Donor Exposure Research Articles

A cohort study of coagulation parameters and the use of blood products in surgery of the thoracic and thoracoabdominal aorta

Objectives: We sought to study the hemostatic profile and the use of blood products in patients undergoing thoracic and thoracoabdominal aortic aneurysm repair. Methods: This is a cohort study comparing three groups of patients: 7 undergoing elective acute normovolemic hemodilution (ANH); 15 undergoing elective procedures without ANH (non-ANH); and 8 undergoing repair of ruptured thoracoabdominal aneurysms. A control group of 10 patients was used for comparison of preoperative hemostasis. The parameters studied were platelet concentration, partial thromboplastin time (PTT), and international normalized ratio (before and after surgery), packed red blood cells, fresh frozen plasma, platelets, cryoprecipitates, donor exposure, and use of desmopressin and epsilon-aminocaproic acid. Analysis of variance and multiple stepwise regression analysis were used. Results: Before operation the patients with aneurysms had PTTs prolonged compared with control subjects (P <.05). After operation the ANH group had higher platelet counts than the ruptured group (P =.001) and higher platelet counts (P =.05) and lower PTTs (P =.001) than the non-ANH group. The ANH group was transfused fewer platelets than the non-ANH group (P =.001) and less of every blood product than the ruptured group (P =.05); statistically significant differences were not observed for packed red blood cells, fresh frozen plasma, or platelets. The ANH group was exposed to an average of 65 donors fewer than the ruptured group (P <.001) and 34 fewer than the non-ANH group (P <.05). These differences could not be explained by baseline coagulation status or by the intraoperative use of desmopressin or epsilon-aminocaproic acid. Conclusions: The coagulation abnormality identified before surgery is that of higher PTT values, suggesting a disturbance of the extrinsic coagulation pathway. Blood losses, donor exposure, and platelet use were highest in the ruptured group and lowest in the ANH group. After surgery the ruptured group exhibited the worst coagulation parameters, and the ANH group exhibited the best with higher platelet count and lower PTT values than the other groups. The ANH technique appears to be an useful adjunct in the anesthetic management of these patients. (J Vasc Surg 2001;33:462-8.)

Blood support for pediatric surgery.

Increasingly complicated surgeries are being performed on neonatal and pediatric patients. Provision of a safe and adequate blood supply is essential for the success of many of these surgeries. Depending on the clinical situation, autologous and/or allogeneic blood may be used. However, in all cases, every attempt should be made to minimize the number of donor exposures to reduce the risk of transfusion transmitted infections. Transfusion of neonatal and pediatric patients requires additional considerations too, such as the risk of graft vs host disease, cytomegalovirus infection, the effects of various preservative anticoagulant solutions, electrolyte levels during blood storage, and wheather or not leukoreduced components are indicated.

Techniques for blood administration in sickle cell patients

Transfusion therapy provides many benefits to individuals with sickle cell disease but may lead to cardiovascular complications, alloimmunization, exposure to infection, and iron overload. Simple transfusion is used to increase oxygen-carrying capacity. Chronic simple transfusion is useful in preventing a number of complications in sickle cell disease. Acute erthrocyte exchange transfusion can reduce the percentage of cells containing sickle hemoglobin while decreasing volume overload and minimizing hyperviscosity. Chronic erythrocyte exchange transfusion reduces iron loading but increases donor exposure. Directed odnation may reduce alloimmunization and exposure to infection.

Stroke in Children With Sickle Cell Anaemia

Cerebral infarction is a frequent, severe complication of sickle cell anaemia. During childhood, most strokes are due to infarction with the majority resulting from occlusion of the large cerebral arteries. Risk factors include transient ischaemic attacks, acute chest syndrome, severe anaemia and elevated blood pressure. Less certain is the association with leucocytosis, or protection provided by alpha-thalassaemia or fetal haemoglobin. Children who have one stroke are at significant risk for having subsequent events that can be substantially reduced by maintaining haemoglobin S below 30%. It has not yet been possible to identify individuals for whom transfusion can be safely stopped. Haemosiderosis is a consequence of intensive and long term transfusion therapy, which requires chelation with deferoxamine. Iron accumulation can be minimised using erythrocytapheresis but this is technically difficult in children, expensive and results in increased donor exposure. In addition to lesions associated with strokes, an additional 17% of patients can be shown to have clinically silent cerebral infarcts. Although these are termed 'silent', those affected have mild neuropsychological deficits. Their relationship to stroke or risk for recurrence is unknown. Transfusion therapy has been shown to provide primary stroke prevention for children who have elevated cerebral artery velocity. Finally, intracranial haemorrhages, more commonly found in adults, also affect children. Subarachnoid haemorrhage is frequently found to result from cerebral artery aneurysms. A condition that mimics the moyamoya syndrome radiographically, as well as for its risk of haemorrhage, can be found in children with partly occluded cerebral arteries either as a result of stroke or silent infarct.

Alloimmunization in preterm infants after repeated transfusions of WBC-reduced RBCs from the same donor.

Preterm infants are among the most heavily transfused of patient groups, yet multiply transfused infants only rarely produce alloantibodies against RBC or WBC antigens. It is not known whether rates of alloimmunization might be increased by repeated exposure to RBCs and WBCs from the same donor, as in limited-donor-exposure programs, or whether infants might benefit from WBC-reduced RBC components as a means of diminishing the risk of possible alloimmunization. Preterm infants (birth weight 0.6-1.3 kg) received prestorage WBC-reduced RBCs from dedicated donors, collected in AS-3 as a means of limiting donor exposures. Blood samples were collected serially from infants shortly after birth until either discharge or age 6 months and were studied for RBC and WBC antibodies-the latter with reactivity against either HLA class I or neutrophil-specific antigens. Thirty preterm infants received 139 transfusions (mean, 4.6; median, 4 transfusions per infant), with 81 percent of transfusions obtained from one donor per infant. Eighty-four blood samples (mean, 2.7/infant) were studied, and no infant produced RBC antibodies. Twenty-seven percent of infants exhibited WBC antibodies, but only 13 percent actually produced WBC antibodies (passive maternal antibody excluded). Of the WBC antibodies produced by infants, three were against HLA class I and one was against neutrophil-specific antigens; none were linked to adverse effects. Because infants only rarely produce RBC antibodies, no changes in blood banking practices are necessary for limited-donor-exposure programs. Although the production of WBC antibodies by infants occurs, it seems to be uncommon; thus, the possible benefits, if any, of WBC reduction are uncertain, and further study is required before changes in practice can be justified.

Determination of red cell volume in infants needing blood transfusion.

The total circulating red cell volume (RCV) is a better guide to the oxygen-carrying capacity of the blood in the whole circulation than is the haemoglobin concentration (Hb) or haematocrit in a blood sample. Pre- and post-transfusion RCV (and blood volume (BV)) may be determined by flow cytometry by exploiting antigen differences between transfused donor red cells and the recipient's red cells. This paper describes the use of red cell antigen differences of Duffy, Kidd, MN and RhD between donor and recipient. In 20 infants, transfused on 21 occasions, pretransfusion RCV ranged from 12 to 39 mL kg(-1) body weight. Only at one transfusion could no usable donor-recipient antigen differences be exploited. Measurement of RCV, used routinely, may determine the transfusion requirements of sick infants more accurately, with the aim of normalizing RCV and BV--securing euvolaemia--at the end of the transfusion. This may allow a complete correction of the RCV deficiency at the first occasion of transfusion. This approach may reduce donor exposures and also optimize oxygen transport and organ perfusion of the infant undergoing intensive management, perhaps leading ultimately to improved survival rates and fewer long-term complications of neonatal intensive care.

Infectious Complications in Renal Transplant Recipients

Infectious complications present major challenges to physicians caring for renal transplant recipients. The high rate of infection reflects the net state of immunosuppression associated with end-stage renal disease, transplantation, donor and environmental exposure. An understanding of the factors that affect the patients' overall state of immunosuppression is essential to prevent and treat infectious complications, which may lead to significant morbidity, graft dysfunction, or mortality. Familiarity with the various pathogens, clinical presentation, diagnostic options, treatment, and prophylaxis is important to care for renal transplant patients. The authors present their approach, based on review of current literature, to these issues.

Transfusion Approach to Neonatal Anemia

After completing this article, readers should be able to: 1. Describe the basis for guidelines for red blood cell (RBC) transfusions to infants. 2. Delineate the guidelines for storing and administering RBCs to preterm infants as a means of reducing donor exposure without causing hyperkalemia or acidosis. 3. Describe an alternative to selecting blood from cytomegalovirus antibody-negative donors to prevent transfusion-transmitted infection. 4. Delineate the procedure used to prevent graft-versus-host disease in preterm infants receiving RBC transfusions. Neonates are given RBC transfusions for several reasons, including hemolytic disease of the newborn due to maternal alloimmunization, congenital abnormalities of RBC enzymes and membranes, and anemia of prematurity due to multiple interacting factors, the most important of which are phlebotomy blood loss and low erythropoietin levels. Although great efforts have been made during the past few years to optimize the transfusion of RBCs to these tiny patients, several questions have not been answered definitively. Accordingly, transfusion practices vary among physicians caring for neonates. This lack of precise approach stems from incomplete knowledge of the cellular and molecular biology of hematopoiesis during the perinatal period as well as an incomplete understanding of the infant’s response to severe anemia. Generally, RBC transfusions are administered in small volumes (15 mL/kg per dose) to maintain a hematocrit (HCT) level that is believed to be most desirable in terms of oxygen delivery and tissue oxygenation for each neonate’s clinical status (Table 1⇓ ). It is widely recognized that this clinical approach is imprecise, and more physiologic indications for RBC transfusions, such as circulating RBC mass, available oxygen, and measurements of oxygen delivery and tissue extraction, have been suggested. However, the means by which these techniques can best be applied to daily clinical practice remain to be defined. Because clearly established indications for neonatal RBC transfusions based on controlled scientific studies …

Standardized units of RBCs: is it time for implementation?

Current practice for the preparation of RBCs from whole blood for transfusion results in poorly standardized contents of RBC Hb. The principle of apheresis, metering the anticoagulant into the collected blood, which is pumped into an empty container, allows variation in the collected volume according to properties of the donor. The total Hb mass of each person in a representative group of Swedish blood donors was evaluated by using Hb concentration and blood volume (BV), with the latter calculated from each donor's weight and height. The number of blood units that could be collected without exceeding 13 percent of the BV was estimated at a standardized content of RBC Hb set at 40, 45, and 50 g. With Hb standards of 45 and 50 g per unit of RBCs, it would be possible to collect 1 unit, but not more, from 93 female donors in the study; with 40 g of Hb as the standard, 2 units could be collected from 6 percent of the donors. Using a standard of 40 g of Hb, it would be possible to collect 2 units or more from 95 percent of 121 male donors. The corresponding figures at Hb standards of 45 and 50 g were 81 and 50 percent, respectively, of the male donors. The largest number of units that could be collected would thus be obtained at a 40-g Hb standard. However, the greatest total mass of RBC Hb would have been obtained at 45 g. Even the yield of plasma would reach a maximum at this RBC Hb standard. Depending on the donor's Hb and BV, it is possible to collect either 1 or 2 units of RBCs without exceeding 13 percent of any donor's BV, provided the collected volume of blood in each unit is less than the current standard. Such practice would allow better use of the donor population. Two-unit blood collections may reduce donor exposure in transfusions. Applying a standard at 45 g of RBC Hb per unit was found to permit the collection of maximum RBC Hb and plasma in the evaluated population of Scandinavian donors. Perhaps it is time to discuss a change in current rules for the preparation of RBCs for transfusion.

Changing practices of red blood cell transfusions in infants with birth weights less than 1000 g

Objective: Extremely low birth weight (ELBW) infants frequently undergo transfusion because they are critically ill, often need artificial ventilation, and have the highest blood sampling loss in relation to their weight. During the last decade our transfusion guidelines were changed 3 times to become more restrictive. We hypothesized that these modifications substantially decreased the number of transfusions in our ELBW infants. Methods: We performed a single-center analysis of 256 infants with birth weights from 500 to 999 g who were admitted from 1989 to 1997 and included 3 study periods, each starting with newly modified transfusion guidelines in April 1989, September 1991, and January 1995. We evaluated prospectively recorded clinical data and retrospective chart analysis for transfusion-related information. Results: The median number of transfusions per infant decreased from 7 in the first period to 2 in the third period, whereas donor exposure decreased from 5 to 1 and blood volume transfused decreased from 131 to 37 mL/kg birth weight ( P < .01). The median venous hematocrit measured before transfusion decreased from 43% to 35% in infants who underwent ventilation and from 41% to 31% in spontaneously breathing infants. The median birth weight decreased from 870 to 740 g and the median gestational age from 27 to 25 completed weeks ( P < .01). The overall survival rate was 75% and did not change. The incidences of retinopathy, intraventricular hemorrhage, and patent ductus arteriosus remained unchanged. Conclusion: Over this 9-year period with increasingly restrictive transfusion guidelines, the transfusion number decreased by 71% and the donor exposure by 80% in ELBW infants without adverse clinical effects. (J Pediatr 2000;136:220-4)

Feasibility and safety of AS-3 red blood cells for neonatal transfusions

Objectives: Most extremely low birth weight (<1 kg) infants receive red blood cell (RBC) transfusions. RBCs stored up to 42 days can be transfused safely in small volumes to preterm infants; however, because the formulation of RBC anticoagulant/preservative solutions differs, clinical studies are required to document the safety of each solution before widespread use. Our goal was to study the feasibility and safety of AS-3 anticoagulant/preservative solution to preterm infants. Study design: Two clinical studies were conducted in sequence: (1) a randomized trial to compare RBC transfusions given as stored (≤42 days) AS-3 RBCs (11 infants) versus fresh (≤7 days) citrate, phosphate, dextrose, and adenine RBCs (10 infants) and (2) a subsequent evaluation of the safety of stored AS-3 RBCs in 33 additional preterm infants given 120 AS-3 RBC transfusions. Results: Results of both the randomized study and the subsequent evaluation documented that AS-3 RBCs stored ≤42 days and transfused in small volumes (15 mL/kg) were safe for RBC transfusions of preterm infants. Donor exposure was significantly reduced, clinical transfusion reactions were rare, and post-transfusion blood hematocrit, pH, and plasma Na, K, Ca, lactate, and glucose measurements were similar when AS-3 and citrate, phosphate, dextrose, and adenine RBC transfusions were compared. Conclusions: AS-3 RBCs can be used safely for small-volume RBC transfusions for preterm infants. (J Pediatr 2000;136:215-9)

Evaluation of a strategy to limit blood donor exposure in high risk premature newborns based on clinical estimation of transfusion need.

Reservation of dedicated series of pedipacks, consisting of 3 to 4 units of 70 ml filtered red cell concentrate in additive solution SAGM from 1 donor, may reduce donor exposure. In this prospective efficacy study the benefits, release and expiration of pedipacks (PP) assigned to preterm infants requiring neonatal intensive care are analyzed. On the basis of clinical assessment of the need for multiple transfusions, 96 preterm neonates (gestational age < 32 wks and/or birth weight < 1500 g) were assigned to either the high risk group (HRG), who were to receive dedicated donor blood units, or the low risk group (LRG). Inclusion criteria for HRG were 1) estimated time of admission > 21 days and 2) expected need for multiple transfusions due to clinical cardiorespiratory instability, prolonged parental feeding or frequent blood sampling. To reduce wastage of donor blood, dedication of donor blood units was limited to 21 days. 50 series (192 PP) were assigned to 42 HRG infants. Two HRG infants received 3 series, 4 received 2 series and 36 received 1 series of PP. Mean transfusion rate was 3.1 PP in the HRG and 0.4 in the LRG. In the LRG 35 of 54 were not transfused, 19 received 1 to 2 PP. In both groups transfused newborns were exposed to 1.1 donors in average. In the HRG of 192 PP, 137 PP (71%) were used within 21 days, and another 30 (16%) before the expiration date < 35 days. Twenty five PP (13%) expired, mainly because of logistical problems in the introduction phase. Assignment of dedicated PP on the basis of clinical parameters at entry considerably reduces donor exposure in HRG. Wastage of dedicated blood transfusions was reduced by limitation of the dedicated period (21 days). In terms of efficacy, reservation and use of PP can be optimized by standardized administrative measures.

Natural history of the TT virus infection through follow-up of TTV DNA–positive multiple-transfused patients

Little is known about the natural history and the pathogenicity of the TT virus (TTV). We present our findings of a cross-sectional study based on the TTV DNA screening of 173 multiple-transfused patients and a longitudinal study based on the follow-up of TTV DNA–positive patients. Overall, 48 patients (27.7%) tested positive for TTV DNA. The influence of the number of blood donor exposures on the prevalence of blood-borne viral infection indicates that TTV, hepatitis C virus (HCV), and an RNA virus known as GB virus C/hepatitis G virus (GBV-C/HGV) share a parenteral transmission, but that TTV, in contrast to the 2 other viruses, is also transmitted by at least another efficient means. The patients having a well-defined date of TTV infection were positive for TTV DNA during a mean period of 3.1 years. A chronic infection was observed in 31 cases (86%). TTV carriage appeared clinically benign in all patients. No clinical evidence of a disease potentially linked to the TTV infection was observed in patients with TTV DNA carriage over several years. The majority of TTV carriers had no biochemical evidence of liver disease. The prevalence of elevated serum alanine aminotransferase (ALT) level was higher in the TTV DNA–positive group, even in the absence of HCV infection, but the observed peaks of ALT level were most often transient and very mild. The prevalence of TTV DNA observed in blood recipients is consistent with that of TTV infection observed in blood donors. TTV infection frequently tends to persist. (Blood. 2000;95:347-351)

Natural history of the TT virus infection through follow-up of TTV DNA–positive multiple-transfused patients

AbstractLittle is known about the natural history and the pathogenicity of the TT virus (TTV). We present our findings of a cross-sectional study based on the TTV DNA screening of 173 multiple-transfused patients and a longitudinal study based on the follow-up of TTV DNA–positive patients. Overall, 48 patients (27.7%) tested positive for TTV DNA. The influence of the number of blood donor exposures on the prevalence of blood-borne viral infection indicates that TTV, hepatitis C virus (HCV), and an RNA virus known as GB virus C/hepatitis G virus (GBV-C/HGV) share a parenteral transmission, but that TTV, in contrast to the 2 other viruses, is also transmitted by at least another efficient means. The patients having a well-defined date of TTV infection were positive for TTV DNA during a mean period of 3.1 years. A chronic infection was observed in 31 cases (86%). TTV carriage appeared clinically benign in all patients. No clinical evidence of a disease potentially linked to the TTV infection was observed in patients with TTV DNA carriage over several years. The majority of TTV carriers had no biochemical evidence of liver disease. The prevalence of elevated serum alanine aminotransferase (ALT) level was higher in the TTV DNA–positive group, even in the absence of HCV infection, but the observed peaks of ALT level were most often transient and very mild. The prevalence of TTV DNA observed in blood recipients is consistent with that of TTV infection observed in blood donors. TTV infection frequently tends to persist. (Blood. 2000;95:347-351)

Pro: The routine use of aprotinin during pediatric cardiac surgery is a benefit

ORE THAN HALF of the children undergoing cardiopulmonary bypass (CPB) in North America are younger than 1 year old, and neonates comprise approximately 36% of this group. 1 Many of these children undergo multiple-stage reconstructive procedures as well as repeat operations to replace conduits and valves, which are often performed at low temperatures with long bypass times. Bleeding complications are common and are secondary to increased tissue friability, extensive suture lines, and increasingly complicated surgical repairs. In addition, clotting mechanisms are incompletely developed in infants, and they tolerate hemorrhage and tamponade poorly. These issues underscore the need to develop therapeutic modalities directed at the attenuation of the inflammatory reaction and coagulation cascade initiated by CPB. Several studies in children suggest that aprotinin is beneficial for pediatric patients during cardiac surgery. Aprotinin, isolated in 1930, is a serine protease inhibitor that has been used in numerous clinical settings, including acute pancreatitis, adult respiratory distress syndrome, trauma, and septic shock. In the 1960s, aprotinin was used in adult cardiac surgery in an attempt to reduce excessive blood loss thought to be due to increased fibrinolysis. By 1984, the benefits of aprotinin in pediatric CPB were being studied, and decreases in postoperative blood loss and fibrin split products were demonstrated. 2 Attention has turned to aprotinin's potential as a kallikrein inhibitor to attenuate the inflammatory response associated with CPB. Numerous studies have demonstrated a reduction in blood loss associated with aprotinin use in pediatric CPB. Herynkopf et aP noted that homologous donor exposure was decreased by about half in the patients who received aprotinin. A study of children undergoing repair of tetralogy of Fallot showed significant decreases in the total volume of blood loss and blood transfused. 4 Penkoske et al 5 showed similar decreases in blood loss, volume of transfusion, and number of units transfused. In pediatric lung transplants, Jaquiss et al6 demonstrated that high-risk patients receiving aprotinin bled less than, or similar to, low-risk transplant patients who had not received aprotinin. In a study at this institution, aprotinin decreased the number of

Con: The routine use of aprotinin during pediatric cardiac surgery is not a benefit

ORE THAN HALF of the children undergoing cardiopulmonary bypass (CPB) in North America are younger than 1 year old, and neonates comprise approximately 36% of this group. 1 Many of these children undergo multiple-stage reconstructive procedures as well as repeat operations to replace conduits and valves, which are often performed at low temperatures with long bypass times. Bleeding complications are common and are secondary to increased tissue friability, extensive suture lines, and increasingly complicated surgical repairs. In addition, clotting mechanisms are incompletely developed in infants, and they tolerate hemorrhage and tamponade poorly. These issues underscore the need to develop therapeutic modalities directed at the attenuation of the inflammatory reaction and coagulation cascade initiated by CPB. Several studies in children suggest that aprotinin is beneficial for pediatric patients during cardiac surgery. Aprotinin, isolated in 1930, is a serine protease inhibitor that has been used in numerous clinical settings, including acute pancreatitis, adult respiratory distress syndrome, trauma, and septic shock. In the 1960s, aprotinin was used in adult cardiac surgery in an attempt to reduce excessive blood loss thought to be due to increased fibrinolysis. By 1984, the benefits of aprotinin in pediatric CPB were being studied, and decreases in postoperative blood loss and fibrin split products were demonstrated. 2 Attention has turned to aprotinin's potential as a kallikrein inhibitor to attenuate the inflammatory response associated with CPB. Numerous studies have demonstrated a reduction in blood loss associated with aprotinin use in pediatric CPB. Herynkopf et aP noted that homologous donor exposure was decreased by about half in the patients who received aprotinin. A study of children undergoing repair of tetralogy of Fallot showed significant decreases in the total volume of blood loss and blood transfused. 4 Penkoske et al 5 showed similar decreases in blood loss, volume of transfusion, and number of units transfused. In pediatric lung transplants, Jaquiss et al6 demonstrated that high-risk patients receiving aprotinin bled less than, or similar to, low-risk transplant patients who had not received aprotinin. In a study at this institution, aprotinin decreased the number of

Optimal dosing and triggers for prophylactic use of platelet transfusions.

Despite the reliance on platelet transfusion support in patients receiving myeloablative therapy, controversies surround platelet transfusion practices. These include the appropriate platelet dose and the threshold at which prophylactic platelet transfusions will be most effective. These issues bear directly on patient outcome (donor exposure and bleeding complications), cost effectiveness of transfusion, and maintenance of adequate platelet inventories. This review examines the recent studies that have taken on the task of resolving these questions in order to provide optimal platelet transfusion guidelines. Studies now have convincingly demonstrated that a 10,000/microL threshold for prophylactic platelet transfusion is safe and effective in uncomplicated thrombocytopenic patients. Although platelet dosages vary, in general, smaller doses are both effective and inventory-sparing in the more complicated inpatient setting, while larger platelet doses allow for an increased transfusion interval for chronic outpatient support.

Cost-effectiveness of a limited-donor blood program for neonatal red cell transfusions.

Very-low-birthweight infants have typically been given fresh red cells (RBCs), a practice in which aliquots of RBCs for several infants were issued each day from a single unit. Recently, to limit donor exposures, large volumes of RBCs are reserved for the long-term transfusion support of individual infants. Medical records were examined retrospectively to assess the costs of a limited-donor program for providing RBC transfusions to very-low-birthweight infants. Costs of multiple- and limited-donor programs were compared by using two samples of 30 consecutive infants treated at The University of Iowa Hospitals and Clinics in 1993 and 1997. Effectiveness was evaluated with respect to the number of donor exposures per infant. The cost, in 1997 dollars, of preparing each small-volume transfusion in the multiple-donor program was $27.86 per transfusion, while that in the limited-donor program was $34.83. This difference was largely attributable to use of white cell reduction in association with the limited-donor program in 1997. Eliminating the costs associated with white cell reduction rendered the costs of the limited- and multiple-donor transfusions comparable. The limited-donor program had donor exposures of 2.0 per infant, while the multiple-donor program had 3.6 exposures per infant (p<0.002). The limited-donor blood program reduces donor exposure without adversely affecting costs.

The cost-effectiveness of reducing donor exposures with single-donor versus pooled random-donor platelets.

Single-donor platelets (SDPs) are frequently preferred over pooled random-donor platelets (RDPs) to reduce donor exposures and the risk for virus transmission or HLA alloimmunization. Transfusion-associated virus-transmission risks have significantly decreased, which suggests that white cell reduction by filtration eliminates any difference in the risk of alloimmunization in transfused leukemic patients. Health care reform pressures of make it appropriate to examine the cost-effectiveness of SDPs versus RDPs in reducing donor exposures. A decision analysis model was developed and sensitivity analyses were used to assess the incremental cost (dollars/quality-adjusted life-year) associated with the use of SDPs versus RDPs for adult patients undergoing hematopoietic progenitor cell transplantation or primary coronary artery bypass grafting (CABG). Among transplant patients, the incremental cost of choosing SDPs as opposed to RDPs ranged from $168,700 to $519,822 per quality-adjusted life-year. For patients undergoing primary CABG, the incremental cost was $192,415 (females) and $216,280 (males). Variations in the cost differential between SDPs and RDPs, the number of random-donor platelets in the RDP, and the risk of bacterial sepsis markedly influenced cost-effectiveness. The model was minimally affected by variations in the risks of transmission of HIV and hepatitis B and C, and human T-lymphotropic viruses. In comparison with other accepted medical interventions, the use of SDPs as opposed to RDPs may not be a cost-effective method of reducing donor exposures in the adult patient populations studied. SDPs were more cost-effective in patients undergoing primary CABG than in leukemia patients undergoing hematopoietic progenitor cell transplantation. Regardless of diagnosis, decreasing the acquisition cost differential would have the greatest impact on improving the cost-effectiveness of SDPs, as opposed to RDPs, to decrease donor exposures.

Hepatitis C lookback programme: a single hospital experience.

As part of the national Hepatitis C (HCV) Lookback Programme, HCV-infected donors donating blood after September 1991 were identified and the fate of their previous donations received at a single hospital were traced; 123 of 160 implicated blood components were traceable and transfused. Only 19 recipients were alive and traceable and were tested for HCV. Nine of the 14 recipients (64%) of HCV-positive donations and 2 of 5 recipients (40%) of HCV-indeterminate donations had evidence of HCV infection. Neither the number of donor exposures nor the type of component was predictive of recipient HCV status. Three recipients have chronic active hepatitis. The Hepatitis C Lookback Programme successfully identifies some but not all cases of transfusion-transmitted HCV. Transfusion records, particularly in the medical case notes, should be substantially improved. Many of the traced recipients are young, so that identification of HCV is of great importance.