The Trauma- Formula-Driven Versus Lab-Guided Study (TRFL Study)

Formula-driven vs Laboratory-guided Transfusion Practices in Bleeding Trauma Patients: A Feasibility Randomized Controlled Study

Background: Bleeding and coagulopathy still accounts for the majority of early in-hospital deaths following trauma. There have been lately several published studies suggesting that higher transfusion ratios of fresh frozen plasma (FFP), platelets (PTL) and cryoprecipitate (CRYO) to red blood cell (RBC) are associated with survival advantages. However, the evidence comes from retrospective data limited by a significant number of unaddressed confounders. In addition, the use of blood products bears known and important risks of complications.

Hypothesis: The adoption of a formula-driven transfusion practice with pre-defined ratios of FFP to PTL to RBC transfusion (1:1:1) is feasible and superior to current laboratory-guided transfusion practice in treating and/or preventing early coagulopathy improving survival rates in massively bleeding trauma patients .

Objective: To exam the feasibility of implementing a pre-defined ratio of FFP to PTL to RBC (1:1:1) transfusion protocol and its impact on a population of bleeding trauma patients.

Design: A two-year pilot feasibility randomized control trial at Sunnybrook Health Sciences Centre. Randomization: 70 patients are expected to be randomized to lab-driven or to formula-driven massive transfusion protocol and followed-up to 28 days or hospital discharge.

Study outcomes: protocol violation; in-hospital mortality by exsanguination; death at 28 days; coagulation competence defined by current standard coagulation tests (INR & PTT < 1.5 times normal; PTL ≥ 50 and Fibrinogen ≥ 1.0) or clotting factor levels ≥ 30%; correlation of current standard coagulation tests with clotting factors levels; cessation of bleeding; incidence of ALI, sepsis, MOF, transfusion-related circulatory overload, transfusion reactions; Ventilator-free days; ICU & Hospital LOS; thromboembolic events.

Intervention protocol: Transfusion of pre-defined ratios of FFP and PTL to RBC (1:1:1) (formula-driven) for the first 12h of hospitalization without coagulation tests guidance while patient is hemorrhaging or before if bleeding stops.

Statistical analysis: protocol compliance rate and in-hospital mortality rates within 24h and at 28 days will be assessed using Chi-square test. ROC analysis will be used to analyze coagulation competence.

Main expected outcomes: implementation of a formula-driven transfusion protocol is feasible and coagulation competence will be achieved faster and more efficiently in the study group.

Inclusion Criteria

Patients were eligible for this study if they:

i) were adult trauma patients assessed by the trauma team; and ii) suffered either penetrating or blunt mechanism of injury; and

1. were bleeding and expected to require massive transfusion (either 4 units within the next 2 hours or ≥ 10 units of RBC in 24 h) or required transfusion of un-cross matched emergency stock red blood cells; and
2. had an episode of hypotension (systolic bp ≤ 90mmHg).

Exclusion Criteria

Patients were excluded if:

i) they were assessed in the trauma room more than six hours after injury; or ii) they received more than two units of RBC transfusion prior to arrival; or iii) they had suffered a concomitant severe brain injury (defined as any of the following: Glasgow Coma Scale of 3 due to severe traumatic brain injury; clear indication of immediate neurosurgical intervention based on clinical findings, mechanism of trauma associated with focal signs (anisocoria, CT evidence of intracranial bleeding with mass effect); or iv) they had evidence of having a catastrophic head injury (such as transcranial gunshot wound, open skull fracture with exposure/loss of brain tissue, or expert opinion by either the trauma team leader or neurosurgical consultant based on initial clinical or initial CT findings); or v) they had evidence that their shock state was unrelated to hemorrhage (ie cardiogenic, septic, anaphylactic, acute adrenal insufficiency, neurogenic, or obstructive (cardiac tamponade, tension pneumothorax and massive pulmonary emboli); or vi) they had a known hereditary or acquired coagulopathy unrelated to the trauma resuscitation (for example: hemophilia, hepatic insufficiency, or anti-coagulant medications); or vii) they were moribund with evidence of unsalvageable injuries.