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Background and Objectives: Debate exists surrounding the optimal duration of red blood cell (RBC) storage. A hypothesis emerging from previous research suggests that exposure to fresh blood may be harmful to patients undergoing cardiac surgery. This study uses a large transfusion medicine database to explore the association between in‐hospital mortality and red cell storage duration. Materials and Methods: This is an exploratory retrospective cohort study of all adult patients at Hamilton, Canada, over a 14‐year period that received at least one allogeneic red cell transfusion during their hospitalization for cardiac surgery requiring bypass. The primary outcome for the study was in‐hospital death. Analysis was performed using multivariate Cox regression modelling with time‐dependent and time‐independent covariates and stratification variables. Five models with varying definitions for short, intermediate and prolonged duration of RBC storage were tested. Results: From March 2004 to December 2017, 11,205 patients met the inclusion criteria and were included in the regression analyses. No significant effect of short‐duration red storage on patient mortality was observed in all statistical models, with the red cells stored for the longest duration as the reference group. When patients who received exclusively fresh (hazard ratio [HR] 1.040, 95% confidence interval [CI] 0.588–1.841, p‐value = 0.893) and older aged (HR 1.038, 95% CI 0.769–1.1.402, p‐value = 0.0801) RBCs were compared with those who received exclusively mid‐age red cells as the reference, statistical significance was similarly not reached. Conclusion: Red cells stored for the shortest duration are not associated with increased risk of mortality among cardiac surgery patients. [ABSTRACT FROM AUTHOR]

Background: In August 2017, Canadian Blood Services extended the shelf‐life of platelet concentrates from 5 to 7 days. The clinical impacts of this policy change remain unclear. Study Design and Methods: We used a before‐after retrospective design of platelet‐transfused adult inpatients in Hamilton, ON, Canada. Data were captured for 18 months before (Period 1: February 2016–July 2017) and 18 months after (Period 2: September 2017–February 2019) 7‐day platelet implementation. Primary outcome was absolute platelet count increment (ACI) in univariate and multivariate analyses adjusted for confounders. Data were obtained from our institution's transfusion database, Ontario's Transfusion Transmitted Injuries Surveillance System, and the blood supplier. Results: Overall, 1360 patients with single dose platelet transfusions were included in Period 1 and 1211 patients in Period 2. Median age at admission was 66 years, and approximately 40% of patients underwent cardiac surgery. Using a non‐inferiority margin of −10 × 109/L, platelets transfused during the 7‐day storage period were non‐inferior to those transfused in the 5‐day storage period [mean count difference − 4.63 × 109/L (95% CI −7.40 to −1.87, p = 0.0001)]. However, platelet ACIs following transfusion consistently trended lower in the 7‐day group for all patients and subgroups. No differences in secondary clinical outcomes were observed. Platelet expiry reduced from 8.1 to 6.3% (p < 0.0001). Conclusion: Platelet transfusions following 7‐day storage policy were non‐inferior to transfusions in the 5‐day policy period, although reduced ACIs were observed. There were no increases in adverse clinical outcomes. [ABSTRACT FROM AUTHOR]

Background: Anti‐K is an alloantibody stimulated in response to the KEL1 antigen and may cause hemolytic disease of the fetus and newborn (HDFN). Provision of KEL1 negative blood to females of child‐bearing potential was not our practice. We assessed the impact of our policy and assessed feasibility of a KEL1 negative transfusion policy. Study design and methods: This is a cohort study spanning Jan 1, 2007–Jun 30, 2017 in Hamilton, Canada. Data were obtained via our institution's transfusion database. Chart reviews of females age ≤45 with anti‐K were performed; data on RBC KEL1 phenotype were obtained from the blood supplier when needed to ascertain the cause of alloimmunization. Descriptive analysis of hospital KEL1 negative inventory demand and supply was performed. Results: From Jan 2007‐Jun 2017, 8.6% of all RBC units transfused were provided to females age ≤45. There were 111 females with detectable anti‐K. Median age at time of antibody detection was 34 years (interquartile range 27–40) and 28 of 111 (25.2%) patients may have been alloimmunized by transfusion. Of 49 pregnancies, seven had complications due to anti‐K. We estimated that our existing RBC inventory (with 16% units known to be KEL1 negative in 2017) is sufficient to meet demand and support a KEL1 negative transfusion policy for females age ≤45. Conclusion: Transfusion was responsible for alloimmunization in 25% of females with anti‐K over 10 years. Analysis of supply and demand can be used to inform feasibility of a KEL1 negative transfusion policy. [ABSTRACT FROM AUTHOR]

Clinical characteristics of blood donors may affect short- and long-term outcomes of transfusion recipients. The impact of donor sex and age on recipient outcomes have not yielded consistent results in observational studies. One recently published randomized controlled trial (iTADS) addressing the impact of donor sex on recipient outcomes noted no differences between a female versus male transfusion strategy; a second Canadian multicenter trial has just been funded. Other donor characteristics - including pregnancy history, smoking status, obesity, and chronic illnesses - remain incompletely explored. More robust clinical studies with vein-to-vein capabilities are needed to understand the complex interplay between donors and recipients. [ABSTRACT FROM AUTHOR]

Background Methods and Discussion Conclusion Health data comprise data from different aspects of healthcare including administrative, digital health, and research‐oriented data. Together, health data contribute to and inform healthcare operations, patient care, and research. Integrating artificial intelligence (AI) into healthcare requires understanding these data infrastructures and addressing challenges such as data availability, privacy, and governance. Federated learning (FL), a decentralized AI training approach, addresses these challenges by allowing models to learn from diverse datasets without data leaving its source, thus ensuring privacy and security are maintained. This report introduces FL and discusses its potential in transfusion medicine and blood supply chain management.FL can offer significant benefits in transfusion medicine by enhancing predictive analytics, personalized medicine, and operational efficiency. Predictive models trained on diverse datasets by FL can improve accuracy in forecasting blood transfusion demands. Personalized treatment plans can be refined by aggregating patient data from multiple institutions using FL, reducing adverse reactions and improving outcomes. Operational efficiency can also be achieved through precise demand forecasting and optimized logistics. Despite its advantages, FL faces challenges such as data standardization, governance, and bias. Harmonizing diverse data sources and ensuring fair, unbiased models require advanced analytical solutions. Robust IT infrastructure and specialized expertise are needed for successful FL implementation.FL represents a transformative approach to AI development in healthcare, particularly in transfusion medicine. By leveraging diverse datasets while maintaining data privacy, FL has the potential to enhance predictions, support personalized treatments, and optimize resource management, ultimately improving patient care and healthcare efficiency. [ABSTRACT FROM AUTHOR]

Background: The efficacy of premedication for the prevention of nonhemolytic transfusion reactions remains controversial. This systematic review and meta-analysis assessed the effect of premedication on the rate of nonhemolytic transfusion reactions after allogeneic blood transfusion.Study Design and Methods: We searched the literature using CENTRAL, MEDLINE, EMBASE, ISI Web of Science, and clinicaltrials.gov databases from inception until October 31, 2018. We included all randomized controlled trials comparing premedication to placebo or no treatment in patients receiving any labile blood product. Outcome measures were reported as relative risks (RRs) with 95% confidence intervals (CIs). Data were combined for similar outcomes where appropriate using a random-effects model. Analyses were done at both the patient and transfusion level.Results: Three randomized trials using acetaminophen and antihistamine as premedication met the inclusion criteria. A total of 517 patients received 4444 red blood cell or platelet transfusions. Pooled patient-level estimates with premedication for all nonhemolytic, febrile nonhemolytic, and minor allergic reactions were RR, 0.92 (95% CI, 0.63-1.35); RR, 0.54 (95% CI, 0.26-1.1); and RR, 1.37 (95% CI 0.81-2.31), respectively. Transfusion-level analyses also showed no benefit with premedication. Of 517 patients randomized, only 27 (5.2%) had a history of transfusion reactions.Conclusion: Routine premedication with acetaminophen and antihistamines did not prevent nonhemolytic transfusion reactions; however, the estimate of effect was greatest for febrile reactions. The impact of premedication in patients with a prior history of transfusion reactions remains unknown and requires further evaluation in future clinical trials. [ABSTRACT FROM AUTHOR]

Background: Platelet (PLT) transfusions are frequently administered in the setting of critical illness but their clinical impacts remain unknown. This study examined the association between PLT transfusions and death in a large intensive care unit (ICU) patient population.Study Design and Methods: Using a transfusion registry spanning 2008 to 2015, this study assessed effect of in-ICU PLT transfusions on ICU and in-hospital mortality using a stratified, time-dependent Cox proportional hazards model adjusted for illness severity, thrombocytopenia, and other confounders. Patients with known malignancy were excluded. Exposure to PLT transfusions were analyzed dichotomously (ever or never transfused) and continuously (number of transfusions). Medical, general surgery, and cardiac surgery subgroups were analyzed separately.Results: Overall 32,842 adult patients were admitted to ICU, and 4927 patients received PLT transfusion(s). Crude in-ICU and in-hospital mortality were higher for PLT-transfused patients compared to nontransfused patients (9.2% vs. 6.7% and 12.3% vs. 9.3%, respectively). After confounders were adjusted for, PLT transfusions (ever vs. never) were not associated with increased mortality in ICU (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.60-1.02; p = 0.06) or in hospital (HR, 0.89; 95% CI, 0.68-1.09; p = 0.41). Continuous exposure analysis also showed no association between PLT transfusions and death. PLT transfusions have a protective effect on in-hospital mortality in the subgroup of general surgery patients (HR, 0.71; 95% CI, 0.51-0.99; p = 0.04; ever or never analysis).Conclusion: Platelet transfusions were not associated with increased risk of death in critically ill patients. Further studies are required to identify subgroups for which PLT transfusions may be beneficial. [ABSTRACT FROM AUTHOR]

Background: Platelet transfusions are commonly used in critically ill patients, but transfusion thresholds, count increments, and predictors of ineffectual transfusions remain unclear.Methods: This retrospective study included consecutive adult nononcology patients who received platelet transfusions in ICUs at three Canadian academic hospitals between 2006 and 2015. Data were collected from a validated transfusion database. We determined independent predictors of ineffectual platelet transfusions, defined as transfusions that raised platelet counts by < 5 × 10(9)/L. Reasons for transfusion were adjudicated in a subgroup of patients who underwent transfusion despite normal platelet counts.Results: We identified 7,320 ICU admissions (n = 7,073 patients) during which 15,879 platelet transfusions were administered. Most admissions (78.7%) were for cardiac surgery. Based on 5,700 analyzable transfusions, the median pretransfusion platelet count was 87 × 10(9)/L (interquartile range [IQR], 57-130). The pretransfusion platelet count was ≥ 50 × 10(9)/L and ≥ 150 × 10(9)/L for 79.6% and 17.8% of transfusions, respectively. Reasons for transfusion despite a normal platelet count were active bleeding or surgery in patients receiving antiplatelet agents or anticoagulants. The median platelet count increment was 23 × 10(9)/L (IQR, 7-44), and 21.8% of transfusions were ineffectual. ABO incompatibility, sepsis, liver disease, and red cell and cryoprecipitate transfusions were associated with a poor platelet count increment.Conclusions: Platelet transfusions were commonly used in the ICU when platelet counts were ≥ 50 × 10(9)/L. One platelet transfusion increased platelet count by 23 × 10(9)/L. One in five transfusions was ineffectual, and ABO incompatibility was identified as a modifiable risk factor. These data can help direct efforts to reduce platelet overuse and improve transfusion quality. [ABSTRACT FROM AUTHOR]

The article reflects on a study which found that serum from patients with autoimmune Heparin-Induced Thrombocytopenia (HIT) contains highly pathogenic IgG that can closely approximate two PF4 molecules; essentially, these PF4-reactive autoantibodies can overcome the inherently repulsive cationic PF4 molecules. It mentions that the process is likely facilitated by nonheparin polyanions found within platelets, such as chondroitin sulfate and polyphosphates.

Symmetrical peripheral gangrene (SPG) is a disabling complication that affects a small proportion of patients who survive critical illness. Its pathogenesis reflects profoundly disturbed procoagulant-anticoagulant balance in susceptible tissue beds secondary to circulatory shock (cardiogenic, septic). There is a characteristic SPG triad: (a) shock (hypotension, lactic acidemia, normoblastemia, multiple organ dysfunction), (b) disseminated intravascular coagulation (DIC), and (c) natural anticoagulant depletion (protein C, antithrombin). In recent years, risk factors for natural anticoagulant depletion have been identified, most notably acute ischemic hepatitis ("shock liver"), which is seen in at least 90% of patients who develop SPG. Moreover, there is a characteristic time interval (2–5 days, median 3 days) between the onset of shock/shock liver and the beginning of ischemic injury secondary to peripheral microthrombosis ("limb ischemia with pulses"), reflecting the time required to develop severe depletion in hepatically-synthesized natural anticoagulants. Other risk factors for natural anticoagulant depletion include chronic liver disease (e.g., cirrhosis) and, possibly, transfusion of colloids (albumin, high-dose immunoglobulin) lacking coagulation factors. A causal role for vasopressor therapy is unproven and is unlikely; this is because critically ill patients who develop SPG do so usually after at least 36–48 hours of vasopressor therapy, implicating a time-dependent pathophysiological mechanism. The most plausible explanation is a progressive time-dependent decline in key natural anticoagulant factors, reflecting ongoing DIC ("consumption"), proximate liver disease whether acute or chronic ("impaired production"), and colloid administration ("hemodilution"). Given these evolving concepts of pathogenesis, a rationale approach to prevention/treatment of SPG can be developed. [ABSTRACT FROM AUTHOR]

We report a case of a 56‐year‐old woman with a history of idiopathic thrombocytopenic purpura (ITP) following splenectomy on mycophenolate mofetil (MMF), who developed moderate bleeding after stopping MMF. Her laboratory testing suggested the presence of an abnormal circulating heparin‐like anticoagulant with demonstrable anti‐Xa activity. She was initially treated with antifibrinolytic therapy and was subsequently started on MMF alongside intravenous immunoglobulin, which significantly improved her bleeding symptoms. The presence of abnormal circulating heparin‐like anticoagulants is a rare cause of coagulopathy. Few cases exist in the literature, with nearly all occurring in the setting of hematologic or solid‐organ malignancy. The mechanism by which these endogenous anticoagulants develop is unclear. Clinical manifestations range from mild bleeding and bruising to life‐threatening hemorrhage refractory to conventional therapy. Diagnosis of a heparin‐like anticoagulant is based on coagulation testing as well as exclusion of other exogenous anticoagulants, acquired inhibitors, and/or factor deficiencies. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented concerning the implementation of an electronic reporting system for transfusion reactions that led to a sustained and significant increase in reporting at a tertiary care hospital with high transfusion activity.

Canadian Blood Services (CBS), Canada’s national blood transfusion service, has for many years sponsored an annual conference, for the education and awareness of interested participants, showcasing the latest evidence-based understanding of both basic science and clinical issues in transfusion medicine and science. The 15th iteration of this symposium took place September 9, 2017 and focused on some of the vital aspects of red blood cells (RBC), in line with the” 3Rs” concept, namely the provision of the Right red blood cell (RBC) product to the Right patient at the Right time. Presentations touched upon: the evolution of blood banking in North America; the monocyte monolayer assay as a predictor of post-transfusion hemolysis; hemoglobin-based oxygen carriers; RBC alloimmunization; serological approaches to complex RBC antibody problems; randomized clinical trials related to the age of stored RBC; RBC genotyping; pathophysiology, prevention and treatment of hemolytic disease of the fetus and newborn (HDFN); and testing and timing in perinatal serology. This commentary provides summaries of all speakers’ presentations annotated with relevant references. Special thanks are due to all contributors for their praiseworthy approaches in sharing their experiences and knowledge on this interesting scientific/clinical and management theme. [ABSTRACT FROM AUTHOR]