====== D-dimer/fibrinogen ratio ======

[[Progressive hemorrhagic injury]] (PHI) greatly affects the prognosis of [[traumatic brain injury]] (TBI). [[D-dimer]]/[[fibrinogen]] ratio (D/F ratio) may be a potential predictor for [[venous thromboembolism]]. A study of Xu et al. sought to describe and evaluate any relationship between D/F ratio and PHI after [[TBI]].

This retrospective study included a cohort of 192 TBI patients. Plasma D-dimer and fibrinogen were measured, and subsequently, D/F ratio was calculated. Multivariate logistic regression analysis was applied to identify predictors of PHI. The receiver operating characteristic (ROC) curve was configured to analyze predictive capability for PHI.

A total of 43 patients (22.4%) experienced PHI. Both [[Glasgow coma scale]] (GCS) score (odds ratio [OR], 0.565; 95% CI, 0.464-0.689) and D/F ratio (OR, 4.026; 95% CI, 2.219-7.305) were the two independent predictor for PHI. Area under ROC curve (AUC) of D/F ratio was similar to that of GCS score (AUC, 0.816; 95% CI, 0.754-0.868 vs. AUC, 0.834; 95% CI, 0.773-0.883; P=0.699). Moreover, D/F ratio significantly improved AUC of GCS score to 0.928 (95% CI, 0.881-0.960; P<0.001).

D/F ratio was strongly predictive of PHI in the studied cohort and, thereby should be considered in the clinical management of TBI patients
((Xu DX, Du WT, Li X, Wu ZX, Yu GF. D-dimer/fibrinogen ratio for the prediction 
of progressive hemorrhagic injury after traumatic brain injury. Clin Chim Acta.
2020 Apr 22. pii: S0009-8981(20)30177-7. doi: 10.1016/j.cca.2020.04.022. [Epub
ahead of print] PubMed PMID: 32333859.
)).
----
A D-dimer level <0·35 μg/ml may exclude the diagnosis of [[pulmonary embolism]]. At a D-dimer cutoff 0·5 μg/ml and D-dimer/fibrinogen ratio cutoff 1·0, the D-dimer/fibrinogen ratio may have better specificity than D-dimer level in the diagnosis of pulmonary embolism, but the D-dimer/fibrinogen ratio may lack sufficient specificity in screening
((Kara H, Bayir A, Degirmenci S, Kayis SA, Akinci M, Ak A, Celik B, Dogru A,
Ozturk B. D-dimer and D-dimer/fibrinogen ratio in predicting pulmonary embolism
in patients evaluated in a hospital emergency department. Acta Clin Belg. 2014
Aug;69(4):240-5. doi: 10.1179/2295333714Y.0000000029. PubMed PMID: 25012747.
)).

===== References =====