The Administration of Blood Products

The administration of blood products requires proper compliance with a written procedure, the important elements of which are outlined in Table 8.1.

First is proper recipient identification and ensuring the compatibility of the product. For red cell transfusions, both ABO and Rhesus compatibility should be ascertained. If there are any questions at this point they should be immediately addressed to the blood bank for clarification. Under certain circumstances, non-identical ABO blood will be administered to patients, for example, blood group O red cells to non-O recipients or blood group A red cells to AB recipients. In addition, Rhesus negative products may be safely transfused to Rhesus positive patients, and on occasion, when Rhesus negative shortages exists, Rhesus positive units may knowingly be transfused to certain groups of Rhesus negative patients. When blood is dispensed from a blood bank, a record is attached to the bag. This record contains information identifying the blood in the container (ABO, Rh and unit #) and information identifying the intended recipient (name, medical record #, other identifiers). This record, therefore, links the suitability of the blood in the container with the recipient. Confirming the correctness of this information at the bedside may be the last opportunity to avert a severe hemolytic reaction.

Inspection of the blood bag for leaks and the general appearance of the product is important to detect contamination of the product with bacteria or other substances. The administration set should have an in-line filter; and routine intravenous infusion sets for fluids are not acceptable. This filter removes particles with an average size of between 170-260 microns (|i). Blood administrations sets commonly have both a drip chamber and a filter chamber, the former allowing the calculation of the rate of administration of blood and the filter chamber ensuring the removal of debris which may have accumulated during storage. The drip chamber allows 10 and 20 drops per minute (10 drops = 1 ml) and the transfusionist can calculate the rate of transfusion and likely duration.

Under some circumstances, the rate of blood transfusion can be increased by the use of either a pressure cuff or an electromechanical device, such as a pump. Although large pressures may be applied with a pressure device, this is not known to be harmful to either red blood cells or platelets. The major concern with pressure cuff devices is either bag rupture or the potential for air embolism. When pumps are used routinely for red cell transfusion, the manufacturer should have information on file that hemolysis of red cells does not occur during normal operation of the device. Pumps can also be used to transfuse platelets, particularly in a pediatric setting. In general, these pumps have not been shown to alter platelet function. Thus, use of electromechanical devices is acceptable practice for the transfusion of blood products. Pumps also allow a greater degree of control of the rate of transfusion than might be possible by visual counting of the number of drops.

Table 8.1. Important steps in blood administration

1. Ensure proper recipient identification, ABO compatibility and Rhesus suitability of the product.

2. Inspection of the blood bag for product appearance and any leaks.

3. Ensure that the administration set has an in-line filter.

4. Do not add to or infuse blood with any fluid or medication, other than 0.9% saline.

5. If a mechanical pump is used routinely, information regarding lack of hemolysis is appropriate.

6. If blood warmers are used, these should be quality controlled at least semi-annually, or more often, depending on use.

7. Vital signs should be taken before the transfusion.

8. The initial rate of transfusion should be slow (about 1-2 ml/minute) to detect and respond to sudden severe unexpected events, i.e., acute hemolysis, bacterial sepsis, or anaphylaxis.

9. The duration of a red cell transfusion is optimally 11/2 hours, but should not exceed 4 hours.

10. Vital signs should be taken after the transfusion or at any time if a reaction occurs.

11. If a reaction occurs, stop the transfusion, maintain an open IV line with saline and evaluate (Chapter 32).

12. Avoid sampling from or above the IV site during, or immediately after, the transfusion.

13. If the transfusion is uneventful, discard the empty bag in a manner consistent with the disposal of biologic waste.

Blood is sometimes transfused using blood warmers. It is rarely necessary to transfuse red cells using a blood warmer when the duration of the transfusion is in excess of 1 hour, the only possible exception being recipients with cold agglutinins. Platelets are stored at room temperature, and other products such as plasma and cryoprecipitate are thawed at 37°C. However, blood warmers are used in the operating room, or in patients with cold agglutinins, or in massive trauma when blood needs to be transfused rapidly, (50-100 ml/min). Particular attention needs to be paid to the quality control of these blood warmers, at least on a quarterly basis, if in frequent use, particularly that excessive temperatures do not occur. When red cells (preferably less than 42°C) are exposed to temperatures higher than 42°C, hemolysis may occur.

With red cells, the initial rate of transfusion should be set at 1-2 ml/min, for approximately 15 minutes. This is to detect and respond to any sudden or unexpected clinical events such as acute hemolytic reactions, bacterial sepsis or anaphylaxis. Although it is not uncommon practice to measure vital signs at this time, simple questioning or observation of the patient as to whether they are experiencing any discomfort is adequate. After this time, the rate of transfusion can be increased in order to complete the transfusion over a period of 1-2 hours. In some institutions, it is practice to routinely transfuse a unit of blood over a period of 4 hours. This is, of course, acceptable, but it is not required, and may be inconvenient. For other blood products, such as plasma or cryoprecipitate, the rate of infusion should be set to meet the desired clinical objective and be consistent with the patient's tolerance for increased intravascular volume. Platelet transfusions are often administered more rapidly, over a period of 15-30 minutes. Such rapid platelet transfusions can occasionally result in the occurrence of febrile or urti-carial reactions in the patient. The occurrence of fever in association with platelet transfusion should keep the transfusion alert to the possibility of bacterial contamination. Therefore, close observation is always appropriate for platelet transfusions whenever such rapid infusions are performed. If a reaction occurs, the critical event is to stop the transfusion, maintain the intravenous line open with saline and evaluate the clinical situation (see Chapter 32). Vital signs should always be taken immediately if a reaction occurs and are required to be taken routinely in the U.S. after completion of an uneventful transfusion. If the transfusion is uneventful, the empty bag may be discarded immediately. However, some institutions retain the bag for a period of 6-8 hours, since rarely a reaction can occur up to several hours after completion of the transfusion.

No fluid or medication other than 0.9% saline should be added or connected in any way to the administration sets in which human blood products are being transfused. The use of solutions in surgery such as Ringers lactate, which contains calcium, may cause small clots to form and other fluids and 5% dextrose can result in hemolysis. In addition, sampling should be avoided from the IV site used for transfusion in the period during and immediately after a transfusion. Red cell products have an Hct of 55-60 and could cause an erroneous blood count result. Stored blood contains high concentrations of potassium (30-50 mEq/L) and glucose (300-500 mg/dl) which may cause confusion in the interpretation of chemistry tests.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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Responses

  • ilkka uppa
    Can i use a pressure cuff when transfusing red cells?
    7 years ago

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