Red blood cell transfusion practices in the neonate

Premature infants, particularly those with a birthweight of less than 1.0 kilograms and respiratory disease, frequently require red blood cell (RBC) transfusions. The major mechanisms causing the anemia of prematurity are phlebotomy blood losses and a diminished ability to mount an effective erythropoietin response to the falling RBC mass. Although the indications for RBC transfusions have not been defined by controlled clinical trials, usual transfusion practices are discussed. In addition, the potential role for recombinant erythropoietin in the treatment of anemia of prematurity is analyzed critically. Finally, an overall approach to managing the anemia of prematurity is provided.

A method to collect, store and issue multiple aliquots of packed red blood cells for neonatal transfusions

Premature neonates require multiple red blood cell (RBC) transfusions. Single-donor programs have been proposed as a means to limit donor exposures, but methods must be developed to collect, store long-term and issue multiple aliquots of RBCs from a single donor. We evaluated a method by which RBCs could be collected, leukocyte depleted, repeatedly centrifuged for issuance as multiple small aliquots of high-hematocrit cells and then resuspended for continued storage throughout 42 days. The quality of RBCs handled by the method were compared to cells stored in standard fashion. Leakage of intracellular potassium, hemoglobin and lactic dehydrogenase into the extracellular fluid from RBCs processed by either method was comparable-indicating maintenance of RBC integrity. Multiple cultures, taken throughout the period of storage, were sterile to document that extensive handling did not introduce contamination. This new method appears promising as a means to provide RBCs for neonates.

Clinical perspectives of platelet transfusions: defining the optimal dose

To halt bleeding in patients with severe thrombocytopenia due to bone marrow failure, it is desirable to achieve a post-transfusion blood platelet count of 40 x 10(9)/L by platelet transfusions. Based on calculations of corrected count increments, each 1 x 10(11) platelets transfused will increase the blood platelet count approximately 10 x 10(9)/L per each square meter of patient body surface area. Thus, the post-transfusion blood platelet count will be approximately 20 x 10(9)/L following transfusion of 3 x 10(11) platelets to a 5 foot, 8 inch patient weighing 170 pounds (2.0 m2), who is bleeding because of a pre-transfusion platelet count of 5 x 10(9)/L. The post-transfusion platelet count likely will be even lower in sick patients (sepsis, amphotericin B plus antibiotic therapy, splenomegaly, graft-vs.-host disease, etc.) or if platelets are lost from the unit by leukofiltration before transfusion. Although a dose of 3 x 10(11) platelets is acceptable, in a regulatory sense for product quality, it is inadequate to control bleeding in most thrombocytopenic adult patients. Adjusting dose for body size, bleeding patients with pre-transfusion blood platelet of < 10 x 10(9)/L and weighing > 120 pounds should receive approximately 6 x 10(11) platelets, those weighing 30 to 120 pounds should receive 3 x 10(11) platelets, and infants weighing < 30 pounds (15 kg) should receive 5-10 ml/kg of platelet concentrate.

Efficacy and safety of plateletpheresis by donors with low-normal platelet counts

Our practice is to defer donors with blood platelet (PLT) counts of < 180 x 10(9)/L because PLT yields are low, when compared to PLT units collected from donors with higher counts. In an attempt to minimize deferral, we determined whether 33 donors, who repeatedly demonstrated low-normal PLT counts (150-180 x 10(9)/L) on multiple occasions during the prestudy period. might safely donate satisfactory apheresis PLT units simply by extending the apheresis collection time by 20 min (men) and 40 min (women). Repeat plateletpheresis procedures were scheduled at > or = 28-day intervals. The mean PLT yield (N = 92) was 5.8 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. Although donors entered the study only after they had repeatedly exhibited predonation PLT counts of < 180 x 10(9)/L, PLT counts were not always below this level at the time of study collections. However, analyzing only donations with true predonation PLT counts of < 180 x 10(9)/L (N = 35), the mean PLT yield was excellent-5.4 x 10(11) with 97% of units containing > or = 4.0 x 10(11) PLTs. The average fall in donor blood PLT counts (pre-vs. postdonation) was 36%, with only ten of 99 postdonation counts being < 100 x 10(9)/L; the lowest was 69 x 10(9)/L. Thus, extending the apheresis collection time permitted donors who in the past were routinely deferred because of low PLT counts to safely donate satisfactory PLT units.

Clinical perspectives of granulocyte transfusions: efficacy to date

The literature pertaining to the use of granulocyte transfusions as treatment for progressive bacterial, yeast, and fungal infections in severely neutropenic patients is reviewed. Efficacy in treating bacterial infections that are unresponsive to antimicrobial therapy is well established--especially if bone marrow failure does not recover rapidly and neutropenia is persistent. The role of therapeutic granulocyte transfusions for yeast and fungal infections has potential merit, but current data are incomplete and findings are inconsistent. The possibility of greater success has been raised by use of recombinant granulocyte colony stimulating factor to greatly increase the yield of neutrophils collected from normal donors.

Neonatal anemia: pathophysiology and treatment

All neonates experience a decline in circulating red blood cell (RBC) mass due to diminished erythropoietin (EPO) levels. This effect is more pronounced in small, premature infants and can lead to severe anemia and need for RBC transfusions--particularly, if repeated phlebotomy is required to monitor acutely-ill neonates. Although optimal RBC transfusion therapy has been a long-term challenge for neonatologists, the emergence of recombinant EPO as promising therapy for neonatal anemia is the major issue for 1994. Accordingly, this report for the 12th International Convocation on Immunology (Transfusion Immunology and Medicine) will focus on this aspect of neonatal transfusion medicine. Although several controlled trials to evaluate EPO as therapy have been completed, definitive answers to all questions regarding efficacy and possible toxicity have not been provided. However, therapy with EPO plus iron and adequate nutrition is likely to be proven effective for the relatively late anemia of stable prematures. To date, EPO has not been shown, convincingly, to alleviate the anemia present early in the life of acutely-ill, premature infants.

Granulocyte transfusion therapy

Although the efficacy of therapeutic granulocyte transfusions as treatment for progressive infections in severely neutropenic patients is supported by the medical literature, this form of therapy is not widely accepted because it has been extremely difficult to transfuse an adequate dose of compatible granulocytes. Recently, the possibility has been raised to greatly increase the number of granulocytes collected by stimulating normal donors with recombinant granulocyte colony-stimulating factor. Accordingly, it is reasonable to reassess the possible role for granulocyte transfusions as therapy for progressive bacterial, yeast, and fungal infections.

Physician recommendation as the key factor in patients' decisions to participate in preoperative autologous blood donation programs: Preoperative Autologous Blood Donation Study Group

To determine whether the physician or patient had initiated the discussion regarding preoperative autologous blood donation (PABD) and to assess the relative importance of the physician's recommendation in patients' decision to donate, responses were obtained from 254 of 409 patients (62%) who had donated preoperatively during the 3 study months. Nearly all (96%) strongly agreed they would donate again for themselves and nearly all (94%) strongly agreed they would recommend PABD to others. Patients initiated the discussion about PABD 23% of the time, while 71% indicated strong surgeon input. The remaining respondents said their surgeon had "mentioned it, but said it was up to me." The importance of avoiding transfusion reactions was rated significantly greater among those whose surgeons had initiated the discussion, as was the relative weight of the surgeon's recommendation. The desire to alleviate the blood shortage was rated much less important among patients who had initiated the discussion themselves.

Recombinant human erythropoietin vs transfusions in the treatment of anemia of prematurity. A cost-benefit analysis

OBJECTIVE

To evaluate the costs relative to the benefits of using recombinant human erythropoietin (rHuEPO) therapy as an alternative to red blood cell (RBC) transfusions in infants with anemia of prematurity.

DESIGN

A cost-benefit analysis of rHuEPO therapy was performed based on its use in very-low-birth-weight premature infants.

SETTING AND PATIENTS

Data were drawn from published studies or were provided by the University of Iowa Hospitals and Clinics, Iowa City.

MAIN OUTCOME MEASURES

Costs and benefits were analyzed as a comparison of incurred costs to averted costs. Incurred and averted costs of rHuEPO therapy and RBC transfusions included direct product costs and estimates of costs of adverse events. The analysis was viewed in terms of net savings. Sensitivity analysis was performed.

RESULTS

The base case analysis yielded a net loss of $299.48 per infant. A 54% reduction in the direct product costs of rHuEPO therapy yielded a break-even point. No other variations in the sensitivity analysis resulted in a net savings.

CONCLUSION

Using assumptions based on the current state of clinical research, it appears that routine use of rHuEPO with supplemental RBC transfusions would not generate any cost savings as an alternative to RBC transfusions alone. As further evidence is compiled on the efficacy of rHuEPO therapy in very-low-birth-weight premature infants, the true costs may be better established.

Concurrent comparison of the safety of paid cytapheresis and volunteer whole-blood donors

BACKGROUND

Historically, paid blood donors were found to transmit hepatitis at higher rates than volunteers. In those older studies, paid donors frequently were recruited from prisons or slum areas--a finding consistent with the belief that monetary payment in itself did not necessarily lead to the high-risk status of commercial blood. Instead, it was the population base from which the donors were recruited that was important.

STUDY DESIGN AND METHODS

Today, cytapheresis donors are in great demand. Because payment is one incentive that might entice donors to undertake the increased commitment of repeated cytapheresis donation, the results were studied of infectious disease history and laboratory testing performed concurrently in 917 volunteer whole-blood donors and 1240 paid cytapheresis donors, who were enrolled in distinct programs at the DeGowin Blood Center from October 7, 1987, through November 30, 1990.

RESULTS

When first, repeat, and overall donations made by these donors were evaluated separately, paid cytapheresis donors were found to exhibit no increase in infectious disease history or test results beyond those of volunteer whole-blood donors.

CONCLUSION

Thus, paid cytapheresis donors, when managed within a formal program, should not necessarily be presumed to be more dangerous than volunteers, from an infectious disease aspect. However, definitive proof of safety (comparison of transfusion-transmitted infection rates in two groups of patients receiving blood components exclusively from either paid cytapheresis or volunteer donors) was not pursued by long-term follow-up studies.

A statistical model for estimating donor postdonation platelet counts after plateletpheresis

BACKGROUND

To avoid the need, in serial apheresis donors, either to delay plateletpheresis until a predonation platelet count is completed or to obtain a postdonation count after each procedure, a statistical model has been developed to predict the postdonation platelet count from the donor predonation platelet count, weight, and hematocrit.

STUDY DESIGN AND METHODS

Predonation and postdonation platelet counts were measured in two groups of approximately 100 consecutive donors (Group A to test the model and Group B to validate it), and the postdonation counts were calculated with the model. Using stepwise multiple linear regression from donor data, estimated postdonation platelet counts were found to be comparable to the postdonation platelet counts actually measured.

RESULTS

Estimated postdonation platelet counts x 10(9) per L (mean +/- SD) for each group, respectively, were Group A, 195 +/- 35, versus actual platelet counts of 195 +/- 39 (p = 0.43), and Group B, 183 +/- 36, versus actual platelet counts of 189 +/- 34 (p = 0.14). Sensitivity and specificity, respectively, were Group A, 57 and 99 percent and Group B, 62 and 99 percent.

CONCLUSION

For most serial apheresis donors, application of this predictor model should preclude the need to obtain an extra postdonation platelet count.

Preoperative autologous donation: surgery clinic staff knowledge/attitudes. Preoperative Autologous Blood Donation Study Group

Preoperative autologous blood donation (PABD) is both under- and overused. Although the decision to order PABD lies with the surgeon, it is quite likely that other surgery clinic personnel influence patient acceptance and enrollment into PABD programs. Accordingly, we measured knowledge, attitudes, and the referral practice of clinic personnel pertaining to PABD. We administered a questionnaire to 102 nurses and 33 clerks working in surgery clinics at three university medical centers--one center in an area with a high incidence of AIDS and two centers in areas of low incidence of AIDS. Knowledge of PABD was poor when assessed by six questions. Only 6% each of nurses and clerks answered all questions correctly; 55% of nurses and 54% clerks missed three or more of the six questions. Surprisingly, no differences (P > .05) in knowledge deficits were noted when personnel from high and low AIDS areas were compared--indicating an overall need for education about PABD. In general, attitudes about PABD were positive, as most respondents (63%) gave favorable answers. Clinic personnel from the high AIDS area had even more favorable attitudes (P = .02). Because of these favorable attitudes, it seems likely that educational programs dealing with PABD would be readily accepted by clinic personnel. Greater knowledge should enhance the effectiveness of clinic staff in identifying, counseling, and referring eligible patients for this service.

Treatment of severe cardiac allograft rejection with extracorporeal photochemotherapy

Two patients were treated with photopheresis for marked cardiac allograft rejection with hemodynamic compromise that had become unresponsive to standard therapy. Multiple episodes of rejection had occurred, and initial response to standard therapy was favorable. However, progressive deterioration was documented by serial endomyocardial biopsies, fever, congestive heart failure, and abnormal cardiac catheterization findings. In the absence of retransplantation, death seemed imminent. Photopheresis was begun. Both patients received oral 8-methoxypsoralen and > or = 5 x 10(9) mononuclear cells were collected, treated with ultraviolet light A for 1.5 hours, and were reinfused. One procedure was performed weekly x4 and then monthly x5. Responses were striking with rapid loss of fever, improvement in exercise tolerance, normalization of cardiac hemodynamics, and improvement in endomyocardial biopsies. Although our experience with these two patients is anecdotal, photopheresis merits further study as treatment for severe cardiac allograft rejection.

Effects on donors of repeated leukocyte losses during plateletpheresis

All blood components collected by automated cytapheresis contain donor leukocytes. The possibility that repeated cytapheresis donation might lead to clinically important leukocyte losses and immunodeficiency has been a long-standing concern. Although convincing data do not exist to substantiate this concern, it is common practice to limit the number of annual cytapheresis donations per donor and to monitor donors for developing lymphocytopenia. Clinically significant immunodeficiency is unlikely to occur unless donors lose > 1 x 10(11) lymphocytes within a few weeks period of time or unless donor lymphocyte counts fall persistently to < 0.5 x 10(9)/L. Each plateletpheresis procedure, when performed using modern cell separators that are designed to produce a relatively "pure" platelet concentrate, leads to the loss of 1.0 x 10(6) to 5.0 x 10(7) leukocytes. Thus, automated plateletpheresis as performed in 1994 is extremely unlikely to cause clinically significant lymphocyte depletion and consequent immunodeficiency.

Potential for transfusion-associated graft-versus-host disease due to apheresis platelets matched for HLA class I antigens

Transfusion-associated graft-versus-host disease (TA-GVHD) has been reported in immunocompetent recipients of nonirradiated cellular blood components from donors who are homozygous for an HLA haplotype shared with the patient. In these cases, donor lymphocytes have no antigens foreign to the recipient, and this similarity in HLA antigens appears important for the development of TA-GVHD. Experience with 65 patients receiving apheresis platelets matched for class I HLA antigens was reviewed to determine the incidence of such a transfusion among HLA-matched, unrelated donor-recipient pairs. In 5 percent of transfusions (31/673), the patient received lymphocytes from a donor exhibiting no antigens foreign to the recipient, but the patient had additional HLA-A or -B antigens not present on donor lymphocytes. Twenty-three percent (n = 15) of patients received at least one such transfusion. In addition, most patients were immunosuppressed as a result of their underlying disease or therapy, which may decrease the degree of antigen matching required to initiate TA-GVHD. Until the pathogenesis of this disease is better understood, it is recommended that the transfusion of an HLA-matched cellular blood component be considered a risk factor for the development of TA-GVHD regardless of the patient's immune status, and that all such blood components be irradiated.

Comparison of plateletpheresis with a standard and an improved collection device

A blood cell separator with a specialized separation chamber ([TNX-6]CS-3000 Plus) was developed for the collection of platelet concentrates with higher platelet yields and lower white cell contamination than obtained with the standard blood cell separator (CS-3000). To compare these devices, normal donors were scheduled for paired plateletpheresis procedures spaced 4 weeks apart, with one procedure using the CS-3000 Plus and the other using the CS-3000. Overall, the platelet yield per unit (mean +/- SEM) was 4.3 +/- 0.1 x 10(11) with the CS-3000 Plus versus 3.7 +/- 0.1 x 10(11) with the CS-3000 (p < 0.001), and the white cell contamination per unit (mean +/- SEM) with the former was 2.4 +/- 0.7 x 10(6) versus 84.1 +/- 21.1 x 10(6) with the latter (p < 0.001). The sequence of procedures (i.e., the order in which the devices were paired) was selected randomly, and similar results were found regardless of sequence. When donors with predonation platelet counts of > or = 200 x 10(9) per L (n = 21) were studied separately, 76 percent of the collections by the CS-3000 Plus contained > or = 4 x 10(11) platelets versus 34 percent of those by the CS-3000 (p < 0.01), and 93 percent of the collections by the former contained < 5 x 10(6) white cells (69% contained < 1 x 10(6)) versus 0 percent of those by the latter (p < 0.01). Thus, platelet collections with the TNX-6 chamber consistently demonstrated high platelet yields and strikingly low white cell contamination--qualities that justify converting standard devices to devices with a TNX-6 chamber.

Efficacy of preoperative donation of blood for autologous use in radical prostatectomy

To determine the amount of blood lost, the number of transfusions, and the effectiveness of preoperative autologous blood donation in radical prostatectomy, 163 patients' records from 1987 to 1991 were reviewed at four university hospitals and three community hospitals. Calculated red cell volume lost was 1003 +/- 535 mL (mean +/- SD), which corresponds to 44 +/- 18 percent (mean +/- SD) of total red cell volume. Preoperative donation of blood for autologous use reduced the rate of transfusion of allogeneic blood from 66 to 20 percent (p < 0.001). Of the patients who donated 1 to 2 units, 32 percent received allogeneic blood; 14 percent of those who donated 3 units received allogeneic blood. Donation of 4 units reduced the allogeneic transfusion rate to 11 percent. However, as the number of units donated increased (1-3 units), the units not transfused also increased (0-21%). Ninety-one (56%) of 163 patients donated fewer than 3 units. Autologous blood donation is effective in minimizing the transfusion of allogeneic blood to radical prostatectomy patients, but many patients do not donate enough blood (< 3 units). The donation of 3 units of blood for autologous use is recommended for patients who undergo radical prostatectomy.