see: [Dunn Disorders of clotting](x-devonthink-item://3D1195DE-A2A3-4B88-8C00-B4B4710AEF1A), [[TEG, ROTEM, coagulation studies]] - hypothermia reduced liver metabolism of citrate. Excess citrate binds to calcium - Decreased **calcium** available for coagulation cofactors - Lower Ca leads to lower pH. Lower ph prolongs clot formation (also ischemia lowers ph) - Ca levels drop due to blood loss. Transfusion with citrate exacerbates this ==INR and APTT correlate poorly with trauma induced coagulpathy== - [[TEG, ROTEM, coagulation studies|TEG and ROTEM]] preferred method of assessment # Trauma induced coagulpathy > **lethal triad** > - hypothermia > - acidemia > - coagulpathy > - (also [[Hypocalcemia]] - hypofibrinogenaemia - platelet receptor inhibition - hypercoagulability due to shut down of fibrinolytic syndrome - coagulpation factor depletion - protein C activation and fibrinolysis -