of intracranial rebleeding, and poorer functional outcomes. Viscoelastic test-guided administration allows dose optimization and reduction of transfusion requirements, while empirical strategies based on serum concentrations and surgical context provide safe alternatives when such technologies are unavailable. Understanding when and how to replace fibrinogen constitutes an essential component of comprehensive patient blood management in neurosurgery. This paradigm, summarized by the principle "think, assess, and replace", consolidates an integrated model of goal-directed neurohemostasis.