Febrile Nonhemolytic Transfusion Reactions Research Articles

Incidence and pattern of 12 years of reported transfusion adverse events in Zimbabwe: a retrospective analysis.

Haemovigilance hinges on a systematically structured reporting system, which unfortunately does not always exist in resource-limited settings. We determined the incidence and pattern of transfusion-related adverse events reported to the National Blood Service Zimbabwe. A retrospective review of the transfusion-event records of the National Blood Service Zimbabwe was conducted covering the period from 1 January 1999 to 31 December 2011. All transfusion-related event reports received during the period were analysed. A total of 308 transfusion adverse events (0.046%) were reported for 670,625 blood components distributed. The majority (61.6%) of the patients who experienced an adverse event were female. The median age was 36 years (range, 1-89 years). The majority (68.8%) of the adverse events were acute transfusion reactions consisting of febrile non-haemolytic transfusion reactions (58.5%), minor allergies (31.6%), haemolytic reactions (5.2%), severe allergic reactions (2.4%), anaphylaxis (1.4%) and hypotension (0.9%). Two-thirds (66.6%) of the adverse events occurred following administration of whole blood, although only 10.6% of the blood was distributed as whole blood. Packed cells, which accounted for 75% of blood components distributed, were associated with 20.1% of the events. The incidence of suspected transfusion adverse events was generally lower than the incidences reported globally in countries with well-established haemovigilance systems. The administration of whole blood was disproportionately associated with transfusion adverse events. The pattern of the transfusion adverse events reported here highlights the probable differences in practice between different settings. Under-reporting of transfusion events is rife in passive reporting systems.

Acute Transfusion Reactions (ATRs) in Intensive Care Unit (ICU): A Retrospective Study

Blood transfusion is a frequent and integral part of critical care. Although life saving, it can occasionally be unsafe and result in a spectrum of adverse events. Acute transfusion reactions (ATRs) are probably under diagnosed in critically ill patients due to confusion of the symptoms with the underlying disease. To analyze the incidence and spectrum of ATRs occuring in critically ill patients. This was a retrospective review conducted from 1(st) April 2011 till 31(st) March 2013. The ATRs related to the administration of blood components in the patients admitted in various Intensive Care Units (ICUs) were recorded, analyzed and classified on the basis of their clinical features and laboratory tests. During the study period 98651 blood components were issued. Out of these 21971 were issued to various ICUs. A total of 225 transfusion reactions were reported from the various critical care departments during this period. The most frequent were Febrile Non Hemolytic Transfusion Reactions (FNHTR) 136 (60.4%), allergic reactions 70 (31.2%), hemolytic reactions 1(0.4%) and non specific reactions 18 (8%). The incidence of ATRs in our study was found to be 1.09% in adult ICUs and 0.36% in pediatric ICUs. Blood transfusion is a vital therapeutic procedure with a potential risk to already critical patients. So a strict vigilance has to be kept and each transfusion has to be monitored carefully with prompt recognition and treatment of ATRs. A rational use of these products considering their deleterious effects can decrease transfusion related morbidity and mortality in the critically ill patients.

Clinical response and transfusion reactions of sheep subjected to single homologous blood transfusion.

Studies in relation to blood conservation and responses to transfusion are scarce for ruminants. We evaluated the clinical manifestations of sheep that received a single homologous transfusion of whole blood, focusing on transfusion reactions. Eighteen adult sheep were subjected to a single phlebotomy to withdraw 40% of the total blood volume, which was placed into CPDA-1 bags and then divided into G0, animals that received fresh blood, and G15 and G35, animals that received blood stored for 15 or 35 days, respectively. Clinical observations were recorded throughout the transfusion, whereas heart rate, respiratory rate, and rectal temperature were assessed at the following times: 24 hours after phlebotomy and before transfusion; 30 minutes, six, twelve, 24, 48, 72, and 96 hours and eight and 16 days after transfusion. All groups presented transfusion reactions, among which hyperthermia was the most frequent (50% of animals). Tachycardia occurred most frequently in the G35 animals (50% of them). During transfusion G35 animals presented more clinical manifestation (P < 0.05). Transfusion of fresh or stored total blood improved the blood volume, but transfusion reactions occurred, demonstrating that a single transfusion of fresh or stored blood can cause inflammatory and febrile nonhemolytic transfusion reactions in sheep.

The impact of platelet additive solution apheresis platelets on allergic transfusion reactions and corrected count increment (CME)

Allergic transfusion reaction (ATR) incidence ranges from 1% to 3% of all transfusions. We evaluated the impact of InterSol platelet additive solution (PAS) apheresis platelets (APs) on the incidence of ATRs and the posttransfusion platelet (PLT) increment. This retrospective study evaluated all ATRs among patients at a university hospital that maintained a mixed inventory of PAS APs and non-PAS APs (standard plasma-suspended PLTs). Corrected count increments (CCIs) were calculated for AP transfusions of individuals who received both a PAS and a non-PAS AP transfusion within a 7-day period. Hypothesis testing was performed with chi-square test for dichotomous variables and t tests for continuous variables. The incidence of ATRs among the non-PAS APs was 1.85% (72 ATRs/3884 transfusions) and 1.01% (12 ATRs/1194 transfusions) for PAS APs (risk ratio [RR], 0.54; 95% confidence interval [CI]=0.30-0.99; p=0.04). However, there was no difference in the incidence of febrile nonhemolytic transfusion reactions between non-PAS APs (incidence, 0.70%; 27/3884) compared to PAS APs (incidence, 0.59%; 7/1194; p=0.69). Among 223 individuals with paired non-PAS and PAS AP transfusions, the mean CCI at 1 to 4 hours after transfusion was 4932 (95% CI, 4452-5412) for non-PAS APs and was lower for PAS APs (CCI, 3766; 95% CI, 3375-4158; p ≤ 0.001). However, there was no significant difference in mean CCI at 12 to 24 hours between non-PAS (CCI, 2135; 95% CI, 1696-2573) and PAS APs (CCI, 1745; 95% CI, 1272-2217; p=0.14). PAS APs substantially reduce the number of ATRs. CCIs for PAS APs were lower immediately after transfusion, but not significantly different at 12 to 24 hours.

Costs and benefits of PAS platelets: A mix of science, quality, and value

Costs and benefits of <scp>PAS</scp> platelets: A mix of science, quality, and value

Incidence of Transfusion-Related Adverse Reactions per Patient Reflects the Potential Risk of Transfusion Therapy in Japan

To describe the frequency of adverse reactions (ARs) after transfusion on both per transfused patient and per transfused unit bases. We performed a retrospective analysis of data available from records of 6 hospitals on the total number of transfusions and documented ARs between January 2008 and December 2009 for RBCs, fresh-frozen plasma (FFP), and platelet concentrates (PCs). The incidence of ARs to RBCs, FFP, and PCs per transfused unit was 0.6%, 1.3%, and 3.8%, respectively. The incidence of ARs to RBCs, FFP, and PCs per patient was 2.6%, 4.3%, and 13.2%, respectively-almost 3-fold higher. Most RBC-ARs were febrile nonhemolytic transfusion reactions and allergic reactions, whereas most FFP-ARs and PC-ARs were allergic reactions. The incidence of ARs per transfused patient may reflect better the potential risk of transfusion with blood components, taking into account the characteristics of the transfused patient.

Retrospective evaluation of adverse transfusion reactions following blood product transfusion from a tertiary care hospital: A preliminary step towards hemovigilance

Background:The goal of hemovigilance is to increase the safety and quality of blood transfusion. Identification of the adverse reactions will help in taking appropriate steps to reduce their incidence and make blood transfusion process as safe as possible.Aims:To determine the frequency and type of transfusion reactions (TRs) occurring in patients, reported to the blood bank at our institute.Materials and Methods:A retrospective review of all TRs reported to the blood bank at the All India Institute of Medical Sciences, between December 2007 and April 2012 was done. All the TRs were evaluated in the blood bank and classified using standard definitions.Results:During the study period a total of 380,658 bloods and blood components were issued by our blood bank. Out of the total 196 adverse reactions reported under the hemovigilance system, the most common type of reaction observed was allergic 55.1% (n = 108), followed by febrile non-hemolytic transfusion reaction (FNHTR) 35.7% (n = 70). Other less frequently observed reactions were Anaphylactoid reactions 5.1% (n = 10), Acute non-immune HTRs 2.6% (n = 5), Circulatory overload 0.5% (n = 1), Transfusion related acute lung injury 0.5% (n = 1), Delayed HTRs 0.5% (n = 1). Not a single case of bacterial contamination was observed.Conclusion:The frequency of TRs in our patients was found to be 0.05% (196 out of 380,658). This can be an underestimation of the true incidence because of under reporting. It should be the responsibility of the blood transfusion consultant to create awareness amongst their clinical counterpart about safe transfusion practices so that proper hemovigilance system can be achieved to provide better patient care.

Prévalence des anticorps antiplaquettes spécifiques chez les receveurs de concentrés plaquettaires avec effet indésirable transfusionnel

Purpose of the studyIn practice, platelet transfusions are frequently performed in patients with haematologic and/or oncologic diseases. Subsequent to these transfusions, platelet specific antibodies may develop and could induce adverse events, such as platelet transfusion refractoriness or post-transfusion purpura. In order to evaluate the prevalence of platelet specific antibodies in these recipients, adverse events with a request for platelet specific antibodies testing, were studied. Patients and methodsRecipients of platelet units with adverse event, excluding platelet transfusion refractoriness or post-transfusion purpura, were evaluated. ResultsFrom January 1st 2009 to October 31st 2011, 125 adverse events with platelet specific antibodies screening, corresponding to 116 recipients (64 females, 52 males) were included. The main aetiology of the adverse event was a febrile non-haemolytic transfusion reaction in 62 cases (49.6%) and allergy in 40 (32.0%). Most samples tested were post-transfusion solely (101 adverse events, 80.8%). Seven of these samples had free platelet specific antibodies, including four anti-HPA-5b, one anti-HPA-2a and two anti-GPIaIIa. In the cross-match test, platelet specific antibodies were found in two pre-transfusion samples (anti-GP IaIIa) and in five post-transfusion samples (anti-GPIaIIa, three cases; anti-GP IbIX, one case; anti-GP IIbIIIa and -GPIbIX, one case). ConclusionAccording to this study on platelet transfusion related adverse event, few platelet specific antibodies were detected on pre- and post-transfusion samples. The implementation of platelet specific antibodies testing before transfusion would give more accurate data and help prevent adverse events as typed platelets would be given when platelet specific antibodies were found.

Effects of Prestorage vs Poststorage Leukoreduction on the Rate of Febrile Nonhemolytic Transfusion Reactions to Platelets

The purpose of this study was to assess the incidence of febrile nonhemolytic transfusion reactions (FNHTRs) to concurrent transfusions of prestorage-leukoreduced (PreSLR) pooled platelets, poststorage-leukoreduced (PostSLR) pooled platelets, nonleukoreduced (NonLR) pooled platelets, and apheresis single-donor platelets (SDPs) to compare the rates of FNHTRs to PreSLR vs PostSLR pooled platelets. Reported transfusion reactions to platelets at 15 hospitals for a period of 45 months were retrospectively reviewed. Reaction rates to different types of platelet products were calculated and compared. During the study period, 70,015 platelet transfusions were administered. Among these, 152 (0.22%) FNHTRs and 111 (0.16%) allergic transfusion reactions were seen. Reported rates of FNHTRs were 0.07% (SDP), 0.16% (PreSLR), 0.30% (PostSLR), and 0.20% (NonLR) (P < .05 for PreSLR vs PostSLR). Rates of allergic reactions were 0.16% (SDP), 0.17% (PreSLR), 0.18% (PostSLR), and 0.11% (NonLR) (P > .05). The rates of reported FNHTRs were low for all types of platelet transfusions. SDPs and PreSLR pooled platelets were associated with a slightly lower rate of FNHTR compared with PostSLR pooled platelets.

Adverse effects of plasma transfusion

Plasma utilization has increased over the past two decades, and there is a growing concern that many plasma transfusions are inappropriate. Plasma transfusion is not without risk, and certain complications are more likely with plasma than other blood components. Clinical and laboratory investigations of the patients suffering reactions after infusion of fresh-frozen plasma (FFP) define the etiology and pathogenesis of the panoply of adverse effects. We review here the pathogenesis, diagnosis, and management of the risks associated with plasma transfusion. Risks commonly associated with FFP include: 1) transfusion-related acute lung injury, 2) transfusion-associated circulatory overload, and 3) allergic and/or anaphylactic reactions. Other less common risks include 1) transmission of infections, 2) febrile nonhemolytic transfusion reactions, 3) red blood cell alloimmunization, and 4) hemolytic transfusion reactions. The effects of pathogen inactivation or reduction methods on these risks are also discussed. Fortunately, a majority of the adverse effects are not lethal and are adequately treated in clinical practice.

Platelets from platelet-rich-plasma versus buffy-coat-derived platelets: what is the difference?

Platelets from platelet-rich-plasma versus buffy-coat-derived platelets: what is the difference?

Pattern of acute blood transfusion reactions in Kano, North-Western Nigeria

Background : Advancement in transfusion medicine has led to the use of large quantities of blood and blood components in modern clinical practice. The purpose of this study is to determine the pattern of acute blood transfusion reactions among adults in North-Western Nigeria. Materials and Methods: This was a descriptive observational study over a 3-month period that evaluated 302 blood transfusions in 180 consenting recipients in Aminu Kano Teaching Hospital. Data was analyzed using descriptive and inferential statistics, and P -values of ≤ 0.05 were regarded as significant. Results: The mean age of the recipients was 37.2 ± 13.7 (95% CI: 35.2 - 39.2) years. The incidence of acute transfusion reaction (ATRs) was 3.6%, out of which 3.3% were febrile non-hemolytic transfusion reaction (FNHTR) and 0.3% were acute allergic reaction (AAR). All the recipients that reacted presented clinically with fever and more than 90% of them had associated chills and/or rigors. There was a significant relationship between ATRs and history of previous transfusion (χ 2 = 4.12; P = 0.04) and stored blood of more than 3 days (χ 2 = 5.20; P = 0.02). Conclusion: Patients with previous history of transfusion should be monitored closely as they have a higher risk of developing transfusion reaction, and transfusion of blood stored for more than 3 days should as much as possible be avoided, especially in patients that have a potential risk of transfusion reaction.

ABO‐mismatched transfusions are not over‐represented in febrile non‐haemolytic transfusion reactions to platelets

ABO-mismatched plasma and platelet (PLT) transfusion have been associated with worse outcomes, including haemolysis and other reactions, compared to recipients of ABO-identical products. The immune complexes that form in a mismatched transfusion have been demonstrated to stimulate pyrogenic cytokine release in vitro. Comparing ABO identical vs. ABO mismatched PLT transfusions, we found no significant difference in the ABO compatibilities between the PLT doses implicated in causing febrile non-haemolytic transfusion reactions (FNHTR) in 162 recipients and both the baseline PLT donor/recipient ABO compatibility (P = 0·67) or the PLTs issued in the 30 days preceding the FNHTR (P = 0·92). ABO-mismatched PLT transfusions do not appear to be aetiological agents of FNHTR in a population routinely receiving both ABO-identical and ABO-mismatched transfusions.

Lyophilized Platelets: Challenges and Opportunities

Abstract : Live platelets have many complex functions other than clot formation. These include the modulation of fibrinolysis, inflammation, vascular tone, and cellular growth through substances released from cytoplasmic granules or direct interaction with endothelial cells, leukocytes, and macrophages. Many of these functions are poorly understood and serve as a reminder of the complexity of the cell that researchers seek to mimic.1 Despite improvements in the production of 22 C liquidstored platelets, conventional PCs have several drawbacks. Recipients continue to be at risk for febrile nonhemolytic transfusion reactions; the transmission of bacterial, viral, and protozoan infections; alloimmunization resulting in refractoriness to future platelet transfusions; and graft-versus-host disease. The potential for transfusion-associated immunosuppression has also been a concern. Shortages in platelet supply occur frequently, and the stockpiling of platelets is not feasible because of the short shelf life of conventional platelet concentrates. The result is often wastage owing to the expiration of platelet products, which is inevitable under current transfusion medicine practices. The decline in the donor pool and increase in platelet use over the past decade compounds the problem. These drawbacks have led to efforts to minimize the exposure of recipients to allogeneic blood products and to develop safe and effective platelet products and substitutes with longer shelf lives.2 Ideally, modified platelet products and substitutes should function hemostatically as live platelets do without causing pathologic thrombosis or a consumptive coagulopathy. A platelet substitute should not transmit infection, nor should it be immunogenic or cause reticuloendothelial blockade. Novel platelet products and platelet substitutes should have a long duration of action to allow long dosing intervals.

Red blood cells transfusions in oncological patients treated with radio- and chemoterapy

Anemia is one of the most frequent hematology disorders in patients with malignant diseases. It has a great influence on reduction of the quality of life, so it requires early diagnosis and an adequate treatment. The aim of this study was to present and analyze the treatment of anemia using red blood cell transfusions in patients with malignancies, to analyze adequate use of red blood cell transfusions according to hemoglobin concentration, and also the influence of the treatment of malignant disease on the level of anemia and use of red blood cells transfusion. This retrospective analysis included the data on the use of red blood cells in Oncological Clinic of Clinical Center Nis in a period from the 1st January 2008 to the 31st December 2008. None of the patients received the whole blood. In this period, 735 patients received 1006 units of red blood cells (red blood cell concentrate, resuspended, washed, filtered). An average use of red blood cell transfusion was 1.37 unit per oncological patient who received transfusion. The use of red blood cell units was adequate (87.60% of patients received transfusion of red cells when Hgb < 80 g/L). During radio- and chemotherapy we noticed a decrease of hematological parameter values. The patients of the experimental group were dependant on red blood cells transfusion. Statistically, a significant decrease of hemoglobin level was observed in patients treated only with radiotherapy who are the greatest consumers of red blood cells. Two patients were registered who more likely to have febrile nonhemolytic transfusion reactions. Posttransfusion alloimmunization occurred in 0.68% of the patients. The use of red blood cells in oncological patients is in compliance with the up to date tendencies and recommendations published in clinical guidelines. For the purpose of efficient transfusion support in patients with malignant diseases, we have to follow the newest knowledge and attitudes about clinical use of blood products.

BeadChip-Human Erythrocyte Antigen Determination for Leukoreduced Blood.

AbstractAbstract 1120 Background:Leukoreduction (LR) is a process by which leukocytes (WBC) are filtered from blood or blood component, as the leukocytes may increase the incidence of alloimmunization to human leukocyte antigens and may cause febrile nonhemolytic adverse transfusion reactions. Current transfusion practice also requires that, at minimum, blood selected for transfusion to a patient be checked (phenotyped) to be antigen negative to the existing alloantibodies in the patient's serum. Human Erythrocyte Antigen (HEA) Beadchip™ (Hashmi, G. et al. Transfusion, 47, April 2007, 736–747) has been adopted by blood centers and transfusion services for routine antigen-negative screening. A recent prospective study (Klapper, E. et al. Transfusion, 50, March 2010, 536–546) conducted in four large hospital transfusion services concluded that it is theoretically feasible to establish an inventory of DNA tested donor components from existing hospital inventories to result in the provision of more extensively matched RBC components than is the current standard of practice. Here described is a HEA LR eMAP-S BeadChip™ platform developed based on a combination of a novel DNA extraction protocol and a novel proprietary assay platform for Human Erythrocyte Antigens determination from leukoreduced blood samples. Methods:The BioArray Solutions HEA LR eMAP-S BeadChip Kit uses the novel Elongation Mediated Multiplexed Analysis of Polymorphisms in Solution (eMAP-S) technology (Lin, X. et al., 2010). The multiplex PCR amplifies 21 DNA fragments covering 24 allele variants associated with 32 human erythrocyte antigens plus one mutation for hemoglobin S. The PCR, is then followed by clean-up, multiplex allele specific primer extension (ASPE), and on-Beadchip™ detection and read-out by using the AIS-400 Array Imaging System. Verification studies was performed using 203 leukoreduced blood segments collected from various blood centers and transfusion services in US. A set of 30 blood samples was also obtained from before leukoreduction (whole blood, WBC count: 2308–6052 cells/ μL) and after leukoreduction (LR blood, WBC count:0.36-2.63 cells/μL), DNAs from LR blood samples were extracted by a novel DNA extraction method (BAS) using commercial reagents ((Qiagen, Inc., Valencia, CA).To evaluate the performance of HEA LR eMAP-S Beadchip™ Kit, the extracted DNA samples from before and after LR were analyzed by both HEA LR eMAP-S Beadchip™ and commercially available HEA 1.2 Beadchip™ Kit along with 88 whole blood DNA samples and positive controls with known HEA calls and analyzed for 10 red blood group systems (Rh, K, JK, FY, MNS, DO, Lu, Yt, Di, Co); and one mutation associated with hemoglobinopathies. Phenotype results obtained from HEA LR eMAP-S BeadChip™ Kit during the studies were compared to the data from the HEA 1.2 BeadChip™ Kit. Results:DNA was successfully extracted from 30 donor DNA samples before (DNA ng/ul: 20–56) and after LR (DNA ng/ul: 8–20) and analyzed using HEA LR eMAP-S Beadchip™ Kit with 100% concordance in HEA phenotype results. The WB DNAs were further analyzed using HEA 1.2 Beadchip™ kit and the results showed 100% concordance with LR DNA results. In addition, results from positive controls (HEA Ref-pA, HEA Ref-pB and cell line DNAs) all produced correct calls, and HEA LR eMAP-S assay and HEA 1.2 assay testing results on 88 donor whole-blood DNAs showed 100% concordance. Conclusion:HEA LR eMAP-S Beadchip™ Kit could be used for reliable determination of human erythrocyte antigens for leukoreduced blood samples. Disclosures:No relevant conflicts of interest to declare.

The cost‐effectiveness of pathogen reduction technology as assessed using a multiple risk reduction model

Pathogen reduction technology (PRT) for labile blood components has the potential to reduce the risk of many adverse events associated with transfusion. Because of the potential broad-spectrum risk reduction capability of PRT, the health economics of PRT could be an important consideration in decision making for this technology. Decision analytic models comparing current blood safety screens and interventions to riboflavin-based whole blood PRT (currently in development) and separately to platelets (PLTs)-and-plasma PRT from the health care system perspective in Canada were used to assess the cost-utility of PRT in reducing the following adverse events: human immunodeficiency virus, hepatitis B virus, hepatitis C virus, human T-lymphotropic virus, syphilis, West Nile virus, bacteria, Chikungunya virus, cytomegalovirus, Trypanosoma cruzi, graft-versus-host disease, febrile nonhemolytic transfusion reactions, and transfusion-related immunomodulation. PRT was modeled as an addition to rather than a replacement for current interventions. The potential of PRT to reduce the risk of an unknown pathogen was not assessed. Whole blood PRT was estimated to have a cost-effectiveness of $1,276,000/quality-adjusted life-year (QALY; 95% confidence interval [CI] approximation, 600,000-3,313,000) compared to current screens and interventions. PLTs-and-plasma PRT was estimated to have a cost-effectiveness of $1,423,000/QALY (95% CI approximation, 834,000-2,818,000) on an all-transfusions basis. Because of the complexity of transfusion risks and practices, the cost-effectiveness of whole blood or PLTs-and-plasma PRT can be modeled provided that assumptions and simplifications are made. Uncertainty remains with respect to the risk reduction that can be achieved for some adverse events. Nevertheless, the results of this cost-effectiveness analysis can be used to inform policy decisions regarding PRT technology in the context of other initiatives designed to improve transfusion safety.

An unusual febrile nonhemolytic reaction occurred after transfusion in a thalassemia major patient with asymptomatic Plasmodium falciparum infection

Febrile nonhemolytic transfusion reactions occur in 0.12% of transfusions, usually during transfusion or within 4 to 6 hours after transfusion and are not medically dangerous. A patient with thalassemia from Togo with asymptomatic malaria in which the infection became clinically manifest only after blood transfusion, mimicking a febrile nonhemolytic transfusion reaction, is presented. Thirty-two hours after transfusion of 2 O D- red blood cell (RBC) units, the patient (phenotype A(2) D+) developed fever and multiorgan failure and was admitted to the intensive care unit. Direct and indirect antiglobulin tests were negative on posttransfusion samples. Blood cultures and infectious diseases testing were negative. No malaria parasites were found at thick blood smear microscopic examination on Days 1 and 2 and the malaria rapid diagnostic test gave inconsistent results. Plasmodium total antibodies were detected in the serum at high levels. On Day 5, routine microscopic examination of blood smear revealed the presence of parasites in a very small number of RBCs. This finding was almost simultaneous to the availability of polymerase chain reaction testing results that were positive for P. falciparum. The sequential agglutination with anti-A antiserum allowed patient's and donors' RBCs to be separated and revealed that the parasitized cells were almost exclusively those of donors (14.4% vs. 0.029%). Malaria infection in implicated donors was excluded. In this patient with thalassemia with asymptomatic malaria, the infusion of two normal RBC units provided a favorable environment for a rapid parasite replication leading to a dramatic acute malaria attack.

Transfusion premedication to prevent acute transfusion reactions: a retrospective observational study to assess current practices

The use of premedication to prevent acute transfusion reactions has been estimated to occur in 50% to 80% of transfusions. While this practice has some biologic rationale, few clinical studies have been performed to assess the efficacy of this practice, and the methodologic quality of these studies is variable. The primary objective of this study was to describe current practices regarding transfusion premedication to prevent febrile nonhemolytic transfusion reactions, mild allergic transfusion reactions, and transfusion-associated circulatory overload. We conducted an observational retrospective chart review of a stratified random sample of 324 transfusions that took place over a 6-month period. Data were abstracted from medical records and then scanned into a database for analysis. We calculated inter- and intraobserver agreement on key abstracted data to estimate assessment error. A two-phase adjudication process was used to determine whether or not medications given before the time of each transfusion were intended as premedications. Of the transfusions sampled, 1.6% (95% confidence interval, 0.4-3.9) were associated with premedication medications to prevent an acute transfusion reaction. Inter- and intraobserver reliability in the abstraction of key data points was good. Good agreement in adjudicator classification of outcomes was achieved only when adjudicators were provided with patient source documents. Premedication use was infrequent and much less common than previously reported. Improved methods of capturing transfusion premedication, which likely require prospective assessments, are needed for future research studies.

Pharmacological interventions for the prevention of allergic and febrile non-haemolytic transfusion reactions

Allergic and febrile non-haemolytic transfusion reactions (NHTRs) are the two most common forms of transfusion reaction. Pretransfusion medication with anti-inflammatory drugs is used in NHTR prevention, however its efficacy and safety remains unclear. To assess the clinical effects and safety of pharmacological interventions for preventing NHTR in patients with and without a history of transfusion reactions. The search strategy included The Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 4, 2008), Cochrane Injuries Group's Specialised Register (December 17, 2008), MEDLINE (1950 to November (week 3) 2008), EMBASE (1988 to November (week 3) 2008), LILACS (1982 to January 12, 2009), CINAHL (1982 to December 2008), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED): 1970 to December 2008). There was no language restriction. Randomised controlled trials (RCTs) assessing the effectiveness of interventions for the prevention of NHTR. Authors independently selected studies, assessed the risks of bias and extracted data. Relative risks (RR) were estimated in RCTs with parallel design (PD). Odds ratio (OR) was estimated for one RCT with crossover design (CD). No meta-analysis was attempted due to differences in the pharmacotherapy of pre-transfusion medication and methodology between the studies; a per-protocol analysis was used. This review includes three RCTs (two PD and one CD). The PD-RCTs employed disparate units of randomisation (UofR); patient or transfusion, while the CD-RCT applied the patient as the UofR. The PD-RCTs administered leukodepleted blood products. Both PD-RCTs compared acetaminophen plus diphenhydramine (ApD) at different regimens with placebo, while the CD-RCT contrasted hydrocortisone pharmacotherapy with diphenhydramine. Both PD-RCTs found no statistically significant difference in allergic reactions (RR 0.13, 95% confidence interval (CI) 0.01 to 2.39, RR 1.46, 95% CI 0.78 to 2.73) and febrile reactions (RR 0.52, 95% CI 0.22 to 1.26). The CD-RCT found a statistically significant difference in the odds of febrile reactions (OR 2.38, 95% CI 1.07 to 5.27). The trials did not report anaphylactic reactions, deaths related to transfusion reactions or other adverse events. None of the three studies found that medication prior to transfusion reduces NHTR. This applied regardless of the patient's history of NHTR and the use of leukodepleted blood products in the transfusion. However, this conclusion is based on three trials of moderate to low quality. A better-powered RCT is necessary to evaluate the role of pretransfusion medication in the prevention of NHTR. Inclusion criteria should be restricted to patients at high risk of developing NHTR, with no restriction by age, history of transfusion reactions and type of blood products (leukodepleted or not).