Current state of undergraduate medical school training in transfusion medicine and its impact on postgraduate trainee knowledge.

BACKGROUND: Studies have described poor transfusion medicine (TM) knowledge in postgraduate trainees. The impact of undergraduate medical TM education on postgraduate knowledge is unclear. METHODS: Canadian medical schools were surveyed on the number of hours dedicated to TM teaching and topics covered by curricula during 2016-2020. Postgraduate trainees attending Transfusion Camp in 2021 completed a pretest of 20 multiple-choice questions. The survey results and pretest scores were compared to evaluate the association between undergraduate medical TM education and pretest scores. RESULTS: The survey was completed by 16 of 17 Canadian medical schools. The number of hours (h) of TM teaching were <2 h (25%), 3-4 h (25%), and >4 h (50%). Twelve of 19 Transfusion Camp topics were covered in ≥50% of schools. Eleven medical schools provided ethics approvals/waivers to include trainee pretest scores in the analysis (N = 200). The median pretest scores by medical school ranged from 48% to 70%. No association was found between number of TM teaching hours and average pretest scores (p = .60). There was an association between higher postgraduate year level and individual pretest score (p < .0001). The analysis by topic demonstrated questions where trainees from different schools performed uniformly well or poorly; other topics showed considerable variation. CONCLUSION: Variation in quantity and content of undergraduate TM teaching exists across Canadian medical schools. In this limited assessment, the number of TM teaching hours was not associated with performance on the pretest. This study raises the opportunity to re-evaluate the delivery (content, timing, consistency) of TM education in undergraduate medical schools.

Rethinking the transfusion pathway in myelodysplastic syndromes: Study protocol for a novel randomized feasibility n-of-1 trial of weekly-interval red cell transfusion in myelodysplastic syndromes.

BACKGROUND: Anemia in myelodysplastic syndromes (MDS) is associated with poorer health-related quality of life (HRQoL) and physical function, and is frequently treated with transfusions. The current common practice of transfusing multiple red blood cells (RBC) units every 2-4 weeks may result in peaks/troughs in hemoglobin (Hb) level, yet maintaining a stable Hb may better improve HRQoL. We describe a study protocol aiming to investigate the feasibility of weekly low-dose RBC transfusion in MDS patients, including assessing HRQoL and physical function outcomes. STUDY DESIGN AND METHODS: In this n-of-1 pilot study, patients receive two treatment arms, with randomly allocated treatment sequence: arm A (patient's usual transfusion schedule) and arm B (weekly transfusion, individualized per patient). To facilitate timely delivery of weekly transfusion, extended-matched RBCs are provided, with transfusion based upon the previous week's Hb/pre-transfusion testing results to eliminate delays of awaiting contemporaneous cross-matching. Primary outcome is the feasibility of delivering weekly transfusion. Secondary outcomes include HRQoL, functional activity measurements, RBC usage, and alloimmunization rates. A qualitative substudy explores patient and staff experiences. RESULTS: The trial is open in Australia, Netherlands, and UK. The first patient was recruited in 2020. Inter-country differences in providing RBCs are observed, including patient genotyping versus serological phenotyping to select compatible units. DISCUSSION: This pilot trial evaluates a novel personalized transfusion approach of weekly matched RBC transfusion and challenges the dogma of current routine pre-transfusion matching practice. Findings on study feasibility, HRQoL, and physical functional outcomes and the qualitative substudy will inform the design of a larger definitive trial powered for clinical outcomes.

How do we achieve blinding in modern electronic and paper medical records during the conduct of transfusion trials?

BACKGROUND: Regulatory aspects of transfusion medicine add complexity in blinded transfusion trials when considering various electronic record keeping software and blood administration processes. The aim of this study is to explore strategies when blinding transfusion components and products in paper and electronic medical records. METHODS: Surveys were collected and interviews were conducted for 18 sites across various jurisdictions in North America to determine solutions applied in previous transfusion randomized control trials. RESULTS: Sixteen responses were collected of which 11 had previously participated in a transfusion randomized control trial. Various solutions were reported which were specific to the laboratory information system (LIS) and electronic medical record (EMR) combinations although solutions could be grouped into four categories which included the creation of a study product code in the LIS, preventing the transmission of data from the LIS to the EMR, utilizing specialized stickers and labels to conceal product containers and documents in the paper records, and modified bedside procedures and documentation. DISCUSSION: LIS and EMR combinations varied across sites, so it was not possible to determine combination-specific solutions. The study was able to highlight solutions that may be emphasized in future iterations of LIS and EMR software as well as procedural changes that may minimize the risk of unblinding.

Iatrogenic blood loss from phlebotomy during adult extracorporeal membrane oxygenation: A retrospective cohort study.

BACKGROUND: Adult extracorporeal membrane oxygenation (ECMO) patients are at high risk for allogeneic blood transfusion. Few studies have characterized iatrogenic blood loss from phlebotomy in adult ECMO patients. We hypothesized that iatrogenic phlebotomy would be a significant source of blood loss during ECMO. METHODS: Adults who had their entire ECMO run at our medical center between 2020 and 2022 were included. Average daily phlebotomy volume and total phlebotomy volume during ECMO were estimated based on the total number of laboratory tests that were processed. In addition, the crude and adjusted association between total phlebotomy volume during ECMO and RBC transfusion during ECMO was evaluated using linear regression and Loess curve analysis. RESULTS: A total of 161 patients who underwent 162 ECMO runs were included. Of the 162 ECMO runs, 88 (54.3%) were veno-arterial and 74 (45.7%) were veno-venous ECMO. Median duration of ECMO was 5 days [25th, 75th percentile = 2, 11]. Median daily phlebotomy volume was 130 mLs [25th, 75th percentile = 94, 170] and median total phlebotomy volume during ECMO was 579 mLs [25th, 75th percentile = 238, 1314]. There was a significant crude and adjusted association between total phlebotomy volume and RBC transfusion during ECMO (beta coefficient = 0.0023 and 0.0024 respectively, both p < .001) based on linear regression analysis. DISCUSSION: Phlebotomy for laboratory testing is a significant source of blood loss during ECMO in adults. Comprehensive patient blood management for adult ECMO patients should include strategies to reduce laboratory testing and/or phlebotomy volume during ECMO.

Protamine dosing and its impact in cardiac surgery transfusion practice-A retrospective bi-institutional analysis.

BACKGROUND: Bleeding after cardiac surgery is common and continues to require 10-20% of the national blood supply. Transfusion of allogeneic blood is associated with increased morbidity and mortality. Excessive protamine in the absence of circulating heparin after weaning off CPB can cause anticoagulation and precipitate bleeding. Hence, adequate dose calculation of protamine is crucial yet under evaluated. STUDY DESIGN: Retrospective cohort study. METHODS: We conducted a retrospective bi-institutional analysis of cardiac surgical patients who underwent cardiopulmonary bypass (CPB)-assisted cardiac surgery to assess the impact of protamine dosing in transfusion practice. Total 762 patients were identified from two institutions using electronic medical records and the Society of Thoracic Surgery (STS) database who underwent cardiac surgery using CPB. Patients were similar in demographics and other baseline characteristics. We divided patients into two groups based on mg of protamine administered to neutralize each 100 U of unfractionated heparin (UFH)-low-ratio group (Protamine: UFH ≤ 0.8) and high-ratio group (Protamine: UFH > 0.8). RESULTS: We observed a higher rate of blood transfusion required in high-ratio group (ratio >0.8) compared with low-ratio group (ratio ≤0.8) (p < .001). The increased requirement was consistently demonstrated for intraoperative transfusions of red blood cells, plasma, platelets, and cryoprecipitate. CONCLUSION: High protamine to heparin ratio may cause increased bleeding and transfusion in cardiac surgical patients. Protamine to heparin ratio of 0.8 or lower is sufficient to neutralize circulating heparin after weaning off cardiopulmonary bypass.

The first two years of the use of low titer group O whole blood during French Military overseas operations: A retrospective study.

BACKGROUND: On the battlefield, hemorrhage is the main cause of potentially preventable death. To reduce mortality due to hemorrhagic injuries, the French Military Medical Service (FMMS) has deployed low titer group O whole blood (LTOWB) since June 2021 during operation BARKHANE in the Sahel-Saharan strip. Questions persist regarding the circumstances under which the FMMS employs LTOWB during overseas operations. STUDY DESIGN: We performed a retrospective analysis of all LTOWB transfused by the FMMS during overseas operations in the Sahel-Saharan strip between June 1, 2021, and June 1, 2023. Information was collected from battlefield forward transfusion sheets. RESULTS: Over the 2-year study period, 40 units of LTOWB were transfused into 25 patients. Of the 25 patients, 18 were combat casualties and seven were transfused for non-trauma surgery. Of the 40 units of LTOWB transfused, 22 were provided during Role 2 care, 11 during tactical medical evacuation (MEDEVAC), and seven in light and mobile surgical units. Among combat casualties, LTOWB was the first blood product transfused in 13 patients. In combat casualties, 6 h post-trauma, the median ratio of plasma: red blood cells (RBCs) was 1.5, and the median equivalent platelet concentrate (PC) transfused was 0.17. No immediate adverse events related to LTOWB transfusion were reported. CONCLUSION: LTOWB is transfused by the FMMS during overseas operations from the tactical MEDEVAC until Role 2 care. Deployment of LTOWB by the FMMS enables an early high-ratio plasma/RBC transfusion and an early platelet transfusion for combat casualties.

Lack of efficacy of aprotinin over tranexamic acid in type A aortic dissection repair.

BACKGROUND: The role of aprotinin in modern cardiac surgery is not well defined. While licensed for use in isolated coronary artery bypass grafting it is more commonly used for cases deemed to be at an increased risk of bleeding. The relative efficacy, and safety profile, of aprotinin as compared to other antifibrinolytics in these high-risk cases is uncertain. STUDY DESIGN AND METHODS: A retrospective observational study with propensity matching to determine whether aprotinin versus tranexamic acid reduced bleeding or transfusion requirements in patients presenting for surgical repair of type A aortic dissection (TAD). RESULTS: Between 2016 and 2022, 250 patients presented for repair of TAD. A total of 231 patients were included in the final analysis. Bleeding and transfusion were similar between both groups in both propensity matched and unmatched cohorts. Compared to tranexamic acid, aprotinin use did not reduce transfusion requirements for any product. Rates of bleeding in the first 12 h, return to theater and return to intensive care unit with an open packed chest were similar between groups. There was no difference in rates of renal failure, stroke, or death. CONCLUSION: Aprotinin did not reduce the risk of bleeding or transfusion requirements in patients undergoing repair of type A aortic dissections. Efficacy of aprotinin may vary depending on the type of surgery performed and the underlying pathology.

Prehospital transfusion of labile blood product using intraosseous perfusion with multi-lumen extender: Why not?

BACKGROUND: French prehospital military medical teams are provided with labile blood products to effectively address hemorrhagic shock. In combat environment, standard good medical practice may limit efficacy of therapeutic goals regarding damage control resuscitation. STUDY DESIGN AND METHODS: We present here a case report describing the management of a soldier heavily wounded during a helicopter forward medical evacuation in Sahel region. RESULTS: We report the challenge encountered by medical team using only a humeral intraosseous route available due to severity of lesions and challenging environment. In this configuration, multi-lumen extender enabled transfusion of two units of packed red blood cells and two units of plasma, and analgesia while limiting manipulation and dislodgment of the fragile intraosseous route. This situation, outside of usual good medical practice, raises issues of hemolysis, physicochemical compability of drugs and blood products, and consequences on flow rate reduction. DISCUSSION: With this case, we emphasize the benefit of multi-lumen extender associated with intraosseous route for early management of heavy casualties in harsh prehospital environment. Literature suggests that hemolysis and physicochemical compability should remain limited. The main issue of this setting consists of flow reduction and can be addressed by prioritizing humeral route, and using counter pressure cuffs, until a second peripheral or central line is available and management can resume without the need for multi-lumen extender.

Consideration for alpha-gal syndrome in two critically ill persons with group O blood who received group B plasma.

BACKGROUND: The U.S. Centers for Disease Control and Prevention (CDC) has reported increasing rates of alpha-gal syndrome, an allergic response after meat ingestion (AGS). AGS has been associated with prior exposure to tick bites or other biologics characterized by a life-threatening immunoglobulin E (IgE)-mediated hypersensitivity to galactose-alpha-1,3-galactose (alpha-gal) an oligosaccharide structurally similar to the group B antigen on red blood cells (RBC) found in most non-primate mammalian meat and products derived from these mammals. In 2023, Transfusion reported 3 group O recipients of group B plasma in the Washington, D.C. metropolitan area with no history of meat allergy who had anaphylactic transfusion reactions compatible with AGS. AIMS: We investigated allergic reactions in 2 additional patients who received ABO minor-incompatible blood products at 2 hospitals in the D.C. area during fall 2023. METHODS: For both patients, a medical chart review was performed and IgE levels to alpha-gal were measured. RESULTS: The first patient, a 64-year-old, O-positive patient status post heart transplant with no known allergies, was admitted with acute COVID-19 induced antibody-mediated transplant rejection and placed on extracorporeal membrane oxygenation (ECMO). While undergoing plasma exchange (PLEX) (50% albumin/50% fresh frozen plasma (FFP)), the patient tolerated 2 units of group O FFP and 1 unit of group A FFP before becoming hemodynamically unstable during transfusion of 1 unit of B-positive FFP. PLEX was stopped. The patient later died of sepsis from underlying causes. The second patient, a 57-year-old O-positive man with a history of melanoma and neuro fibromatosis type 1, was undergoing an abdominal resection including transfusion of 3 units of O-positive RBC when he suffered hypotension and ventricular tachycardia requiring intraoperative code after receiving 2 units of group B FFP. Hiveswere noted after resuscitation. The patient had a history of tick bites but no known allergies. He is alive 5 months after the possible allergic event. Both patients had full transfusion reaction evaluations and immunology testing results above the positive cutoff for anti-alpha-gal IgE. DISCUSSION AND CONCLUSION: Two patients with O-positive blood and no known allergies experience danaphyl axis after transfusion with group B FFP. The symptoms cannot definitively be imputed to an allergic transfusion reaction, but the presence of IgE against alpha-gal supports an association. Medicating patients with antihistamines and IV steroids pre-transfusion may prevent allergic reactions. Restricting group B plasma-containing products (plasma, platelets, cryoprecipitate) for patients who experience AGS-like symptoms may be considered.

Alloimmunization in myelodysplastic syndrome is associated with higher healthcare costs, longer hospitalizations, and increased mortality.

BACKGROUND: Transfusion of red blood cells (RBC) is an important component of treatment for myelodysplastic syndromes (MDS). Patients receiving frequent transfusions are more likely to develop alloimmunization, an immune reaction to minor RBC antigens that increases the risk of complications including delayed hemolysis. Phenotypic matching is believed to reduce alloimmunization although rigorous evidence is lacking. This study examines the association of alloimmunization with clinical and economic outcomes and may give insight into the potential benefit of phenotypic matching in MDS. STUDY DESIGN AND METHODS: This study used data from 1054 hospitals included in the Premier hospital chargemaster dataset. Alloimmunized MDS patients (January 2015 to June 2019) were indirectly identified by ICD-10 codes (antiglobulin crossmatch and RBC antibody identification). The primary objective was assessment of the association between incremental cost per patient encounter and alloimmunization in MDS patients. Secondary objectives were assessment of the association of length of stay, intensive care unit (ICU) admission, and inpatient mortality for alloimmunized versus non-alloimmunized MDS patients. RESULTS: Worse clinical and economic outcomes were observed for the alloimmunized group. Higher costs (14%), more ICU admissions (38%), longer hospital (21%) and ICU stays (55%), and greater mortality (30%) were observed among alloimmunized MDS patients compared to non-alloimmunized (p < .0001 for all comparisons). DISCUSSION: Alloimmunization may be associated with higher costs and greater risk of ICU admission and death in patients with MDS. While further mechanistic research is needed, it seems that MDS patients may benefit substantially from practices that limit risk of alloimmunization, including providing prophylactic antigen matching.

Transfusion management and hemoglobin-based oxygen carrier treatment in a patient with anti-Rh17 antibody.

BACKGROUND: A 54-year-old Hispanic OPos female with known history of anti-Rh17 antibodies was diagnosed with Philadelphia-Chromosome positive (Ph+) acute lymphoblastic leukemia (ALL). Rh17, also known as Hr0, is a high-frequency antigen composed of several epitopes on the RhCE protein. Anti-Rh17 antibodies can be made by individuals with missing or varied C/c, E/e antigens. Anti-Rh17 antibodies are clinically significant given multiple case reports of hemolytic disease of the fetus and newborn (HDFN). Finding compatible units for patients with anti-Rh17 can be particularly difficult given that only 1 in 100,000 people are Rh17 negative. STUDY DESIGN AND METHODS: Search for compatible units was conducted by the American Rare Donor Program (ARDP) with no leads. After chemotherapy induction and despite erythropoiesis stimulating agent administration, the patient's hemoglobin continued to trend down to a nadir of 2.8 g/dL. Here we report transfusion of incompatible pRBC to this patient with critically symptomatic anemia. HBOC-201 (Hemopure) was obtained and administered under an emergency compassionate/expanded access designation from the Food and Drug Administration (FDA) under an emergency Investigational New Drug (IND) application. RESULTS AND DISCUSSION: Overall difficulties in this case included the challenge of finding compatible units, dilemma of transfusing incompatible units in a patient with severe anemia and obtaining alternatives to blood products. This case report demonstrates the successful use of HBOC-21 in treating life-threatening anemia.