Donor screening.

The primary goals of donor screening are to protect the recipient and safeguard the donor. These goals are accomplished through a variety of techniques, the most important of which is the donor medical history interview. This article reviews all elements of predonation donor screening, including donor education, the medical history interview, and the confidential unit exclusion procedure. Specific guidelines, including a proposed national uniform donor medical history questionnaire, are provided for all aspects of donor screening.

Creating a uniform donor medical history questionnaire.

Blood Centers of California, Inc. (BCC) is a consortium of 19 independent blood centers that collectively draw approximately 800,000 units of whole blood each year. Over the past several years, a committee of BCC, composed primarily of medical and nursing directors at member institutions, developed a Uniform Donor Medical History Questionnaire (UDMHQ). The UDMHQ, consisting of 42 questions, satisfies the requirements of the United States Food and Drug Administration, the State of California, the American Association of Blood Banks, and the special concerns of the members of BCC. The primary benefit of standardizing the donor medical history was an improvement in its content. Other, unproved benefits include delivering a consistent message to donors and potentially providing some legal protection to participating blood centers.

Impact of explicit questions about high-risk activities on donor attitudes and donor deferral patterns. Results in two community blood centers.

Concern about the ineffectiveness of indirect questioning of donors about participation in activities with a high-risk of exposure to human immunodeficiency virus (HIV) led our two community blood centers independently to begin direct and explicit questioning of donors about such activities. The impact of direct questioning was assessed via a donor attitude survey and by comparing the number of donors deferred for a positive response to a direct verbal question with the number previously deferred for a positive response to indirect questions. Our donor attitude survey indicated 90% donor approval of direct questioning, and analysis of donor deferral patterns indicated almost a five-fold increase in the number of donors deferred for participation in high-risk activities. Our experience documents the acceptability of direct questioning of donors and indicates that such questioning may well have a positive impact on blood safety.

Safety and effectiveness of predeposit autologous transfusions in preteen and adolescent children.

Although there is documentation in the literature of the safety and effectiveness of predeposit autologous transfusions among adult patients contemplating surgery, there are no comparable data for preteen and teenage children. We report our experience with 180 children between the ages of 8 and 18 years participating in a community blood center-based predeposit autologous transfusion program. Children as young as 8 years old and weighing as little as 27 kg predonated a prescribed amount of blood prior to elective orthopedic (169) or plastic (11) surgery. Only four children experienced a donor reaction; none of them was severe. No child was unable to donate the prescribed number of units. Eighty-eight percent of the children were able to supply their complete blood requirements, thus avoiding exposure to homologous blood. Our experience documents both the safety and effectiveness of predeposit autologous transfusions in preteen and adolescent children and should encourage existing predeposit autologous transfusion programs to extend participation to thousands of children for whom the opportunity to use their own blood is currently denied.

Neonatal Th activation.

A case is reported of a 1-month-old infant with bowel obstruction and suspected sepsis whose red cells were found to be Th activated during the course of evaluating weakened A antigen activity. Neither Th activation nor weakened A antigen activity was present on the red cells of either parent. The Th activation and the weak reactivity obtained with commercial anti-A reagents were unrelated.

Applications and limitations of hemapheresis.

Hemapheresis is the selective collection of any blood component. With the use of automated equipment, hemapheresis has become practical both for procuring specific components for transfusion and for removing specific components considered pathogenic factors in clinical disease. This review considers all aspects of hemapheresis, including its role in blood component procurement and its potential therapeutic applications. Attention is focused on the clinical indications for the use of apheresis-harvested components, and on the rationale for the effectiveness of therapeutic cytapheresis and plasma exchange.

Impact of cytomegalovirus testing on blood collection facilities.

561 consecutive O-negative blood donors were tested for the presence of cytomegalovirus (CMV) antibodies using an indirect fluorescent antibody test. 427 (76.1%) donors were CMV antibody positive, while 134 (23.9%) were seronegative. Males (75.1%) and females (78%) did not differ significantly in seropositivity. 17- to 20-year-old males had the lowest frequency of seropositivity (38.5%), though donors in this category represented only 4% of the 561 consecutive donors. The incidence of seropositivity increased consistently with age. Because of the difficulty in confidently generating sufficient CMV-seronegative donors, it is suggested that the exclusive use of frozen-thawed, or washed, leukocyte-poor blood, be evaluated as an alternative.

Evaluation of a low-ionic-strength solution-monospecific anti-IgG antiglobulin technique for donor antibody screening.

Three different techniques of antibody screening of donor bloods were sequentially evaluated. Group I (16,300 donors) was a standard saline-albumin-AHG technique utilizing polyvalent serum, including incubation at room temperature. In Group II (26,243 donors), incubations (including room temperature) were performed in LISS, and monovalent anti-IgG serum was used. For Group III (15,840 donors), the room temperature incubation was not used for the LISS-IgG method of Group II. The three methods were comparable in terms of detection of clinically significant antibodies, while in Group III the detection of clinically nonsignificant antibodies was eliminated. Cost analysis indicates that for a donor center processing approximately 50,000 units per year and willing to prepare its own LISS solutions, conversion to LISS-IgG could produce a savings of between $5,000 and $8,000 per year. LISS-IgG is thus a sensitive and economical technique highly recommended for the donor center committed to manual donor antibody screening.

Autologous transfusions. Experience in a community blood center.

Review of the clinical records of 103 patients participating in a community-blood-bank-sponsored autologous transfusion program confirmed the safety of autologous blood and the practically of such a community-centered program. There were no transfusion reactions, increased morbidity, or reports of hepatitis among the autologous donor-patients. A previously unobserved phenomenon was that surgeons tended to transfuse less blood to patients who had autologous blood available, rarely exceeding the number donated, although this varied from one to three units for similar surgery. Only eight of the 103 patients intentionally received a transfusion with homologous blood in addition to their autologously donated blood. Patients, their physicians, and the blood bank can all benefit substantially from such a program.

ASA-dipyridamole prophylaxis in elective total hip replacement.

A prospective, double-blind clinical study was performed to evaluate the combination of dipyridamole 225 mg/day and acetylsalicylic acid 1 gm/day prophylaxis of postoperative venous thromboembolism in elective total hip replacement. Patients were stratified according to age, and randomly assigned to receive drug or placebo. All patients were followed with 125I-labeled fibrinogen scanning for one week postoperatively, or until fully mobile. Venography was performed in 79/132 patients; in 36 patients the venogram was obtained to confirm a positive fibrinogen scan, in 43 patients an elective venogram was obtained on the seventh postoperative day to evaluate the operated thigh (a blind area for scanning). Thrombosis (by scan or venogram) was found in 17/68 (25%) in the control group, and in 23/64 (36%) in the treated group. Overall incidence was 40/132 (30%). Correlation of scan with venography was 90%. There were no clinically significant pulmonary emboli in either group. The combination of acetylsalicylic acid (ASA) and dipyridamole as given in this study is not effective prophylaxis in elective total hip replacement.

Clinical value of washed-platelet concentrates in patients with non-hemolytic transfusion reactions.

In patients with severe allergic reactions to plasma proteins it is possible to observe such reactions to even the small quantity of plasma contained in platelet concentrates. A platelet washing solution was designed, and platelet concentrates for four such patients were washed before infusion. Transfusion reactions were completely eliminated by the washing procedure. Platelet recovery was equivalent to that of unwashed platelets, and hemostatic effectiveness of the infused platelet concentrates was evidenced by abrupt cessation of bleeding episodes, including purpura and hematuria. Platelet washing represents a valuable, rapid and simple approach to the problem patient with thrombocytopenia and severe reactions to plasma proteins.