Effects of an Early Prehospital Administration of Tranexamic Acid on Hyperfibrinolysis in Multiple Trauma

Study Overview
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Brief Summary
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Severe external and internal bleedings are common in multiple trauma patients. Uncontrollable blood loss is the cause for about one third of all trauma deaths. A number of blood clotting mechanisms are known to be triggered by major blood losses. These mechanisms shall secure the organisms from loosing even more blood. To avoid an overshooting clotting behavior, inhibiting mechanisms occur as well. An important inhibiting (or fibrinolytic) mechanism is the fibrinolysis that is based on the conversion of plasminogen to plasmin. In severe bleeding situations this mechanism tends to overshoot and therewith contributes to the severity of the bleeding. This phenomena is called hyperfibrinolysis and is found in approximately one third of all multiple trauma patients. Mortality rates are increased in these patients. Tranexamic acid is an antifibrinolytic drug that inhibits the conversion from plasminogen to plasmin and therefore is able to limit the effects hyperfibrinolysis. A large study showed positive influence of tranexamic acid on mortality rates and blood loss in severely injured patients, when it was administered in an early clinical setting. In this study we want to answer the question wether a hyperfibrinolysis can be seen in an early prehospital (on the scene) setting and how it is influenced by an early prehospital administration of tranexamic acid.

Detailed Description
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In patients suffering from multiple trauma the initially responding emergency physician on the scene will take a blood sample for thrombelastometry immediately after i.v. access is established. According to the initial trauma life support protocols a number of patients will receive a dose of tranexamic acid during the initial treatment on the scene or during transport to the hospital. A second blood sample will be taken after arrival in the resuscitation area of the hospital. Thrombelastometric measurements will be performed with both blood samples and the extent of hyperfibrinolysis in both samples will be compared. In a second step the outcome of the patients who received tranexamic acid on the scene will be compared to those who did not receive the drug before reaching hospital.

Conditions
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Hyperfibrinolysis, Haemorrhage, Mortality

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Multiple trauma ISS > 15 Age > 18 years Exclusion Criteria: No informed consent Inclusion to an interventional clinical trial Death of the patient on the scene or before the hospital was reached Delayed thrombelastometric measurement (> 4 hours)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Tranexamic acid<br>patients with multiple trauma who received tranexamic acid on the scene | |
| Non tranexamic acid<br>patients with multiple trauma who did not receive tranexamic acid on the scene | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Initial state of hyperfibrinolysis | State of hyperfibrinolysis quantified by thromelastometry and PAP-Complex (Plasmin-Antiplasmin-Complex) from a blood sample taken a soon as possible on the scene | Minutes after arrival on the scene | 
| State of hyperfibrinolysis on hospital admission | State of hyperfibrinolysis quantified by thrombelastometry and PAP-Complex from a blood sample taken as soon as possible after hospital arrival | minutes to hours after incident | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| transfusion of packed red blood cells | units of packed RBC units transfused within 48 hours after hospital admission | 48 hours | 
| substitution of coagulation products | number and type of coagulation products given within 48 hours after hospital admission | 48 hours after hospital admission | 
| length of stay intensive care unit (LOS ICU) | length of the first ICU stay | one year | 
| length of hospital stay | length of stay in the acute care hospital (not rehabilitation facilities) | one year | 
| mortality | dead within 90 days after hospital admission | 90 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Multiple trauma, Polytrauma, Hyperfibrinolysis, Tranexamic acid, Thrombelastometry