[Adequacy of blood component transfusion according to previously established criteria]. / Adecuación de la transfusión de hemoderivados a criterios previamente establecidos.

PURPOSE: Transfusion is not devoid of adverse effects; therefore every transfusional procedure must be indicated correctly. With this in mind in 1991 transfusion guidelines were published by our Hospital Transfusion Committee. Four years later, a retrospective audit was performed. MATERIAL AND METHODS: We have evaluated all blood component orders (order is a transfusion request) during one month, classifying them as appropriate or inappropriate according to the transfusion guidelines. The evaluation was performed 24 hours after transfusion. The results obtained were compared with the ones obtained before the published transfusion guidelines. RESULTS: 481 transfusion orders were studied. 87 percent (420/481) were considered appropriate according to the transfusion guidelines. These 481 orders referred to the transfusion of 1178 units to 293 patients. 12 percent of the transfused units was considered as inappropriate. 16 percent of the patients (48/239) had at least on inappropriate transfusion procedure. The comparison with the data obtained in 1991 showed a significant increase of the appropriate transfusion orders (74 versus 87 percent). The use of fresh frozen plasma showed the greatest incidence in inappropriate use, mainly in haemorrhagic disorders without factor deficit. The patients with haemoglobin levels between 70 and 100 g/L without signs of hypoxia were the most important cause of inappropriate use of red cell concentrates. And the patients with platelet levels > 20 x 10(9)/L were the major cause of inappropriate use of platelet concentrates. CONCLUSION: Transfusion guidelines knowledge improves the use of blood components.

[Thrombophilia in patients with venous thromboembolism]. / Trombofilia en pacientes con tromboembolismo venoso.

PURPOSE: To assess the incidence of congenital and acquired thrombophilia and to analyse the clinical characteristics of a group of patients with high risk criteria for thrombophilia. PATIENTS AND METHODS: Two hundred and eighty-five consecutive patients seen at the anticoagulant outpatient clinic of the Oviedo Central Hospital between 1987 and 1993 were evaluated. The patients had to meet one or more of the following: 1) venous thrombosis (VT) under 45 years of age; 2) repeat VT; 3) family history of VT; 4) unusual VT location (mesenteric, brain, etc.). The study was performed 4 to 7 months after the first acute episode and at least one month after suppression of anti-vitamin K treatment. The following test were carried out: blood cell counts, basic coagulation tests (APTT, PT, TT, RT and fibrinogen), lupus-like anticoagulant detection, with and without platelet extract, diluted tissular thromboplastin inhibition test, antibodies, anticardiolipin, liver and kidney functional screen, cholesterol, HDL, triglycerides and glycaemia. The venous occlusion test after 20-minute stasis was used for the global fibrinolysis study. The statistical evaluation was performed with the SPSS programme. RESULTS: Biologic alterations were present in 98 patients (35%), 12% corresponding to congenital thrombophilia and 23% to acquired thrombophilia. The study was normal in 187 patients (65%). Of the patients with congenital thrombophilia, 4.9% had protein C (PC) deficit, 3.4% protein S (PS) deficit, and 2.4% antithrombin III (AT-III) deficit. Of the patients with acquired thrombophilia, 4.5% had antiphospholipid antibodies and 18% had impaired fibrinolysis. Of all the data analysed, the patient history was found of scarce predictive value as to the risk for thrombophilia. Significant differences were found for family history of VT (p < 0.0005) and for the association of more than one criteria for inclusion (p < 0.001). CONCLUSIONS: No conclusions could be drawn from this study regarding the prophylactic attitude in patients with congenital abnormalities or anti-phospholipid antibodies. It is recommended to assess in such patients PC, PS and AT-III activities.

[Alloimmunization in polytransfused patients. Usefulness of selecting erythrocytes compatible with antigens different from ABO and D]. / Aloinmunización en pacientes politransfundidos. Utilidad de seleccionar hematíes compatibles para antígenos differentes al ABO y D.

PURPOSE: Antibody formation against red blood cells' antigen is a very important complication due to transfusions, and it can make the following transfusions difficult. To avoid this, it has been proposed giving identical red blood cells for the antigens more frequently involved in sensitizations. To evaluate this fact, we have accomplished a study with the transfused patients in our Hospital since 1990. MATERIAL AND METHODS: 10,308 transfused patients in the Hospital Nitra. Sra. de Covadonga (Oviedo), between January 1990 and March 1994, were studied. The patients have been included in two groups: The first one was constituted by 4,226 patients from the Haematology and the Nephrology Departments, who received red blood cells units compatible with ABO and CcDEe antigens. The second group was formed by the remainding patients transfused with red blood cells compatible only with ABO and D antigens. RESULTS: All 165 antibodies were detected in 132 patients, which means an incidence of 1.3 percent. In 63 cases, antibodies were present before the first transfusion. In the remaining patients, an allosentitization of 0.2 percent in group 1 and 1 percent in group 2 (p < 0.0001) was shown. This difference cannot be explained only for transfusing red blood cells with the same Rh phenotype in the group 1, because a lower immune response had persisted when we analyzed the other antibodies. More than 70 percent of antibodies appeared before the 10th transfusion. DISCUSSION: A lower sensitization exist in the patients of group 1. This seems to be caused by a state of immunosuppression for their disease or their treatments. However, in some patients, the risk of allosensitization persists, so we think it is a good practice to transfuse red blood cells without the most immunogenic antigens in haematological and nephrological patients who already have one antibody.