Procuring Blood and Blood Products

Procuring Blood and Blood Products

BLOOD DONATION

To protect both the donor and the recipients, all prospective donors are examined and interviewed before they are allowed to donate their blood. The intent of the interview is to assess the general health status of the donor and to identify risk factors that might harm a recipient of the donor’s blood. Donors should be in good health and without any of the following:

•        A history of viral hepatitis at any time in the past, or a his-tory of close contact with a hepatitis or dialysis patient within 6 months

•        A history of receiving a blood transfusion or an infusion of any blood derivative (other than serum albumin) within 6 months

•         A history of untreated syphilis or malaria, because these dis-eases can be transmitted by transfusion even years later. A person who has been free of symptoms and off therapy for 3 years after malaria may be a donor.

•        A history or evidence of drug abuse in which substances were self-injected, because many intravenous/injection drug users are hepatitis carriers and because the risk for human immunodeficiency virus (HIV) is high in this group

•        A history of possible exposure to HIV; the population at risk includes people who engage in anal sex, people with multiple sexual partners, intravenous/injection drug users, sexual partners of people at risk for HIV, and people with hemophilia

•        A skin infection, because of the possibility of contami-nating the phlebotomy needle, and subsequently the blood itself

•        A history of recent asthma, urticaria, or allergy to medica-tions, because hypersensitivity can be transferred passively to the recipient

•        Pregnancy within 6 months, because of the nutritional de-mands of pregnancy on the mother

•        A history of tooth extraction or oral surgery within 72 hours, because such procedures are frequently associated with tran-sient bacteremia

•        A history of exposure to infectious disease within the past 3 weeks, because of the risk of transmission to the recipient

•        Recent immunizations, because of the risk of transmitting live organisms (2-week waiting period for live, attenuated organisms; 1 month for rubella; 1 year for rabies)

•        A history of recent tattoo, because of the risk of blood-borne infections (eg, hepatitis, HIV)

•        Cancer, because of the uncertainty about transmission of the disease

•        A history of whole blood donation within the past 56 days

Potential donors should be asked whether they have consumed any aspirin or aspirin-containing medications within the past 3 days. Although aspirin use does not render the donor ineligible, the platelets obtained would be dysfunctional and therefore not useful. Aspirin does not affect the RBCs or plasma obtained from the donor.

All donors are expected to meet the following minimal re-quirements:

•        Body weight should exceed 50 kg (110 pounds) for a stan-dard 450-mL donation. Donors weighing less than 50 kg do-nate proportionately less blood. People younger than 17 years of age are disqualified from donation.

•        The oral temperature should not exceed 37.5°C (99.6°F).

•        The pulse rate should be regular and between 50 and 100 beats per minute.

•        The systolic arterial pressure should be 90 to 180 mm Hg, and the diastolic pressure should be 50 to 100 mm Hg.

•        The hemoglobin level should be at least 12.5 g/dL for women and 13.5 g/dL for men.

Directed Donation

At times, friends and family of a patient wish to donate blood for that person. These blood donations are termed directed dona-tions. These donations are not any safer than those provided by random donors, because directed donors may not be as willing to identify themselves as having a history of any of the risk factors that disqualify a person from donating blood.

Standard Donation

Phlebotomy consists of venipuncture and blood withdrawal. Standard precautions are used. Donors are placed in a semi-recumbent position. The skin over the antecubital fossa is carefully cleansed with an antiseptic preparation, a tourniquet is applied, and venipuncture is performed. Withdrawal of 450 mL of blood usually takes less than 15 minutes. After the needle is removed, donors are asked to hold the involved arm straight up, and firm pressure is applied with sterile gauze for 2 or 3 minutes or until bleeding stops. A firm bandage is then applied. Donors remain recumbent until they feel able to sit up, usually within a few min-utes. Donors who experience weakness or faintness should rest for a longer period. Donors then receive food and fluids and are asked to remain another 15 minutes.

Donors are instructed to leave the dressing on and to avoid heavy lifting for several hours, to avoid smoking for 1 hour, to avoid drinking alcoholic beverages for 3 hours, to increase fluid intake for 2 days, and to eat a healthy meals for 2 weeks. Specimens from this donated blood are tested to detect in-fections and to identify the specific blood type (see later discussion).

Autologous Donation

A patient’s own blood may be collected for future transfusion; this method is useful for many elective surgeries where the po-tential need for transfusion is high (eg, orthopedic surgery). Pre-operative donations are ideally collected 4 to 6 weeks before surgery. Iron supplements are prescribed during this period to prevent depletion of iron stores. Occasionally, erythropoietin (epoetin-alfa [Epogen, Procrit]) is given to stimulate erythro-poiesis to ensure that the donor’s hematocrit remains high enough to be eligible for donation. Typically, 1 unit of blood is drawn each week; the number of units obtained varies with the type of surgical procedure to be performed (ie, the amount of blood anticipated to be transfused). Phlebotomies are not per-formed within 72 hours of surgery. Individual blood compo-nents can also be collected.

The primary advantage of autologous transfusions is the pre-vention of viral infections from another person’s blood. Other ad-vantages include safe transfusion for patients with a history of transfusion reactions, prevention of alloimmunization, and avoid-ance of complications in patients with alloantibodies. The policy of the American Red Cross requires autologous blood to be trans-fused only to the donor. If the blood is not required, it can be frozen until the donor needs it in the future (for up to 10 years). The blood is never returned to the general donor supply of blood products to be used by someone else.

The disadvantage of autologous donation is that it may be per-formed even when the likelihood that the anticipated procedure will necessitate a transfusion is small. Needless autologous dona-tion is expensive, takes time, and uses resources inappropriately. Moreover, in an emergency situation, the autologous units avail-able may be inadequate, and the patient may still require additional units from the general donor supply.

Contraindications to donation of blood for autologous transfusion are acute infection, severely debilitating chronic disease, hemoglobin level less than 11 g/dL, hematocrit less than 33%, unstable angina, and acute cardiovascular or cere-brovascular disease. A history of poorly controlled epilepsy may be considered a contraindication in some centers. Patients with cancer may donate for themselves.

Intraoperative Blood Salvage

This transfusion method provides replacement for patients who are unable to donate before surgery and for those undergoing vas-cular, orthopedic, or thoracic surgery. During a surgical proce-dure, blood lost into a sterile cavity (eg, hip joint) is suctioned into a cell-saver machine. The RBCs are washed, often with saline solution, and then returned to the patient as an intravenous in-fusion. Salvaged blood cannot be stored, because bacteria cannot be completely removed from the blood.

Hemodilution

This transfusion method is initiated before or after induction of anesthesia. About 1 or 2 units of blood are removed from the pa-tient through a venous or arterial line and simultaneously replaced with a colloid or crystalloid solution. The blood obtained is then reinfused after surgery (Kreimeier & Messmer, 2002). The advan-tage of this method is that the patient loses fewer RBCs during surgery, because the added intravenous solutions dilute the con-centration of RBCs and lower the hematocrit. Patients who are at risk for myocardial injury, however, should not be further stressed by hemodilution.

COMPLICATIONS OF BLOOD DONATION

Excessive bleeding at the donor’s venipuncture site is sometimes caused by a bleeding disorder in the donor but more often results from a technique error: laceration of the vein, excessive tourniquet pressure, or failure to apply enough pressure after the needle is withdrawn.

Fainting is common after blood donation and may be related to emotional factors, a vasovagal reaction, or prolonged fasting be-fore donation. Because of the loss of blood volume, hypotension and syncope may occur when the donor assumes an erect position. A donor who appears pale or complains of faintness should im-mediately lie down or sit with head lowered below the knees; he or she should be observed for another 30 minutes.

Anginal chest pain may be precipitated in patients with un-suspected coronary artery disease. Seizures can occur in donors with epilepsy, although the incidence is very low. Both angina and seizures require further medical evaluation.

Many people have the misconception that donating blood can cause AIDS and other infections. Potential donors need to be ed-ucated that the equipment used in donation is sterile, a closed sys-tem, and not reusable; they are at no risk for acquiring such infections from donating blood.

BLOOD PROCESSING

Samples of the unit of blood are always taken immediately after donation so that the blood can be typed and tested. Each do-nation is tested for antibodies to HIV 1 and 2, hepatitis B core antibody (anti-HBc), hepatitis C virus (HCV), and human T-cell lymphotropic virus, type I (anti-HTLV-I/II). The blood is also tested for hepatitis B surface antigen (HbsAG) and for syphilis. Negative reactions are required for the blood to be used, and each unit of blood is labeled to certify the results. A new testing method, using nucleic acid amplification testing (NAT), has increased the ability to detect the presence of HCV and HIV infection, because it directly tests for genomic nucleic acids of the virus itself, rather than for the presence of antibodies to the virus (Korman, Leparc & Benson, 2001). This testing significantly shortens the “window” of inability to detect HIV and HCV from a donated unit, further ensuring the safety of the blood. Blood is also screened for CMV; if it tests positive for CMV, it can still be used, except in recipients who are neg-ative for CMV and who are immunocompromised (eg, BMT or PBSCTrecipients).

Equally important to viral testing is accurate determination of the blood type. More than 200 antigens have been identified on the surface of RBC membranes. Of these, the most important for safe transfusion are the ABO and Rh systems. The ABO system identifies which sugars are present on the membrane of an indi-vidual’s RBCs: A, B, both A and B, or neither A nor B (type O). To prevent a significant reaction, the same type of RBCs should be transfused. Previously, it was thought that in an emergency sit-uation in which the patient’s blood type was not known, type O blood could be safely transfused. This practice is no longer ad-vised by the American Red Cross.

The Rh antigen (also called D) is present on the surface of RBCs in 85% of the population (Rh-positive). Those who lack the D antigen are called Rh-negative. RBCs are routinely tested for the D antigen as well as ABO. Patients should receive PRBCs with a compatible Rh type.

TRANSFUSION

Administration of blood and blood components requires knowl-edge of correct administration techniques and possible complica-tions. It is very important to be familiar with the agency’s policies and procedures for transfusion therapy. Methods for transfusing blood components are presented in Charts 33-16 and 33-17. Potential complications of transfusion follow.

Setting

Although most blood transfusions are performed in the acute care setting, patients with chronic transfusion requirements often can receive transfusions in other settings. Free-standing infusion cen-ters, ambulatory care clinics, a physician’s office, and even the home may be appropriate settings for transfusion. Typically, pa-tients who need chronic transfusions but are otherwise stable physically are appropriate candidates for outpatient therapy. Ver-ification and administration of the blood product are performed much as in a hospital setting. Although most blood products can be transfused in the outpatient setting, the home is typically lim-ited to transfusions of PRBCs and factor components (eg, factor VIII for patients with hemophilia)

Pretransfusion Assessment

PATIENT HISTORY

Patient history is an important component of the pretransfu-sion assessment to determine the history of previous transfu-sions as well as previous reactions to transfusion. The history should include the type of reaction, its manifestations, the in-terventions required, and whether any preventive interventions were used in subsequent transfusions. It is important to assess the number of pregnancies a woman has had, because an in-creased number can increase her risk for reaction due to anti-bodies developed from exposure to fetal circulation. Other concurrent health problems should also be noted, with careful attention to cardiac, pulmonary, and vascular disease.

PHYSICAL ASSESSMENT

A systematic physical assessment and measurement of baseline vital signs are important before transfusing any blood product. The res-piratory system should be assessed, including careful auscultation of the lungs and for use of accessory muscles. Cardiac system as-sessment should include careful inspection for any edema as well as other signs of cardiac failure (eg, jugular venous distention). The skin should be observed for rashes, petechiae, and ecchy-moses. The sclera should be examined for icterus. In the event of a possible transfusion reaction, a comparison of findings can help differentiate between types of reactions.

Patient Teaching

Reviewing the signs and symptoms of a potential transfusion re-action is crucial for patients who have not received a transfusion be-fore. Even for those patients who have received prior transfusions, a brief review of signs and symptoms of potential transfusion reac-tions is advised. Signs and symptoms of a possible reaction include fever, chills, respiratory distress, low back pain, nausea, pain at the intravenous site, or anything “unusual.” Although a thorough re-view is very important, it is also important to reassure the patient that the blood is carefully tested against the patient’s own blood (cross-matched) to diminish the likelihood of any untoward reac-tion. Such assurance can be extremely beneficial in allaying anxi-ety. Similarly, it can be useful to mention again the very low possibility of contracting HIV from the transfusion; this fear per-sists among many people.