Current transfusion practice and need for new blood products to ensure blood supply for patients with major hemorrhage in Europe.

BACKGROUND: New blood products are considered for treatment of patients with major hemorrhage. The aim of this report is to describe the current transfusion practices in Europe for patients with major hemorrhage and explore the need for new or modified blood products to ensure prehospital and in-hospital blood supply. STUDY DESIGN AND METHOD: The European Blood Alliance (EBA) Working Group on Innovation and New Blood Products' subgroup on major hemorrhage performed a survey among the EBA member states. RESULTS: The response rate was 58% (17 responses from 15 of the 26 EBA member states). Of these, sixteen (94%) provide massive transfusion packages (MTPs) with balanced ratio of red blood cells and plasma. Seven of the respondents included platelets from the start of treatment. Eleven (65%) provide prehospital blood products, mainly red cell concentrates or dried and/or thawed plasma with 5 days of extended storage. Two countries provide prehospital whole blood. Twelve respondents (71%) saw a need for implementation of new or modified blood components in their institution. The top three priorities were whole blood (12 of 12, 100%), dried plasma (8 of 12, 67%), and cold-stored platelets (7 of 12, 58%). DISCUSSION: Current national guidelines for use of blood products in patients with major hemorrhage in Europe agree on the use of balanced transfusion, however the timing and source of platelets differ. Blood products for prehospital transfusion are available in several European countries. An interest in new or modified blood products for patients with major hemorrhage was observed, especially for whole blood.

In vitro quality of cold and delayed cold-stored platelet concentrates from interim platelet units during storage for 21 days.

BACKGROUND AND OBJECTIVES: Based on previous success using apheresis platelets, we wanted to investigate the in vitro quality and platelet function in continuously cold-stored and delayed cold-stored platelet concentrates (PCs) from interim platelet units (IPUs) produced by the Reveos system. MATERIALS AND METHODS: We used a pool-and-split design to prepare 18 identical pairs of PCs. One unit was stored unagitated and refrigerated after production on day 1 (cold-stored). The other unit was stored agitated at room temperature until day 5 and then refrigerated (delayed cold-stored). Samples were taken after pool-and-split on day 1 and on days 5, 7, 14 and 21. Swirling was observed and haematology parameters, metabolism, blood gas, platelet activation and platelet aggregation were analysed for each sample point. RESULTS: All PCs complied with European recommendations (EDQM 20th edition). Both groups had mean platelet content >200 × 109 /unit on day 21. The pH remained above 6.4 for all sample points. Glucose concentration was detectable in every cold-stored unit on day 21 and in every delayed cold-stored unit on day 14. The cold-stored group showed a higher activation level before stimulation as measured by flow cytometry. The activation levels were similar in the two groups after stimulation. Both groups had the ability to form aggregates after cold storage and until day 21. CONCLUSION: Our findings suggest that PCs from IPUs are suitable for cold storage from day 1 until day 21 and delayed cold storage from day 5 until day 14.

The Norwegian blood preparedness project: A whole blood program including civilian walking blood banks for early treatment of patients with life-threatening bleeding in municipal health care services, ambulance services, and rural hospitals.

BACKGROUND: Civilian and military guidelines recommend early balanced transfusion to patients with life-threatening bleeding to improve survival. To provide the best care to patients with hemorrhagic shock in regions with reduced access to evacuation, blood preparedness must be ensured also on a municipal health care level. The primary aim of the Norwegian Blood Preparedness project is to enable rural hospitals, prehospital ambulance services, and municipal health care services to start early balanced blood transfusions for patients with life-threatening bleeding regardless of etiology. STUDY DESIGN AND METHODS: The project is designed based on three principles: (1) Early balanced transfusion should be provided for patients with life-threatening bleeding, (2) Management of an emergency requires a planned and rehearsed day-to-day system for blood preparedness, and (3) A decentralized system is needed to ensure local self-sufficiency in an emergency. We developed a system for education and training in blood-based resuscitation with a focus on the municipal health care service. RESULTS: In this publication, we describe the implementation of emergency whole blood collections from a preplanned civilian walking blood bank in the municipal health care service. This includes donor selection, whole blood collection, emergency transfusion and quality assessment of practice. CONCLUSION: We conclude that implementation of a Whole Blood based emergency transfusion program is feasible on all health care levels and that a preplanned civilian walking blood bank should be considered in locations were prolonged transport-times may reduce access to blood transfusion for patients with life threatening bleeding.

Blood donor eligibility criteria for medical conditions: A BEST collaborative study.

BACKGROUND AND OBJECTIVES: Donor eligibility questions and criteria for medical conditions vary between blood centres, suggesting that they are based more on local regulations or experience, rather than on published data, which are limited. As the donor population ages, medical conditions become more common. We assessed donor health assessment criteria at blood centre members of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative. Our aim was to compare eligibility criteria and determine their underlying basis. MATERIALS AND METHODS: A REDCap survey was sent to blood centre participants, based on medical conditions of greatest interest suggested by the Donor Studies Team of the BEST Collaborative. Participants were asked about current donor health assessment questions, deferral criteria and the basis for their deferral policy (donor risk, recipient risk or both) for 20 medical conditions. RESULTS: Complete responses were received from 26 blood donor centres (24 separate responses) representing a combination of hospital-based centres, large regional centres and community/national blood centres in 14 different countries. Most centres specifically ask about heart and lung conditions, whereas fewer than half inquire about kidney, gastrointestinal or neurological conditions. North American blood centres tended to be less restrictive, while regulatory restrictions are more prevalent in Europe. Most participants felt that the criteria were based on regulatory requirements or experience, rather than on published data. CONCLUSION: There is considerable variability in criteria by region. Ideally, criteria would be more evidence-based rather than based on regulatory requirements or experience. Deferral criteria must balance donor and recipient safety and maintain an adequate blood supply.

International Society of Blood Transfusion survey of experiences of blood banks and transfusion services during the COVID-19 pandemic.

BACKGROUND AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has impacted blood systems worldwide. Challenges included maintaining blood supplies and initiating the collection and use of COVID-19 convalescent plasma (CCP). Sharing information on the challenges can help improve blood collection and utilization. MATERIALS AND METHODS: A survey questionnaire was distributed to International Society of Blood Transfusion members in 95 countries. We recorded respondents' demographic information, impacts on the blood supply, CCP collection and use, transfusion demands and operational challenges. RESULTS: Eighty-two responses from 42 countries, including 24 low- and middle-income countries, were analysed. Participants worked in national (26.8%) and regional (26.8%) blood establishments and hospital-based (42.7%) institutions. CCP collection and transfusion were reported by 63% and 36.6% of respondents, respectively. Decreases in blood donations occurred in 70.6% of collecting facilities. Despite safety measures and recruitment strategies, donor fear and refusal of institutions to host blood drives were major contributing factors. Almost half of respondents working at transfusion medicine services were from large hospitals with over 10,000 red cell transfusions per year, and 76.8% of those hospitals experienced blood shortages. Practices varied in accepting donors for blood or CCP donations after a history of COVID-19 infection, CCP transfusion, or vaccination. Operational challenges included loss of staff, increased workloads and delays in reagent supplies. Almost half of the institutions modified their disaster plans during the pandemic. CONCLUSION: The challenges faced by blood systems during the COVID-19 pandemic highlight the need for guidance, harmonization, and strengthening of the preparedness and the capacity of blood systems against future infectious threats.

Effect of leukoreduction and temperature on risk of bacterial growth in CPDA-1 whole blood: A study of Escherichia coli.

BACKGROUND: Collection of non-leukoreduced citrate-phosphate-dextrose-adenine (CPDA-1) whole blood is performed in walking blood banks. Blood collected under field conditions may have increased risk of bacterial contamination. This study was conducted to examine the effects of WBC reduction and storage temperature on growth of Escherichia coli (ATCC® 25922™) in CPDA-1 whole blood. METHODS: CPDA-1 whole blood of 450 ml from 10 group O donors was inoculated with E. coli. Two hours after inoculation, the test bags were leukoreduced with a platelet-sparing filter. The control bags remained unfiltered. Each whole blood bag was then split into three smaller bags for further storage at 2-6°C, 20-24°C, or 33-37°C. Bacterial growth was quantified immediately, 2 and 3 h after inoculation, on days 1, 3, 7, and 14 for all storage temperatures, and on days 21 and 35 for storage at 2-6°C. RESULTS: Whole blood was inoculated with a median of 19.5 (range 12.0-32.0) colony-forming units per ml (CFU/ml) E. coli. After leukoreduction, a median of 3.3 CFU/ml (range 0.0-33.3) E. coli remained. In the control arm, the WBCs phagocytized E. coli within 24 h at 20-24°C and 33-37°C in 9 of 10 bags. During storage at 2-6°C, a slow self-sterilization occurred over time with and without leukoreduction. CONCLUSIONS: Storage at 20-24°C and 33-37°C for up to 24 h before leukoreduction reduces the risk of E. coli-contamination in CPDA-1 whole blood. Subsequent storage at 2-6°C will further reduce the growth of E. coli.

A whole blood based resuscitation strategy in civilian medical services: Experience from a Norwegian hospital in the period 2017-2020.

BACKGROUND: Civilian and military guidelines recommend early balanced transfusion to patients with life-threatening bleeding. Low titer group O whole blood was introduced as the primary blood product for resuscitation of massive hemorrhage at Haukeland University Hospital, Bergen, Norway, in December 2017. In this report, we describe the whole blood program and present results from the first years of routine use. STUDY DESIGN AND METHODS: Patients who received whole blood from December 2017 to April 2020 were included in our quality registry for massive transfusions. Post-transfusion blood samples were collected to analyze isohemagglutinin (anti-A/-B) and hemolysis markers. Administration of other blood products, transfusion reactions, and patient survival (days 1 and 30) were recorded. User experiences were surveyed for both clinical and laboratory staff. RESULTS: Two hundred and five patients (64% male and 36% female) received 836 units in 226 transfusion episodes. Patients received a mean of 3.7 units (range 1-35) in each transfusion episode. The main indications for transfusion were trauma (26%), gastrointestinal (22%), cardiothoracic/vascular (18%), surgical (18%), obstetric (11%), and medical (5%) bleeding. There was no difference in survival between patients with blood type O when compared with non-group O. Haptoglobin level was lower in the transfusion episodes for non-O group patients, however no clinical hemolysis was reported. No patients had conclusive transfusion-associated adverse events. Both clinical and laboratory staff preferred whole blood to component therapy for massive transfusion. DISCUSSION: The experience from Haukeland University Hospital indicates that whole blood is feasible, safe, and effective for in-hospital treatment of bleeding.

Civilian walking blood bank emergency preparedness plan.

BACKGROUND: The current global pandemic has created unprecedented challenges in the blood supply network. Given the recent shortages, there must be a civilian plan for massively bleeding patients when there are no blood products on the shelf. Recognizing that the time to death in bleeding patients is less than 2 h, timely resupply from unaffected locations is not possible. One solution is to transfuse emergency untested whole blood (EUWB), similar to the extensive military experience fine-tuned over the last 19 years. While this concept is anathema in current civilian transfusion practice, it seems prudent to have a vetted plan in place. METHODS AND MATERIALS: During the early stages of the 2020 global pandemic, a multidisciplinary and international group of clinicians with broad experience in transfusion medicine communicated routinely. The result is a planning document that provides both background information and a high-level guide on how to emergently deliver EUWB for patients who would otherwise die of hemorrhage. RESULTS AND CONCLUSIONS: Similar plans have been utilized in remote locations, both on the battlefield and in civilian practice. The proposed recommendations are designed to provide high-level guidance for experienced blood bankers, transfusion experts, clinicians, and health authorities. Like with all emergency preparedness, it is always better to have a well-thought-out and trained plan in place, rather than trying to develop a hasty plan in the midst of a disaster. We need to prevent the potential for empty shelves and bleeding patients dying for lack of blood.

Prehospital Whole Blood Transfusion Programs in Norway.

BACKGROUND: Prehospital management of severe hemorrhage has evolved significantly in Norwegian medical emergency services in the last 10 years. Treatment algorithms for severe bleeding were previously focused on restoration of the blood volume by administration of crystalloids and colloids, but now the national trauma system guidelines recommend early balanced transfusion therapy according to remote damage control resuscitation principles. MATERIALS AND METHODS: This survey describes the implementation, utilization, and experience of the use of low titer group O whole blood (LTOWB) and blood components in air ambulance services in Norway. Medical directors from all air ambulance bases in Norway as well as the blood banks that support LTOWB were invited to participate. RESULTS: Medical directors from all 13 helicopter emergency medical services (HEMS) bases, the 7 search and rescue (SAR) helicopter bases, and the 4 blood banks that support HEMS with LTOWB responded to the survey. All HEMS and SAR helicopter services carry LTOWB or blood components. Four of 20 (20%) HEMS bases have implemented LTOWB. A majority of services (18/20, 90%) have a preference for LTOWB, primarily because LTOWB enables early balanced transfusion and has logistical benefits in time-critical emergencies and during prolonged evacuations. CONCLUSION: HEMS services and blood banks report favorable experiences in the implementation and utilization of LTOWB. Prehospital balanced blood transfusion using whole blood is feasible in Norway.

Cold-stored whole blood in a Norwegian emergency helicopter service: an observational study on storage conditions and product quality.

BACKGROUND: Increasing numbers of emergency medical service agencies and hospitals are developing the capability to administer blood products to patients with hemorrhagic shock. Cold-stored whole blood (WB) is the only single product available to prehospital providers who aim to deliver a balanced resuscitation strategy. However, there are no data on the safety and in vitro characteristics of prehospital stored WB. This study aimed to describe the effects on in vitro quality of storing WB at remote helicopter bases in thermal insulating containers. STUDY DESIGN AND METHODS: We conducted a two-armed single-center study. Twenty units (test) were stored in airtight thermal insulating containers, and 20 units (controls) were stored according to routine procedures in the Haukeland University Hospital Blood Bank. Storage conditions were continuously monitored during emergency medical services missions and throughout remote and blood bank storage. Hematologic and metabolic variables, viscoelastic properties, and platelet (PLT) aggregation were measured on Days 1, 8, 14, and 21. RESULTS: Storage conditions complied with the EU guidelines throughout remote and in-hospital storage for 21 days. There were no significant differences in PLT aggregation, viscoelastic properties, and hematology variables between the two groups. Minor significantly lower pH, glucose, and base excess and higher lactate were observed after storage in airtight containers. CONCLUSION: Forward cold storage of WB is safe and complies with EU standards. No difference is observed in hemostatic properties. Minor differences in metabolic variables may be related to the anaerobic conditions within the thermal box.

A Pilot Trial of Platelets Stored Cold versus at Room Temperature for Complex Cardiothoracic Surgery.

BACKGROUND: This pilot trial focused on feasibility and safety to provide preliminary data to evaluate the hemostatic potential of cold-stored platelets (2° to 6°C) compared with standard room temperature-stored platelets (20° to 24°C) in adult patients undergoing complex cardiothoracic surgery. This study aimed to assess feasibility and to provide information for future pivotal trials. METHODS: A single center two-stage exploratory pilot study was performed on adult patients undergoing elective or semiurgent complex cardiothoracic surgery. In stage I, a two-armed randomized trial, platelets stored up to 7 days in the cold were compared with those stored at room temperature. In the subsequent single-arm stage II, cold storage time was extended to 8 to 14 days. The primary outcome was clinical effect measured by chest drain output. Secondary outcomes were platelet function measured by multiple electrode impedance aggregometry, total blood usage, immediate and long-term (28 days) adverse events, length of stay in intensive care, and mortality. RESULTS: In stage I, the median chest drain output was 720 ml (quartiles 485 to 1,170, n = 25) in patients transfused with room temperature-stored platelets and 645 ml (quartiles 460 to 800, n = 25) in patients transfused with cold-stored platelets. No significant difference was observed. The difference in medians between the room temperature- and cold-stored up to 7 days arm was 75 ml (95% CI, -220, 425). In stage II, the median chest drain output was 690 ml (500 to 1,880, n = 15). The difference in medians between the room temperature arm and the nonconcurrent cold-stored 8 to 14 days arm was 30 ml (95% CI, -1,040, 355). Platelet aggregation in vitro increased after transfusion in both the room temperature- and cold-stored platelet study arms. Total blood usage, number of adverse events, length of stay in intensive care, and mortality were comparable among patients receiving cold-stored and room temperature-stored platelets. CONCLUSIONS: This pilot trial supports the feasibility of platelets stored cold for up to 14 days and provides critical guidance for future pivotal trials in high-risk cardiothoracic bleeding patients.

Red-blood-cell alloimmunization and prophylactic antigen matching for transfusion in patients with warm autoantibodies.

BACKGROUND: Warm autoantibodies (WAA) are antibodies that react with an antigen on a patient's own red-blood-cells and can complicate compatibility testing whether or not they cause clinical haemolysis. The goal of this study was to understand the overall prevalence of WAA, the risk of RBC alloimmunization and determine whether RBC selection practices have an impact on alloimmunization. MATERIALS AND METHODS: Records of patients (>1 year of age) with an indirect antibody detection test (IAT) and serologic evidence of WAA over a 10-year-period were included. Eight centres from 5 countries collectively reviewed 1 122 245 patients who had an IAT. RESULTS: Of patients having IAT, 1214 had WAA (0·17%). Transfusion information for 1002 of the patients was available; 631 were transfused after identification of the WAA (63%); of the transfused patients, 390 received prophylactic antigen-matched (PAM) RBCs and 241 did not. Of the 372 patients with WAA who were transfused and had serologic testing 30+ days following transfusion (30-2765 days), 56 developed new RBC alloimmunization (15·1%). Patients who were transfused using a PAM strategy were not protected from new RBC alloimmunization [14·6% (31 of 212 patients) having PAM transfusion approach compared with those not receiving PAM approach (15·6%, 25 of 160 patients, P = 0·8837)]. CONCLUSIONS: The prevalence of WAA in patients having an IAT is low (<1%). A significant portion of patients with WAA form new RBC alloimmunization (15·1%); however, the use of PAM approach for RBC selection was not found to be protective against new alloimmunization.

In vitro quality and platelet function of cold and delayed cold storage of apheresis platelet concentrates in platelet additive solution for 21 days.

BACKGROUND: Cold storage of platelets may extend shelf life compared to room temperature storage. This study aimed to investigate in vitro platelet quality and function in cold-stored and delayed-cold-stored nonagitated apheresis platelets in platelet additive solution during storage for 21 days. STUDY DESIGN AND METHODS: Ten double apheresis platelet concentrates in 37% plasma/63% PAS-IIIM were split into two groups; nonagitated 2 to 6°C storage (CSPs) and delayed cold storage (DCSPs) with 7 days agitated storage at 20-24°C followed by nonagitated cold storage for 14 additional days. Platelet count, metabolism, viscoelastic properties, and aggregation ability were measured on Days 1, 7, 14, and 21. RESULTS: All platelet units, both CSPs and DCSPs, complied with the EU guidelines throughout storage for 21 days. Swirling was not detectable after cold storage. Cold storage improved platelet function; however, DCSP on Day 7 showed poorer results compared to CSP. Cold storage slowed down metabolism, with lower lactate and higher glucose concentrations in the CSP compared to the DCSP throughout storage for 21 days. CONCLUSION: Cold storage of platelets improved platelet function in in vitro assays, even though delayed cold storage on Day 7 showed poorer results compared to continuous cold storage. This difference could be explained by accelerated metabolism and higher glucose consumption during the period of room temperature storage. Cold storage and delayed cold storage could ease inventory management. Further studies investigating the in vitro and clinical effects of cold-stored and delayed-cold-stored platelets are encouraged.

How do I get an emergency civilian walking blood bank running?

The shift toward using a transfusion strategy in a ratio to mimic whole blood (WB) functionality has revitalized WB as a viable option to replace severe blood loss in civilian health care. A military-civilian collaboration has contributed to the reintroduction of WB at Haukeland University Hospital in Bergen, Norway. WB has logistical and hemostatic advantages in both the pre- and in-hospital settings where the goal is a perfectly timed balanced transfusion strategy. In this paper, we describe an event leading to activation of our emergency WB collection strategy for the first time. We evaluate the feasibility of our civilian walking blood bank (WBB) to cover the need of a massive amount of blood in an emergency situation. The challenges are discussed in relation to the different stages of the event with the recommendations for improvement in practice. We conclude that the use of pre-screened donors as a WBB in a civilian setting is feasible. The WBB can provide platelet containing blood components for balanced blood resuscitation in a clinically relevant time frame.

Not all red cell concentrate units are equivalent: international survey of processing and in vitro quality data.

INTRODUCTION: In vitro qualitative differences exist in red cell concentrates (RCCs) units processed from whole blood (WB) depending on the method of processing. Minimal literature exists on differences in processing and variability in quality data. Therefore, we collected information from blood manufacturers worldwide regarding (1) details of WB collection and processing used to produce RCCs and (2) quality parameters and testing as part of routine quality programmes. METHODS: A secure web-based survey was developed, refined after pilot data collection and distributed to blood centres. Descriptive analyses were performed. RESULTS: Data from ten blood centres in nine countries were collected. Six blood centres (60%) processed RCCs using the top-and-top (TAT) method which produces RCCs and plasma, and eight centres (80%) used the bottom-and-top (BAT) which additionally produces buffy coat platelets. Five of the centres used both processing methods; however, four favoured BAT processing. One centre utilized the Reveos automated system exclusively. All centres performed pre-storage leucoreduction. Other parameters demonstrated variability, including active cooling at collection, length of hold before processing, donor haemoglobin limits, acceptable collection weights, collection sets, time to leucoreduction, centrifugation speeds, extraction devices and maximum RCC shelf life. Quality marker testing also differed amongst blood centres. Trends towards higher RCC unit volume, haemolysis and residual leucoctyes were seen in the TAT compared with BAT processing across centres. CONCLUSION: Methods and parameters of WB processing and quality testing of RCCs differ amongst surveyed blood manufacturers. Further studies are needed to assess variations and to potentially improve methods and product quality.

A methodological review of the quality of reporting of surveys in transfusion medicine.

BACKGROUND: Surveys are a common tool used to gather information about practices across many medical specialties. The quality of survey reporting impacts the strength of any conclusions. Thorough and accurate reporting of survey-based research is critical for evaluation of the validity, reliability, and generalizability of the results. The objective of this study was to appraise the quality of recently reported surveys in transfusion medicine (TM). STUDY DESIGN AND METHODS: A systematic review of the literature was performed to identify studies evaluating clinical practices in TM that used a questionnaire as the research tool and were published between January 2001 and November 2017. Manuscripts that met eligible criteria were appraised using a modified Survey Reporting Guideline questionnaire. RESULTS: The search identified 1632 references, from which 54 abstracts met eligibility criteria for analysis. Only seven (13%) manuscripts reported reliability and validity of the survey tool, 26 (48%) provided a description of the survey population and sample frame, and 11 (20%) indicated the representativeness of the underlying population. Additional reporting limitations included 31 (57%) manuscripts reporting the response rate calculation, two (4%) the analysis of nonresponse error, nine (17%) the method description for handling of missing data, 11 (20%) the analysis of responder and nonresponder characteristics, and 23 (43%) explicitly discussed the generalizability of the results. CONCLUSION: Our findings document quality deficiencies in the reporting of research conducted using surveys in TM. Validated guidelines for the reporting of survey-based clinical research should be developed and applied to improve the quality of survey reporting in TM.

Blood transfusion-associated anaphylaxis in perioperative- and non-perioperative patients in Western Norway 2002-2021.

BACKGROUND: Anaphylaxis after blood transfusion is a feared complication accounting for severe morbidity. A retrospective study was performed at Haukeland University Hospital, Bergen, Norway, to investigate the rate and features of transfusion-associated anaphylaxis (TAA) occurring between 2002-2021. MATERIALS AND METHODS: Identified cases of TAA were studied by an immunologist and an allergist to extract information about general characteristics, amplifying factors, co-morbidity, treatment, and treatment responses. TAA was reported as perioperative or non-perioperative. RESULTS: We identified 29 cases of TAA: 13 perioperative and 16 non-perioperative. Allergic transfusion reaction had an incidence rate of 34/100,000 transfusions and TAA a rate of 7/100,000 transfusions. The incidence of allergic reactions and TAA increased 2.6- and 6.4-fold during the study period. The first perioperative TAA was discovered 12 years into the study period but was equally frequent as non-perioperative transfusion-associated anaphylaxis in the last five years of the study period. 52% of the TAA cases had relevant co-morbidity and 100% of them had amplifying factors. Although only 38% of the non-perioperative patients received epinephrine as treatment, 94% of them had a good treatment response to their total treatment regimen. Poorer treatment response was observed with higher age, more cardiovascular- and respiratory disease, higher use of amplifying and sedating medications and a higher severity score. DISCUSSION: Our findings indicate that TAA, especially in the perioperative setting, is underdiagnosed. The increased incidence of TAA in our study is temporally related to the introduction of a national hemovigilance program, introduction of standardized laboratory testing for anaphylaxis and increased multidisciplinary focus on the condition. In conclusion, increased awareness of TAA, and especially in the perioperative setting, is needed. A multidisciplinary approach is necessary to improve identification and reporting of TAA.