Introduction: Current guidelines lack consensus on fibrinogen replacement thresholds in critical hemorrhage. This study aims to establish evidence-based supplementation thresholds and optimal targets for ICU patients with major bleeding, providing a framework for individualized coagulation management. Methods: This prospective multicenter cohort study enrolled 197 patients with severe hemorrhage and coagulopathy from 12 tertiary ICUs in China. Standardized systems collected demographics, laboratory parameters, and interventions. Analysis comprised two phases: (1) Restricted cubic spline (RCS) models evaluated nonlinear associations between baseline fibrinogen and outcomes (hemostasis, ICU mortality), identifying a critical threshold at 1.54 g/L; (2) Post-treatment fibrinogen peaks (within 72h) were stratified into subgroups based on prior MIMIC-IV validation: < 1.54 g/L (low-risk), 1.54–2.0 g/L (intermediate), 2.0–2.5 g/L (target), ≥2.5 g/L (high-level). Statistical analyses included Cochran-Armitage test (dose-response), Firth’s regression (small-sample bias correction), and Kruskal-Wallis tests with Benjamini-Hochberg FDR correction (FDR< 0.05; transfusion heterogeneity). Results: We enrolled 197 patients with massive hemorrhage (treatment: n=98; control: n=99). Baseline data showed the treatment group had significantly greater blood loss (1735vs.967 mL, P=0.013), lower fibrinogen (1.49vs.2.04 g/L, P=0.001), and higher APACHE II scores (19.5vs.16.7, P=0.047). Pretreatment fibrinogen showed nonlinear associations with hemostasis and ICU mortality (both Pnon-linear< 0.001), identifying a critical threshold at 1.54 g/L. Post-treatment fibrinogen levels of 2.0-2.5 g/L achieved a hemostasis rate of 75%-80%; higher levels (2.5-3.5 g/L) showed slightly reduced efficacy. Mortality was 35% for levels < 1.5 g/L, significantly decreasing to 15% at 2.0-2.5 g/L, and approaching zero at 2.5-3.5 g/L. Post-treatment levels also showed nonlinear associations with outcomes (both Pnon-linear< 0.001), with a critical threshold at 2.5 g/L. Conclusions: Fibrinogen levels predict outcomes in critically ill patients with massive hemorrhage. Initiation of fibrinogen supplementation is recommended when levels fall below 1.5g/L, targeting 2.0–2.5g/L as the optimal therapeutic window to improve prognosis.
Ren et al. (Sun,) studied this question.