Blood Transfusion Basic Concepts, Blood Transfusion in ICU and Anaesthesia • Introduction • Indications • Components • Hazards • ???? • Anesthesiologists, the perioperative physicians, are major users of blood and blood products. • Therefore thorough knowledge of transfusion practices becomes imperative in this speciality. Hemostasis following trauma/ surgery dependent on • Vascular spasm • Formation of platelet plug (primary hemostasis) • Coagulation of blood (secondary hemostasis) Normal Coagulation Factors • I- FIBRINOGEN • II-PROTHROMBIN • III-TISSUE THROMBOPLASTIN • IV-CALCIUM • V-PROACCELERIN • VII-PROCONVERTIN • VIII-ANTIHEMOPHILIC FACTOR • IX-CHRISTMAS FACTOR • X-STUART FACTOR • XI-PLASMA THRMBOPLASTIN ANTECEDENT • XII- HAGEMAN FACTOR • XIII-FIBRIN STABILIZING FACTOR Coagulation Pathway Intrinsic pathway Extrinsic pathway (Contact) (Tissue factor) X Xa TThhrorommbbiinn Prothrombin Fibrinogen Fibrin Intrinsic Pathway Contact (Eg: with glass) XIIa XII XIa XI IX IXa VIIIa PL Ca++ X Xa When To Transfuse 1. Monitor blood loss – • Visual assessment of the surgical field • Blood loss >25% of total blood volume • MABL a. estimate blood volume b. RBC volume at preop hematocrit c. RBC volume at hematocrit 30% d. RBC volume lost when hematocrit is 30% = b – c. e. MABL = 3 x d. When To Transfuse Monitor for inadequate 2. perfusion & oxygenation of vital organs. • Sr. lactate > 2meq/lit • O extraction 50%.(O extraction = Sa O 2 2 2 – Scv O . 2 • U/O < 0.5ml /kg/ hr. • BP, HR, O saturation, ABG 2 When To Transfuse 3. ASA guidelines (2006) transfusion indicators • Transfusion rarely indicated when Hb>10gm/dl and almost always indicated when Hb <6gm/dl • Patients with Hb b/w 6-10 gm/dl should be based on patient risk for complications of inappropriate oxygenation , rate and magnitude of ongoing bleeding and patient intravascular volume status Practice Guidelines for Perioperative Blood Transfusion and AdjuvanTherapies. Anesthesiology 2006; 105:198–208