Blood conservation in a congenital cardiac surgery program

AORN Journal, June, 2008 by Tracey John, Roberta Rodeman, Roslyn Colvin

The increase in public concern regarding allogenic blood transfusions (ie, transfusions using the stored blood of others) has led many institutions to develop blood conservation programs.' This is primarily a result of

* the risks associated with allogenic transfusions or the public's perception of these risks,

* the costs of blood transfusion, and

* the need to use resources efficiently (ie, an estimated 3 million pints of blood are used annually for elective surgeries in the United States(2)). (1)

In addition, members of certain religions (eg, Jehovah's Witnesses) refuse blood transfusions because they believe blood is sacred. (3) In the Jehovah's Witness faith, when blood is detached (ie, completely separated) from the body, it should not be returned. (4) The patient's own blood may exit the body, however, and be readministered if it is kept in a continuous closed circuit.

The term bloodless surgery refers to the act of performing surgery and recovery without transfusing any blood or blood products. (5) The term blood conservation refers to the treatment strategies used to achieve bloodless surgery. (5) Innovative surgical techniques aimed at blood conservation continue to be developed, including

* minimally invasive surgical procedures;

* specialized coagulation devices (eg, argon beam coagulators, ultrasonic scalpels);

* acute normovolemic hemodilution; and

* cell salvage. (6)

Cardiopulmonary bypass (CPB) techniques also have been modified in ways that increase the possibility of bloodless cardiac surgeries. (7)

Bloodless surgery is not exclusively about surgical strategies, however. Preoperative, intraoperative, and postoperative clinicians must work in unison when caring for these patients to deliver optimal comprehensive care.

PREOPERATIVE MANAGEMENT

When a patient wants to forego blood transfusion, attention must be focused on legal consent. For example, most Jehovah's Witnesses refuse transfusion of red blood cells, platelets, plasma, or whole blood, and also refuse to undergo preoperative autologous blood donation. It is considered a matter of conscience, however, for the Jehovah's Witness patient to accept plasma products and other coagulation factors? Each patient must make his or her own decision on whether to accept blood products based on his or her own interpretation of the Bible and own moral and ethical beliefs. (8)

Clear delineation is required in the surgical consent to reflect the patient's wishes. Although adults have the right to refuse blood products even if death is imminent, many state laws prohibit withholding blood from a minor when there is a threat to organs or life. (9) Each state and federal law is uniquely written. According to the US Supreme Court in Prince v Commonwealth of Massachusetts, the court determines the person's right to practice religion freely, however, that does not include the liberty to expose children to ill health or death. (10) These issues need to be clearly discussed so that all members of the perioperative team act in accordance with the patient's desires and adhere to legal statutes.

Preoperative screening and management of a patient in a blood conservation program is critical to achieving successful patient outcomes. A patient with a prior history of unexpected bleeding or clotting problems or the presence of underlying conditions (eg, cardiac or pulmonary disease, hyperlipidemia, hypertension, anemia, history of cerebral vascular disease, use of beta-blockers) has a greater risk of requiring surgical blood transfusions? Neonates or older adult patients also have a greater risk? Health care practitioners must ensure that the patient fully understands what measures will be taken in the attempt to conserve blood and the risks associated with each measure.

In an effort to reduce the effects of blood loss during surgery, the primary health care provider or surgeon may prescribe epoetin alpha, a synthetic form of erythropoietin (EPO), for at least four weeks before surgery. Erythropoietin is a naturally occurring glycoprotein that stimulates the bone marrow to produce red blood cells in response to tissue hypoxia.

Epoetin alpha (eg, Procrit, Epogen) is administered intramuscularly in weekly doses of 500 units/kg during the preoperative period to elevate the hematocrit (HCT) in preparation for intraoperative blood loss. (11) In addition, the primary care clinician should advise the patient to take an iron supplement and a multivitamin containing vitamin C for iron absorption, folic acid, and [B.sub.12] for DNA synthesis and red cell production. The clinician also may recommend that the patient take supplements or eat foods high in vitamin K, which aids the liver in the synthesis of clotting factors.

The perioperative nurse must review and document all medications and herbal or dietary supplements that the patient currently is taking. The nurse should note whether the patient takes anticoagulants and other nonsteroidal anti-inflammatory medications that may interfere with coagulation. Certain antibiotics (eg, cephalosporins) may cause coagulation abnormalities by affecting the patient's bowel flora, which can affect vitamin K absorption. (12) It is important for the nurse to specifically ask the patient whether he or she uses herbal or dietary supplements, which may affect the body's hemostatic process. The primary care clinician or surgeon should instruct the patient to discontinue these therapies before surgery, if possible.