Transfusion-related acute lung injury

Freeze-dried platelets are a promising alternative in bleeding thrombocytopenic patients with hematological malignancies

Thrombosomes are trehalose-stabilized, freeze-dried group O platelets with a 3-year shelf life. They can be stockpiled, rapidly reconstituted, and infused regardless of the recipient's blood type. Thrombosomes thus represent a potential alternative platelet transfusion strategy. The present study assessed the safety and potential early signals of efficacy of Thrombosomes in bleeding thrombocytopenic patients. We performed an open-label, phase 1 study of single doses of allogeneic Thrombosomes at three dose levels in three cohorts, each consisting of eight patients who had hematologic malignancies, thrombocytopenia, and bleeding. Adverse events, dose-limiting toxicities (DLTs), World Health Organization (WHO) bleeding scores, and hematology values were assessed. No DLTs were reported. The median age was 59 years (24-71). Most patients had AML (58%) or ALL (29%), followed by MDS (8%) and myeloproliferative neoplasm (4%). The WHO scores of 22 patients who were actively bleeding at a total of 27 sites at baseline either improved (n = 17 [63%]) or stabilized (n = 10 [37%]) through day 6. Twenty-four hours after infusion, 12 patients (50%) had a clinically significant platelet count increase. Of eight patients who received no platelet transfusions for 6 days after Thrombosomes infusion, 5 had a clinically significant increase in platelet count of ≥5000 platelets/μL and 2 had platelet count normalization. Thrombosomes doses up to 3.78 × 10⁸ particles/kg demonstrated safety in 24 bleeding, thrombocytopenic patients with hematological malignancies. Thrombosomes may represent an alternative to conventional platelets to treat bleeding. A phase 2 clinical trial in a similar patient population is underway.

Fluid Management in Acute Respiratory Distress Syndrome

One of the defining features of acute respiratory distress syndrome (ARDS) is noncardiogenic pulmonary edema, resulting from increased permeability of the alveolar-capillary barrier and passage of protein-rich fluid into the interstitium and alveolar spaces. The loss of protein from the intravascular space disrupts the normal oncotic pressure differential and causes patients with ARDS to be particularly sensitive to the hydrostatic forces that correlate with intravascular volume. Conservative fluid management, in which diuretics are administered and intravenous fluid administration is minimized, may decrease hydrostatic pressure and increase serum oncotic pressure, potentially limiting the development of pulmonary edema. However, the cause of death in most patients with ARDS is multiorgan system failure, not hypoxemia, and the impact of conservative fluid management on the incidence of extrapulmonary organ failure during ARDS is unclear. These physiologic observations have led to a series of studies examining the impact of fluid management on the development of, resolution of, survival from, and long-term outcomes from ARDS. While questions remain, the current literature makes it clear that fluid management is an integral part of the care of patients with ARDS.

Severe Transfusion-related Acute Lung Injury in the Intensive Care Unit Secondary to Transfusion of Fresh Frozen Plasma

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of transfusion of blood products. A case of severe TRALI secondary to infusion of fresh frozen plasma in the intensive care unit is discussed. Additionally, the aetiology and pathogenesis of this relatively under-diagnosed and under-reported clinical entity is reviewed. It is our conclusion that proper diagnosis and reporting is necessary for prompt and appropriate treatment of the patient and to prevent additional reactions in other patients.

HLA Class Ia and Ib Polyreactive Anti-HLA-E IgG2a Monoclonal Antibodies (TFL-006 and TFL-007) Suppress Anti-HLA IgG Production by CD19+ B Cells and Proliferation of CD4+ T Cells While Upregulating Tregs

The anti-HLA-E IgG2a mAbs, TFL-006 and TFL-007, reacted with all HLA-I antigens, similar to the therapeutic preparations of IVIg. Indeed, IVIg lost its HLA reactivity, when its HLA-E reactivity was adsorbed out. US-FDA approved IVIg to reduce antibodies in autoimmune diseases. But the mechanism underlying IVIg-mediated antibody reduction could not be ascertained due to the presence of other polyclonal antibodies. In spite of it, the cost prohibitive high or low IVIg is administered to patients waiting for donor organ and for allograft recipients for lowering antiallograft antibodies. A mAb that could mimic IVIg in lowering Abs, with defined mechanism of action, would be highly beneficial for patients. Demonstrably, the anti-HLA-E mAbs mimicked several functions of IVIg relevant to suppressing the antiallograft Abs. The mAbs suppressed activated T cells and anti-HLA antibody production by activated B cells, which were dose-wise superior to IVIg. The anti-HLA-E mAb expanded CD4+, CD25+, and Foxp3+ Tregs, which are known to suppress T and B cells involved in antibody production. These defined functions of the anti-HLA-E IgG2a mAbs at a level superior to IVIg encourage developing their humanized version to lower antibodies in allograft recipients, to promote graft survival, and to control autoimmune diseases.

TRALI following fresh frozen plasma resuscitation from burn shock

INTRODUCTION

Resuscitation from burn shock using fresh frozen plasma (FFP) has been described. Critics of FFP resuscitation cite the development of transfusion related acute lung injury (TRALI) as a deterrent to its use. This study examines the occurrence of TRALI with FFP resuscitation of critically ill burned patients.

METHODS

A retrospective chart review was conducted of severely burned patients who received FFP resuscitation. Data points included age, TBSA, TBSA full thickness, presence of alternate etiologies of acute lung injury, total FFP administered, and signs and symptoms of TRALI as defined per the Canadian Blood Services Consensus Conference.

RESULTS

Eighty-three patients met the definition of severe burn and received FFP resuscitation. Of those, 65 met exclusion criteria. Eighteen patients were left for analysis with only one found to have signs and symptoms of TRALI. That patient suffered a 53.5% TBSA burn, received a total of 6228ml FFP, had no competing etiologies of ALI, and was diagnosed with TRALI within 6h of completing the FFP transfusion.

CONCLUSION

The possible occurrence of TRALI in burn patients receiving FFP resuscitation should be weighed against the reported benefits of such a resuscitation strategy.

Transfusion Related Acute Lung Injury (TRALI): A Single Institution Experience of 15 Years

Transfusion related acute Lung injury (TRALI) though a serious blood transfusion reaction with a fatality rate of 5-25 % presents with acute respiratory distress with hypoxaemia and noncardiac pulmonary oedema within 6 h of transfusion. In non fatal cases, it may resolve within 72 h or earlier. Although reported with an incidence of 1:5000, its true occurrence is rather unknown. Pathogenesis is believed to be related to sequestration and adhesion of neutrophils to the pulmonary capillary endothelium and its activation leading to its destruction and leaks. The patient's underlying condition, anti-neutrophil antibody in the transfused donor plasma and certain lipids that accumulate in routinely stores blood and components are important in its aetiopathogenesis. Patient's predisposing conditions include haematological malignancy, major surgery (especially cardiac), trauma and infections. The more commonly incriminated products include fresh frozen plasma (FFP), platelets (whole blood derived and apheresis), whole blood and Packed RBC. Occasional cases involving cryoprecipitate and Intravenous immunoglobulin (IVig) have also been reported. We present a 15 year single institution experience of TRALI, during which we observed 9 cases among 170,871 transfusions, giving an incidence of 1:19,000. We did not encounter cases of haematological malignancy or cardiac surgery in our TRALI patients. Among the blood products, that could be related to TRALI in our patients included solitary cases receiving cryoprecipitate, IVIg, and recombinant Factor VII apart from platelets and FFP. All patients were treated with oxygen support. Six patients required mechanical ventilation. Off label hydrocortisone was given to all patients. There were no cases of fatality among our patients.

Red Blood Cell Transfusion

Blood is classified as a drug and transfusion is one of the most commonly performed procedures in the USA. General knowledge of blood manufacturing, shelf life and storage media, common component modifications, blood types, and product compatibility allows the clinician to better communicate their needs and to understand what options may be available when ordering blood products. All transfusions offer benefits, and the clinician must comprehend the possible adverse events, especially those related to TRALI, which continues to be the most common cause of transfusion-related death reported to FDA, with TACO as the second most-commonly reported event. Transfusing in the setting of hemorrhagic blood loss adds additional challenges regarding volume overload, coagulopathy, and optimum transfusion ratios of red cells, plasma, platelets, and cryoprecipitate. The information imparted in this chapter will help equip the clinician with the knowledge needed to make the best decisions for patients requiring blood products, especially injured patients.

Immunoglobulin (Ig)G purified from human sera mirrors intravenous Ig human leucocyte antigen (HLA) reactivity and recognizes one's own HLA types, but may be masked by Fab complementarity-determining region peptide in the native sera

Intravenous immunoglobulin (IVIg) reacted with a wide array of human leucocyte antigen (HLA) alleles, in contrast to normal sera, due possibly to the purification of IgG from the pooled plasma. The reactivity of IgG purified from normal sera was compared with that of native sera to determine whether any serum factors mask the HLA reactivity of anti-HLA IgG and whether IgG purified from sera can recognize the HLA types of the corresponding donors. The purified IgG, unlike native sera, mirrored IVIg reactivity to a wide array of HLA-I/-II alleles, indicating that anti-HLA IgG may be masked in normal sera - either by peptides derived from soluble HLA or by those from antibodies. A < 3 kDa peptide from the complementarity-determining region (CDR) of the Fab region of IgG (but not the HLA peptides) masked HLA recognition by the purified IgG. Most importantly, some of the anti-HLA IgG purified from normal sera - and serum IgG from a few donors - indeed recognized the HLA types of the corresponding donors, confirming the presence of auto-HLA antibodies. Comparison of HLA types with the profile of HLA antibodies showed auto-HLA IgG to the donors' HLA antigens in this order of frequency: DPA (80%), DQA (71%), DRB345 (67%), DQB (57%), Cw (50%), DBP (43%), DRB1 (21%), A (14%) and B (7%). The auto-HLA antibodies, when unmasked in vivo, may perform immunoregulatory functions similar to those of therapeutic preparations of IVIg.

Red blood cell storage: how long is too long?

Red blood cells (RBCs) undergo biochemical and structural changes during storage, commonly referred to as the "storage lesion." Evidence suggests that the longer the RBC product is stored, the less effective is the transfused blood. Many studies linking morbidity to transfusion have not considered duration of RBC storage as a variable that may modulate the effect. In addition, the effects of supply and demand and RBC inventory management strategies have been incompletely investigated. It is possible to envision a blood management system based on modern inventory management strategies that could greatly reduce storage duration.

Guideline on the investigation and management of acute transfusion reactions. Prepared by the BCSH Blood Transfusion Task Force

Although acute non-haemolytic febrile or allergic reactions (ATRs) are a common complication of transfusion and often result in little or no morbidity, prompt recognition and management are essential. The serious hazards of transfusion haemovigilance organisation (SHOT) receives 30-40 reports of anaphylactic reactions each year. Other serious complications of transfusion, such as acute haemolysis, bacterial contamination, transfusion-related acute lung injury (TRALI) or transfusion-associated circulatory overload (TACO) may present with similar clinical features to ATR. This guideline describes the approach to a patient developing adverse symptoms and signs related to transfusion, including initial recognition, establishing a likely cause, treatment, investigations, planning future transfusion and reporting within the hospital and to haemovigilance organisations. Key recommendations are that adrenaline should be used as first line treatment of anaphylaxis, and that transfusions should only be carried out where patients can be directly observed and where staff are trained in manging complications of transfusion, particularly anaphylaxis. Management of ATRs is not dependent on classification but should be guided by symptoms and signs. Patients who have experienced an anaphylactic reaction should be discussed with an allergist or immunologist, in keeping with UK resuscitation council guidelines.

A threshold model for the susceptibility to transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is a serious, often life-threatening pulmonary transfusion reaction characterized by non-cardiogenic lung oedema, hypoxemia and respiratory distress in temporal association with blood transfusion. The critical mechanism in TRALI is the sudden increase in permeability of the pulmonary endothelium and the subsequent, often extensive shift of fluid into the alveolae. The rapid clinical recovery seen in most patients makes it likely that this is a temporary phenomenon. Reactive oxygen species released by neutrophils or other cells are attractive candidate mediators of this process. There is experimental and clinical evidence that several pathways can induce barrier breakdown in TRALI, a concept known as the threshold model of TRALI. Surprisingly, neutrophils may not always be required. Other cells may play a role as multipliers or attenuators of TRALI, depending on recipient-related and transfusion-related factors involved. This review will summarize recent findings on pathophysiology, with a focus on newly discovered or disenchanted recipient-related and transfusion-related risk factors for TRALI and will present the threshold model of TRALI as a unifying concept on how TRALI develops.

Anesthetic Considerations in Hepatectomies under Hepatic Vascular Control

Background. Hazards of liver surgery have been attenuated by the evolution in methods of hepatic vascular control and the anesthetic management. In this paper, the anesthetic considerations during hepatic vascular occlusion techniques were reviewed. Methods. A Medline literature search using the terms "anesthetic," "anesthesia," "liver," "hepatectomy," "inflow," "outflow occlusion," "Pringle," "hemodynamic," "air embolism," "blood loss," "transfusion," "ischemia-reperfusion," "preconditioning," was performed. Results. Task-orientated anesthetic management, according to the performed method of hepatic vascular occlusion, ameliorates the surgical outcome and improves the morbidity and mortality rates, following liver surgery. Conclusions. Hepatic vascular occlusion techniques share common anesthetic considerations in terms of preoperative assessment, monitoring, induction, and maintenance of anesthesia. On the other hand, the hemodynamic management, the prevention of vascular air embolism, blood transfusion, and liver injury are plausible when the anesthetic plan is scheduled according to the method of hepatic vascular occlusion performed.

"Possible TRALI" developed during bilateral total knee arthroplasty replacement -A case report-

Transfusion-related acute lung injury (TRALI) is one of the leading causes of transfusion-related morbidity and mortality. However, it is frequently not diagnosed and under-reported, which could result in inappropriate treatment. Diagnostic definition for TRALI consists of hypoxia and bilateral pulmonary edema occurring during or within 6 hours of a transfusion in the absence of cardiac failure or intravascular volume overload. Here, we report a fatal case, which resulted from under-recognition and misdiagnosis of TRALI occurring during transfusion with packed red blood cells during a bilateral total knee replacement.

Conversion to low transfusion-related acute lung injury (TRALI)-risk plasma significantly reduces TRALI

BACKGROUND

Transfusion-related acute lung injury (TRALI) is an uncommon but serious transfusion reaction. Studies have shown that the transfusion of HLA and HNA antibodies in donor plasma can lead to TRALI. Female donors are more likely to have such antibodies due to alloantigen exposure during pregnancy. Many blood suppliers have now implemented various TRALI risk reduction strategies to unknown effect. A retrospective analysis of TRALI reactions in plasma recipients before and after the conversion to low-TRALI-risk plasma (all-male donor plasma, male-predominant plasma, nulliparous female plasma, and HLA antibody-tested plasma) is reported.

STUDY DESIGN AND METHODS

Transfusion reaction reports at three large hospitals 16 months before and 16 months after the conversion to low-TRALI-risk plasma were analyzed. Respiratory reactions were categorized as TRALI, possible TRALI, or other (e.g., transfusion-associated circulatory overload or allergic reactions). Reactions were reported as a percentage of total units transfused and rates for the two time periods were compared. Trends in reaction rates for other components were also compared.

RESULTS

A total of 2156 transfusion reactions in association with 461,598 transfused blood components were reviewed. The incidence of combined TRALI or possible TRALI reactions, due to the transfusion of plasma, decreased from 0.0084% to zero (p = 0.052). The rate of TRALI or possible TRALI reactions in red blood cell and platelet recipients did not change significantly.

CONCLUSION

The conversion to low-TRALI-risk plasma has reduced the incidence of TRALI reactions in plasma recipients.

Alternative procedures for reducing allogeneic blood transfusion in elective orthopedic surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

Cryoprecipitate: no longer the best therapeutic choice in congenital fibrinogen disorders?

Congenital abnormalities of fibrinogen are rare disorders classified as quantitative (afibrinogenemia and hypofibrinogenemia) or qualitative types (dysfibrinogenemia and hypodysfibrinogenemia). Fibrinogen is essential to haemostasis as the substrate for fibrin clot formation and also acts in primary haemostasis as a key ligand in platelet aggregation. Quantitative deficiency of fibrinogen can result in severe bleeding, or arterial and venous thromboembolism, and poor wound healing. Dysfibrinogenemia is characterized by functional abnormalities of fibrinogen, which may be asymptomatic (in 50% of cases), or cause bleeding (25%) or thrombosis (25%). Replacement of the deficient or abnormal fibrinogen with frozen plasma, cryoprecipitate, or fibrinogen concentrate has been found to be effective in practice in treating haemostatic complications of these disorders. Although cryoprecipitate is the most commonly used replacement material, pathogen-reduced fibrinogen concentrates have several advantages, most importantly a lower potential risk of viral transmission and standardized fibrinogen content allowing accurate dosing. They also avoid transfusing unwanted clotting factors, platelet microparticles and immunoglobulins, and can be administered rapidly without thawing. The use of fibrinogen concentrate to treat congenital fibrinogen disorders is strongly supported in principle and increasingly by practical experience and evidence.

The role of neutrophils in the pathogenesis of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is the major cause of transfusion related morbidity and mortality, world wide. Efforts to reduce or eliminate this serious complication of blood transfusion are hampered by an incomplete understanding of its pathogenesis. Currently, TRALI is thought to be mediated by donor alloantibodies directed against host leukocytes or the result of 2 distinct clinical events. For both proposed mechanisms, the neutrophil is the key effector cell. This article reviews TRALI pathophysiology, explores the role of the neutrophil, details practical information for appropriate diagnosis and promotes further studies into the pathogenesis of TRALI.

Transfusion and pulmonary morbidity after cardiac surgery

BACKGROUND

True lung injury is among the leading causes of transfusion-related mortality. Pulmonary morbidity after cardiac surgery has been related to damaging effects of cardiopulmonary bypass and transfusion, but is confounded by cardiac-related events that may not reflect true lung injury. Thus, cardiac surgery poses unique challenges to criteria-specific diagnosis of transfusion-related acute lung injury (TRALI). Our objective was to determine the prevalence of pulmonary morbidity related to transfusion and whether TRALI consensus-criteria are applicable to cardiac surgery.

METHODS

A total of 16,847 patients underwent on-pump, coronary artery bypass grafting (CABG), valve, or CABG-valve surgery from September 1998 to February 1, 2006. We performed four propensity-score-matching analyses with logistic regression on probability of receiving a transfusion: total hospital red blood cell (RBC) and fresh frozen plasma (FFP) transfusion and intraoperative RBC and FFP transfusion. Outcomes included traditional cardiac-surgery-defined pulmonary morbidity and ratio of arterial partial pressure of oxygen to fractional inspired oxygen concentration (PaO(2)/FiO(2)), a criterion for TRALI.

RESULTS

Patients receiving RBC transfusion had more risk-adjusted pulmonary complications: respiratory distress 4.8% vs 1.5%, p < 0.001; respiratory failure 2.2% vs 0.39%, p < 0.0001; longer intubation times, 9.9 hours vs 7.5 hours, p < 0.0001; acute respiratory distress syndrome, 0.64% vs 0.21%, p = 0.015; and reintubation, 5.6% vs 1.3%, p < 0.0001. The FFP was similarly related to more pulmonary complications after surgery. By TRALI criteria, the majority manifested "lung injury" (PaO(2)/FiO(2) ratio < 300) but unrelated to transfusion (65% vs 64%).

CONCLUSIONS

Transfusion is associated with many measures of postoperative pulmonary morbidity. Yet the PaO(2)/FiO(2) ratio as important criterion of TRALI is unrelated to transfusion. Thus, due to the nature of cardiac surgery, application of consensus guided diagnosis of TRALI is problematic.

Long-term survival and quality of life after transfusion-associated pulmonary edema in critically ill medical patients

BACKGROUND

Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) commonly complicate transfusion in critically ill patients. Prior outcome studies of TACO and TRALI have focused on short-term morbidity and mortality, but the long-term survival and quality of life (QOL) of these patients remain unknown.

METHODS

In a nested case-control study, we compared survival and QOL between critically ill medical patients who developed pulmonary edema after transfusion (TRALI or TACO) and medical critically ill transfused controls, matched by age, gender, and admission diagnostic group. QOL in survivors was assessed with a 36-item short form health survey 1 year after initial hospitalization.

RESULTS

Hospital, 1-year, and 2-year mortality among the 74 TRALI cases and 74 matched controls were 43.2% vs 24.3% (P = .020), 63.8% vs 46.4% (P = .037) and 74.3% vs 54.3% (P = .031), whereas among the 51 TACO cases and 51 matched controls these values were 7.8% vs 11.8% (P = .727), 38.0% vs 28.0% (P = .371), and 44.9% vs 38.8% (P = .512). When adjusted for age and baseline severity of illness in a Cox proportional hazard analysis, the development of TRALI remained associated with decreased survival (hazard ratio 1.86; 95% CI, 1.19-2.93; P = .006). Both TRALI (P = .006, P = .03) and TACO (P = .03, P = .049) were associated with prolonged ICU and hospital lengths of stay.

CONCLUSIONS

In critically ill medical patients, development of TRALI, but not TACO, is independently associated with decreased long-term survival.

Transfusion-related acute lung injury (TRALI): current concepts and misconceptions

Transfusion-related acute lung injury (TRALI) is the most common cause of serious morbidity and mortality due to hemotherapy. Although the pathogenesis has been related to the infusion of donor antibodies into the recipient, antibody negative TRALI has been reported. Changes in transfusion practices, especially the use of male-only plasma, have decreased the number of antibody-mediated cases and deaths; however, TRALI still occurs. The neutrophil appears to be the effector cell in TRALI and the pathophysiology is centered on neutrophil-mediated endothelial cell cytotoxicity resulting in capillary leak and ALI. This review will detail the pathophysiology of TRALI including recent pre-clinical data, provide insight into newer areas of research, and critically assess current practices to decrease it prevalence and to make transfusion safer.

Transfusion-Related Acute Lung Injury — A Review

Transfusion-related acute lung injury (TRALI), a type of non-cardiogenic pulmonary oedema related to blood transfusion, is gaining prominence as a common adverse event related to blood transfusions in hospitals. Various mechanisms have been postulated to cause TRALI including both antibody-related and non-immune mechanisms. Although transfusion of all types of blood components have been implicated, by far the commonest product related to TRALI was, until recently, fresh frozen plasma, especially that obtained from female donors. However the use of male-only plasma donation in the UK has resulted in an increased observance of TRALI with platelet and red cell transfusions. The diagnosis of this condition is primarily one of exclusion of other causes of pulmonary oedema, with specialist laboratory tests performed to support the diagnosis. The management of TRALI is early diagnosis and good supportive care with, occasionally, ventilatory support. An increased awareness of this complication among intensive care physicians is desirable to prevent one of the commonest and most frequently under-recognised transfusion-related adverse events of the present day.

Animal models of transfusion-related acute lung injury

Currently, more than 50 years after its apparent early recognition in case reports, and more than 20 years after its name was coined to denote a distinct entity of pulmonary transfusion reactions, transfusion-related acute lung injury (TRALI) has emerged as a serious cause of transfusion-associated morbidity and the subject of an exponentially growing scientific literature. However, review articles, clinical case reports, and case series continue to dominate the published literature on the topic and experimental studies aimed at modeling and elucidating TRALI mechanisms are less frequent. This article reviews the current status of the known experimental models of TRALI, with particular emphasis on efforts to establish in vivo animal models of this important pulmonary transfusion reaction.

Plasma from stored packed red blood cells and MHC class I antibodies causes acute lung injury in a 2-event in vivo rat model

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion death. We hypothesize that TRALI requires 2 events: (1) the clinical condition of the patient and (2) the infusion of antibodies against MHC class I antigens or the plasma from stored blood. A 2-event rat model was developed with saline (NS) or endotoxin (LPS) as the first event and the infusion of plasma from packed red blood cells (PRBCs) or antibodies (OX18 and OX27) against MHC class I antigens as the second event. ALI was determined by Evans blue dye leak from the plasma to the bronchoalveolar lavage fluid (BALF), protein and CINC-1 concentrations in the BALF, and the lung histology. NS-treated rats did not evidence ALI with any second events, and LPS did not cause ALI. LPS-treated animals demonstrated ALI in response to plasma from stored PRBCs, both prestorage leukoreduced and unmodified, and to OX18 and OX27, all in a concentration-dependent fashion. ALI was neutrophil (PMN) dependent, and OX18/OX27 localized to the PMN surface in vivo and primed the oxidase of rat PMNs. We conclude that TRALI is the result of 2 events with the second events consisting of the plasma from stored blood and antibodies that prime PMNs.

Transfusion-Related Acute Lung Injury

Transfusion-related acute lung injury (TRALI) refers to a clinical syndrome of acute lung injury that occurs in a temporal relationship with the transfusion of blood products. Because of the difficulty in making its diagnosis, TRALI is often underreported. Three not necessarily mutually exclusive hypotheses have been described to explain its etiogenesis: antibody mediated, non-antibody mediated, and two hit mechanisms. Treatment is primarily supportive and includes supplemental oxygen. Diuretics are generally not indicated, as hypovolemia should be avoided. Compared with many other forms of acute lung injury, including the acute respiratory distress syndrome, TRALI is generally transient, reverses spontaneously, and carries a better prognosis. A variety of prevention strategies have been proposed, ranging from restrictive transfusion strategies to using plasma derived only from males.

Association of RBC Transfusion With Mortality in Patients With Acute Lung Injury

BACKGROUND

RBC transfusion has been associated with increased morbidity and mortality in a variety of clinical settings. We assessed the effect of RBC transfusion on in-hospital mortality in patients with acute lung injury (ALI).

METHODS

Cohort study of 248 consecutive patients with ALI. RBC transfusion was evaluated as both dichotomous and continuous variables, with outcome being in-hospital mortality adjusted for clinical confounders and length of total hospital stay.

RESULTS

Overall in-hospital mortality rate was 39.5%. Of these patients, 207 of 248 patients (83.5%) received > or = 1 U of packed RBCs. The transfusion of any packed RBCs was associated with an increased risk of death (adjusted odds ratio [OR], 3.12; 95% confidence interval [CI], 1.28 to 7.58; p < 0.001). The overall OR per unit was 1.06 (95% CI, 1.04 to 1.09; p < 0.001) in the complete multivariable model. Transfusion after ALI onset was associated with an adjusted OR of 1.13 (95% CI, 1.07 to 1.20; p < 0.001), while transfusion before ALI onset was not associated with higher risk. The adjusted OR per unit of nonleukoreduced RBC transfused was 1.14 (95% CI, 1.07 to 1.21; p < 0.001), while the adjusted OR for leukoreduced cells per unit transfused was 1.06 (95% CI, 1.03 to 1.09; p < 0.001).

CONCLUSIONS

Transfusion of RBCs in patients with ALI was associated with increased in-hospital mortality. This risk occurred with RBC transfusion after the onset of ALI, and was greater for nonleukoreduced than for leukoreduced RBCs. Aggressive transfusion strategies in patients with established ALI should be questioned, pending further study.

Fresh-Frozen Plasma and Platelet Transfusions Are Associated With Development of Acute Lung Injury in Critically Ill Medical Patients

BACKGROUND

Transfusion has long been identified as a risk factor for acute lung injury (ALI)/ARDS. No study has formally evaluated the transfusion of specific blood products as a risk factor for ALI/ARDS in critically ill medical patients.

METHOD

In this single-center retrospective cohort study, 841 consecutive critically ill patients were studied for the development of ALI/ARDS. Patients who received blood product transfusions were compared with those who did not, in univariate and multivariate propensity analyses.

RESULTS

Two hundred ninety-eight patients (35%) received blood transfusions. Transfused patients were older (mean [+/- SD] age, 67 +/- 17 years vs 62 +/- 19 years; p < 0.001) and had higher acute physiologic and chronic health evaluation (APACHE) III scores (74 +/- 32 vs 58 +/- 23; p < 0.001) than those who had not received transfusions. ALI/ARDS developed more commonly (25% vs 18%; p = 0.025) in patients exposed to transfusion. Seventeen patients received massive RBC transfusions (ie, > 10 U of blood transfused within 24 h), of whom 13 also received fresh-frozen plasma (FFP) and 11 received platelet transfusions. When adjusted for the probability of transfusion and other ALI/ARDS risk factors, any transfusion was associated with the development of ALI/ARDS (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.24 to 3.75). Among those patients receiving individual blood products, ALI/ARDS was more likely to develop in patients who received FFP transfusions (OR, 2.48; 95% CI, 1.29 to 4.74) and platelet transfusions (OR, 3.89; 95% CI, 1.36 to 11.52) than in those who received only RBC transfusions (OR, 1.39; 95% CI, 0.79 to 2.43).

CONCLUSION

Transfusion is associated with an increased risk of the development of ALI/ARDS in critically ill medical patients. The risk is higher with transfusions of plasma-rich blood products, FFP, and platelets, than with RBCs.

[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.

Serious hazards of transfusion: a decade of hemovigilance in the UK

The Serious Hazards of Transfusion (SHOT) scheme is a UK-wide, independent, professionally led hemovigilance system focused on learning from adverse events. SHOT was established in 1996 as a confidential reporting system for significant transfusion-related events, building an evidence base to support blood safety policy decisions, clinical guidelines, clinician education, and improvements in transfusion practice. Recommendations are formulated by an independent steering group drawn from medical royal colleges and professional bodies. Ten years after its inception, SHOT has analyzed 2630 transfusion safety events, published 8 annual reports with recommendations, and presented data nationally and internationally. These recommendations have underpinned key initiatives, in particular the UK Department of Health "Better Blood Transfusion" strategy. SHOT has encouraged open reporting of adverse events and "near-misses" in a supportive, learning culture, vigilance in hospital transfusion practice, and evaluation of information technology to support this process. The importance of education and training has been emphasized. Detailed analysis of events has identified weaknesses in the transfusion chain. A collaborative initiative between SHOT, the Chief Medical Officer for England's National Blood Transfusion Committee, and the National Patient Safety Agency aims to reduce ABO-incompatible transfusions by improving bedside practice. Cumulative SHOT data have documented the decline in transfusion-related graft vs host disease after implementation of leucodepletion and have highlighted transfusion-related acute lung injury and bacterial contamination of platelets as important causes of death and morbidity. The UK blood services have developed strategies to reduce these risks. Future SHOT data will evaluate the success of these and other blood safety improvements.

Transfusion-related acute lung injury (TRALI)--an important, severe transfusion-related complication

BACKGROUND

Transfusion-related acute lung injury (TRALI) is an immune-mediated transfusion reaction that can cause severe complications or even death. It is now the leading cause of transfusion-related death in the United States.

METHODS

The TRALI syndrome is presented in two cases in a surgical intensive care unit and discussed against the background of the present literature. In both cases, concomitant diseases led to an extremely difficult course of TRALI.

CONCLUSIONS

Knowledge of the TRALI syndrome is necessary to enable early diagnosis and treatment. It should be taken into consideration at any time when cardiopulmonary instability occurs after transfusion of blood products, which is a frequent event on surgical Intensive Care Units. TRALI remains a clinical diagnosis supported by serologic studies if these are available. Against the background of this potentially life-threatening complication, every single indication to transfuse blood products needs to be scrutinized carefully.

Transfusion-related acute lung injury: a literature review

Transfusion-related acute lung injury (TRALI) is a serious and potentially fatal complication of transfusion of blood and blood components. TRALI is under-diagnosed and under-reported because of a lack of awareness. A number of models have been proposed to explain the pathogenesis of TRALI: an antibody mediated model; a two-event biologically active mediator model; and a combined model. TRALI can occur with any type of blood product and can occur with as little as one unit. Its presentation is similar to other forms of acute lung injury and management is predominantly supportive. The main strategy in combating TRALI is prevention both through manipulation of the donor pool and through clinical strategies directed at reducing transfusion of blood products including, but not limited to, evidence-based lower transfusion thresholds. This article presents a review of TRALI and addresses the definition, pathology, pathogenesis, clinical manifestations, treatment and prevention of the syndrome.

Transfusion-Related Acute Lung Injury (TRALI): Current Clinical and Pathophysiologic Considerations

Transfusion-related acute lung injury (TRALI) is a rare transfusion reaction presenting as respiratory distress during or after transfusion of blood products. TRALI varies in severity, and mortality is not uncommon. TRALI reactions have equal gender distributions and can occur in all age groups. All blood products, except albumin, have been implicated in TRALI reactions. TRALI presents as acute respiratory compromise occurring in temporal proximity to a transfusion of a blood product. Other causes of acute lung injury should be excluded in order to definitively diagnose TRALI. Clinically and pathologically, TRALI mimics acute respiratory distress syndrome (ARDS), with neutrophil-derived inflammatory chemokines and cytokines believed to be involved in the pathogenesis of both entities. Anti-HLA and anti-neutrophil antibodies have been implicated in some cases of TRALI. Treatment for TRALI is supportive; prevention is important. It is suspected that TRALI is both underdiagnosed and underreported. One of the difficulties in the evaluation of potential TRALI reactions is, until recently, the lack of diagnostic criteria. A group of transfusion medicine experts, the American-European Consensus Conference (AECC), recently met and developed diagnostic criteria of TRALI, as well as recommendations for management of donors to prevent future TRALI reactions. In light of the AECC consensus recommendations, we report an incident of TRALI in an oncology patient as an example of the potential severity of the lung disease and the clinical and laboratory evaluation of the patient. We also review the literature on this important complication of blood transfusion that internists may encounter.

The two-event model of transfusion-related acute lung injury

The objective of this review is to present the two-event model of transfusion-related acute lung injury (TRALI), a life-threatening complication of transfusions that has been the most common cause of transfusion-related death over the past 2 yrs in the United States. The two-event model of TRALI, which is identical to the pathogenesis of the acute respiratory distress syndrome (ARDS), is reviewed and contrasted to antibody-mediated TRALI. Laboratory studies, both in vitro and in vivo, are discussed as well as human studies of TRALI. Methods to avoid patient exposure to blood components that may cause TRALI are also discussed.

Transfusion-related acute lung injury (TRALI): clinical presentation, treatment, and prognosis

The term transfusion-related acute lung injury (TRALI) was coined in 1983 to describe a constellation of clinical and laboratory features seen within 6 hrs of the transfusion of plasma-containing blood products. These products contain antibodies directed to human leukocyte antigens (and subsequently described to nonhuman leukocyte antigens) found on white blood cells. In the intervening 2 decades, other cases not associated with antibodies have been reported as TRALI and an association with passive infusion of lipids accumulated in stored cellular blood products has been made in those cases. This has led to confusion as to what should be considered to constitute TRALI. Therefore, the true incidence of this pulmonary reaction to blood products is currently conjectural at best. Recent consensus development conferences have been held to develop and standardize definitions of TRALI so that epidemiologic and research aspects of this condition can be explored in a scientific manner. These conferences have set out criteria by which TRALI is distinguished from other causes of acute lung injury. This review outlines the widely accepted clinical (mainly pulmonary) features of TRALI, the treatment options, and the excellent long-term prognosis for patients who survive the initial pulmonary insult.

Risks and side effects of therapy with plasma and plasma fractions

Transfusion of plasma can lead to adverse reactions or events. Immune-mediated reactions are most common--these include allergic and anaphylactic reactions, transfusion-related acute lung injury (TRALI) and haemolysis. They can range in severity from mild to fatal. Fluid overload and citrate toxicity can occur after rapid or massive transfusion. In developed countries, microbial transmission rates are low because of donor selection and testing. Pathogen reduction processes can be applied to either single-unit components (methylene blue) or plasma pools (solvent-detergent). They have the unwanted effect of reducing some coagulation factors but reduce viral transmission risk even further. Reactions associated with plasma products or fractions also include allergic reactions, although TRALI is rare. Viral transmission risk is very low because of the use of two independent viral inactivation steps. Different products have particular specific unwanted effects: intravenous immunoglobulin has been associated with thrombotic events, renal toxicity and aseptic meningitis; coagulation factors are associated with development of inhibitors and thrombotic events. The risk of transmission of variant Creutzfeldt-Jakob disease in both plasma components and pooled plasma products is as yet unknown. If anything, the low titre of prion infectivity in the blood of an infected individual (approximately 10 infectious units/ml) will be massively diluted by the thousands of units of plasma in the pool. Subsequent manufacturing processes also remove prions from the final product.

HLA class II antibodies in transfusion-related acute lung injury (TRALI). A case report

TRALI, a serious complication of blood transfusion, is underdiagnosed. Anti-granulocyte and anti-HLA class I molecules in donors or recipients and very recently, lipids in stored blood as well as anti-HLA class II have been associated with the syndrome. We present a TRALI case which occurred in a 56 year old woman after plasma transfusion. HLA class II antibodies were identified in the donor and were correlated with the recipients' HLA antigens. The presence of HLA class II antibodies without anti-HLA class I has been reported in very few cases and may facilitate the understanding of the pathogenesis of the syndrome.

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.

Massive Blood Loss and Transfusion in Obstetrics and Gynecology

Massive perioperative or periparturitional bleeding occasionally occurs in obstetric and gynecologic patients. Placenta previa, uterine atony, and ectopic pregnancy are just a few examples of many conditions that could predispose patients to significant blood loss. Therefore, it is important for physicians specializing in obstetrics and gynecology to be proficient in managing episodes of massive hemorrhage and the practice of the most commonly used blood components. We review and update the management of massive hemorrhage for obstetrics and gynecologic patients. In addition, we explore blood component therapy, its risks and benefits.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning.

OBJECTIVES

After completion of this article, the reader should be able to explain the necessity of being proficient in managing episodes of massive hemorrhage, list the indications for use of various blood components, and summarize the risks and benefits of blood component therapy.