Trending Fibrinolytic Dysregulation: Fibrinolysis Shutdown in the Days After Injury Is Associated With Poor Outcome in Severely Injured Children.

OBJECTIVE

To trend fibrinolysis after injury and determine the influence of traumatic brain injury (TBI) and massive transfusion on fibrinolysis status.

BACKGROUND

Admission fibrinolytic derangement is common in injured children and adults, and is associated with poor outcome. No studies examine fibrinolysis days after injury.

METHODS

Prospective study of severely injured children at a level 1 pediatric trauma center. Rapid thromboelastography was obtained on admission and daily for up to 7 days. Standard definitions of hyperfibrinolysis (HF; LY30 ≥3), fibrinolysis shutdown (SD; LY30 ≤0.8), and normal (LY30 = 0.9-2.9) were applied. Antifibrinolytic use was documented. Outcomes were death, disability, and thromboembolic complications. Wilcoxon rank-sum and Fisher exact tests were performed. Exploratory subgroups included massively transfused and severe TBI patients.

RESULTS

In all, 83 patients were analyzed with median (interquartile ranges) age 8 (4-12) and Injury Severity Score 22 (13-34), 73.5% blunt mechanism, 47% severe TBI, 20.5% massively transfused. Outcomes were 14.5% mortality, 43.7% disability, and 9.8% deep vein thrombosis. Remaining in or trending to SD was associated with death (P = 0.007), disability (P = 0.012), and deep vein thrombosis (P = 0.048). Median LY30 was lower on post-trauma day (PTD)1 to PTD4 in patients with poor compared with good outcome; median LY30 was lower on PTD1 to PTD3 in TBI patients compared with non-TBI patients. HF without associated shutdown was not related to poor outcome, but extreme HF (LY30 >30%, n = 3) was lethal. Also, 50% of massively transfused patients in hemorrhagic shock demonstrated SD physiology on admission. All with HF (fc31.2%) corrected after hemostatic resuscitation without tranexamic acid.

CONCLUSIONS

Fibrinolysis shutdown is common postinjury and predicts poor outcomes. Severe TBI is associated with sustained shutdown. Empiric antifibrinolytics for children should be questioned; thromboelastography-directed selective use should be considered for documented HF.