**4. Blood bank transfusion for urgent procedures**

In transfusion practice safety requires that allogeneic blood be cross-matched with the recipient's blood; the test takes about 60 min. In emergency live-saving procedures or unexpected massive blood losses, it is possible to perform transfusion after a minor crossmatch test or without it, or to administer ABO/Rh compatible blood or O-type blood.

If immediate transfusion is necessary and the recipient's blood group is not known, then it is justified to use uncrossmatched type-O packed red blood cells (UORBC) that lack A and B surface antigens. For potential expecting mothers, the UORBCs should always be Rh negative to avoid sensibilisation and damage to the foetus in case the mother is Rh-negative. The patients should be given no more that 10 UORBC units and subsequently receive transfusion with standard blood testing.

If there is time to do blood group testing, ABO-compatible PRBCs are administered without a cross-match test.

In about 3 % of the human population, serum contains anti-erythrocyte antibodies which in a great majority (85 %) are of one type only. The magnitude of risk for a post-transfusion reaction is equal to this frequency, but the results from trauma centres show that it is in fact

Thrombocyte concentrates are transfusion products obtained from full blood by centrifugation. A pooled-donor TC is derived from four to six blood donors to give one therapeutic thrombocyte transfusion unit for an adult patient. A single-donor TC is obtained by apheresis using a platelet separator. Both products contain over 200 x 109 platelets in a 250- to 350-ml plasma volume. The TCs are stored in special storage bags allowing gas exchange on a shaking apparatus at 20-24°C for up to 5 days. In TC infusion, the ABO-blood group/Rhesus factor of the patient must be respected. If a TC of the required blood group is not available, thrombocytes suspended in plasma ABO compatible with the recipient's erythrocytes can be administered. Other options include a TC from an O-blood group donor who has a low titre of anti-A and anti-B agglutinins or the use of platelets resuspended in a plasma substitute. An Rh-positive donor can receive a TC from an Rh-negative donor, but

In major surgical procedures, it is recommended to maintain the platelet count above 50 x109/l because of a risk for microvascular bleeding. In cardiac surgery with cardiopulmonary bypass, where platelet-related defects are the most frequent cause of haemostatic abnormality, the recommended platelet count is 50-100 x109/l [42]. An increase above this level is justified only in severe platelet dysfunction. Platelet concentrates should not be administered routinely in cardiac surgery because it has been associated with increase in multi-organ failure and death [43, 44]. One therapeutic TC unit in an adult patient increases the platelet count by 10-20 x109/l. The therapeutic efficacy is assessed by clinical signs (decrease of bleeding) or laboratory evidence of increased platelet

An insufficient increase in platelet counts can be due to reasons such as low TC quality or higher requirements for platelet counts in patients with trauma or disseminated intravascular coagulation. However, the most serious cause involves immune destruction of platelets by alloantibodies or autoantibodies, and this is suspected when other causes are

In transfusion practice safety requires that allogeneic blood be cross-matched with the recipient's blood; the test takes about 60 min. In emergency live-saving procedures or unexpected massive blood losses, it is possible to perform transfusion after a minor crossmatch test or without it, or to administer ABO/Rh compatible blood or O-type blood. If immediate transfusion is necessary and the recipient's blood group is not known, then it is justified to use uncrossmatched type-O packed red blood cells (UORBC) that lack A and B surface antigens. For potential expecting mothers, the UORBCs should always be Rh negative to avoid sensibilisation and damage to the foetus in case the mother is Rh-negative. The patients should be given no more that 10 UORBC units and subsequently receive

If there is time to do blood group testing, ABO-compatible PRBCs are administered without

In about 3 % of the human population, serum contains anti-erythrocyte antibodies which in a great majority (85 %) are of one type only. The magnitude of risk for a post-transfusion reaction is equal to this frequency, but the results from trauma centres show that it is in fact

**4. Blood bank transfusion for urgent procedures** 

transfusion with standard blood testing.

a cross-match test.

**3.3 Thrombocyte concentrate (TC)** 

not vice versa [41].

counts.

excluded.

even lower. Gervin et al. have recorded no reaction in 875 transfusions without crossmatching in 160 patients [45].

When more time is available (about 20 min), a minor cross-match test is done which reveals most of the donor uncommon anti-erythrocyte antibodies. It fails to detect abnormal antibodies in only 0.04% of the patients and this makes the probability of post-transfusion reaction extremely low.

It can be concluded that, seen in a historical perspective, the needs for blood transfusion in cardiac surgery have varied, but are still high. With advances in cardiac surgery during the last 50 years, a significant decrease was recorded in the average blood product requirement per patient, but this trend has recently had declining tendency. The reason lies in increasing numbers of reoperations and surgery on very old and polymorbid patients with preoperative anemia. Our conclusion suggests a multi-modality blood-saving strategy ranging from patient pre-operative preparation, over surgical and autotransfusion techniques and drug intervention to homeostatic maintenance. So far this strategy has brought about results in the form of an increasing number of operations not requiring transfusion; this is currently more than 50 % of all cardiac surgery procedures. Despite its risks, allogenic blood transfusion still remains an important supportive and life-saving measure in ultimate situations.
