Measures to prevent TRALI

Transfusion-Related Acute Lung Injury (TRALI) in Postoperative Anesthesia Care Unit (PACU) After One Unit of Platelets: A Case Report

Transfusion-related acute lung injury (TRALI) following transfusion of all plasma-containing blood products is a rare but serious syndrome characterized by the acute onset of non-cardiogenic pulmonary edema with severe hypoxemia with or without symptoms of hypotension, pinkish frothy secretions, fever, and cyanosis. In this report, we present a case of a 66-year-old female with a medical history significant for hypertension, hyperlipidemia, hepatitis C, liver cirrhosis, tobacco use disorder, metastatic spindle cell carcinoma of the lung status post chemotherapy who developed TRALI after administration of one unit of platelets. Although a rare occurrence, there can be a considerable risk of TRALI following transfusion of all plasma-containing blood products and there is great importance in considering each patient’s risk factors for TRALI development prior to blood product administration.

Managing patients with side effects and adverse events to immunoglobulin therapy

Immunoglobulin therapy has not only served as a lifesaving approach for the prevention and treatment of infections in primary and secondary immunodeficiency diseases, but has also been used as an immunomodulatory agent for autoimmune and inflammatory disorders and to provide passive immunity for some infectious diseases. Most of the adverse effects associated with immunoglobulin therapy are mild, transient and self-limiting. However, serious side effects also occur. Therefore, to minimize the adverse events of immunoglobulin therapy, specialist review of patient clinical status and immunoglobulin products, in addition to selection of appropriate treatment strategy for the management of patients with associated side effects and adverse events, are crucial.

The impact of policies to restrict the use of plasma containing products and apheresis platelets from female donors to mitigate transfusion related acute lung injury (TRALI) in Brazil

BACKGROUND AND OBJECTIVES

Although the incidence of TRALI is unknown in Brazil, some blood centers have adopted strategies to prevent TRALI. We evaluated the impact of three policies to mitigate TRALI on the supply of blood products: to divert the production of whole blood-derived plasma from female donors; to defer all female donors from apheresis platelet collections, and to defer only multiparous female donors from apheresis platelet collections.

MATERIALS AND METHODS

Data from allogeneic whole blood and apheresis platelet donations from April 2008 to December 2009 were collected in three Brazilian blood centers and the impact of the aforementioned strategies was evaluated.

RESULTS

Of 544,814 allogeneic blood donations, 30.8% of whole blood plasma and 24.1% of apheresis platelet donations would be reduced if only male donor plasma was issued for transfusion and all female donors were deferred from apheresis donation, respectively. If only multiparous donors were deferred from apheresis donation, there would be a 5% decrease of all apheresis platelet collections.

CONCLUSION

Restricting the use of whole blood derived plasma to male-only donors and deferring all female apheresis platelet donors would impact two out of three Brazilian blood centers. A deferral policy on multiparous apheresis platelet donors may be acceptable as a temporary measure, but may cause more stress on a system that is already working at its limit.

Transfusion-related acute lung injury: a preventable syndrome?

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality. Recent insights into the pathophysiology of TRALI have led to various preventive strategies. Strategies in donor management range from antibody testing of sensitized donors to the deferral of female plasma donors altogether. However, knowledge on the efficacy of measures to reduce TRALI is limited. In addition, the various measures may lead to a substantial loss of donors, hampering steady blood supply. Thereby, consensus among countries and blood-collecting facilities regarding the optimal strategy to prevent TRALI is lacking. In this review, the advantages and disadvantages of various preventive measures to prevent TRALI are discussed, related to both patient factors as well as blood component-processing strategies, including transfusion policy, donor management and practices of preparation and storage conditions of blood components.

Age of blood and recipient factors determine the severity of transfusion-related acute lung injury (TRALI)

Introduction

Critical care patients frequently receive blood transfusions. Some reports show an association between aged or stored blood and increased morbidity and mortality, including the development of transfusion-related acute lung injury (TRALI). However, the existence of conflicting data endorses the need for research to either reject this association, or to confirm it and elucidate the underlying mechanisms.

Methods

Twenty-eight sheep were randomised into two groups, receiving saline or lipopolysaccharide (LPS). Sheep were further randomised to also receive transfusion of pooled and heat-inactivated supernatant from fresh (Day 1) or stored (Day 42) non-leucoreduced human packed red blood cells (PRBC) or an infusion of saline. TRALI was defined by hypoxaemia during or within two hours of transfusion and histological evidence of pulmonary oedema. Regression modelling compared physiology between groups, and to a previous study, using stored platelet concentrates (PLT). Samples of the transfused blood products also underwent cytokine array and biochemical analyses, and their neutrophil priming ability was measured in vitro.

Results

TRALI did not develop in sheep that first received saline-infusion. In contrast, 80% of sheep that first received LPS-infusion developed TRALI following transfusion with "stored PRBC." The decreased mean arterial pressure and cardiac output as well as increased central venous pressure and body temperature were more severe for TRALI induced by "stored PRBC" than by "stored PLT." Storage-related accumulation of several factors was demonstrated in both "stored PRBC" and "stored PLT", and was associated with increased in vitro neutrophil priming. Concentrations of several factors were higher in the "stored PRBC" than in the "stored PLT," however, there was no difference to neutrophil priming in vitro.

Conclusions

In this in vivo ovine model, both recipient and blood product factors contributed to the development of TRALI. Sick (LPS infused) sheep rather than healthy (saline infused) sheep predominantly developed TRALI when transfused with supernatant from stored but not fresh PRBC. "Stored PRBC" induced a more severe injury than "stored PLT" and had a different storage lesion profile, suggesting that these outcomes may be associated with storage lesion factors unique to each blood product type. Therefore, the transfusion of fresh rather than stored PRBC may minimise the risk of TRALI.

TRALI-new challenges for histocompatibility and immunogenetics in transfusion medicine

Antibodies against human leukocyte antigens (HLAs) have long been associated with transfusion-related acute lung injury (TRALI). In contrast to febrile transfusion reactions and refractoriness to platelet transfusions in immunized patients, the causative antibodies in TRALI are present in the transfused blood component, i.e. they are formed by the blood donor and not by the recipient. Consequently, blood components with high plasma volume are particularly associated with TRALI. In addition to antibodies against HLAs, antibodies directed against human neutrophil antigens (HNAs) present in the plasma of predominantly multiparous female blood donors can induce severe TRALI reactions. Especially, antibodies to HLA class II and HNA-3a antigens can induce severe or even fatal ALI in critically ill patients. Over the last decade, the clinical importance of TRALI as major cause for severe transfusion-related morbidities has led to the establishment of new guidelines aimed at preventing this condition, including routine testing for HLA and -HNA antibodies for plasma donors with a history of allogeneic sensitization. This, in turn, poses new challenges for close collaboration between blood transfusion centers and histocompatibility and immunogenetics laboratories, for sensitive and specific detection of the relevant antibodies.

Benefit of transfusion-related acute lung injury risk-minimization measures--German haemovigilance data (2006-2010)

OBJECTIVE

Based on the frequency of immune-mediated and non-immune-mediated transfusion-related acute lung injury (TRALI), the effect of risk-minimization measures was evaluated during a period of 5 years (2006-2010). Risk-minimization measures were implemented in 2008/2009, consisting of exclusion of female donors with a history of pregnancy or exclusion of female donors with human leucocyte antigen (HLA)/human neutrophil alloantigen (HNA) antibodies.

METHODS

TRALI was confirmed according to the criteria of the International Haemovigilance Network. Based upon the results of donor testing of white-blood-cell antibodies (WBC-Ab) against HLA or HNAs, confirmed cases were classified as immune- or non-immune-mediated TRALI. Reporting rates were calculated on the basis of the annually transfused blood components, and pre- and post-implementation periods were compared.

RESULTS

In total, 60 immune-mediated (75%) and 20 non-immune-mediated (25%) TRALI reactions were confirmed. A total of 68 (64 women and four men) donors were involved: seven red-blood-cell concentrates donors (13%), six platelet concentrate donors (10%), and 48 fresh frozen plasma (FFP) donors (77%). The reporting rate of immune-mediated TRALI caused by FFP decreased continuously; from 12·71 per million units in 2006/2007 to 6·81 per million units in 2008/2009 and no case in 2010.

CONCLUSION

The comparison of the pre- and the post-implementation period demonstrated a significantly reduced risk of TRALI events comparing 2006/2007 with 2010 (P-value: <0·01). Furthermore, no case of TRALI-induced fatality occurred after the implementation of risk-minimization measures.

The Leukocyte Antibody Prevalence Study-II (LAPS-II): a retrospective cohort study of transfusion-related acute lung injury in recipients of high-plasma-volume human leukocyte antigen antibody-positive or -negative components

BACKGROUND

We used a multicenter retrospective cohort study design to evaluate whether human leukocyte antigen (HLA) antibody donor screening would reduce the risk of transfusion-related acute lung injury (TRALI) or possible TRALI.

STUDY DESIGN AND METHODS

In the Leukocyte Antibody Prevalence Study-II (LAPS-II), we evaluated pulmonary outcomes in recipients of 2596 plasma-rich blood components (transfusable plasma and plateletpheresis) sent to participating hospitals; half of the components were collected from anti-HLA-positive donors (study arm) and half from anti-HLA-negative donors (control arm) matched by sex, parity, and blood center. A staged medical record review process was used. Final recipient diagnosis was based on case review by a blinded expert panel of pulmonary or critical care physicians.

RESULTS

TRALI incidence was 0.59% (seven cases) in study arm recipients versus 0.16% (two cases) in control arm recipients for an odds ratio (OR) of 3.6 (95% confidence interval [CI], 0.7-17.4; p = 0.10). For possible TRALI cases (nine study arm, eight control arm), the OR was 1.2 (95% CI, 0.4-3.0; p = 0.81), and for TRALI and possible TRALI aggregated together, it was 1.7 (95% CI, 0.7-3.7; p = 0.24). Transfusion-associated circulatory overload incidence was identical in the two arms (1.17 and 1.22%, respectively; OR, 1.0; p = 1.0).

CONCLUSIONS

TRALI incidence in recipients of anti-HLA-positive components was relatively low for a lookback study (1 in 170) and was higher than in the control arm, but did not reach significance. Based on this trend, the data are consistent with the likelihood that TRALI risk is decreased by selecting high-volume plasma components for transfusion from donors at low risk of having HLA antibodies.

Blood aging, safety, and transfusion: capturing the "radical" menace

Throughout their life span, circulating red blood cells (RBCs) transport oxygen (O(2)) primarily from the lungs to tissues and return with carbon dioxide (CO(2)) from respiring tissues for final elimination by lungs. This simplistic view of RBCs as O(2) transporter has changed in recent years as other gases, for example, nitric oxide (NO), and small molecules, such as adenosine triphosphate (ATP), have been shown to either be produced and/or carried by RBCs to perform other signaling and O(2) sensing functions. In spite of the numerous biochemical and metabolic changes occurring within RBCs during storage, prior to, and after transfusion, perturbations of RBC membrane are likely to affect blood flow in the microcirculation. Subsequent hemolysis due to storage conditions and/or hemolytic disorders may have some pathophysiological consequences as a result of the release of Hb. In this review, we show that evolution has provided a multitude of protection and intervention strategies against free Hb from "cradle" to "death"; from early biosynthesis to its final degradation and a lot more in between. Furthermore, some of the same naturally occurring protective mechanisms can potentially be employed to oxidatively inactivate this redox active protein and control its damaging side reactions when released outside of the RBC.

A novel in vivo ovine model of transfusion-related acute lung injury (TRALI)

BACKGROUND AND OBJECTIVES

Even with the introduction of specific risk-reduction strategies, transfusion-related acute lung injury (TRALI) continues to be a leading cause of transfusion-related morbidity and mortality. Existing small animal models have not yet investigated TRALI resulting from the infusion of heat-treated supernatant from whole blood platelet concentrates. In this study, our objective was the development of a novel in vivo two-event model of TRALI in sheep.

MATERIALS AND METHODS

Lipopolysaccharide (LPS; 15 μg/kg) as a first event, modelled clinical infection. Transfusion (estimated at 10% of total blood volume) of heat-treated pooled supernatant from date-of-expire human whole blood platelet concentrates (d5-PLT-S/N) was used as a second event. TRALI was defined by both hypoxaemia that developed either during the transfusion or within two hours of its completion and post-mortem histological evidence of pulmonary oedema.

RESULTS

LPS infusion did not cause lung injury itself, but did result in decreased circulating levels of lymphocytes and neutrophils with evidence of the latter becoming sequestered in the lungs. Sheep that received LPS (first event) followed by d5-PLT-S/N (second event) displayed decreased pulmonary compliance, decreased end tidal CO(2) and increased arterial partial pressure of CO(2) relative to control sheep, and 80% of these sheep developed TRALI.

CONCLUSIONS

This novel ovine two-event TRALI model presents a new tool for the investigation of TRALI pathogenesis. It represents the first description of an in vivo large animal model of TRALI and the first description of TRALI caused by transfusion with heat-treated pooled supernatant from human whole blood platelet concentrates.

Manufacture of red cells in additive solution from whole blood refrigerated for 5 days or remanufactured from red cells stored in plasma

BACKGROUND AND OBJECTIVES

To investigate methods for the production of red cell concentrates (RCC) in saline, adenine, glucose and mannitol (SAG-M), from whole blood or red cells stored in plasma for 5 or 6 days and to provide evidence that exchange transfusion RCC in citrate phosphate dextrose (CPD) plasma or citrate, phosphate, dextrose, adenine (CPDA-1) plasma are of comparable quality.

METHODS AND MATERIALS

Ten RCC in SAG-M were produced following the remanufacture of red cells in CPD plasma on day 5/6 or after 5 days hold as leucodepleted CPD whole blood. In addition, 10 RCC in CPD plasma and 9 in CPDA-1 plasma were stored without further processing. Units were assessed for red cell parameters including haemolysis, adenosine triphosphate (ATP), 2,3-diphosphoglycerate (2,3-DPG) and extracellular potassium.

RESULTS

Units in SAG-M produced by remanufacture of RCC in plasma or by delayed manufacture of whole blood had comparable levels of haemolysis, ATP and 2,3-DPG. Furthermore, these units underwent biochemical changes similar to reference SAG-M units, with the exception of haemolysis which was greater at the end of shelf life and supernatant potassium which was lower following remanufacture. As expected, the decline in ATP was greater in red cells stored in CPD plasma compared with CPDA-1 plasma. In general, units in CPD plasma were of similar quality at day 28 compared to those in CPDA-1 plasma at day 35.

CONCLUSIONS

RCC produced following the remanufacture of RCC in plasma or the delayed manufacture of whole blood are of acceptable in vitro quality and should be assigned the same shelf life as standard RCC in SAG-M.

A national survey of transfusion-related acute lung injury risk reduction policies for platelets and plasma in the United States

BACKGROUND

Little information exists on the specific transfusion-related acute lung injury (TRALI) risk reduction practices used by multiple blood collecting institutions in the United States.

STUDY DESIGN AND METHODS

An AABB-appointed TRALI working group designed a set of questions about TRALI risk reduction for platelets (PLTs) and plasma. AABB member institutions were asked to respond via an Internet-based survey during a 3-week period in August through September 2009.

RESULTS

Valid responses were received from 47 US blood centers (accounting for 1.57 million apheresis PLT units and 3.15 million whole blood-derived transfusable plasma units) and 56 hospital blood collectors. Among the blood centers, 87 and 98% had initiated some PLT and plasma risk reduction, respectively. HLA antibody testing of plateletpheresis donors was performed by 20 (43%) blood centers. There was substantial variation in the number of pregnancies (from one to more than four) that triggered testing and most centers did not screen based on a transfusion history. Almost all centers had policies to redirect HLA antibody-positive donors to whole blood donation and to potentially retest HLA antibody-negative donors. There were no blood centers performing HNA antibody testing. Sex-based risk reduction policies for plasma included all male, or predominantly male, and never-pregnant females; these varied by blood center, blood group, and method of plasma collection. A majority of centers indicated increased production of plasma frozen within 24 hours after phlebotomy.

CONCLUSIONS

Almost 3 years after the publication of the initial AABB bulletin on this issue, TRALI risk reduction strategies are commonly employed at most US blood centers. However, procedures are not uniform.

Blood still kills: six strategies to further reduce allogeneic blood transfusion-related mortality

After reviewing the relative frequency of the causes of allogeneic blood transfusion-related mortality in the United States today, we present 6 possible strategies for further reducing such transfusion-related mortality. These are (1) avoidance of unnecessary transfusions through the use of evidence-based transfusion guidelines, to reduce potentially fatal (infectious as well as noninfectious) transfusion complications; (2) reduction in the risk of transfusion-related acute lung injury in recipients of platelet transfusions through the use of single-donor platelets collected from male donors, or female donors without a history of pregnancy or who have been shown not to have white blood cell (WBC) antibodies; (3) prevention of hemolytic transfusion reactions through the augmentation of patient identification procedures by the addition of information technologies, as well as through the prevention of additional red blood cell alloantibody formation in patients who are likely to need multiple transfusions in the future; (4) avoidance of pooled blood products (such as pooled whole blood-derived platelets) to reduce the risk of transmission of emerging transfusion-transmitted infections (TTIs) and the residual risk from known TTIs (especially transfusion-associated sepsis [TAS]); (5) WBC reduction of cellular blood components administered in cardiac surgery to prevent the poorly understood increased mortality seen in cardiac surgery patients in association with the receipt of non-WBC-reduced (compared with WBC-reduced) transfusion; and (6) pathogen reduction of platelet and plasma components to prevent the transfusion transmission of most emerging, potentially fatal TTIs and the residual risk of known TTIs (especially TAS).

Impact of fresh-frozen plasma from male-only donors versus mixed-sex donors on postoperative respiratory function in surgical patients: a prospective case-controlled study

BACKGROUND

To reduce the risk of transfusion-related acute lung injury (TRALI), plasma products are mainly made from male donors in some countries because of the lower possibility of alloimmunization; other countries are considering this policy. The advantage of male-only fresh-frozen plasma (FFP) should be examined in a prospective case-control study.

STUDY DESIGN AND METHODS

This study compared pulmonary function after the transfusion of FFP derived from either male donors only (FFP-male) or mixed donors (FFP-mixed) in informed surgical patients treated at a tertiary university hospital in Japan. The factors contributing to pulmonary distress (PD) after transfusion were then statistically examined.

RESULTS

Eighty-two patients participated in this study (FFP-male, n = 55; FFP-mixed, n = 27). Nineteen patients developed PD (PaO(2)/FiO(2) ratio [P/F] < 300) within 6 hours after transfusion: seven had congestive pulmonary edema (transfusion-associated circulatory overload), five had permeability pulmonary edema (possible TRALI), and seven had no apparent pulmonary edema. A multivariate logistic regression analysis revealed that the use of cardiopulmonary bypass and preoperative liver dysfunction were significantly associated with a P/F of less than 300 (odds ratios [ORs], 8.95 [p = 0.004] and 6.54 [p = 0.005], respectively), while the use of FFP-male was significantly associated with the absence of PD (OR, 0.219; p = 0.022). All the patients with possible TRALI had received either white blood cell or granulocyte antibody-positive FFP. The lysophosphatidylcholine level was not correlated with PD.

CONCLUSIONS

Our data suggests that the use of FFP derived from male donors may be advantageous for posttransfusion pulmonary function, although PD is also determined by background characteristics.

Effects of leukoreduced blood on acute lung injury after trauma: a randomized controlled trial

OBJECTIVE

The requirement for a blood transfusion after trauma is associated with an increased risk of acute lung injury. Residual leukocytes contaminating red cells are potential mediators of this syndrome. The goal of this trial was to test our hypothesis that prestorage leukoreduction of blood would reduce rates of posttraumatic lung injury.

DESIGN

Double blind, randomized, controlled clinical trial.

SETTING

University-affiliated level I trauma center in King County, Seattle, WA.

PATIENTS

Two hundred sixty-eight injured patients requiring red blood cell transfusion within 24 hrs of injury.

INTERVENTIONS

Prestorage leukoreduced vs. standard allogeneic blood transfusions.

MEASUREMENTS AND MAIN RESULTS

We compared the incidence of acute lung injury and acute respiratory distress syndrome at early (< or = 72 hrs) and late (> 72 hrs) time points after injury. In a subset, we compared plasma levels of surfactant protein-D and von Willebrand factor antigen between intervention arms. Rates of acute lung injury (relative risk [RR] 1.06, 95% confidence interval [CI] .69-1.640) and acute respiratory distress syndrome (RR .96, 95% CI 0.48-1.91) were not statistically different between intervention arms early after injury. Similarly, no statistically significant effect of leukoreduced transfusion on rates of acute lung injury (RR .88, 95% CI .54-1.44) or acute respiratory distress syndrome (RR .95, 95% CI .58-1.57) was observed to occur late after injury. There was no significant difference in the number of ventilator-free days or in other ventilator parameters between intervention arms. No statistically significant effect of leukoreduced blood on plasma levels of surfactant protein-D or von Willebrand factor antigen was identified.

CONCLUSIONS

Prestorage leukoreduction had no effect on the incidence or timing of lung injury or on plasma measures of systemic alveolar and endothelial inflammation in a population of trauma patients requiring transfusion. The relationship between transfusion and lung injury is not obviously explained by mechanistic pathways involving the presence of transfused leukocytes.

The effects of preserved red blood cells on the severe adverse events observed in patients infused with hemoglobin based oxygen carriers

The severe adverse events observed in patients who received hemoglobin based oxygen carriers (HBOCs) were associated with the Ringer's D.L lactate resuscitative solution administered and to the excipient used in the HBOCs containing Ringer's D,L lactate and the length of storage of the preserved RBC administered to the patient at the time that the HBOCs were infused. This paper reports the quality of the red blood cells preserved in the liquid state at 4 degrees C and that of previously frozen RBCs stored at 4 degrees C with regard to their survival, function and safety. Severe adverse events have been observed related to the length of storage of the liquid preserved RBC stored at 4 degrees C prior to transfusion. The current methods to preserve RBC in the liquid state in additive solutions at 4 degrees C maintain their survival and function for only 2 weeks. The freezing of red blood cells with 40% W/V glycerol and storage at -80 degrees C allows for storage at -80 degrees C for 10 years and following thawing, deglycerolization and storage at 4 degrees C in the additive solution (AS-3, Nutricel) for 2 weeks with acceptable 24 hour posttransfusion survival, less than 1% hemolysis, and moderately impaired oxygen transport function with no associated adverse events. Frozen deglycerolized RBCs are leukoreduced and contain less than 5% of residual plasma and non-plasma substances. Frozen deglycerolized RBCs are the ideal RBC product to transfuse patients receiving HBOCs.

Swiss Haemovigilance Data and Implementation of Measures for the Prevention of Transfusion Associated Acute Lung Injury (TRALI)

SUMMARY: In Switzerland, blood donations are collected exclusively from healthy non-remunerated voluntary blood donors mainly by 13 regional Blood Transfusion Services throughout the country. Thereby, self-sufficient blood supply for a population of about 7.5 million is achieved, and approximately 300,000 units of red cells, 75,000 therapeutic units of fresh plasma, and 20,000 therapeutic units of platelets are transfused annually. Reporting to Swissmedic (the Swiss agency for therapeutic products) of all suspected adverse transfusion events on a standardised form is mandatory. Data are then analysed to estimate the risks of the most serious transfusion events. Together with transfusion of an incorrect blood component and bacterial contamination of platelet concentrates, TRALI is a significant risk of transfusion in Switzerland and occurs in approximately every 8,000-20,000 FFP transfusions according to current haemovigilance data. Among 25 reported cases between 2002 and November 2007, 4 are proven immune TRALI, 2 are highly likely immune TRALI, 10 are possibly immune TRALI, 8 are non-immune TRALI, and 1 is a suspected case which could not be confirmed as TRALI. Based on the hypothesis of an immunological trigger of TRALI, an exclusion of the transfusion of plasma from female donors can be considered as a precautionary measure which might have prevented 4 cases of proven immune TRALI, 2 cases of highly likely immune TRALI, and an unknown number of the 10 cases of possibly immune TRALI. Based on these data and encouraging preliminary reports of the effects of comparable measures in other countries, the decision was made that starting with January 1st 2007 the production of quarantined FFP is restricted to donations from men or from women confirming that they have never been pregnant (to their knowledge) or with negative tests for antibodies against HLA class I and II. The analysis of further vigilance data is needed to elucidate the efficacy of this preventive measure.

Case report: transfusion-related acute lung injury (TRALI) - a clear and present danger

PURPOSE

To describe a case of transfusion-related acute lung injury (TRALI) after platelet transfusion immediately following cardiac surgery, and to review the clinical features, pathophysiology, management, and morbidity and mortality associated with such an event.

CLINICAL FEATURES

A 62-yr-old man was transferred to our centre for urgent coronary artery bypass grafting in the setting of recent anti-platelet medication use. Soon after surgery he received platelet transfusions despite having only moderate blood loss. Shortly following the platelet transfusion, he suffered acute hypoxic and hypotensive decompensation requiring nitric oxide therapy, inotropic support, and prolonged need for mechanical ventilation. The patient was eventually discharged from the intensive care unit nine days following the event. The diagnosis of TRALI was made by clinical and radiographic criteria.

CONCLUSION

Transfusion-related acute lung injury is now the leading cause of transfusion-related fatalities. Early diagnosis of TRALI is important and these reactions should be reported to the blood transfusion service so that appropriate action can be taken to prevent future morbidity and mortality in other patients. To reduce serious transfusion reactions, inappropriate transfusions must be minimized and the decision to transfuse blood products should be taken with care.

Nonsurgical bleeding diathesis in anemic thrombocytopenic patients: role of temperature, red blood cells, platelets, and plasma-clotting proteins

Research at the Naval Blood Research Laboratory (Boston, MA) for the past four decades has focused on the preservation of red blood cells (RBCs), platelets (PLTs), and plasma-clotting proteins to treat wounded servicemen suffering blood loss. We have studied the survival and function of fresh and preserved RBCs and PLTs and the function of fresh and frozen plasma-clotting proteins. This report summarizes our peer-reviewed publications on the effects of temperature, RBCs, PLTs, and plasma-clotting proteins on the bleeding time (BT) and nonsurgical blood loss. The term nonsurgical blood loss refers to generalized, systemic bleeding that is not corrected by surgical interventions. We observed that the BT correlated with the volume of shed blood collected at the BT site and to the nonsurgical blood loss in anemic thrombocytopenic patients after cardiopulmonary bypass surgery. Many factors influence the BT, including temperature; hematocrit (Hct); PLT count; PLT size; PLT function; and the plasma-clotting proteins factor (F)VIII, von Willebrand factor, and fibrinogen level. Our laboratory has studied temperature, Hct, PLT count, PLT size, and PLT function in studies performed in non-aspirin-treated and aspirin-treated volunteers, in aspirin-treated baboons, and in anemic thrombocytopenic patients. This monograph discusses the role of RBCs and PLTs in the restoration of hemostasis, in the hope that a better understanding of the hemostatic mechanism might improve the treatment of anemic thrombocytopenic patients. Data from our studies have demonstrated that it is important to transfuse anemic thrombocytopenic patients with RBCs that have satisfactory viability and function to achieve a Hct level of 35 vol percent before transfusing viable and functional PLTs. The Biomedical Excellence for Safer Transfusion (BEST) Collaborative recommends that preserved PLTs have an in vivo recovery of 66 percent of that of fresh PLTs and a life span that is at least 50 percent that of fresh PLTs. Their recommendation does not include any indication that preserved PLTs must be able to function to reduce the BT and reduce or prevent nonsurgical blood loss. One of the hemostatic effects of RBC is to scavenge endothelial cell nitric oxide, a vasodilating agent that inhibits PLT function. In addition, endothelin may be released from endothelial cells, a potent vasoconstrictor substance,to reduce blood flow at the BT site. RBCs, like PLTs at the BT site, may provide arachidonic acid and adenosine diphosphate to stimulate the PLTs to make thromboxane, another potent vasoconstrictor substance and a PLT-aggregating substance. At the BT site, the PLTs and RBCs are activated and phosphatidyl serine is exposed on both the PLTs and the RBCs. FVa and FXa, which generate prothrombinase activity to produce thrombin, accumulate on the PLTs and RBCs. A Hct level of 35 vol percent at the BT site minimizes shear stress and reduces nitric oxide produced by endothelial cells. The transfusion trigger for prophylactic PLT transfusion should consider both the Hct and the PLT count. The transfusion of RBCs that are both viable and functional to anemic thrombocytopenic patients may reduce the need for prophylactic leukoreduced PLTs, the alloimmunization of the patients, and the associated adverse events related to transfusion-related acute lung injury. The cost for RBC transfusions will be significantly less than the cost for the prophylactic PLT transfusions.

Transfusion-related acute lung injury and leucocyte-reacting antibodies

BACKGROUND AND OBJECTIVES

Transfusion-related acute lung injury (TRALI) is underdiagnosed and underreported. This is why we present cases suspected for TRALI, in which leucocyte antibodies were examined.

MATERIAL AND METHODS

We analysed 44 patients with respiratory insufficiency, related to transfusion, who met criteria of acute lung injury (ALI). Lymphocyte and granulocyte antibodies were examined in donors and patients by six methods.

RESULTS

Based on recent trends, we divided patients into two groups: TRALI (without risk factors for ALI) and possible TRALI (with probable risk factors). The incidence of antibodies was 68.2%, the majority were human leucocyte antigen (HLA) class I and/or II, the minority were non-specific granulocyte antibodies; half of all detected antibodies, however, reacted with granulocytes. Antibodies were found in 17 donors (more often in TRALI than in possible TRALI) and in 19 patients (in four - suspected to be of the donor origin, which would diminish the number of antibodies to 15). In seven available cases, we observed cognate antigen and/or positive cross-match. In the majority of patients, TRALI occurred after transfusion of red cells, in 56.2%- stored above 14 days; all the units were non-leucoreduced. Lookback in two donors showed that transfusions in 20 patients did not result in reported TRALI, even in the patient with cognate antigen.

CONCLUSIONS

Our clinical observations suggest that to distinguish between TRALI and possible TRALI is difficult and the results are equivocal - it is worth considering whether it can be omitted. We have confirmed that antibodies are involved in TRALI, although their role is very complex. The role of stored red blood cells in the development of TRALI requires further observations in comparison with a control group of patients without TRALI.