- Last Update On : 2012-12-23
Autologous donor programs allow a patient to donate blood for their own use. Autologous transfusion indicates that the blood donor and transfusion recipient are identical. This is the safest possible transfusion a patient can receive and is an excellent option for patients facing elective surgery.
Autologous collections should be used as part of a comprehensive strategy of blood conservation that includes careful attention to the proper indications for transfusion, acceptance of normovolemic anemia and avoidance of excessive blood sampling for diagnostic testing. Autologous donation is a safe procedure, even for very young or elderly patients. The three types of autologous collections are preoperative collection, hemodilution, and intraoperative or postoperative blood salvage.
Collection of autologous blood prior to surgery peaked in 1992 at 8% of the United States blood supply and has declined significantly thereafter. The decline has been largely attributed to the increasing safety of the volunteer allogeneic blood supply. Autologous collections have been used most successfully for orthopedic and urologic surgery. Autologous blood is also beneficial for the patient with alloantibodies to multiple high incidence antigens. Autologous blood should not be collected for surgical or obstetrical procedures, which seldom require transfusion. The ideal patient for autologous donation is one who:
- Has 2 or more weeks before surgery
- Is likely to require blood transfusion during or after surgery
- Has a hemoglobin level greater than 11 g/dL (hematocrit 33%)
Because of the special medical value of autologous collection, blood donor criteria have been relaxed compared to allogeneic donation. The medical director may adjust the hemoglobin criterion higher or lower depending on the clinical circumstances of the donor. There are no age or weight limits. Pediatric donors require more preparation, attention and parental participation.
Some individuals may not be good candidates for autologous donation. Patients taking antihypertensive medications such as beta-blockers may not be able to maintain blood pressure following multiple donations. Autologous blood donation by pregnant women is beneficial only in selected cases such as alloantibodies to multiple or high-incidence antigens, placenta previa, high-risk pregnancy, and bleeding disorders. Patients with severe aortic stenosis, unstable angina, recent myocardial infarction, cyanotic heart disease, cerebrovascular accident, uncontrolled hypertension, active seizure disorder, and bacteremia are usually considered at too high a risk for autologous donation.In addition to general information about blood donation, autologous donors need information about additional fees charged for autologous services. Because preoperative autologous units require special handling and tracking, most facilities charge an additional autologous fee. Many of these additional charges are not covered by health insurance and are billed to the patient. Medicare covers autologous donation, but some major health insurers do not. Patients also need to be informed that they are responsible for charges even if the unit is not used.
As soon as the surgery date has been scheduled, the attending physician prescribes the number of units to be donated. The patient's physician should request autologous blood collection in writing and the collection site should retain the written order. Requests should include patient's name, the number of units, component, anticipated surgical date, surgical procedure, and the physician's signature.
In order for an autologous program to be effective, a sufficient number of units should be drawn from these patients to minimize the possibility of exposure to allogeneic blood. The underlying principles of autologous blood donation are that red blood cells are donated before elective surgery and sufficient time is allowed for the bone marrow to regenerate all of the donated red cell mass, thereby providing additional red cell volume at the time of surgery. In order to insure that autologous donation is beneficial the following recommendations should be considered:
- Autologous donation should not be ordered unless transfusion is likely.
- Single unit autologous donations should be avoided.
- More than 2 weeks should be allowed between the last donation and surgery.
A schedule for donations should be established with the donor. Donations can be made at 72-hour intervals, but one week is preferred. The last donation needs to occur at least one week before the scheduled surgery to allow time for adequate volume repletion prior to general anesthesia and for all testing of the donated units to be completed.
Each unit of blood donated decreases a patient's hemoglobin by 1g/dL. When a donation is made 2 to 3 weeks before surgery, less than one fourth of the blood loss is regenerated. In order to maximize the benefit of autologous transfusions, sufficient time must be allowed for regenerative erythropoiesis to occur. If not, autologous donation may decrease the patient's preoperative hemoglobin level and place them at higher risk of leaving the hospital more anemic than if they had not donated. Alternatively, the patient may require an allogeneic transfusion.
Iron therapy should be started immediately. Ideally, the requesting physician prescribes supplemental iron even before the first donation to allow maximum time for iron intake. Iron deficiency is frequently the limiting factor for individuals seeking to donate multiple units of blood.
All autologous units must be tested for ABO and Rh. If a unit is to be transfused at a facility other than the collecting facility, it must be tested for all disease markers required by FDA. If a donor tests repeatedly reactive for any marker, then a biohazard label is placed on all of their autologous units. Some blood centers leukocyte reduce all autologous and directed donor RBC units.
Indications for transfusion of autologous units are similar to allogeneic transfusions, and autologous units should not be transfused indiscriminately to an asymptomatic patient merely because it is available. Although autologous blood is the safest form of blood transfusion, adverse reactions can occur. Any transfusion may result in fluid overload. Clerical identification errors can occur, leading to the transfusion of incompatible blood to one and maybe two patients. Bacterial contamination can lead to septic shock.
Some anesthesiologists hemodilute their patients immediately before surgery. While preparing a patient for surgery, they may withdraw 1 to 2 units of fresh whole blood and replace this volume with IV fluids. The units of blood must be labeled properly and stored at room temperature. They must be reinfused to the patient within 8 hours after collection to prevent deterioration of platelets and coagulation factors. No additional testing is necessary.
This protocol reduces the need to use someone else's blood for transfusion. It also reduces the total red cell mass lost during surgery since the blood is diluted with IV fluids. However, only a limited number of units can be collected this way and not all patients can tolerate such changes in blood volume.