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Coagulation and cardiac ITU. 2 Approaches. Understand and treat appropriately Give platelets, FFP, and cryoprecipitate. Overview. How clotting system works Drugs that affect it Effect of CPB on coagulation Medical conditions that affect it Tests of coagulation
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2 Approaches • Understand and treat appropriately • Give platelets, FFP, and cryoprecipitate
Overview • How clotting system works • Drugs that affect it • Effect of CPB on coagulation • Medical conditions that affect it • Tests of coagulation • Assessing the bleeding patient • Treatments
Coagulation system • Why have it ? • What stops it working ? • What causes its activation ?
How it works 1 Activation intrinsic- collagen and connective tissue and extrinsic- tissue factor from damaged cells Platelets Soluble clotting factors Fibrin RBC Clot
How it works 4 Thrombin Soluble factors Thrombin Platelet Clot
Drugs that affect coagulation • Bleed • Aspirin • Warfarin • Heparin / LMWH • Clopidogrel / Ticlopidine • ReoPro / Integrilin • Steptokinase / Alteplase • Non steroidal anti inflammatory drugs • Clot • Protamine • Tranexamic acid • Aprotinin • Vit K
Aspirin TxA2 Platelet PgI2 Endothelium
Warfarin • Inhibits Vitamin K • Factors 11, V11, 1X, and X • Factor 11 most important “thrombin” Soluble factors Thrombin Platelet Clot
Heparin / LMWH • Complex molecule of multiple sugars molecules AT 111 Thrombin Heparin
ReoPro / Integrilin Platelet Platelet GP 11b/111a Fibrin GP 11b/111a
Steptokinase / Alteplase / TPA Steptokinase / Alteplase / TPA Plasmin Plasminogen Fibrin Degradation products Fibrin Fibrinogen Coagulation cascade
Non steroidal anti inflammatory drugs TxA2 Platelet PgI2 Endothelium
Protamine Protamine Heparin Inactive complex
Tranexamic acid Plasmin Plasminogen Fibrin Degradation products Fibrin Fibrinogen Coagulation cascade Tranexamic acid
Aprotinin • Kallikrein Kinin inhibitor • PAR-1 antagonist • Anti fibrinolytic • Multiple different doses • Full dose / half dose / pump prime
Vit K • Slow IV • Liver disorders
Effect of CPB on coagulation • Soluble factors • Consumption • denatured • Platelets • Consumption • Desensitisation
Medical conditions that affect • Drugs • Renal / liver failure • Haemophilia • Christmas disease • Von Willebrands
Drugs • Discussed already
Renal failure • Platelets don’t work • Uraemia Liver failure • All clotting factors other than V111 produced in liver
Von Willebrands Platelet Factor V111 vWF Endothelium
Tests of coagulation • PT / INR • APPT • Fibrinogen • D-Dimer • ACT / KCT • Platelet function tests / thromboelastography
Assessing the bleeding patient • Blood pressure • Acid base • CXR • Pumping up tubing • Sudden stop of bleeding esp 2nd clotting factors • Drop in Hb • TAMPONADE Clotting studies / Preop medications & conditions / what operation
Treatments • Surgical factor VII (prolene 7-0) • FFP • Cryoprecipitate • Specific isolated factors • Platelets • Blood / Hb
FFP fresh frozen plasma • All soluble clotting factors except 1 and V111
Cryoprecipitate • Fibrinogen – factor 1 • vWF • V111
Platelets • Depends on preop med’n, count and operation
Specific isolated factors • 1 • V111 • 1X • vWF • Blood / Hb
Next week ECG Interpretation