NMS. Surgery

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Part I ♦ Foundations Transfusion Alternatives I. Elective surgery (if the time of blood loss is known) A. Autologous banked blood B. Epoetin alpha: Increases Hct preoperatively to help avoid transfusion; useful in renal failure patients and those with chronic anemia. C. Autotransfusion: Recycle blood lost during surgery. D. Acute normovolemic hemodilution 1. Once a patient is anesthetized, blood can be removed, stored, and replaced with crystalloid or colloid to maintain euvolemia. 2. Benefits a. Blood lost during surgery has a lower Hct; therefore, fewer red cells are shed. b. Those that are shed can be replaced with fresh (not stored) autologous blood that was just removed. E. Directed donor: Risk of virus transmission is lower, but similar risks of immunomodulation and other reactions exist. F. Hemostatic agents: Prevent blood loss in the first place. 1. FFP/cryoprecipitate: For patients with coagulopathy. 2. DDAVP: For platelet dysfunction, especially renal failure. 3. Tranexamic acid: Inhibits serine proteases, including plasmin, and is therefore antifibrinolytic; increasingly used in trauma. 4. Lysine analogs: є -aminocaproic acid. 5. Topical hemostatics: Fibrin glue. II. Acute unexpected blood loss A. Autotransfusion: May still be an option, if readily available. 1. Emergent aortic rupture 2. Trauma laparotomy 3. Hemothorax: Autotransfuse blood from the chest tube. B. Prevent further blood loss.

Quick Cuts • The longer blood is stored, the worse it performs. • Blood is an immunosuppressant. • A transfusion trigger is 7 g/dL or less.

NUTRITION AND THE SURGICAL PATIENT Energy Sources: Protein, Glucose, and Fat I. Protein A. Requires conversion to glucose via hepatic gluconeogenesis. B. Adequate intake is important for muscle mass maintenance and other protein-dependent, nonenergy-producing processes.