Transfusion Medicine Reviews最新文献

Introduction

Objective

Design and Methods

Results

Conclusions

Introduction

Methods

Results

Conclusions

The actual risk of providing RhD-positive units to RhD-negative recipients remains debatable. There is no standard of care in the United States (US) to guide transfusion decisions regarding RhD type for patients with an unknown blood type, except for women of childbearing age and neonates. The risk of alloantibody formation by an RhD-negative patient exposed to RhD-positive blood is reported to be from 3% to 70%. Due to such wide variations, this review was undertaken to determine the prevalence of anti-D alloimmunization in trauma patients who are RhD-negative and were transfused RhD-positive blood products. This study used the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) approach to answer the question, “In trauma patients who were transfused blood, what is the prevalence of alloimmunization to the D-antigen?” The review included all published articles through April 3, 2022 in databases. Articles published after the search period found by the authors were added to the manuscript if they addressed the primary question and there was unanimous consensus. There were 1683 full-text articles that met the search criteria, with 19 studies meeting eligibility criteria. In addition, 57 references were added after the search period had closed. The incidence of anti-D alloimmunization in adult trauma patients receiving whole blood varied from 7.8% to 42.7%. In contrast, incidence varied in patients receiving red blood cells (RBCs), from 0 to 94%, depending on number of categories analyzed. Anti-D alloimmunization with platelet transfusions varied from 0% to 19%. The alloimmunization rate increased with age and was detected only in children older than 5 years. Recent guidelines recommend the administration of Rh immune globulin (RhIG) to all traumatically injured patients who are both RhD-negative and pregnant. However, there is no specific guidance focused on the RhD-negative patient, pregnant or nonpregnant, and who have received RhD-positive red blood cells (RBC) and platelets. While numerous studies have attempted to evaluate the frequency of RhD alloimmunization rate in trauma settings, emerging data suggests that many factors affect this phenomenon. Additionally, the role of RhIG administration in cases of RhD-incompatible transfusions within the trauma setting adds complexity. As our trajectory propels us towards precision medicine and tailored transfusion practices, gaining a big data approach becomes indispensable.

Race and ethnicity are sociopolitical and not biological constructs, and assertions that these population descriptors have scientific meaning has caused significant harm. A critical assessment of the transfusion medicine literature is an important aspect of promoting race-conscious as opposed to race-based medicine. Utilizing current definitions and health equity frameworks, this review will provide a critical appraisal of transfusion medicine studies at the intersection of race and healthcare disparities, with a focus on larger methodological challenges facing the transfusion medicine community. Moving forward, risk modelling accounting for upstream factors, patient input, as well as an expert consensus on how to critically conduct and evaluate this type of literature are needed. Further, when using race and ethnicity in research contexts, investigators must be aware of existing guidelines for such reporting.

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the world and can lead to severe complications in immunocompromised individuals. HEV is primarily transmitted through eating pork, which has led to an increased in anti-HEV IgG seropositivity in the general population of Europe in particular. However, it can also be transmitted intravenously, such as through transfusions. The growing evidence of HEV contamination of blood products and documented cases of transmission have given rise to practice changes and blood product screening of HEV in many European countries. This review covers the abundant European literature and focuses on the most recent data pertaining to the prevalence of HEV RNA positivity and IgG seropositivity in the North American general population and in blood products from Canada and the United States. Currently, Health Canada and the Food and Drug Administration do not require testing of HEV in blood products. For this reason, awareness among blood product prescribers about the possibility of HEV transmission through blood products is crucial. However, we also demonstrate that the province of Quebec has a prevalence of anti-HEV and HEV RNA positivity similar to some European countries. In light of this, we believe that HEV RNA blood donation screening be reevaluated with the availability of more cost-effective assays.

Routine hemostasis parameters such as prothrombin time and fibrinogen are frequently abnormal in patients with chronic liver disease and have been demonstrated to be poor predictors for periprocedural bleeding. Alterations in procoagulant and anticoagulant factors in this population result in a state of rebalanced hemostasis, which is not reflected by routine hemostatic measures. Viscoelastic hemostatic assays (VHA) present a point of care measure of global hemostasis with an emerging role in guiding transfusion in the liver transplant setting. The potential role for VHA in guiding periprocedural transfusion is unknown. Here we critically appraise the available limited evidence on the use of VHA to guide prophylactic treatment in patients with cirrhosis undergoing procedures. We assess whether the impact of a VHA-guided approach improves clinical outcomes. Suggested areas for future research with a focus on clinically relevant outcomes, particularly periprocedural bleeding, are highlighted.

Hemoglobin-based red blood cell transfusion (RBC) triggers do not clearly identify which patients with moderate anemia (hemoglobin 7-10 g/dL) will benefit from RBC transfusion. The National Heart, Lung, and Blood Institute has recognized the need for bedside oxygenation measures to enhance transfusion decision-making. This narrative review uses four studies to explore the potential of the oxygen extraction ratio (O₂ER)—the ratio of consumed oxygen to delivered oxygen in a critical tissue bed as a more physiologically relevant indicator for guiding RBC transfusions in patients with moderate anemia. The aim of this review is to present existing data on the relationship between O₂ER and responsiveness to RBC transfusion, as well as the feasibility of O₂ER as bedside measure of tissue oxygenation. This review presents a narrative appraisal of three critical papers that investigate the relationship between O₂ER and transfusion outcomes, and one paper that demonstrates proof-of-concept for a noninvasive device to measure O₂ER at the bedside. Despite limitations in the existing studies, including small sample sizes and observational designs, the evidence collectively suggests that O₂ER has the potential to enhance transfusion decision accuracy. The development of noninvasive measurement devices could facilitate widespread implementation in many kinds of care settings.

Surgical patients are often transfused to manage bleeding and anemia. Best practices for red blood cell (RBC) transfusion administration in patient having noncardiac surgery remains controversial and a robust evaluation and description of perioperative transfusion practices is lacking. We characterized perioperative hemoglobin concentrations and transfusion practices from the prospective VISION cohort which included 39,222 patients aged ≥45 years who had inpatient noncardiac surgery. Variations in transfusion practices were analyzed using hierarchical mixed models, and associations with mortality and complications were evaluated using a nested frailty survival model. Within the cohort, 16.1% (n = 6296) were given perioperative RBC transfusions, with the fraction declining from 20% to 13% over the 6-year study period. The proportion of patients transfused varied by surgery type from 6.4% for low-risk operations (i.e., minor surgery) to 31.5% for orthopedic surgeries. Variations were largely associated with patient hemoglobin concentrations, but also with center (range: 3.7%-27.3%) and country (0.4%-25.3%). Even after adjusting for baseline hemoglobin, comorbidities and type of surgery, both center and country were significant sources of variation in transfusion practices. Among transfused participants, 60.4% (n = 3728/6170) had at least 1 hemoglobin concentration ≤80g/L and 86.0% (n = 5305/6170) had at least 1 hemoglobin concentration ≤90g/L, suggesting that relatively restrictive transfusion strategies were used in most. The proportion of patients receiving at least 1 RBC transfusion declined from 20% to 13% over 6 years. However, there was considerable unexplained variation in transfusion practices.