Preoperative Management Aimed at optimizing patient hemoglobin levels to allow for better patient stress tolerance at the time of surgery vitamin supplementation iron major building block of hemoglobin and functions to bind oxygen in the porphyrin ring structure supplementation provides material for hemoglobin synthesis some studies have demonstrated a significant decrease in postoperative transfusions in patients with anemia-reducing vitamins increased side effects constipation acid reflux/heartburn abdominal pain folate and vitamin B12 supplementation are essential vitamins for DNA synthesis that are necessary for erythropoiesis anemia-associated vitamin supplementation iron 256 mg/day, vitamin C 1 g/day, and folate 5 mg/day for 30-45 days preoperatively have been associated with decreased transfusion rates should only be used in patients with specific deficiency erythropoietin (EPO) recombinant protein of natural glycoprotein produced by renal pericapillary cells signals bone marrow cells to stimulate red blood cell (RBC) production studies have demonstrated greater efficacy than preoperative autologus blood donation and reinfusion systems high cost associated with use treatment cost equivalent to 4 units of allogenic blood transfusion recommended for high risk patients (e.g. low preoperative hemoglobin, surgeries with significant blood loss anticipated, etc.) three dosing regimens have been proposed: 600 IU/kg - 4 doses: preoperative days 21, 14, 7, and 0 300 IU/kg - 15 doses: preoperative day 10 to postoperative day 4 150 IU/kg - 9 doses: preoperative day 5 to postoperative day 3 preoperative autologous blood donation preoperative procurement of 1 to 2 units of autologous blood performed at least 3 weeks from the planned surgery to allow for recovery of hemoglobin levels may be of benefit in patients with normal Hb (>14 g/dL) ubdergoing procedures with high expected blood loss may be performed in any patient with Hb > 11 g/dL and body weight >50 kg with sufficient time prior to procedure current literature does not seem to support efficacy and cost effectiveness in the management of postoperative anemia concerns that there is a high incidence of unused units preoperative embolization standard treatment for oncology cases with highly vascular tumors renal cell carcinoma performed within 24 hours of the procedure Preoperative labs CBC evaluate hemoglobin levels determine mean corpuscular volume microcytic anemia suggests iron deficiency macrocytic anemia suggests folate and vitamin B12 deficiency folate B12 Intraoperative Management Acute normovolemic hemodilution autologus blood harvested right before or at the time of surgery removed volume is replaced with colloid extracted blood is transfused in the perioperative period requires less planning than preoperative autologus blood transfusion not commonly performed due to increased time in OR and associated labor Tourniquet allows for a dry surgical field and better theoretical cement interdigitation during arthroplasty cases minimum inflation pressure of 100 -150 mm Hg of systolic pressure may use of esmarch bandage to exsanguinate limb prior to inflating tourniquet avoid in infections and tumor cases may also elevate limb for gravity exsanguination prior to inflating tourniquet avoid use longer than 2 hours tourniquets should be cautiously used in patients with severe peripheral vascular disease risk of arterial complications associated with: history of arterial insufficiency absence of pedal pulses suspected popliteal aneurysm radiographic arterial calcifications preoperative vascular surgery consultation in high risk patients Tranexamic acid (TXA) lysine derivative that competitively blocks plasmin binding sites on fibrin results in a decrease in fibrinolysis and stabilized clot formation multiple studies have demonstrated a significant reduction in operative blood loss and transfusion rates with perioperative administration no increased risk of DVT and PE does not alter PT and PTT times multiple dosing regimens and routes of administration utilized IV, oral, and topical all appear equally efficacious contraindications active intravascular clotting severe drug allergy (anaphylaxis) subarachnoid hemorrhage side effects seizures binds to glycine and GABA channels leading to a reduced seizure threshold Aminocaproic acid lysine derivative that competitively inhibits plasmin results in decreased fibrinolysis studies have demonstrated decreased blood loss with aminocaproic acid in arthroplasty lower cost than TXA does not decrease seizure threshold Topical hemostatic agents collagen agents stimulate the instrinsic pathway of coagulation cascade to promote hemostasis microfibrillar collagen dry, fine, white powder must be applied with dry surgical instruments to a dry field fibrin sealant consists of two seperate mixtures one contains fibrin and factor XIII one contains thrombin and calcium combining the mixtures creates a fibrin seal where it is sprayed platelet-rich plasma centrifugation of patient's blood to isolate plasma with high contents of platelets, growth factors, and clotting factors proposed benefit of improved hemostasis, wound healing and recovery platelet-poor plasma isolated from centrifugation process combined with thrombin and calcium to provide an autologous fibrin sealant gelfoam sponges manufactured from animal-skin gelatin and processed into sponge-form isolated use exerts mostly mechanical hemostasis against low-pressure bleeders can be soaked with thrombin, which can act as a scaffold for the coagulation cascade excess gelfoam should be removed as it may interfere with bone healing topical hemostatic agents do not appear to be cost-effective in total joint arthroplasty cases beneficial in spine surgery to promote hemostasis without inflicting harm to adjacent neural structures topical TXA typically administered near the end of the procedure to control postoperative bleeding decreases fibrinolysis and stabilizes clot formation may be an alternative route of adminstration in patients with higher risk of complications history of MI, CAD, or CVA gelatin-thrombin matrix commonly used in spine surgery to control epidural bleeding brand names include Floseal and Surgiflo consists of porcine or bovine gelatine matrix combined with human derived thrombin acts at the end stage of the coagulation cascade leading to fibrin formation Reinfusion systems (cell saver) recycles intraoperative blood loss for later transfusion can be transfused intraoperatively during longer procedure collected blood is filtered, washed, and transfused within 6 to 8 hours from the procedure serves as an alternative to allogenic blood transfusion theoretical benefits of minimizing wound complications and hematoma formation complications coagulopathy altered composition of the transfused blood containing elevated fibrin split products and inflammatory cytokines (TNF-α and interleukins) especially problematic in unwashed systems can lead to increased wound drainage contamination cost Postoperative Management Allogenic blood transfusion preoperative hemoglobin strongest risk factor for postoperative blood transfusion other risk factors female gender increased age larger patient size longer procedures lateral releases in total knee arthroplasty 1 unit of packed red blood cells generally increases hemoglobin by 1 g/dL no absolute criteria for transfusion transfusion should especially be considered at hemoglobin <8 g/dL routine transfusion should be avoided for hemoglobin > 8 g/dL no increased mortality has been seen with this criteria, even in patients with cardiac history initiate transfusion if patient is symptomatic orthostatic hypotension tachycardia unresponsive to fluids Allogenic platelet transfusion blood product most likely to be contaminated stored at room temperature infections in 10 cases per million units transfused gram positive organisms most common thrombocytopenia platelet count below 5,000/mm^3 give platelets to avoid spontaneous bleeding platelet count below 50,000/mm^3 give platelets before surgery platelet count below 100,000/mm^3 consider giving platelets before surgery platelet count above 100,000/mm^3 no need to transfuse Postoperative iron supplementation daily oral iron supplementation for mild acute blood loss anemia related to surgery Special Consideration Jehovah's Witness (JW) hold beliefs that blood transfusions are forbidden by the Bible some patients may still consent to a blood transfusion some patients may consider the use of cell saver as an alternative to allogenic blood transfusion use of colloids and coagulation factors are not forbidden and a matter of personal choice bovine-derived hemostatic agents are generally approved by JW products derived from human plasma are a personal decision of JW preoperative discussion about the use of any special agents