R. Yanney1, H. B. Moore3, K. M. Mueck1, I. Liras1, J. C. Cardenas1, M. T. Harting1,2, B. A. Cotton1 1University Of Texas Health Science Center At Houston,Houston, TX, USA 2Children’s Memorial Hermann Hospital,Houston, TX, USA 3Denver Health Medical Center,Aurora, CO, USA
Introduction: Fibrinolysis is a physiologic process that attempts to maintain microvascular patency by breaking down excessive clot. Previous data in both adults and children has shown that hyperfibrinolysis (HF) is associated with a doubling in mortality. Recently, data in adults has demonstrated that fibrinolysis shutdown (SD), an acute impairment of fibrinolysis, is also associated with significant increases in mortality. The purpose of the current study was to assess (1) the incidence and presentation of fibrinolysis phenotypes in pediatric trauma patients and (2) the impact of SD on mortality among these patients.
Methods: Pediatric trauma patients (0-17 years of age) who (1) were admitted 2010-2014, (2) met highest-level trauma activation and (3) had severe anatomic injury were included in this analysis. Severe anatomic injury was defined as injury severity score (ISS) >15. Admission fibrinolysis phenotypes were defined by the clot lysis measured by TEG at 30 minutes (LY30): SD ≤ 0.8%, physiologic 0.9-2.9%, HF ≥ 3%. Massive transfusion was defined as >10 U RBC in 6 hours. Continuous and dichotomous variables were evaluated with ANOVA and Kruskal-Wallis, respectively.
Results: 489 patients met inclusion. 34% demonstrated evidence of SD on arrival (38% were physiologic, 28% were HF). SD patients were older (median age 16 vs. 12;p<0.001) and more likely to be female (41 vs. 28%;p=0.044) compares to HF. WHile mechanism and ISS were similar between SD and HF, ISS was higher in HF than in the physiologic group (median 27 vs. 25; p=0.010). Arrival blood pressure, pulse and GCS were similar between the three groups. SD patients were more hypocoagulable by TEG k-time (median 1.5 vs. 1.3 min;p=0.029), and alpha-angle (72 vs. 73 deg; p=0.020) than the HF cohort. HF were more hypocoagulable than physiologic group by TEG ACT (median 128 vs. 121 sec; p=0.002) and mA (62 vs. 64 mm; p=0.003). All other arrival labs were similar between groups. Both SD and HF patients had incresed massive transfusion (12 and 10%, respectively vs. 3%; p=0.004) and mortality rates (19 and 20%, respectively vs. 8%; p=0.003) compared to the physiologic group (FIGURE). When the analysis was repeated among only those children 5 years of age or less, the results were similar, including that of higher mortality (SD: 15 vs. HF: 10 vs. physiologic: 2%; p=0.026).
Conclusion: Fibrinolysis shutdown (SD) appears to carry similar mortality risk to that of HF among severely injured children. The current study provides additional evidence of distinct phenotypes of coagulation impairment and that individualized hemostatic therapy may be required. While HF may be addressed with anti-fibrinolytics, SD presents a significant treatment challenge in the injured patient.
