Transfusion-free Surgery is a Treatment Plan for All Patients

AORN Journal, Nov, 1998 by Tricia Trovarelli, Barbara Kahn, Sharon Vernon

ERYTHROPOIETIN

Erythropoietin alfa, a new treatment option for patients undergoing elective surgical procedures, is now available and approved by the FDA for use in orthopedic procedures. Although it has been used for many years to stimulate erythropoiesis in patients with renal failure, erythropoietin alfa has only recently gained acceptance as an adjunct to replenish red blood cells in the surgical setting.

Erythropoietin is a glycoprotein hormone secreted by the kidneys in response to tissue hypoxia, leading to red cell production in the bone marrow.(19) Although small losses of blood, such as during the predonation of one unit, can cause production of erythropoiesis, sharp increases usually occur after major blood losses.(20) Erythropoietin is effective only when adequate supplies of iron, folic acid, and vitamin B12 are available. Vitamin B 12 and folic acid are necessary for DNA synthesis, and iron is necessary for adequate hemoglobin production.(21)

Recombinant human erythropoietin plays a role in patients undergoing orthopedic procedures.(22) Erythropoietin alfa increases red blood cell mass when used in weekly doses of 600 U/kg or daily doses of 300 U/kg. Erythropoietin alfa has been studied in patients undergoing major orthopedic surgery who were unable to participate in autologous donation preoperatively.(23)

HEMODILUTION

Several alternative methods exist whereby blood loss during surgery can be minimized or blood volume can be restored. When used independently or in conjunction with erythropoietin, these methods are useful in decreasing the need for transfusion. Acute normovolemic hemodilution is intentional preoperative hemodilution induced by the isovolemic exchange of whole blood with crystalloid solutions to preserve autologous blood while maintaining normovolemia.(24) During hemodilution, blood is withdrawn preoperatively or intraoperatively, collected in bags, and stored as citrate phosphate dextrose blood, allowing for the preservation of red blood cells and clotting factors.(25) This method allows for the safe return of autologous blood postoperatively. It is used in patients undergoing elective procedures and has been useful in total hip arthroplasty and other orthopedic procedures.(26)

Contraindications to hemodilution include heart disease, renal disease, significant anemia, obstructive pulmonary disease or emphysema, severe hypertension, and clotting deficiencies.(27) It must be used with extreme caution in elderly patients because there is rapid change in blood volume due to increased cardiac output and decreased blood viscosity to maintain oxygen delivery.(28)

INTRAOPERATIVE BLOOD SALVAGE

Intraoperative blood salvage, or autotransfusion, involves the retrieval of red blood cells through suction devices followed by washing and centrifuge. This method is used when the patient's estimated blood loss exceeds 1,000 mL.(29) It is most useful in revision arthroplasty procedures or with complicated surgeries involving prolonged intraoperative duration. Approximately 60% of the red blood cells lost during orthopedic surgery can be salvaged using this method.