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Transfusion Evidence Alert and Round-Up

On this page you can view articles from previous editions of the Transfusion Evidence Alert and Round-Up; use the button on the left to sign up to receive future editions direct to your inbox. The Transfusion Evidence Alert is a monthly overview of 10 selected evidence-based publications in the field of transfusion medicine, including relevant COVID-19 articles. The articles are selected by experts in the field from the Systematic Review Initiative, funded by the four UK blood services. The Transfusion Evidence Round-Up is a quarterly overview of the top 10 high quality studies about an internationally relevant subject in the field of transfusion medicine. The articles are selected by members from the International Society of Blood Transfusion and drawn from the Transfusion Evidence Library and where relevant Stem Cell Evidence.

June 2022


  1. Assessing unintentional creation of bias against men who have sex with men as a function of exposure to blood donor screening questionnaire: A national randomized controlled trial
    Transfusion. 2022

    Abstract

    BACKGROUND Canadian Blood Services (CBS) screens donors based on group status (e.g., men who have sex with men, MSM) instead of specific, high-risk sexual practices (e.g., occurrence of condomless sex). The MSM screening question is embedded in a cluster of questions about stigmatized attributes such as history of imprisonment and illicit substance use. This juxtaposition of the "MSM question" and stigmatized attributes may unintentionally cause blood donors to perceive MSM more negatively. The aim of this research is to determine whether the CBS donor eligibility questionnaire generates negative bias against MSM. STUDY DESIGN AND METHODS A national, randomized online study of 903 CBS donors was conducted. Participants completed either the existing blood donor eligibility questionnaire or a modified donor questionnaire that repositioned the MSM question among neutral questions. After completing the existing or modified questionnaire, bias against MSM was measured using the sexuality implicit association test (IAT) and Modern Homonegativity Scale - Gay Men (MHS-G). Lastly, participants estimated prevalence rates among MSM of certain stigmatized behaviors. RESULTS Participants who completed the existing donor eligibility questionnaire more strongly associated gay men with negative attributes on the IAT (p(one-tailed) = .045), suggesting question position generated implicit negative bias toward MSM. Responses to the MHS-G (p(one-tailed) = .506) and prevalence estimation task (p = .443) indicated that question order had no significant impact on explicit bias. DISCUSSION Positioning the MSM screening question among stigmatizing questions creates implicit negative bias against MSM. Policy makers should be mindful of question positioning when designing donor questionnaires.
    PICO Summary

    Population

    Blood donors registered in the Canadian Blood Services (n= 903).

    Intervention

    Modified donor questionnaire that repositioned the men who have sex with men (MSM) question among neutral questions (n= 457).

    Comparison

    Existing blood donor eligibility questionnaire (n= 446).

    Outcome

    Participants who completed the existing donor eligibility questionnaire more strongly associated gay men with negative attributes on the sexuality implicit association test (IAT), suggesting question position generated implicit negative bias toward MSM. Responses to the Modern Homonegativity Scale - Gay Men (MHS-G) and prevalence estimation task indicated that question order had no significant impact on explicit bias.
  2. Autologous red blood cell transfusion does not result in a more profound increase in pulmonary capillary wedge pressure compared to saline in critically ill patients: A randomized crossover trial
    Vox sanguinis. 2022

    Abstract

    BACKGROUND AND OBJECTIVES Transfusion-associated circulatory overload (TACO) is a major cause of severe transfusion-related morbidity. Transfusion of red blood cells (RBCs) has been shown to induce hydrostatic pressure overload. It is unclear which product-specific factors contribute. We set out to determine the effect of autologous RBC transfusion versus saline on pulmonary capillary wedge pressure (PCWP) change. MATERIALS AND METHODS In a randomized crossover trial, patients who had undergone coronary bypass surgery were allocated to treatment post-operatively in the intensive care unit with either an initial 300 ml autologous RBC transfusion (salvaged during surgery) or 300 ml saline infusion first, followed by the other. Primary outcome was the difference in PCWP change. Secondary outcome measures were the difference in extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI). RESULTS Change in PCWP was not higher after autologous RBC transfusion compared to saline (ΔPCWP 0.3 ± 0.4 vs. 0.1 ± 0.4 mmHg). ΔEVLWI and ΔPVPI were significantly decreased after autologous RBC transfusion compared to saline (ΔEVLWI -1.6 ± 0.6 vs. 0.2 ± 0.4, p = 0.02; ΔPVPI -0.3 ± 0.1 vs. 0.0 ± 0.1, p = 0.01). Haemodynamic variables and colloid osmotic pressure were not different for autologous RBC transfusion versus saline. CONCLUSION Transfusion of autologous RBCs did not result in a more profound increase in PCWP compared to saline. RBC transfusion resulted in a decrease of EVLWI and PVPI compared to saline. Our data suggest that transfusing autologous RBCs may lead to less pulmonary oedema compared to saline. Future studies with allogeneic RBCs are needed to investigate other factors that may mediate the increase of PCWP, resulting in TACO.
    PICO Summary

    Population

    Patients undergoing coronary bypass surgery (n= 16).

    Intervention

    Autologous red blood cells (RBCs) transfusion, with a subsequent infusion of saline (RBCs: Saline, n= 8).

    Comparison

    Saline infusion with a subsequent transfusion of RBCs (Saline: RBCs, n= 8).

    Outcome

    The primary outcome was the difference in pulmonary capillary wedge pressure (PCWP) before and after transfusion (ΔPCWP). Secondary outcome measures were the difference in extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI). Change in PCWP was not higher after autologous RBCs transfusion compared to saline (ΔPCWP 0.3 ± 0.4 vs. 0.1 ± 0.4 mmHg). ΔEVLWI and ΔPVPI were significantly decreased after autologous RBCs transfusion compared to saline (ΔEVLWI -1.6 ± 0.6 vs. 0.2 ± 0.4; ΔPVPI -0.3 ± 0.1 vs. 0.0 ± 0.1). Haemodynamic variables and colloid osmotic pressure were not different for autologous RBCs transfusion versus saline.
  3. Prospective individual patient data meta-analysis of two randomized trials on convalescent plasma for COVID-19 outpatients
    Nature communications. 2022;13(1):2583

    Abstract

    Data on convalescent plasma (CP) treatment in COVID-19 outpatients are scarce. We aimed to assess whether CP administered during the first week of symptoms reduced the disease progression or risk of hospitalization of outpatients. Two multicenter, double-blind randomized trials (NCT04621123, NCT04589949) were merged with data pooling starting when <20% of recruitment target was achieved. A Bayesian-adaptive individual patient data meta-analysis was implemented. Outpatients aged ≥50 years and symptomatic for ≤7days were included. The intervention consisted of 200-300mL of CP with a predefined minimum level of antibodies. Primary endpoints were a 5-point disease severity scale and a composite of hospitalization or death by 28 days. Amongst the 797 patients included, 390 received CP and 392 placebo; they had a median age of 58 years, 1 comorbidity, 5 days symptoms and 93% had negative IgG antibody-test. Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of CP for improved disease severity scale was 0.936 (credible interval (CI) 0.667-1.311); OR for hospitalization or death was 0.919 (CI 0.592-1.416). CP effect on hospital admission or death was largest in patients with ≤5 days of symptoms (OR 0.658, 95%CI 0.394-1.085). CP did not decrease the time to full symptom resolution. TRIAL REGISTRATION Clinicaltrials.gov NCT04621123 and NCT04589949. REGISTRATION NCT04621123 and NCT04589949 on https://www. CLINICALTRIALS gov.
    PICO Summary

    Population

    COVID-19 outpatients enrolled in two multicenter trials: COnV-ert and CoV-Early (n= 797).

    Intervention

    Convalescent plasma (n= 390).

    Comparison

    Placebo (n= 392).

    Outcome

    Seventy-four patients were hospitalized, 6 required mechanical ventilation and 3 died. The odds ratio (OR) of convalescent plasma for improved disease severity scale was 0.936; OR for hospitalization or death was 0.919. The convalescent plasma effect on hospital admission or death was largest in patients with ≤5 days of symptoms (OR 0.658). Convalescent plasma did not decrease the time to full symptom resolution.
  4. Improving donor retention following a temporary deferral: A cluster randomized controlled trial of deferral educational materials
    Transfusion. 2022

    Abstract

    BACKGROUND Providing educational materials to deferred donors has been shown to increase their understanding about their deferral and knowledge about their return. The aim of this study was to determine the effectiveness of educational materials in increasing the retention of deferred donors. STUDY DESIGN AND METHODS A three-arm cluster randomized controlled trial was conducted, with the following conditions: (a) Incenter Brochure plus Email; (b) Email Only; (c) Control. The Incenter Brochure plus Email condition also included a guided conversation led by staff at the point of deferral. Donors were followed up for 3 months after their deferral had ended to determine if they had attempted to donate. RESULTS Compared with the Control condition, donors in the Incenter Brochure plus Email condition had increased odds of return at 3 months after their deferral ended (OR: 1.16; 95% CI 1.00-1.33). Subgroup analysis highlighted that novice (OR: 1.38; 95% CI 1.04-1.83) and established donors (OR: 1.36; 95% CI 1.13-1.64) had increased odds of return if they received the incenter materials. Donors who were deferred to maintain their well-being (OR: 1.28; 95% CI 1.03-1.60) and donors with a prior deferral history (OR: 1.55; 95% CI 1.15-1.55) had increased odds of return if they received the incenter materials. No significant differences were found between the Email Only and Control conditions. DISCUSSION This trial demonstrates the benefits of providing onsite educational materials to donors at the point of deferral. This is a simple, effective strategy to increase the return behavior of donors within 3 months of their deferral ending.
    PICO Summary

    Population

    Deferred blood donors from 30 Australian Lifeblood donor centers (n= 6,039).

    Intervention

    Incenter educational materials consisting of a brochure about referral and a ‘conversation guide’ prompting staff to be empathetic, plus a follow up email (Incenter Brochure plus Email group, n= 2,022).

    Comparison

    Business-as-usual incenter process and a follow up email (Email only group, n= 2,028). Business-as-usual deferral process (Control group, n= 1,989).

    Outcome

    Compared with donors in the Control group, donors in the Incenter Brochure plus Email group had increased odds of return at 3 months after their deferral ended (odds ratio (OR): 1.16). Subgroup analysis highlighted that novice (OR: 1.38) and established donors (OR: 1.36) had increased odds of return if they received the incenter materials. Donors who were deferred to maintain their well-being (OR: 1.28) and donors with a prior deferral history (OR: 1.55) had increased odds of return if they received the incenter materials. No significant differences were found between the Email Only and Control conditions.
  5. Cardiovascular Benefits for Blood Donors? A Systematic Review
    Transfusion medicine reviews. 2022

    Abstract

    It has been proposed that blood donation could be protective against cardiovascular disease. The aim of this study is to systematically summarize and evaluate existing observational and experimental studies on effects of blood donation on cardiovascular risk and disease in donor and general populations. The electronic databases PubMed and EMBASE were searched until March 2019 for experimental and observational studies on blood donation and cardiovascular risk or disease. Excluded were studies performed in patient populations or with controls compared to a patient population, and studies performed in individuals aged <18 or >70. All identified studies were independently screened for eligibility and quality using validated scoring systems by 2 reviewers. A total of 44 studies met all criteria. We included 41 observational studies and 3 experimental studies. 14 studies had a quality assessment score of 7 or higher. Of those, a majority of 9 studies reported a protective effect of blood donation, while 5 studies found no effects on cardiovascular risk factors. Results on other various outcomes were inconsistent and study quality was generally poor. Whether or not blood donation protects against cardiovascular disease remains unclear. Studies showing beneficial effects may have inadequately dealt with the healthy donor effect. High quality studies are lacking and therefore definite conclusions cannot be drawn. Large RCTs or cohort studies of high quality with sufficient follow-up should be conducted to provide evidence on the possible association between blood donation and cardiovascular disease.
    PICO Summary

    Population

    Blood donors (41 observational studies and 3 experimental studies).

    Intervention

    Systematic review to summarize and evaluate existing observational and experimental studies on effects of blood donation on cardiovascular risk and disease in donor and general populations.

    Comparison

    Outcome

    From the 44 included studies, 14 had a quality assessment score of 7 or higher. Of those, a majority of 9 studies reported a protective effect of blood donation, while 5 studies found no effects on cardiovascular risk factors. Results on other outcomes were inconsistent and study quality was generally poor. It was unclear whether blood donation protected against cardiovascular disease. High quality studies were lacking.
  6. A physiology-based trigger score to guide perioperative transfusion of allogeneic red blood cells: A multicentre randomised controlled trial
    Transfusion medicine (Oxford, England). 2022

    Abstract

    BACKGROUND Restrictive blood transfusion is recommended by major guidelines for perioperative management, but requires objective assessment at 7-10 g/dl haemoglobin (Hb). A scoring system that considers the physiological needs of the heart may simply the practice and reduce transfusion. METHODS Patients (14-65 years of age) undergoing non-cardiac surgery were randomised at a 1:1 ratio to a control group versus a Perioperative Transfusion Trigger Score (POTTS) group. POTTS (maximum of 10) was calculated as 6 plus the following: adrenaline infusion rate (0 for no infusion, 1 for ≤0.05 μg·kg(-1) ·min(-1) , and 2 for higher rate), FiO(2) to keep SpO(2) at ≥95% (0 for ≤35%, 1 for 36%-50%, and 2 for higher), core temperature (0 for <38°C, 1 for 38-40°C, and 2 for higher), and angina history (0 for no, 1 for exertional, and 2 for resting). Transfusion is indicated when actual Hb is lower than the calculated POTTS in individual patients. Transfusion in the control group was based on the 2012 American Association for Blood Banks (AABB) guideline. The primary outcome was the proportion of the patients requiring transfusion of allogeneic red blood cells (RBCs) during the perioperative period (until discharge from hospital), as assessed in the intention-to-treat (ITT) population (all randomised subjects). RESULT A total of 864 patients (mean age 44.4 years, 244 men and 620 women) were enrolled from December 2017 to January 2021 (433 in the control and 431 in the POTTS group). Baseline Hb was 9.2 ± 1.8 and 9.2 ± 1.7 g/dl in the control and POTTS groups, respectively. In the ITT analysis, the proportion of the patients receiving allogeneic RBCs was 43.9% (190/433) in the control group versus 36.9% (159/431) in the POTTS group (p = 0.036). Lower rate of allogeneic RBCs transfusion in the POTTS group was also evident in the per-protocol analysis (42.8% vs. 35.5%, p = 0.030). Transfusion volume was 4.0 (2.0, 6.0) and 3.5 (2.0, 5.5) units (200 ml/unit) in the control and POTTS groups, respectively (p = 0.25). The rate of severe postoperative complications (Clavien-Dindo grade IIIa and higher) was 3.9% in the control group versus 1.2% in the POTTS group (p = 0.010). CONCLUSION Transfusion of allogeneic RBCs based on the POTTS was safe and reduced the transfusion requirement in patients undergoing non-cardiac surgery.
    PICO Summary

    Population

    Patients (14-65 years old) undergoing non-cardiac surgery (n= 864).

    Intervention

    Transfusion based on a perioperative transfusion trigger score (POTTS), (n= 431).

    Comparison

    Restrictive transfusion (n= 433).

    Outcome

    In the intention to treat analysis, the proportion of the patients receiving allogeneic red blood cells (RBCs) was 43.9% (190) in the restrictive group vs. 36.9% (159) in the POTTS group. Lower rate of allogeneic RBCs transfusion in the POTTS group was also evident in the per-protocol analysis (42.8% vs. 35.5%). Transfusion volume was 4.0 (2.0, 6.0) and 3.5 (2.0, 5.5) units (200 ml/unit) in the restrictive and POTTS groups, respectively. The rate of severe post-operative complications was 3.9% in the restrictive group vs. 1.2% in the POTTS group.
  7. Pathophysiology and mechanism of long COVID: a comprehensive review
    Annals of medicine. 2022;54(1):1473-1487

    Abstract

    BACKGROUND After almost 2 years of fighting against SARS-CoV-2 pandemic, the number of patients enduring persistent symptoms long after acute infection is a matter of concern. This set of symptoms was referred to as "long COVID", and it was defined more recently as "Post COVID-19 condition" by the World health Organization (WHO). Although studies have revealed that long COVID can manifest whatever the severity of inaugural illness, the underlying pathophysiology is still enigmatic. AIM: To conduct a comprehensive review to address the putative pathophysiology underlying the persisting symptoms of long COVID. METHOD We searched 11 bibliographic databases (Cochrane Library, JBI EBP Database, Medline, Embase, PsycInfo, CINHAL, Ovid Nursing Database, Journals@Ovid, SciLit, EuropePMC, and CoronaCentral). We selected studies that put forward hypotheses on the pathophysiology, as well as those that encompassed long COVID patients in their research investigation. RESULTS A total of 98 articles were included in the systematic review, 54 of which exclusively addressed hypotheses on pathophysiology, while 44 involved COVID patients. Studies that included patients displayed heterogeneity with respect to the severity of initial illness, timing of analysis, or presence of a control group. Although long COVID likely results from long-term organ damage due to acute-phase infection, specific mechanisms following the initial illness could contribute to the later symptoms possibly affecting many organs. As such, autonomic nervous system damage could account for many symptoms without clear evidence of organ damage. Immune dysregulation, auto-immunity, endothelial dysfunction, occult viral persistence, as well as coagulation activation are the main underlying pathophysiological mechanisms so far. CONCLUSION Evidence on why persistent symptoms occur is still limited, and available studies are heterogeneous. Apart from long-term organ damage, many hints suggest that specific mechanisms following acute illness could be involved in long COVID symptoms. KEY MESSAGESLong-COVID is a multisystem disease that develops regardless of the initial disease severity. Its clinical spectrum comprises a wide range of symptoms.The mechanisms underlying its pathophysiology are still unclear. Although organ damage from the acute infection phase likely accounts for symptoms, specific long-lasting inflammatory mechanisms have been proposed, as well.Existing studies involving Long-COVID patients are highly heterogeneous, as they include patients with various COVID-19 severity levels and different time frame analysis, as well.
    PICO Summary

    Population

    Patients with long COVID-19 (98 studies).

    Intervention

    Systematic review to address the putative pathophysiology underlying the persisting symptoms of long COVID-19.

    Comparison

    Outcome

    Of all the included studies, 54 addressed hypotheses concerning potential underlying mechanisms of long COVID-19 symptoms, while 44 studies comprised patient data. Evidence about the persistence of long COVID-19 symptoms was limited, and the underlying mechanisms remained ambiguous. Many hypotheses were put forth by articles reviewing the potential pathophysiology. Included articles reporting patient data were highly heterogeneous, as their patients had various COVID-19 severity levels and different time frame analysis.
  8. Comparison of Risk Scores for Lower Gastrointestinal Bleeding: A Systematic Review and Meta-analysis
    JAMA network open. 2022;5(5):e2214253

    Abstract

    IMPORTANCE Clinical prediction models, or risk scores, can be used to risk stratify patients with lower gastrointestinal bleeding (LGIB), although the most discriminative score is unknown. OBJECTIVE To identify all LGIB risk scores available and compare their prognostic performance. DATA SOURCES A systematic search of Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1990, through August 31, 2021, was conducted. Non-English-language articles were excluded. STUDY SELECTION Observational and interventional studies deriving or validating an LGIB risk score for the prediction of a clinical outcome were included. Studies including patients younger than 16 years or limited to a specific patient population or a specific cause of bleeding were excluded. Two investigators independently screened the studies, and disagreements were resolved by consensus. DATA EXTRACTION AND SYNTHESIS Data were abstracted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline independently by 2 investigators and pooled using random-effects models. MAIN OUTCOMES AND MEASURES Summary diagnostic performance measures (sensitivity, specificity, and area under the receiver operating characteristic curve [AUROC]) determined a priori were calculated for each risk score and outcome combination. RESULTS A total of 3268 citations were identified, of which 9 studies encompassing 12 independent cohorts and 4 risk scores (Oakland, Strate, NOBLADS [nonsteroidal anti-inflammatory drug use, no diarrhea, no abdominal tenderness, blood pressure ≤100 mm Hg, antiplatelet drug use (nonaspirin), albumin <3.0 g/dL, disease score ≥2 (according to the Charlson Comorbidity Index), and syncope], and BLEED [ongoing bleeding, low systolic blood pressure, elevated prothrombin time, erratic mental status, and unstable comorbid disease]) were included in the meta-analysis. For the prediction of safe discharge, the AUROC for the Oakland score was 0.86 (95% CI, 0.82-0.88). For major bleeding, the AUROC was 0.93 (95% CI, 0.90-0.95) for the Oakland score, 0.73 (95% CI, 0.69-0.77) for the Strate score, 0.58 (95% CI, 0.53-0.62) for the NOBLADS score, and 0.65 (95% CI, 0.61-0.69) for the BLEED score. For transfusion, the AUROC was 0.99 (95% CI, 0.98-1.00) for the Oakland score and 0.88 (95% CI, 0.85-0.90) for the NOBLADS score. For hemostasis, the AUROC was 0.36 (95% CI, 0.32-0.40) for the Oakland score, 0.82 (95% CI, 0.79-0.85) for the Strate score, and 0.24 (95% CI, 0.20-0.28) for the NOBLADS score. CONCLUSIONS AND RELEVANCE The Oakland score was the most discriminative LGIB risk score for predicting safe discharge, major bleeding, and need for transfusion, whereas the Strate score was best for predicting need for hemostasis. This study suggests that these scores can be used to predict outcomes from LGIB and guide clinical care accordingly.
    PICO Summary

    Population

    Patients with lower gastrointestinal bleeding (LGIB), (9 studies).

    Intervention

    Systematic review and meta-analysis to identify all LGIB risk scores available and to compare their prognostic performance.

    Comparison

    Outcome

    Four risk scores were identified: Oakland, Strate, NOBLADS, and BLEED. Summary diagnostic performance measures (sensitivity, specificity, and area under the receiver operating characteristic curve [AUROC]) determined a priori were calculated for each risk score and outcome combination. For the prediction of safe discharge, the AUROC for the Oakland score was 0.86. For major bleeding, the AUROC was 0.93 for the Oakland score, 0.73 for the Strate score, 0.58 for the NOBLADS score, and 0.65 for the BLEED score. For transfusion, the AUROC was 0.99 for the Oakland score and 0.88 for the NOBLADS score. For haemostasis, the AUROC was 0.36 for the Oakland score, 0.82 for the Strate score, and 0.24 for the NOBLADS score.
  9. Hyperkalaemia Following Blood Transfusion-a Systematic Review Assessing Evidence and Risks
    Transfusion medicine reviews. 2022

    Abstract

    Hyperkalaemia following transfusion is widely reported in the literature. Our objective was to critically review recent evidence on hyperkalaemia in association with transfusion and to assess whether specific aspects of transfusion practice can affect the likelihood of developing hyperkalaemia. We searched 9 electronic databases (including MEDLINE, Embase, and Transfusion Evidence Library) using a predefined search strategy, from 2010 to April 8, 2021. Three reviewers performed dual screening, extraction, and risk of bias assessment. We used Cochrane risk of bias (ROB) 2 for assessment of RCTs, ROBINS-I for non-RCTs, and GRADE to assess the certainty of the evidence. We report 7 comparisons of interest in n = 3729 patients from 28 studies (11 RCTs, 4 prospective cohort studies, and 13 retrospective cohort studies): (1) age of blood, (2) washing, (3) filtration, (4) irradiation, (5) fluid type, (6) transfusion vs no transfusion, (7) blood volume/rate. Of the 28 studies included, 25 reported outcomes of potassium (K+) concentration, 17 the number developing hyperkalaemia, 13 mortality, 10 cardiac arrest, and 10 cardiac arrhythmia. Only 16 studies provided analysable data suitable for quantitative analysis. Evidence addressing our outcomes was of very low certainty (downgraded for incomplete outcome data, baseline imbalance, imprecision around the estimate, and small sample size). While 5 studies showed a difference in K+ concentration up to 6 hours posttransfusion for 3 comparisons (age of blood, washing, and transfusion volume/rate), and 3 studies showed a difference in the diagnosis of hyperkalaemia for 2 comparisons (age of blood, and transfusion volume/rate), the evidence was inconsistent across all included studies. There was no difference in any reported outcomes for 4 comparisons (filtration, irradiation, fluid type, or transfusion vs no transfusion). Overall, the reported evidence was too weak to support identification of groups most at risk of hyperkalaemia or to support recommendations on use of short-storage RBC. For other commonly used risk mitigations for hyperkalaemia in transfusion medicine, the (low certainty) evidence was either conflicting or not supportive.
    PICO Summary

    Population

    Neonates, children, and adults receiving red blood cell transfusions (28 studies, n= 3,729).

    Intervention

    To systematically review hyperkalaemia in association with transfusion and to assess whether specific aspects of transfusion practice can affect the likelihood of developing hyperkalaemia.

    Comparison

    Outcome

    25 studies reported outcomes of potassium (K+) concentration, 17 the number developing hyperkalaemia, 13 mortality, 10 cardiac arrest, and 10 cardiac arrhythmia. While 5 studies showed a difference in K+ concentration up to 6 hours post-transfusion for age of blood, washing, and transfusion volume/rate, and 3 studies showed a difference in the diagnosis of hyperkalaemia for age of blood, and transfusion volume/rate, the evidence was inconsistent across all included studies. There was no difference in any reported outcomes for filtration, irradiation, fluid type, or transfusion vs. no transfusion. Overall, the reported evidence was too weak to support identification of groups most at risk of hyperkalaemia or to support recommendations on use of short-storage red blood cells.
  10. Economic evaluation of Restrictive Vs. Liberal Transfusion Strategy Following Acute Myocardial Infarction (REALITY): trial-based cost effectiveness and cost utility analyses
    European heart journal. Quality of care & clinical outcomes. 2022

    Abstract

    AIM: To estimate the cost effectiveness and cost utility ratios of a restrictive vs liberal transfusion strategy in acute myocardial infarction (AMI) patients with anemia. METHODS AND RESULTS Patients (n = 666) with AMI and hemoglobin between 7-8 and 10 g/dL recruited in 35 hospitals in France and Spain were randomly assigned to a restrictive (n = 342) or a liberal (n = 324) transfusion strategy with 1-year prospective collection of resource utilization and quality of life using the EQ5D3L questionnaire. The economic evaluation was based upon 648 patients from the per-protocol population. The outcomes were 30-day and 1-year cost-effectiveness, with major adverse cardiovascular event averted (MACE) as the effectiveness outcome; and 1-year cost utility ratio.The 30-day incremental cost-effectiveness ratio was €33,065€ saved per additional MACE averted with the restrictive versus the liberal strategy, with an 84% probability for the restrictive strategy to be cost-saving and MACE reducing (i.e.dominant). At 1-year, the point estimate of the cost-utility ratio was 191,500 € saved per QALY gained; however cumulated MACE were outside the pre-specified non-inferiority margin, resulting in a decremental cost effectiveness ratio with a point estimate of €72,000 saved per additional MACE with the restrictive strategy. CONCLUSION In patients with acute myocardial infarction and anemia, the restrictive transfusion strategy was dominant (cost-saving and outcome-improving) at 30 days. At 1 year, the restrictive strategy remained cost-saving but clinical noninferiority on MACE was no longer maintained. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02648113.
    PICO Summary

    Population

    Acute myocardial infarction patients with anaemia, enrolled in the REALITY trial in 35 hospitals in France and Spain (n= 666).

    Intervention

    Restrictive transfusion strategy (n= 342).

    Comparison

    Liberal transfusion strategy (n= 324).

    Outcome

    The 30-day incremental cost-effectiveness ratio was €33,065 saved per additional major adverse cardiovascular event (MACE) averted with the restrictive versus the liberal strategy, with an 84% probability for the restrictive strategy to be cost-saving and MACE reducing. At 1-year, the point estimate of the cost-utility ratio was €191,500 saved per quality-adjusted life year gained; however cumulated MACE were outside the pre-specified non-inferiority margin, resulting in a decremental cost effectiveness ratio with a point estimate of €72,000 saved per additional MACE with the restrictive strategy.