Toxoplasmosis transmitted by blood transfusions

Blood from humans collected into heparin or citrate was inoculated with toxoplasma organisms. After storage at 4 C up to 28 days, samples were injected into the ear veins of rabbits. The test rabbits developed toxoplasmosis. Similar results were obtained by transfusing rabbits with blood obtained from rabbits subcutaneously injected with toxoplasma organisms.     

A retrospective study evaluating single-unit red blood cell transfusions in reducing allogeneic blood exposure

Although guidelines recommend the use of single-unit red blood cell (RBC) transfusions to minimize allogeneic blood exposure, clinical practice remains dominated by two-unit transfusions. This study assesses the potential impact of a single-unit transfusion policy on reducing RBC utilization. We performed a retrospective analysis of adult patients admitted to a tertiary care hospital who received one or two RBC units. In subjects transfused two units, the effect of one unit was estimated by dividing the change in haemoglobin by 2. The proportion of patients reaching a haemoglobin threshold of 70, 75, 80, 85 and 90 g L(-1) with a single RBC unit was estimated. Of 302 included patients, only 65 received a one-unit transfusion. Based on thresholds of > or = 90, > or = 80 and > or = 70 g L(-1), a single-unit transfusion would be sufficient in 42.0% (RRR = 0.54), 79.6% (RRR = 0.23) and 98.0% (RRR = 0.02) of cases, respectively. This corresponds to 0.21, 0.57 and 0.82 mean RBC units saved per patient. In the orthopaedic subpopulation, the mean RBC units saved are 0.53, 0.88 and 1.00 for the same haemoglobin targets. Adopting a policy of transfusing RBC in single-unit aliquots could significantly improve RBC utilization and decrease patient exposure to allogeneic blood.     

Decreasing seroprevalence of human immunodeficiency virus type 1 in a regional blood donor population

Blood banks have intensified their efforts to discourage donations from individuals at risk for the human immunodeficiency virus (HIV-1). Since the onset of HIV-1 donor screening in April 1985, a marked reduction in seroprevalence has been seen at the authors' institutions: from 51 cases per 100,000 donors in 1985 to 13 per 100,000 in the first 6 months of 1988. Data from 3.5 years have been analyzed for temporal trends in the association of HIV-1 seroprevalence with donation site (urban vs. non-urban) and donor gender. The association of HIV-1 seropositivity with an urban donation site decreased through 1987 as the urban-to-nonurban donation odds ratio declined from 6.48 in 1985 to 2.54 in 1987. Despite this decrease, both men and women who donated in urban areas had a significantly higher seroprevalence than those in nonurban areas. Male donors had a higher overall HIV-1 seroprevalence than female donors. However, the male-to-female odds ratio declined from 2.94 in 1985 to 1.96 in 1988, and male gender was no longer significantly associated with HIV-1 seropositivity. This change in the donor profile appears to reflect declining numbers of seropositive men who acknowledge risk factors and greater numbers of women with no identified risks for HIV-1. This study documents a dramatic decrease in HIV-1-seropositive donors and suggests that the deferral of high-risk individuals has become increasingly successful.     

Postponing or eliminating red blood cell transfusions of very low birth weight neonates by obtaining all baseline laboratory blood tests from otherwise discarded fetal blood in the placenta

BACKGROUND: Safely reducing the proportion of very low birth weight neonates (<1500 g) that receive a red blood cell (RBC) transfusion would be an advance in transfusion practice. STUDY DESIGN AND METHODS: We performed a prospective, single‐centered, case‐control, feasibility analysis, preparatory to designing a definitive trial. Specifically, we sought to determine whether we could obtain all baseline neonatal intensive care unit blood tests from the placenta, after placental delivery, thereby initially drawing no blood from the neonate. RESULTS: Ten cases where all baseline blood tests were drawn from the placenta, and 10 controls where all tests were drawn from the neonate, were closely matched for birth weight, gestational age, sex, and race. Early cord clamping was used for all 20. Over the first 18 hours the hemoglobin increased in nine cases versus two controls (p = 0.005). During the first 72 hours one case versus five controls qualified for and received an RBC transfusion. In the first week the cases received four transfusions and the controls received 16 (p = 0.02). None of the cases had an intraventricular hemorrhage (IVH) but four of the controls had a Grade 1 and two had a Grade 3 (p = 0.01). CONCLUSION: We speculate that this method is feasible and generally postpones the first RBC transfusion until beyond the period of peak vulnerability to IVH.     

AS-1 red cells for neonatal transfusions: a randomized trial assessing donor exposure and safety

BACKGROUND: Despite recent optimism about the use of erythropoietin therapy to treat the anemia of prematurity, very-low-birth-weight infants who are severely ill receive multiple red cell (RBC) transfusions. Many physicians transfuse relatively fresh RBCs to newborn infants, exposing them to multiple donors and possibly increasing their risk of acquiring transfusion-transmitted infections. STUDY DESIGN AND METHODS: A randomized, single-blind clinical trial was conducted to determine, as the primary endpoint, whether RBCs collected from one dedicated donor and stored for < or = 42 days in AS-1 storage media could safely supply all small-volume RBC transfusions (15 mL/kg/dose) needed by very-low-birth-weight infants (0.6-1.3 kg) during the first 84 days of life. Secondary endpoints were the assessment of the possible adverse clinical and biochemical effects of transfusing AS- 1 RBCs stored for < or = 42 days. Control infants received identical nursery care, except they received fresh RBCs stored < or = 7 days in CPDA-1. RESULTS: Infants transfused with AS-1 RBCs were exposed to a mean of 1.6 donors,-compared with an exposure to 3.7 donors for infants given CPDA-1 RBCs (p < 0.05). Neither clinical transfusion reactions nor the results of multiple laboratory tests were significantly different in infants who received slow transfusions (15 mL/kg) of AS-1 RBCs stored for < or = 42 days and in infants who received the same volume of CPDA-1 RBCs stored < or = 7 days. CONCLUSION: AS-1 RBCs, usually from only one dedicated donor, can safely supply all RBCs needed by most very-low-birth-weight infants-a practice that decreases donor exposure and likely increases transfusion safety.     

Understanding the blood group system and blood transfusions

Having a blood transfusion carries risks for patients. To minimise these risks, nurses must be aware of the ABO group system, components of blood and how they should be stored, handled, checked and administered. They must also be aware of possible adverse events during or after transfusion, how to monitor patients and how to deal with adverse events should they occur. All staff involved at any stage must be trained and aware of hospital policy and all actions must be accurately recorded to ensure the process is as safe as possible.     

Effect on the quality of blood components after simulated blood transfusions using volumetric infusion pumps

BACKGROUND: It is unknown whether the use of volumetric infusion pumps for the transfusion of red blood cells (RBCs) or platelet (PLT) concentrates (PCs) affects the quality of the blood components. We therefore investigated the in vitro quality of these components after use of infusion pumps. STUDY DESIGN AND METHODS: Ten different volumetric infusion pumps were used to simulate transfusion with RBCs and PCs. To prevent donor‐dependent differences multiple units were pooled and divided into equal portions. The storage time of RBCs was 30 to 35 days (n = 10 experiments), and for PCs, either 2 (n = 5) or 7 days (n = 5). For RBCs an infusion rate of 100 or 300 mL/hr was used, and for PCs, 600 mL/hr. Transfusions without an infusion pump served as a reference. RESULTS: None of the infusion pumps induced an increase of free hemoglobin, annexin A5 binding, or formation of echinocytes in RBCs compared to reference units. In 2‐ and 7‐day‐old PCs no effect was shown on PLT concentration, annexin A5 binding, mean PLT volume, and morphology score compared to the reference. The CD62P expression of 2‐day‐old PCs was significantly lower after transfusion compared to the reference, that is, 11.7 ± 2.1% versus 8.1 ± 1.3% (p < 0.01). CONCLUSION: There was no adverse effect on the in vitro quality of RBCs or PCs after simulated transfusion using volumetric infusion pumps. A decrease in PLT activation was observed, which can probably be explained by capturing of activated or damaged PLTs in the 200‐µm filter present in the infusion system.     

A novel strategy to limit blood donor exposure and blood waste in multiply transfused premature infants

Small, premature infants require frequent small-volume transfusions. Traditional methods of transfusion expose these infants to multiple blood donors. It has recently been demonstrated that multiple donor exposures can be safely prevented in these infants by the assignment of fresh units to them and by the use of a sterile connecting device to remove blood for transfusion, as needed until the expiration of the unit. However, the program resulted in the wasting of approximately 60 percent of the blood in each unit. STUDY DESIGN AND METHODS: To minimize blood waste without compromising the goal of limiting donor exposure, a model designed to predict each infant's transfusion requirements was investigated. The model assigned infants predicted to have high transfusion requirements to receive blood from a unit dedicated to their individual use. All other infants were assigned to receive blood from a unit that could be shared among as many as four similar infants. Infant donor exposure and blood unit wastage after institution of the infant assignment model were compared with the same measurements obtained before the use of the model, during which time infants were assigned to dedicated units at the discretion of the physician. RESULTS: The numbers of transfusions per infant (3.5 +/− 2.3) and of donor exposures per infant (1.5 +/− 0.7) under the assignment model were unaltered from those in controls (4.1 +/− 2.9 transfusions and 1.6 +/− 0.8 donor exposures); however, there was significantly less blood wastage in the group assigned to shared units (32 +/− 28%) than in the group assigned to dedicated units (62 +/− 17%; p < 0.05) or than was seen in an earlier study (60 +/− 23% wasted; p < 0.05). CONCLUSION: Improved management of blood resources can be achieved within the context of a transfusion program designed to safely limit donor exposure in infants who require frequent transfusion.     

Effects of red blood cell transfusions during the first week of life on acid-base, glucose, and electrolytes in preterm neonates

BACKGROUND: More than 90 percent of extremely low‐birth‐weight infants receive one or more transfusions of red blood cells (RBCs). The objective was to assess if RBC transfusions may induce significant changes of plasma acid‐base, electrolyte, and glucose status in extremely preterm infants. STUDY DESIGN AND METHODS: Records of infants with gestational age of less than 31 weeks who were transfused with RBCs during the first week of life were reviewed (n = 61). Blood samples were collected from infants before and after transfusions to evaluate hemoglobin (Hb) level, hematocrit, acid‐base, electrolyte, and glucose status. Then infants were stratified into four groups that received a RBC volume of less than 15, 15 to 20, more than 20 to 25, or more than 25 mL per kg. RESULTS: Infants received 20.7 (±1.5) mL per kg RBCs. After transfusions, a significant increase of pO₂ (p < 0.0001) and decrease of Ca²⁺ (p = 0.047) and glycemia (p < 0.0001) were observed. Infants who were transfused with more than 25 mL per kg were significantly less immature, heavier, and more anemic than infants in other groups. A positive relationship was found between changes of patients' potassium plasma level and K⁺ intake through RBC transfusion (r = 0.442, p = 0.008). Three (4.9%) infants developed hyperkalemia, one (1.6%) had an exacerbation of his hypocalcemia, and another (1.6%) of his hypoglycemia. CONCLUSIONS: RBC transfusions were effective in correcting anemia in our patients and induced a slight increase of pH and pO₂ and decrease of Ca²⁺ and glycemia, which were not clinically relevant. A linear direct correlation was observed between potassium intake by RBC transfusions and changes of kalemia in our infants, but there was not an increase of K⁺ plasma level after transfusions.     

The annual cost of blood transfusions in the UK

This study estimated the annual UK cost of blood transfusions in 2000/2001, updating a study we performed in 1994/1995. The analysis was based on published data, information from interviews with National Health Service (NHS) personnel and a structured questionnaire for blood donors. The annual cost of provision and transfusion of blood products increased by 256% in real terms, to pounds 898 million in 2000/2001, whereas the number of whole-blood donations increased by 2% to 2.8 million. The number of apheresis donations decreased by 52% to 70 000. Total blood product units issued to hospitals in 2000/2001 increased by 17% and were used in an estimated 1.7 million transfusions. The estimated NHS cost for an adult transfusion was pounds 635 for red blood cells, pounds 378 for fresh frozen plasma, pounds 347 for platelets and pounds 834 for cryoprecipitate. Blood donors incurred an annual direct cost of pounds 8.1 million and 3.1 million hours of used leisure time. There was also an indirect cost of pounds 7.2 million arising from lost productivity. The large increases since 1994/1995 reflect a real increase in expenditure by the blood transfusion services, partly due to the introduction of leucodepletion, greater hospital resource use due to more transfusions being undertaken and under-recording of hospital activity in 1994/1995.