Hemovigilance network in France: organization and analysis of immediate transfusion incident reports from 1994 to 1998

Blood transfusions in children: a multi-institutional analysis of practices and complications

BACKGROUND

Blood product transfusions are a valuable health-care resource. Guidelines for transfusion exist, but variability in their application, particularly in children, remains. The risk factors that threaten transfusion safety are well established, but because their occurrence in children is rare, single-institution studies have limited utility in determining the rates of occurrence. An epidemiologic approach that investigates blood transfusions in hospitalized children may help improve our understanding of transfused blood products in this vulnerable population.

STUDY DESIGN AND METHODS

This was a nonconcurrent cohort study of pediatric patients not more than 18 years of age hospitalized from 2001 to 2003 at 35 academic children's hospitals that are members of the Pediatric Health Information System (PHIS).

RESULTS

A total of 51,720 (4.8%) pediatric patients received blood product transfusions during the study period. Red blood cells (n = 44,632) and platelets (n = 14,274) were the two most frequently transfused products. The rate of transfusions was highest among children with neutropenia, agranulocytosis, and sickle cell crisis. Asian and American Indian patients had important differences in the rate of blood transfusions and their complications. Resource use in terms of length of stay and costs were higher in patients who received transfusion. Of those patients who received transfusions, 492 (0.95%) experienced a complication from the administered blood product. This accounted for a rate of complications of 10.7 per 1,000 units transfused.

CONCLUSIONS

The administration of blood products to children is a common practice in academic children's hospitals. Complications associated with these transfused products are rare.

Prevention of bedside errors in transfusion medicine (PROBE-TM) study: a cluster-randomized, matched-paired clinical areas trial of a simple intervention to reduce errors in the pretransfusion bedside check

BACKGROUND

Transfusion of the incorrect blood component is a frequent serious incident associated with transfusion and often involves misidentification of the patient and/or the unit of blood. The objective of this study was to assess the effect of a simple intervention designed to improve performance of the bedside check and to observe the durability of any effect. The intervention was a tag on blood bags reminding staff to check the patient's wristband. The tag was positioned in such a way that the transfusionist was required to remove the tag to spike the unit.

STUDY DESIGN AND METHODS

The intervention was tested in a multicenter cluster-randomized controlled trial incorporating short-term and long-term follow-up periods. The primary endpoint was the proportion of patients transfused with red cell units for whom the key elements of the bedside check were all correctly completed.

RESULTS

Fifteen matched-paired clinical areas at 12 participating hospitals in six countries were included in the trial. Combining data from all participating hospitals, the bedside check was correctly performed in 37 percent of transfusions during the baseline audit period. There was no evidence of a favorable effect of the intervention immediately after its introduction (pooled odds ratio, 1.09; 95% confidence interval, 0.54-2.17). There was similarly no evidence of a favorable effect after continued use of the intervention for an additional 8 weeks.

CONCLUSIONS

A simple intervention in the form of a barrier warning label on blood bags reminding staff to check the patient's wristband failed to improve bedside transfusion practice. The robust study design developed for this study could be applied to investigate other interventions to improve the safety of bedside transfusion practice.

Ex vivo production of human red blood cells from hematopoietic stem cells: what is the future in transfusion?

There is difficulty in obtaining adequate supplies of blood components, as well as disappointing performance of stabilized or recombinant hemoglobins, limited indications of oxygen transporters (perfluorocarbons), and slow development of "universal" red blood cells (RBCs). There is, therefore, a need for complementary sources of RBCs for transfusion. Thus, an attempt to generate erythroid cells in vitro makes good sense. We describe in this article a methodology permitting the massive ex vivo production of mature human RBCs having all the characteristics of native adult RBCs from hematopoietic stem cells of diverse origins: blood, bone marrow, or cord blood. This protocol allows both the massive expansion of hematopoietic stem cells/progenitors and their complete differentiation to the stage of perfectly functional mature RBCs. The levels of amplification obtained (10(5) to 2 x 10(6)) are compatible with an eventual transfusion application. We discuss in this article the state of the art of this new concept and evoke possible obstacles that need to be overcome to pass from a laboratory model to clinical practice. We analyze its possible indications in the medium and long term, discuss the economic aspects, and raise the question: Can we afford the luxury of developing this approach, one that could represent a considerable advance in blood transfusion?

Transfusion-transmitted infections

Although the risk of transfusion-transmitted infections today is lower than ever, the supply of safe blood products remains subject to contamination with known and yet to be identified human pathogens. Only continuous improvement and implementation of donor selection, sensitive screening tests and effective inactivation procedures can ensure the elimination, or at least reduction, of the risk of acquiring transfusion transmitted infections. In addition, ongoing education and up-to-date information regarding infectious agents that are potentially transmitted via blood components is necessary to promote the reporting of adverse events, an important component of transfusion transmitted disease surveillance. Thus, the collaboration of all parties involved in transfusion medicine, including national haemovigilance systems, is crucial for protecting a secure blood product supply from known and emerging blood-borne pathogens.

Les bactéries : je dépiste ou j’inactive ?

The main cause of adverse events secondary to the transfusion of platelet concentrates (PC) is due to bacterial contamination. The detection of bacteria in PC is not associated with a beneficial effect in terms of prevention of fatal septic events. Inactivation of pathogen in PC using photochemical techniques is targeted not only to bacteria but also to a wide spectrum of viruses, spirochetes, parasites and leukocytes. Pathogen inactivation is a pro-active method which anticipates the contamination of the blood pool by emerging pathogens.

Introduction en pratique transfusionnelle des concentrés de plaquettes en solution de conservation

Platelet additive solutions (PAS) have been developed since the years 1980. However, decisive improvements have been made in the last five years, leading nowadays to several PAS available for transfusion practice. Few compounds are present in PAS, with the intention of controlling platelet metabolic alterations and activation that occur during storage: acetate, which is a substrate for the tricarboxylic acid cycle, enables to maintain oxidative metabolism, is present in all PAS; a buffer effect is required to prevent the progressive pH fall during storage, and is obtained either with sodium phosphate or gluconate; platelet activation is controlled by citrate, and in the latest PAS, by magnesium and potassium. It is important to note that whatever the PAS used, it is mandatory to maintain a final concentration of 20-40% of plasma, mainly in order to ensure glucose availability. The use of PAS leads to a more rationalized blood processing, as it provides an additional volume of plasma available for plasma fractionation, it contributes to standardization of blood components, and it is part of at least one pathogen reduction process. The expected benefit for patient is the reduction of adverse reactions related to plasma. There is already evidence that the incidence of allergic adverse reactions is reduced. In the case of other less frequent adverse reactions such as transfusion related acute lung injury (TRALI) or haemolytic reaction due to minor ABO incompatibility, only a long-term follow-up through haemovigilance organization will be informative.

[Transfusion-related acute lung injury]

OBJECTIVES

The transfusion-related acute lung injury frequency was for a long time underestimated since it lacked both a widely accepted clinical definition and a comprehensive etiologic description. Recent clinical and biological data have underlined its frequency and have allowed a better understanding of its mechanisms.

CURRENT KNOWLEDGE AND KEY POINTS

Trali is an interstitial lung injury occurring within 6 hours after the beginning of a blood transfusion. This time relationship between blood injection and the occurrence of lung edema is sufficient for a positive diagnosis, if any other cause of interstitial lung edema have been excluded. The clinical definition relies on a desaturation of arterial blood associated to a lack of any cardiac failure or circulation overload. The link between transfusion and lung edema is not univocal and several categories of mechanisms have been discussed. At least 2 of them are well identified; the first one is an immune conflict, and the second one is an activation of neutrophils by injection of biological modifiers such as lipids or CD40 soluble ligand. Evidences exist for the occurrence of Trali only in predisposing condition that mostly consists of a preceding leucostase in lung capillaries. Trali is treated like other lung interstitial edema by oxygen therapy and mechanical ventilation.

FUTURE PROJECTS

A better knowledge of Trali offers the opportunity of improving the understanding of the role of blood transfusion in lung edema occurring in complex situations and open the way for a better definition of at risk patient and at risk blood components.

A revised classification scheme for acute transfusion reactions

BACKGROUND

Although the standard classification system for acute transfusion reactions adequately describes the general features associated with the various types of reactions, it was not designed to provide strict criteria for diagnosis and classification. Consequently, its use to classify individual reactions can result in significant inter- and intraobserver variability, which can complicate patient management and clinical research.

STUDY DESIGN AND METHODS

A total of 595 transfusion reactions that occurred at a single institution between January 1, 1996, and December 31, 2003, were reviewed and were initially classified according to the established conventions of the AABB. Each reaction was then reclassified with a revised system that refines and clarifies reaction categories, adds severity grades in the format of the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE), and includes terminology to indicate the attribution or likelihood that the adverse event is related to the transfusion.

RESULTS

Comparison of the two approaches as applied to these 595 transfusion reactions showed clear advantages for the revised system. Of 128 reactions classified by AABB criteria as inconclusive, a mixture of reaction types, or otherwise qualified, all but 5 were accommodated by discrete categories within our revised scheme. In each case with a classifiable reaction, the severity of the reaction could be readily graded.

CONCLUSION

The advantages of this revised classification scheme for acute transfusion reactions warrant prospective evaluation and ultimately consideration of its incorporation into clinical practice.

The first data from the haemovigilance system in Italy

BACKGROUND

Haemovigilance is defined as the surveillance of adverse reactions occurring in donors and in recipients of blood components and as epidemiological surveillance of donors. The ultimate purpose of haemovigilance is to prevent the repetition of adverse events and reactions. Since the 2002/98/EC Directive came into force, the introduction of haemovigilance systems has become a priority for all countries in the European Community. The Italian haemovigilance system is essentially in line with the Directive, although it does not include surveillance of adverse events in donors and does not have a national level of registration of severe incidents connected with the collection, processing and storage of blood and blood components. Epidemiological surveillance of donors has been performed nationally since 1989 for HIV and since 1999 for HBV, HCV and Treponema pallidum. Surveillance of adverse events in recipients was started at the end of 2004.

MATERIALS AND METHODS

The national form proposed for notifying adverse reactions (PETRA) was prepared by the National Institute of Health and distributed to all Transfusion Structures.

RESULTS

The data collected (adverse reactions, errors, and near miss errors) came from 21.0% of the Transfusion Structures in 2004 and 38.4% in 2005. The system monitored 49.6 % of all the units distributed in Italy. Overall 1,495 adverse reactions were reported, which is equivalent to 0.8 reactions/1,000 units of blood components distributed. There were 16 reports of errors involving transfusions to the wrong patient. Not all the Transfusion Structures sent their data using the PETRA form. From the 986 PETRA forms received, it was possible to analyse the relevance of the transfusion, the outcome of the patient, the type of blood component involved, the type of error and the type of near miss error.

CONCLUSIONS

This study is the first Italian report on transfusion errors and adverse reactions.

New technology for transfusion safety

Hemovigilance programs from around the world document that the greatest risk to recipients of blood transfusion is human error, resulting in transfusion of the incorrect blood component. Errors in transfusion care have strong parallels with errors in medication administration. Errors often result from 'lapse' or 'slip' mistakes in which details of patient identification are overlooked. Three areas of transfusion are focal points for improved care: the labelling of the patient's pre-transfusion sample, the decision to transfuse and the final bedside check designed to prevent mis-transfusion. Both barcodes and radio-frequency identification technology, each ideally suited to matching alpha-numeric identifiers, are being implemented in order to improve performance sample labelling and the bedside check. The decision to transfuse should ultimately be enhanced through the use of nanotechnology sensors, computerised order entry and decision support systems. Obstacles to the deployment of new technology include resistance to change, confusion regarding the best technology, and uncertainty regarding the return-on-investment. By focusing on overall transfusion safety, deploying validated systems appropriate for both medication and blood administration, thoughtful integration of technology into bedside practice and demonstration of improved performance, the application of new technologies will improve care for patients in need of transfusion therapy.

Acute transfusion reactions in the pediatric intensive care unit

BACKGROUND

Acute transfusion reactions (ATRs) are probably underdiagnosed in critically ill children because associated symptoms can frequently be attributed to the patient's underlying disease. This study was undertaken to determine the incidence, type, imputability, and severity of ATRs observed in a tertiary care pediatric intensive care unit (PICU).

STUDY DESIGN AND METHODS

All transfusions of labile blood product administered to consecutive patients admitted to our PICU, between February 2002 and February 2004, were prospectively recorded. For each transfusion, the bedside nurse recorded the patient's status before, during, and up to 4 hours after the transfusion, as well as the presence of any new sign or symptom suggesting an ATR. Three independent experts retrospectively reviewed all transfusion event reports and hospital charts. The presence, type, imputability, and severity of ATRs were adjudicated by consensus of two of three experts (Delphi method), with predefined criteria.

RESULTS

A total of 2509 transfusions were administered to 305 patients during the study. Forty transfusion events (1.6%) were confirmed to be ATRs by expert consensus: 24 febrile nonhemolytic, 6 minor allergic, 4 isolated hypotension, 3 bacterial contamination, 1 major allergic (anaphylactic shock), 1 TRALI, and 1 hemolytic reaction. Imputability of ATRs was probable or possible in 35 cases (88%). ATRs led to an immediate vital threat in 15 percent of cases.

CONCLUSION

Improved surveillance of transfusions given to PICU patients and better knowledge of these reactions by health care professionals should improve the safety of transfusions in the PICU.

Differential sensitivities of pathogens in red cell concentrates to Tri-P(4)-photoinactivation

BACKGROUND AND OBJECTIVES

Photodynamic treatment (PDT) with the cationic porphyrin, mono-phenyl-tri-(N-methyl-4-pyridyl)-porphyrin chloride [Tri-P(4)], has previously been shown to be effective at inactivating vesicle stomatitis virus (VSV) in red cell concentrates (RCC) with limited damage to red blood cells (RBC). The aim of this study was to determine the pathogen-inactivating capacity of PDT with Tri-P(4) for a broader range of pathogens and to establish the associated effect on in vitro RBC quality.

MATERIALS AND METHODS

A series of viruses and bacteria was spiked into 60% RCC. Pathogen inactivation was determined after PDT with 25 microm Tri-P(4) and red light up to 360 kJ/m2. Human immunodeficiency virus (HIV)-infected cells were evaluated for cell death induction, and RCC were analysed for the induction of haemolysis and ATP content.

RESULTS

For the lipid-enveloped viruses bovine viral diarrhoea virus, HIV and pseudorabies virus, and for the Gram positive bacterium, Staphylococcus aureus, and the Gram-negative bacteria, Pseudomonas aeruginosa and Yersinia enterolitica, inactivation of > or = 5 log10 was measured after 60 min of PDT with Tri-P(4). The required treatment time to achieve this level of inactivation was four times longer than required for VSV. For cell-associated HIV, only 1.7 log10 of inactivation was found, despite clear induction of cell death of HIV-infected cells. The non-enveloped virus, canine parvovirus, was completely resistant to the treatment. PDT of RCC with Tri-P(4) for 60 min, and subsequent storage in AS-3, resulted in 4% haemolysis after 35 days of storage. The ATP content of untreated and treated RBC declined with similar kinetics during storage.

CONCLUSION

PDT of RCC with Tri-P(4) for 60 min inactivates a wide range of pathogens, but not cell-associated HIV and a non-enveloped virus, and compromises RBC quality. This reduces the suitability of PDT with Tri-P(4) for red cell sterilization. Therefore, further improvements in the treatment procedures to potentiate pathogen inactivation and to preserve RBC integrity will be required to generate an effective treatment for sterilizing RCC.

The clinical benefits of the leukoreduction of blood products

Many adverse events associated with the transfusion of allogeneic blood products have been shown to be related to the presence of allogeneic leukocytes in the blood product transfused. Until recently little attention has been paid to the leukocytes present in various blood components, however, over the past two decades it has been shown that the removal of such "passenger" leukocytes is associated with improved clinical outcomes. These include: the reduction in the incidence and severity of febrile transfusion reactions; reducing the CMV transfusion transmission risk; reducing the risk of alloimmune platelet refractoriness; the possible avoidance of vCJD transmission; as well as reducing the risk of mortality and organ dysfunction in cardiac surgery patients, and possibly in other categories of patients.

Risks of fresh frozen plasma and platelets

Both fresh frozen plasma (FFP) and platelets are heavily used in massive transfusion. Although FFP can partially correct abnormal coagulation, a recent systematic review revealed no randomized trials showing clinical benefit. Although the overall risks of FFP and platelets are low, they are the least safe blood components, due to immunologic reactions such as allergy/anaphylaxis, transfusion-related acute lung injury (TRALI) and hemolysis due to anti-A or anti-B if transfused across ABO groups. TRALI, an acute syndrome of dyspnoea, hypoxia and pulmonary 'white-out' is now a major cause of transfusion-related death. Since it is usually triggered by donor HLA antibodies, selecting non- immune donors for FFP production may be beneficial. For platelet components, risks may be reduced by platelet additive solution, allowing removal of 70% of plasma. Platelets have the additional hazard of bacterial contamination, with donor skin the predominant source. Improved arm cleansing, divert pouches for the first 30-50 mL blood and bacterial screening have been adopted internationally. Virus risks are now vanishingly low, although new agents e.g. West Nile virus can still appear. Pathogen reduction for FFP is now well established in Europe, with solvent detergent and methylene blue methods licensed, and the psoralen amotosalen in trial. Loss of clotting factors and natural anti-coagulants are recognized side effects. Amotosalen is also licensed for platelet concentrates, with the added benefit of bacterial killing. In the UK, concern regarding vCJD has led to importation of US FFP for children.

Detection of a new weak A blood-group allele (Aw11)

BACKGROUND AND OBJECTIVES

Weak ABO variants may escape tests using unlicensed sera.

MATERIALS AND METHODS

Prior to transfusion, ABO grouping was performed using an automated system and in-house diluted sera, and manual and bedside test techniques. Genotyping and sequencing were performed using standard methods.

RESULTS

Initially, the red blood cells (RBC) of the first-time blood donor were typed as B, but pretransfusion testing carried out using the bedside test indicated the presence of an additional A phenotype. Serological re-examination confirmed the bedside test results, and the allele in question was identified, by genotyping, as a new weak A variant (Aw11).

CONCLUSIONS

The use of CE-marked and licensed antisera is recommended to avoid ABO mistyping.

Evaluation of the enhanced bacterial detection system for screening of contaminated platelets

BACKGROUND

The Pall third-generation enhanced bacterial detection system (eBDS) was recently approved for detection of bacterial contamination in leukoreduced platelets (PLTs). The method is based on the measurement of the oxygen content as a marker for bacteria. eBDS incorporates major modifications including removal of the sample-set filter, modification of the culture medium, and incubation with agitation of the sample pouch.

STUDY DESIGN AND METHODS

Ten whole blood-derived random-donor PLT units collected on Day 1 after donation and 10 single-donor apheresis PLT units were spiked with low levels of bacteria in three different blood transfusion centers. Inoculation was performed at a final concentration of 5 to 50 colony-forming units per mL with reference strains of five organisms involved in severe transfusion-associated infections. PLT units were stored at 22 degrees C for 24 hours before sampling. Six sample sets were then sterile-connected to each unit and placed on a horizontal agitator at 35 degrees C for 18 or 24 hours of incubation.

RESULTS

No false-positive results were obtained, indicating a 100 percent specificity of the assay. Of 126 spiked sample pouches tested, 61 of 63 (96.82%) and 63 of 63 (100%) were detected positive after 18 or 24 hours of incubation, respectively. In the two missed cases that failed to detect Bacillus cereus, the measured oxygen was slightly above the detection threshold but was markedly different from the negative samples.

CONCLUSION

The eBDS method allows definitive testing of PLTs as soon as 42 hours after collection and offers an alternative culture method to the BacT/ALERT system.

Assessment of the economic value of the INTERCEPT blood system in Belgium

Emerging pathogens continue to threaten blood safety, requiring novel safety approaches. INTERCEPT Blood System for platelets (IBSP) inactivates pathogens, aiming at eliminating the risk of transmitting current and emerging pathogens. The objective was to evaluate the incremental cost-effectiveness ratio (ICER) for IBSP in Belgium. A decision model comparing a 'world with IBSP' to a 'world without IBSP' calculates lifetime costs and 'quality adjusted life years' (QALYs) following platelet transfusion in different indications. Disease-specific life expectancy and consequences of transfusion-transmitted infections were obtained from literature. Transfusion safety and costs were obtained from official sources. Hepatitis C virus-like emerging pathogen was simulated. A wide range of ICERs was observed, highly sensitive to the risk of emerging pathogen trans- mission, underlying disease and age. In the most conservative approach, ICER ranged from 3,459,201 Euro/QALY in absence of emerging pathogen to 195,364 Euro/QALY. The mean threshold of emerging infection risk for IBSP dominance (saving money and producing health gains) ranged from 1/1,079 to 1/2,858 transfusions. Considering the high value authorities appear to place on preventing accidental injury, and ICER of recent implementations in transfusion medicine (NAT: up to 2.3 million Euro per lifeyear), IBSP can be considered cost-effective, taking into account the potential risk of emerging pathogens.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a life-threatening adverse event of transfusion, which has an increasing incidence in the United States and is the leading cause of transfusion-related death. TRALI and acute lung injury (ALI) share a common clinical definition except that TRALI is temporally- and mechanistically-related to transfusion of blood or blood components. A number of different models have been proposed to explain the pathogenesis. The first is an antibody-mediated event whereby transfusion of anti-HLA, class I or class II, or anti-granulocyte antibodies into patients whose leukocytes express the cognate antigens. The antibody:antigen interaction causes complement-mediated pulmonary sequestration and activation of neutrophils (PMNs) resulting in TRALI. The second is a two-event model: the first event is the clinical condition of the patient resulting in pulmonary endothelial activation and PMN sequestration, and the second event is the transfusion of a biologic response modifier (including anti-granulocyte antibodies, lipids, and CD40 ligand) that activates these adherent PMNs resulting in endothelial damage, capillary leak, and TRALI. These hypotheses are discussed with respect to animal models and human studies that provide the experimental and clinical relevance. The definition of TRALI, patient predisposition, treatment, prevention and reporting guidelines are also examined.

ABO incompatible transfusions--experience from the UK Serious Hazards of Transfusion (SHOT) scheme Transfusions ABO incompatible

The Serious Hazards of Transfusion (SHOT) scheme has now accumulated 8 years' data. The most frequently occurring adverse event, accounting for 1832/2628 (70%) of incidents reported, is 'incorrect blood component transfused' (IBCT) in which the patient receives a blood component that did not meet the correct specification or that was intended for another patient. Errors can occur at all stages of the transfusion chain and, in about half of cases, multiple system failures can be identified. Analysis of 130 ABO incompatible transfusions reported between 1999 and 2003 identified 221 separate errors, 68% of which took place in clinical areas and 29% in hospital laboratories. The commonest single error is failure to check at the bedside that the right blood is being given to the right patient. Certain patients, e.g. neonates, those transfused at night and in critical care situations, appear to be particularly vulnerable. It is encouraging that, against a background of ever increasing numbers year-on-year of reports of IBCT, the incidence of ABO incompatible transfusions already shows a downward trend, suggesting the emergence of a safety culture.

Reducing adverse events in blood transfusion

Against a background of ever increasing expenditure on blood safety, less attention has been paid to improving the safety of the transfusion chain within hospitals. Based on reports to the Serious Hazards of Transfusion (SHOT scheme) between 1996 and 2003, the risk of an error occurring during transfusion of a blood component is estimated at 1:16 500, an ABO incompatible transfusion at 1:100 000 and the risk of death as a result of an 'incorrect blood component transfused' (IBCT) is around 1:1 500 000. There are opportunities for error at a number of critical points in the transfusion chain, starting with the decision to transfuse, prescription and request, patient sampling, pretransfusion testing and finally the collection of the component from the blood refrigerator and administration to the patient, consistently the commonest error in successive SHOT reports. Successive 'Better Blood Transfusion' initiatives and the 2003 Annual Report of the Chief Medical Officer for England have drawn welcome attention to the importance of safe and appropriate transfusion and the National Patient Safety Agency has now set a target of reducing the number of ABO incompatible transfusions by 50% over 3-5 years.

Bicarbonate inhibits the growth of Staphylococcus epidermidis in platelet concentrates by lowering the level of non-transferrin-bound iron

BACKGROUND

Platelet concentrates (PCs) contain non-transferrin-bound iron (NTBI) owing to the displacement of iron from plasma-derived transferrin by citrate. NTBI in the PC medium supports the growth of Staphylococcus epidermidis. The possibilities of lowering the level of NTBI have been studied with the aim to inhibit the growth of S. epidermidis in the PC medium.

STUDY DESIGN AND METHODS

NTBI in PC supernatants was determined by a chelation method and by the bleomycin-detectable iron assay. Iron binding by transferrin was determined by spectrophotometry. The growth of inoculated S. epidermidis in PC supernatants was monitored by optical density and determination of viable counts.

RESULTS

Bicarbonate enhanced in a dose-dependent manner transferrin iron binding in citrate-containing solutions, including citrated plasma and PAS-II. The use of a modified anticoagulant supplemented with bicarbonate effectively lowered the level of NTBI and inhibited bacterial growth in citrated plasma. Supplementation of bicarbonate to the additive solution to increase the ratio of bicarbonate to citrate in a reconstituted PC medium further inhibited bacterial growth. Maintenance of stable pH and bicarbonate level in the reconstituted medium necessitated storage under 5 percent CO(2).

CONCLUSIONS

The relatively low bicarbonate level in PC medium promotes iron displacement by citrate from plasma-derived transferrin. The appearance of NTBI can be decreased and iron-dependent bacterial growth can be inhibited by increasing bicarbonate level in citrated plasma and PC medium. To achieve the same beneficial effect in blood banking, other more practical ways to bind NTBI in a harmless form should be developed.

Transfusion-related acute lung injury (TRALI): a serious adverse event of blood transfusion

BACKGROUND AND OBJECTIVES

Analyses of fatal transfusion reactions in the UK and USA have shown that transfusion-related acute lung injury (TRALI) is among the most common causes of fatal transfusion reactions.

MATERIAL AND METHODS

Review of the literature was used to analyse TRALI.

RESULTS

TRALI is characterized by acute respiratory distress and non-cardiogenic lung oedema developing during, or within 6 h of, transfusion. In atypical cases, TRALI can become symptomatic much later. TRALI must be carefully differentiated from transfusion-associated circulatory overload. In its fulminant presentation, TRALI can be clinically indistinguishable from acute respiratory distress syndrome occurring as a result of other causes. The severity of TRALI depends upon the susceptibility of the patient to develop a more clinically significant reaction as a result of an underlying disease process, and upon the nature of triggers in the transfused blood components, including granulocyte-binding alloantibodies (immune TRALI) or neutrophil-priming substances such as biologically active lipids (non-immune TRALI). Immune TRALI, which occurs mainly after the transfusion of fresh-frozen plasma and platelet concentrates, is a rare event (about one incidence per 5000 transfusions) but frequently ( approximately 70%) requires mechanical ventilation (severe TRALI) and is not uncommonly fatal (6-9% of cases). Non-immune TRALI, which occurs mainly after the transfusion of stored platelet and erythrocyte concentrates, seems to be characterized by a more benign clinical course, with oxygen support sufficient as a form of therapy in most cases, and a lower mortality than immune TRALI.

CONCLUSIONS

By virtue of its morbidity and mortality, TRALI has become one of the most serious current complications of transfusion. To prevent further antibody-mediated cases, the evaluation of TRALI should include leucocyte antibody testing of implicated donors. However, further studies are necessary for the prevention of this serious transfusion complication.

Reengineering transfusion and cellular therapy processes hospitalwide: ensuring the safe utilization of blood products

Efforts to make blood transfusion as safe as possible have focused on making the blood in the bag as disease-free as possible. The results have been dramatic, and the costs have been correspondingly high. Although blood services will have to continue to deal with emerging pathogens, efforts to reduce the transfusion of infectious agents presently posing a risk will require high incremental costs and result in only improvements of a small magnitude. The other aspect of safe blood transfusion, the actual transfusion process performed primarily in hospitals, has been accorded considerably less interest. We should turn our attention to enhancing overall blood safety by focusing on improving the process of blood transfusion. Errors involving patient, specimen, and blood product identification put transfused patients at risk, increasing the mortality risk for some. Solutions that could improve the transfusion process are discussed as a focus of this article.

Failure of bedside ABO testing is still the most common cause of incorrect blood transfusion in the Barcode era

BACKGROUND AND OBJECTIVES

ABO-incompatible red blood cell (RBC) transfusions are a major risk in transfusion medicine. Identification of factors leading to this hazard is important to improve transfusion safety.

MATERIAL AND METHODS

All consecutive erroneous ABO-incompatible transfusions occurring from January 1997 to December 2004 at the Charité University Hospital in Berlin, Germany were analysed.

RESULTS

A total of 343,432 RBC units were transfused, and eight patients erroneously received 13 ABO-incompatible RBC concentrates. The most frequent error was incorrect bedside testing (n=7). Intensive care treatment was required in two cases, but there were no fatal mistransfusions. Four patients had no or only mild reactions.

CONCLUSION

Mistransfusions are still a considerable risk in transfusion medicine despite quality control systems and electronic data processing. An increase in transfusion safety may require the introduction of further systems, e.g. radio-frequency identification (RFID) tags.

Errors in transfusion medicine

In the past two decades, health services in the developed world have directed much resource toward improving the safety of the blood supply. Blood is collected, tested, and processed within a carefully controlled environment, and quality is assured by rigorous donor selection procedures and increasingly sensitive and sophisticated testing for transfusion-transmitted pathogens. Additional safety strategies implemented by some blood services include leukocyte reduction, bacterial screening, and pathogen inactivation. Thus, the transfusion chain from the donor to the point of issue from the blood center is highly regulated and secure, and transfusion-transmitted infection is an increasingly rare event.

Haemovigilance in a general university hospital: need for a more comprehensive classification and a codification of transfusion-related events

BACKGROUND AND OBJECTIVES

The purpose of this study was to analyse the transfusion-related events recorded in a general university hospital.

MATERIALS AND METHODS

The method we used was retrospective analysis of the data collected between 1999 and 2003.

RESULTS

The incidence of transfusion reactions (n = 394) was 4.19 per 1000 blood products distributed: 59% (n = 231) were febrile non-haemolytic transfusion reactions; 22% (n = 88) were caused by allergy; 5% (n = 21) were caused by bacterial infection; and 14% (n = 54) were classified as other reactions. Platelet concentrates gave rise to a significantly greater number of reactions than erythrocyte concentrates and fresh-frozen plasma. Transfusion errors and near-miss events were also observed and were analysed separately. A series of transfusion-related events, such as haemosiderosis, metabolic disturbances or volume overload, were not reported.

CONCLUSIONS

Our experience prompts us to propose a more comprehensive classification and codification of transfusion-related events.

De la détection bactérienne à l'inactivation des pathogènes

Bacterial contamination of blood components remains the highest infectious risk in blood transfusion, the risk is particularly high when it affects platelet concentrates (PC). In France, the residual risk of transfusion reaction due to bacterial contamination of PC has been decreasing slowly since 1994 but for all severity 1 case occurs with about 25,000 distributed PC and one death occurs with 200,000 distributed units. This reduction of the risk may be due to the measures which were implemented during the last 10 years in order to prevent contamination during donation. Improving strategies for reducing the risks of bacterial contamination is one of the priorities of the French National Blood Transfusion Service (l'Etablissement Français du sang - EFS). The main target remains PC. Bacterial detection or pathogens inactivation are now available and are able to reduce (for detection) or prevent (for inactivation) the occurrence of reaction due to bacterial contamination of PC. Up to now, the choice is in favour of bacterial detection. A national study was carried out in seven regional EFS at the end of 2004. It aims at confirming the feasibility of a systematic bacterial screening of PC before their delivery. The first conclusions show that this screening can be implemented with acceptable modifications in term of platelets availability. We can expect in a next future that new pathogens reduction technique and/or new detection systems will be available, certainly more efficient to prevent reaction due to bacterial contamination. Implementation of actual detection methods is probably a temporary solution.

Protecting the blood supply from emerging pathogens: the role of pathogen inactivation

Although the risk of infection by blood transfusion is relatively low, breakthrough infections still occur, Transfusion-related fatalities caused by infections continue to be reported, and blood is not tested for many potentially dangerous pathogens. The current paradigm for increasing the safety of the blood supply is the development and implementation of laboratory screening methods and restrictive donor criteria. When considering the large number of known pathogens and the fact that pathogens continue to emerge, it is clear that the utility of new tests and donor restrictions will continue to be a challenge when considering the cost of developing and implementing new screening assays, the loss of potential donors, and the risk of testing errors. Despite improving the safety of blood components, testing remains a reactive approach to blood safety. The contaminating organisms must be identified before sensitive tests can be developed. In contrast, pathogen inactivation is a proactive strategy designed to inactivate a pathogen before it enters the blood supply. Almost all pathogen inactivation technologies target nucleic acids, allowing for the inactivation of a variety of nucleic acid-containing pathogens within plasma, platelets, or red blood cells thus providing the potential to reduce transfusion-transmitted diseases. However, widespread use of a pathogen inactivation technology can only be realized when proven safe and efficacious and not cost-prohibitive.

Satisfaction survey in general hospital personnel involved in blood transfusion: implementation of the ISO 9001: 2000 standard

As part of its policy of constant quality improvement, Etablissement francais du sang (EFS) des pays de la Loire (Pays de la Loire Regional Blood Transfusion Centre) carried out a satisfaction survey among the hospital personnel involved in prescribing and using immunohaematological tests and labile blood products (LBP). The polling tool selected by agreement between the Saint Nazaire's hospital management and Quality Assurance (QA) Department was a questionnaire that permitted item rating and free commentary. It addressed the personnel's perception of the quality of erythrocyte immunohaematological (EIH) testing and of the products administered, as well as their perception of the quality of communications with the local EFS. The questionnaire was sent to 26 physicians and 32 senior nurses in 15 hospital departments. The reply rate was 60% and expressed an 85% overall satisfaction level. Dissatisfaction causes were more specifically analysed, the main one involving LBP distribution in emergency situations. A joint undertaking by the EFS and the hospital led to the implementation of corrective measures, including the writing and implementation of a common standard operating procedure for emergency transfusion management. The results obtained demonstrated the feasibility of this type of survey and the interest, to a blood transfusion centre and the hospital personnel involved in transfusion, of assessing their very own perception of service quality.

Worldwide overview of existing haemovigilance systems

Haemovigilance is a "quality process" with the aim to improve quality and increase safety of blood transfusion, taking into account that haemovigilance covers and surveys all activities of the blood transfusion chain from donors to recipients. Haemovigilance is indispensable when it comes to safety and quality of blood transfusions. Within the European Union (EU), the European Blood Directive requires haemovigilance in each Member State: the intention has been to rely on the existing or developing national systems. There are significant differences in haemovigilance around the world, in terms of definition, organisational schemes, state of development and implementation. These differences are more pronounced outside the EU: in some countries, even basic traceability causes a problem while in others systems similar as the most developed ones in the EU are implemented.

Six years' experience of using the BacT/ALERT system to screen all platelet concentrates, and additional testing of outdated platelet concentrates to estimate the frequency of false-negative results

BACKGROUND AND OBJECTIVES

Approximately 1 in every 2000 units of platelets is contaminated with bacteria. The BacT/ALERT automated blood culture system can be used to screen platelet concentrates (PCs) for bacterial contamination.

MATERIALS AND METHODS

Data were collected from May 1998 until May 2004. The number of PCs tested during this period was 36 896, most of which were produced from pools of four buffy-coats. On the day following blood collection or platelet apheresis, a 5-10 ml sample of the PC was aseptically transferred to a BacT/ALERT culture bottle for detection of aerobic bacteria. The sample was monitored for bacterial growth during the entire storage period of the PC (6.5 days). When a positive signal was generated, the culture bottle, the PC and the erythrocyte concentrates were tested for bacterial growth. In order to determine the frequency of false-negative BacT/ALERT signals, 1061 outdated PCs were tested during the period from May 2002 to May 2004.

RESULTS

Eighty-eight positive signals were detected by the BacT/ALERT system, of which 12 were interpreted as truly positive. Fourteen signals were interpreted as truly false positive. Thirty-three signals were interpreted to be probably false positive. Two of 1061 outdated units tested positive, and Bacillus spp. and Staphylococcus epidermidis, respectively, were isolated from these PCs.

CONCLUSIONS

Between 0.03% and 0.12% of the PCs were contaminated with bacteria. BacT/ALERT is an efficient tool for monitoring PCs for bacterial contamination; however, it is important to realize that false-negative results may occur.

Medication safety and transfusion errors in the ICU and beyond

The modern day intensive care unit (ICU) is a place in which patients can receive continuous monitoring of physiologic variables with concentrated patient observation and care. Despite the "intensive care," errors do occur. This article reviews medication and transfusion errors, including the different types, causes, and possible solutions to prevent these errors from occurring in ICUs and the hospital at large.

Technology for enhanced transfusion safety

Data from reporting systems around the world document that non-infectious hazards are the leading cause of serious morbidity or mortality resulting from blood transfusion. Among these non-infectious hazards, mis-transfusion represents the most frequently observed serious hazard and occurs at an estimated rate of 1 in 14,000 transfusions. Mis-transfusion events result from "lapse errors" (slip ups) rather than cognitive mistakes. Lapse errors are more likely to occur during repetitive tasks when individuals are distracted, rushed, or fatigued--conditions to which machines are not susceptible. The final bedside check and the collection of patient samples for pre-transfusion testing are key "error spots" and are candidates for new technology innovation. Existing technology includes non-computerized devices; bedside devices based on bar code technology; and the use of radiofrequency chips. Several commercial systems employing bar-code technology have reached clinical application or are undergoing refinement. Radiofrequency-based systems are on the near horizon. Nearly all systems begin with the application of machine-readable data to the patient's wristband. The third error spot--the decision to transfuse--will be a challenging area for future application of information technology. Computerized physician order-entry, decision support and ultimately active computer-based decision-making are expected to enhance transfusion decisions. Despite the explosive growth in information technology in modern society, healthcare has lagged behind many other sectors in the use of enhanced information technology. Studies are needed to identify which technologies improve patient outcomes. Healthcare workers, administrators, and regulators need to embrace the use of new technology in order to reduce errors and improve safety for patients.

Emerging infections in transfusion medicine

The risk of transfusion-transmitted infectious diseases (TTIDs) has declined dramatically in high-income nations over the past 2 decades, primarily because of extraordinary success in preventing HIV and other established transfusion-transmitted viruses from entering the blood supply. Despite this achievement, TTIDs remain a public health concern, and attention is refocusing on new and emerging pathogens, such as West Nile virus, infectious proteins (the presumed cause of variant Creutzfeldt-Jakob disease), and other transmissible organisms such as bacteria and parasites. In this article the authors concentrate on this heterogeneous group of infectious agents, describe individual pathogens and the risks they pose to transfusion recipients, and comment on existing and evolving procedures that are designed to protect the blood supply from this threat.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a life-threatening adverse effect of transfusion that is occurring at increasing incidence in the United States and that, in the past 2 reporting years, has been the leading cause of transfusion-related death. TRALI and acute lung injury (ALI) share a common clinical definition except that TRALI is temporally and mechanistically related to the transfusion of blood/blood components. In prospective studies, 2 patient groups, 1 requiring cardiac surgery and 1 with hematologic malignancies and undergoing induction chemotherapy, were predisposed. Two different etiologies have been proposed. The first is a single antibody-mediated event involving the transfusion of anti-HLA class I and class II or antigranulocyte antibodies into patients whose leukocytes express the cognate antigens. The second is a 2-event model: the first event is the clinical condition of the patient resulting in pulmonary endothelial activation and neutrophil sequestration, and the second event is the transfusion of a biologic response modifier (including lipids or antibodies) that activates these adherent polymorphonuclear leukocytes (PMNs), resulting in endothelial damage, capillary leak, and TRALI. These hypotheses are discussed, as are the animal models and human studies that provide the experimental and clinical relevance. Prevention, treatment, and a proposed definition of TRALI, especially in the context of ALI, are also examined.

Influence of blood prestorage conditions and white blood cell filtration on the bacterial load of blood deliberately inoculated with Gram-positive and Gram-negative pathogens

BACKGROUND AND OBJECTIVES

Currently, the bacterial contamination of blood constitutes one of the major infectious risks of transfusion. The aim of this study was to evaluate the bactericidal effect of blood on various bacterial species and to determine the influence of prestorage conditions and white blood cell (WBC) filtration on the reduction of the bacterial load in isolated red blood cells (RBCs).

MATERIALS AND METHODS

The growth kinetics of eight different species of bacteria were studied at 20 degrees C in deliberately contaminated RBC units. Further experiments evaluated the effect of prestorage conditions and WBC filtration on the viability of two model bacteria (Klebsiella oxytoca and Staphylococcus epidermidis) in comparison to previous results obtained with Yersinia enterocolitica.

RESULTS

For bacteria susceptible to the bactericidal effect of blood (mainly Gram-negative rods), a reduction of the bacterial load was obtained within 2 h of prestorage at 20 degrees C. When the prestorage period was prolonged beyond 3 h at 20 degrees C, rapid growth was observed with some Enterobacteriaceae. Whereas WBC filtration reduced dramatically the viability of Y. enterocolitica, it had only a minimal effect on the viability of S. epidermidis and K. oxytoca. However, the two latter species of bacteria did not survive prolonged storage at 4 degrees C.

CONCLUSIONS

Experiments conducted under realistic conditions are needed to determine whether it would be worthwhile recommending the rapid storage of RBCs at 4 degrees C after WBC reduction of the blood product.

[Satisfaction survey in general hospital personnel involved in blood transfusion: implementation of the ISO 9001: 2000 standard]

As part of its policy of constant quality improvement, Etablissement Français du Sang (EFS) des Pays de la Loire (Pays de la Loire Regional blood transfusion institution) carried out a satisfaction survey among the hospital personnel involved in prescribing and using immuno-hematological tests and labile blood products. The polling tool selected by agreement between the hospital management and quality assurance department was a questionnaire that permitted item rating and free commentary. It addressed the personnel's perception of the quality of erythrocyte immuno-hematological (EIH) testing and of the products administered, as well as their perception of the quality of communications with the local EFS. The questionnaire was sent to 26 physicians and 32 senior nurses in 15 hospital departments. The reply rate was 60% and expressed a 85% overall satisfaction level. Dissatisfaction causes were more specifically analysed, the main one involving labile blood product distribution in emergency situations. A joint undertaking by the EFS and the hospital led to the implementation of corrective measures, including the writing and implementation of a common standard operating procedure for emergency transfusion management. The results obtained demonstrated the feasibility of this type of survey and the interest, to a blood transfusion centre and the hospital personnel involved in transfusion, of assessing their very own perception of service quality.

Strategies for transfusion therapy

Transfusion of allogeneic red blood cells (RBCs), fresh frozen plasma (FFP) and platelets is associated with risks, and outcome studies comparing liberal and restrictive transfusion regimens are lacking in surgical patients. Therefore, guidelines have been established. They recommend first maintaining normovolaemia by the use of crystalloids and colloids. RBC transfusions are recommended for haemoglobin levels < 6 g/dl and for physiological signs of inadequate oxygenation such as haemodynamic instability, oxygen extraction > 50% and myocardial ischaemia (new ST-segment depressions > 0.1 mV, new ST-segment elevations > 0.2 mV or new wall motion abnormalities in transoesophageal echocardiography). FFP transfusions are recommended for urgent reversal of anticoagulation, known coagulation factor deficiencies, microvascular bleeding in the presence of elevated (> 1.5 times normal) prothrombin time (PT) or partial thromboplastin time (PTT) and microvascular bleeding after the replacement of more than one blood volume when PT or PTT cannot be obtained. Platelet transfusions are recommended prior to major operations in patients with platelet counts < 50,000/microl, intraoperatively with microvascular bleeding at platelet counts < 50,000/microl and in the range of 50,000-100,0000/microl following cardiopulmonary bypass and in patients undergoing surgery where already minimal bleeding may cause major damage such as in neurosurgery.

Experience with the medical event reporting system for transfusion medicine (MERS-TM) at three hospitals

BACKGROUND

The MERS-TM assists hospital transfusion services to identify, analyze, and correct system events relating to the delivery of blood to patients.

METHODS

The MERS-TM system was used from February of 1999 to December 2002. All reported near-miss and actual events were recorded and analyzed.

RESULTS

During these 47 months, 4670 events were reported by the transfusion service. Of these events, 94% were classified as a near-miss event and 93% were detected before the blood product was administered. No ABO-incompatible transfusions were detected despite transfusion of 50,137 units of red blood cells. High severity events with the potential for patient harm accounted for 241 (5%) of the 4670 events. Nursing related events accounted for 188 (78%) of the high severity events. In one out of 4430 (0.023%) samples tested, a high severity sample-testing event was detected. In one out of 1550 (0.06%) samples collected, a high severity sample-collection event was detected.

CONCLUSION

An event reporting system is essential if one is to determine where and how often events are occurring within the transfusion process.

Stability of coagulation factors in thawed, solvent/detergent-treated plasma during storage at 4 oC for 6 days

BACKGROUND AND OBJECTIVES

Transfusion of fresh-frozen plasma is still a pillar in emergency medicine for using to prevent dilutional coagulopathy or disseminated intravascular coagulation after severe blood loss, but thawing procedures can delay its availability. On the other hand, the wastage of plasma, once thawed and not transfused within a defined time-period, represents an inefficient handling of economic resources and is contradictory to blood donor intentions. In this study we investigated the stability of coagulation factor activities and plasma protein levels during 6 days of storage of thawed solvent/detergent (S/D)-treated plasma at +4 degrees C. Our results may form the basis for reconsideration of expiry times of thawed S/D-treated plasma.

MATERIALS AND METHODS

Five units of S/D-treated plasma (Octaplas) were thawed and warmed to 20 degrees C, then recooled and stored at +4 degrees C for 6 days. The activities of coagulation factors II, V, VII, VIII, IX, X, XI and XII, fibrinogen, antithrombin (AT), protein C, protein S and von Willebrand factor antigen (vWF:Ag) were measured on days 0, 1, 2, 3 and 6.

RESULTS

Except for protein S, the activities of all coagulation factors and inhibitors were at least 0.5 U/ml during storage at 4 degrees C for 6 days. The mean levels, during storage, of factors IX, X, XI and XII, vWF:Ag, fibrinogen and protein C were at least 94%, and of factors II, V and VIII, and AT at least 78%, of the levels immediately after thawing; the activity of factor VII decreased to 83% and of protein S to 43% of the baseline values.

CONCLUSIONS

Thawed S/D-treated plasma stored at +4 degrees C for up to 6 days still contains sufficient coagulation activities and plasma proteins to be regarded as suitable for transfusion in the established indications.

The French Haemovigilance System: organization and results for 2003

In 1993 by law, in France, haemovigilance became a national system of surveillance and alert, from blood collection to the follow-up of the recipients, gathering and analysing all adverse events of blood transfusion in order to prevent their recurrences. In 2003, 2911 incidents with strong imputability have been specially analysed, among them seven confirmed cases of bacterial contamination, 137 incorrect blood components transfused with 12 cases of ABO incompatibility, 15 adverse reactions diagnosed as TRALI and 12 deaths. The analysis of information provided by haemovigilance has led to the implementation of new guidelines.

Bacterial contamination in blood components and preventative strategies: an overview

Bacterial contamination of blood and its cellular components remains an unresolved problem in transfusion medicine and is considered to be the most common microbiological cause of transfusion associated morbidity and mortality. This is because contaminated units may contain large numbers of virulent bacteria as well as endotoxins that are considered to be fatal to the recipient. Accordingly, measures have been proposed to prevent or at least control the potential risk of transfusion associated bacteria infections. Broadly, these approaches include: bacterial avoidance; bacterial growth inhibition and bacterial load reduction by leucofiltration/viral inactivation. Unfortunately, none of the current approaches alone or in combination have received overall acceptance in terms of operational practice and safety/efficacy. Considerable effort has also been directed towards improving bacterial detection in order to provide a scientific basis for the lengthening of the shelf life of liquid stored platelets, without affecting, to a large extent their safety/efficacy. These issues have been highlighted in this overview on the current status and future trends.