Red blood cell transfusion triggers in acute leukemia: a randomized pilot study

Restrictive versus liberal red blood cell transfusion strategies for people with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without haematopoietic stem cell support

BACKGROUND

An estimated one-quarter to one-half of people diagnosed with haematological malignancies experience anaemia. There are different strategies for red blood cell (RBC) transfusions to treat anaemia. A restrictive transfusion strategy permits a lower haemoglobin (Hb) level whereas a liberal transfusion strategy aims to maintain a higher Hb. The most effective and safest strategy is unknown.

OBJECTIVES

To determine the efficacy and safety of restrictive versus liberal RBC transfusion strategies for people diagnosed with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without a haematopoietic stem cell transplant (HSCT).

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and non-randomised studies (NRS) in MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1982), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2023, Issue 2), and eight other databases (including three trial registries) to 21 March 2023. We also searched grey literature and contacted experts in transfusion for additional trials. There were no language, date or publication status restrictions.

SELECTION CRITERIA

We included RCTs and prospective NRS that evaluated restrictive versus liberal RBC transfusion strategies in children or adults with malignant haematological disorders receiving intensive chemotherapy or radiotherapy, or both, with or without HSCT.

DATA COLLECTION AND ANALYSIS

Two authors independently screened references, full-text reports of potentially relevant studies, extracted data from the studies, and assessed the risk of bias. Any disagreement was discussed and resolved with a third review author. Dichotomous outcomes were presented as a risk ratio (RR) with a 95% confidence interval (CI). Narrative syntheses were used for heterogeneous outcome measures. Review Manager Web was used to meta-analyse the data. Main outcomes of interest included: all-cause mortality at 31 to 100 days, quality of life, number of participants with any bleeding, number of participants with clinically significant bleeding, serious infections, length of hospital admission (days) and hospital readmission at 0 to 3 months. The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

Nine studies met eligibility; eight RCTs and one NRS. Six hundred and forty-four participants were included from six completed RCTs (n = 560) and one completed NRS (n = 84), with two ongoing RCTs consisting of 294 participants (260 adult and 34 paediatric) pending inclusion. Only one completed RCT included children receiving HSCT (n = 6); the other five RCTs only included adults: 239 with acute leukaemia receiving chemotherapy and 315 receiving HSCT (166 allogeneic and 149 autologous). The transfusion threshold ranged from 70 g/L to 80 g/L for restrictive and from 80 g/L to 120 g/L for liberal strategies. Effects were reported in the summary of findings tables only for the trials that included adults to reduce indirectness due to the limited evidence contributed by the prematurely terminated paediatric trial. Evidence from RCTs Overall, there may be little to no difference in the number of participants who die within 31 to 100 days using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 451 participants; RR 1.00, 95% CI 0.27 to 3.70, P=0.99; very low-certainty evidence). There may be little to no difference in quality of life at 0 to 3 months using a restrictive compared to a liberal transfusion strategy, but the evidence is very uncertain (three studies; 431 participants; analysis unable to be completed due to heterogeneity; very low-certainty evidence). There may be little to no difference in the number of participants who suffer from any bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies; 448 participants; RR 0.91, 95% CI 0.78 to 1.06, P = 0.22; low-certainty evidence). There may be little to no difference in the number of participants who suffer from clinically significant bleeding at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (four studies; 511 participants; RR: 0.94, 95% CI 0.74 to 1.19, P = 0.60; low-certainty evidence). There may be little to no difference in the number of participants who experience serious infections at 0 to 3 months using a restrictive compared to a liberal transfusion strategy (three studies, 451 participants; RR: 1.20, 95% CI 0.93 to 1.55, P = 0.17; low-certainty evidence). A restrictive transfusion strategy likely results in little to no difference in the length of hospital admission at 0 to 3 months compared to a liberal strategy (two studies; 388 participants; analysis unable to be completed due to heterogeneity in reporting; moderate-certainty evidence). There may be little to no difference between hospital readmission using a restrictive transfusion strategy compared to a liberal transfusion strategy (one study, 299 participants; RR: 0.89, 95% CI 0.52 to 1.50; P = 0.65; low-certainty evidence). Evidence from NRS The evidence is very uncertain whether a restrictive RBC transfusion strategy: reduces the risk of death within 100 days (one study, 84 participants, restrictive 1 death; liberal 1 death; very low-certainty evidence); or decreases the risk of clinically significant bleeding (one study, 84 participants, restrictive 3; liberal 8; very low-certainty evidence). No NRS reported on the other eligible outcomes.

AUTHORS' CONCLUSIONS

Findings from this review were based on seven studies and 644 participants. Definite conclusions are challenging given the relatively few included studies, low number of included participants, heterogeneity of intervention and outcome reporting, and overall certainty of evidence. To increase the certainty of the true effect of a restrictive RBC transfusion strategy on clinical outcomes, there is a need for rigorously designed and executed studies. The evidence is largely based on two populations: adults with acute leukaemia receiving intensive chemotherapy and adults with haematologic malignancy requiring HSCT. Despite the addition of 405 participants from three RCTs to the previous review's results, there is still insufficient evidence to answer this review's primary outcome. If we assume a mortality rate of 3% within 100 days, we would need a total of 1492 participants to have an 80% chance of detecting, at a 5% level of significance, an increase in all-cause mortality from 3% to 6%. Further RCTs are needed overall, particularly in children.

A pilot randomized study for optimal red cell transfusion in acute myeloid leukemia patients with intensive chemotherapy

BACKGROUND

Although blood transfusion is fundamental throughout the course of hematologic malignancies, acute myeloid leukemia (AML) patients requiring intensive chemotherapy are left at the edges of patient blood management programs because current guidelines do not have established recommendations for red blood cell (RBC) transfusion threshold in patients treated for hematological disorders with anemia and accompanied severe thrombocytopenia. To provide answers for the trigger and doses of ideal RBC transfusion in such situation, we conducted this prospective randomized trial.

MATERIALS AND METHODS

Newly diagnosed non-acute promyelocytic AML patients undergoing chemotherapy were considered eligible for enrollment. Patients were randomized into 4 groups using a 2 by 2 factorial design, according to the RBC transfusion trigger (hemoglobin [Hb], 7 vs 8 g/dL) and the number of units per transfusion episode (quantity, single vs double-unit).

RESULTS

Initially 91 patients were randomized into 4 groups, but the protocol adherence rate was 90.1%. Hb trigger did not affect the amount of RBC transfusion required during treatment. Patients receiving RBC transfusion at Hb <7 g/dL used a median of 4 units of RBC (range 0-12), and those receiving transfusion at Hb <8 g/dL also used a median of 4 units of RBC (range 0-24) (p=0.305). The number of RBC units per transfusion did not affect the total amount of RBC transfusion required during treatment. AML treatment outcomes and bleeding events did not differ across the 4 groups.

DISCUSSION

This study demonstrated the feasibility for restrictive RBC transfusion (Hb <7 g/dL, RBC 1 unit) in AML patients undergoing chemotherapy, regardless of chemotherapy intensity.

An analysis of quality of life and functional outcomes as reported in randomized trials for red cell transfusions

BACKGROUND

Meta-analyses of randomized controlled trials (RCTs) evaluating thresholds for red blood cell (RBC) transfusion typically focus on mortality; however, other outcomes are highly relevant. The aim of this study is to summarize the effects of different transfusion thresholds on the outcomes of quality of life (QoL) and function.

STUDY DESIGN

We extracted data from RCTs identified in a recently published Cochrane systematic review. Primary analysis was descriptive.

RESULTS

A total of 23 RCTs with 13,743 adult participants were included. Fifteen RCTs included patients in the postoperative period, of which 9 RCTs were conducted in hip (n = 3024) and 6 (n = 8672) in cardiac surgeries; 5 RCTs (n = 489) were in patients with hematological malignancies; 2 in the setting of bleeding (gastrointestinal bleed [n = 936] and postpartum [n = 521]); and one RCT (n = 936) included critically ill patients. QoL and function were reported using a variety of questionnaires and tools. The timing of assessments varied between trials. No clear clinical differences in QoL outcomes were identified in comparisons between restrictive and liberal transfusion thresholds.

DISCUSSION

There is no evidence that a liberal transfusion strategy improves QoL and functional outcomes. However, the substantial limitations of many included studies indicate the need for further well-designed and adequately powered trials.

Divergent CD4+ T-cell profiles are associated with anti-HLA alloimmunization status in platelet-transfused AML patients

Introduction

Acute myeloid leukemia (AML) is one of the commonest hematologic disorders. Due to the high frequency of disease- or treatment-related thrombocytopenia, AML requires treatment with multiple platelet transfusions, which can trigger a humoral response directed against platelets. Some, but not all, AML patients develop an anti-HLA immune response after multiple transfusions. We therefore hypothesized that different immune activation profiles might be associated with anti-HLA alloimmunization status.

Methods

We tested this hypothesis, by analyzing CD4+ T lymphocyte (TL) subsets and their immune control molecules in flow cytometry and single-cell multi-omics.

Results

A comparison of immunological status between anti-HLA alloimmunized and non-alloimmunized AML patients identified differences in the phenotype and function of CD4+ TLs. CD4+ TLs from alloimmunized patients displayed features of immune activation, with higher levels of CD40 and OX40 than the cells of healthy donors. However, the most notable differences were observed in non-alloimmunized patients. These patients had lower levels of CD40 and OX40 than alloimmunized patients and higher levels of PD1. Moreover, the Treg compartment of non-alloimmunized patients was larger and more functional than that in alloimmunized patients. These results were supported by a multi-omics analysis of immune response molecules in conventional CD4+ TLs, Tfh circulating cells, and Tregs.

Discussion

Our results thus reveal divergent CD4+ TL characteristics correlated with anti-HLA alloimmunization status in transfused AML patients. These differences, characterizing CD4+ TLs independently of any specific antigen, should be taken into account when considering the immune responses of patients to infections, vaccinations, or transplantations.

Considerations for Drug Development in Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) have historically been challenging diseases for drug development due to their biology, preclinical modeling, and the affected patient population. In April 2022, the FDA convened a panel of regulators and academic experts in MDS to discuss approaches to improve MDS drug development. The panel reviewed challenges in MDS clinical trial design and endpoints and outlined considerations for future trial design in MDS to facilitate drug development to meaningfully meet patient needs. Challenges for defining clinical benefit in patients with MDS include cumbersome response criteria, standardized transfusion thresholds, and application and validation of patient reported outcome instruments. Clinical trials should reflect the biology of disease evolution, the advanced age of patients with MDS, and how patients are treated in real-world settings to maximize the likelihood of identifying active drugs. In patients with lower-risk disease, response criteria for anemic patients should be based on baseline transfusion dependency, improvement in symptoms, and quality of life. For higher-risk patients with MDS, trials should include guidance to prevent dose reductions or delays that could limit efficacy, specify minimal durations of treatment (in the absence of toxicity or progression), and have endpoints focused on overall survival and durable responses. MDS trials should be designed from the outset to allow the practicable application of new therapies in this high-needs population, with drugs that can be administered and tolerated in community settings, and with endpoints that meaningfully improve patients' lives over existing therapies.

Effect of Single-unit Transfusion in Patients Treated for Haematological Disease Including Acute Leukemia: A Multicenter Randomized Controlled Clinical Trial

BACKGROUND

Retrospective studies in hematological unit have suggested that single red blood cell (1-RBC) unit transfusion policy may reduce the number of RBC used without negative clinical impact.

METHOD

Acute leukemia patients requiring intensive chemotherapy or patients receiving autologous or allogeneic transplantation were randomly assigned to receive either single RBC (1-RBC arm) or double RBC (2-RBC arm) per transfusion with a hemoglobin trigger of 8 g/dL. The primary composite endpoint was the percentage of patients experiencing serious complications, such as a non-hematological adverse event grade ≥ 3 or intensive care admission or death.

FINDINGS

A total of 981 and 592 RBC transfusions were required in the 1-RBC arm (n = 125) and the 2-RBC arm (n = 120), respectively. The mean pre-transfusion hemoglobin levels were 7.49 ± 0.83 g/dL in the 1-RBC arm and 7.46 ± 0.67 g/dL in the 2-RBC arm (p = 0.275). The predefined non-inferiority criteria was achieved with 28/125 patients reaching the primary endpoint in the 1-RBC arm (22.4 %) and 28/120 patients in the 2-RBC arm (23.3 %) (Risk difference 0.009; 95 %, Confidence interval [-0.0791 to 0.0978], p = 0.021). The median (IQR) of RBC units transfused per patient was 7 (4-12) in the 1-RBC arm and 8 (4-12) in 2-RBC arm. Hemoglobin levels at discharge were also comparable in both arms.

INTERPRETATION

The results of this trial indicate that a single RBC transfusion policy is not inferior to a double RBC transfusion policy for patients receiving a bone marrow transplant or intensive chemotherapy in a hematological intensive care unit. However, the single RBC transfusion policy did not reduce the number of RBC units transfused per stay.

FUNDING

This trial was funded by a grant from the French Ministry of Health.

New horizons for reduction of blood use: Patient blood management

A countrywide study over the eras indicates overuse of blood transfusion can have considerable risks to patients accompanied by significant costs of blood transfusion for patients, hospitals, and health-care systems. Besides, more than 30% of the world's population is anemic. Typically, blood transfusion helps continue suitable oxygen transfer in anemia, i.e., more and more documented as a threatening factor with several adverse outcomes including long hospitalization, morbidity, and mortality. Transplantation of allogeneic blood is thus like a two-edged sword. There is no doubt that the blood transfusion is a life-saving treatment, but it should be underpinned by much of up-to-date health-care services. The new theory considered for patient blood management (PBM) also discusses the timely application of evidence-based surgical and clinical theories and focuses on patient outcomes. Furthermore, PBM involves a multidisciplinary methodology to reduce unnecessary transfusions, minimize costs, and cut risks.

When Guideline-Concordant Standardized Care Results in Healthcare Disparities

AbstractClinical red blood cell transfusion guidelines have been widely adopted in clinical practice, resulting in standardized transfusion practices in hospitalized patients with anemia. Standardization of transfusion practice has been welcomed by clinicians and health systems as a mechanism for reducing unnecessary, harmful, and costly practice variation that results in healthcare disparities. However, overzealously applied guidelines can have deleterious consequences for individual patients, ultimately resulting in and/or exacerbating healthcare disparities, rather than resolving them. This article provides empirical examples of the adverse consequences from the well-meaning attempt to standardize transfusion practice based on clinical practice guidelines and discusses the ethical implications of standardized transfusion practice.

The Analysis of the Effect of Blood Transfusion on Changes of Blood Platelet Parameters in Patients with Leukemia Treated with Chemotherapy

Objective

To study and analyze the effect of blood transfusion on the change of blood platelet parameters in patients with leukemia treated with chemotherapy.

Methods

Ninety-eight patients with leukemia treated with chemotherapy in the First Affiliated Hospital of Xi'an Jiaotong University from January 2021 to January 2022 were selected to observe the changes of platelet parameters before and after blood transfusion.

Results

There was significant difference between pre-transfusion and post-transfusion indexes (platelet count, mean platelet volume, and hematocrit) (P < 0.05). After binary logistic regression analysis, the use of antibiotics (OR = 2.235), blood transfusion history (OR = 3.086), abnormal white blood cell count (OR = 1.134), and frozen plasma transfusion (OR = 3.121) were the main factors of blood platelet parameters after transfusion in leukemia patients (P < 0.05).

Conclusion

Blood transfusion is beneficial to improve blood platelet parameters and prevent bleeding in patients with leukemia treated with chemotherapy. Attention should be paid to patients with risk factors for poor response to blood platelet transfusion and early intervention.

Racial differences in red blood cell transfusion in hospitalized patients with anemia

BACKGROUND

Guidelines recommend transfusion of red blood cells (RBC's) when a hospitalized patient's hemoglobin (Hb) drops below a restrictive transfusion threshold, either at 7 or 8 g. Hospitals have implemented transfusion policies to encourage compliance with guidelines and reduce variation in transfusion practice. However, variation in transfusion practice remains. The purpose of this study was to examine whether there is variation in the receipt of transfusion by patient race.

METHODS

Hospitalized general medicine patients with anemia (Hb < 10 g/dL) were eligible. Chi-squared tests were used to compare the percent of patients receiving a transfusion by race overall and within strata of their nadir Hb. Linear regression was used to test the association between a patient's race, their nadir Hb, receipt of an RBC transfusion, and the number of units transfused.

RESULTS

Four thousand nine hundred and fifty-one patients consented, including 1363 (28%) who received a transfusion. 71% of patients were African American, 25% were White, and 4% were Other Race. Overall African Americans were less likely to be transfused compared to Whites (25% vs. 30%, p < .01), and within Hb strata below a Nadir Hb of 9 g/dL (Hb 8.0-8.9 g/dL 1% vs. 7%, p < .01; 7.0-7.9 g/dL 15% vs. 28%, p < .01; <7 g/dL 80% vs. 86%, p < .01). African Americans also received fewer units of RBC's (β = -.17, p < .01) overall and at lower Hb levels (β = .14, p < .01) compared to Whites.

DISCUSSION

The Hb level at which patients are transfused at and the total number of RBC units received during hospitalization differ by patient race.

The impact of pathogen-reduced platelets in acute leukaemia treatment on the total blood product requirement: a subgroup analysis of an EFFIPAP randomised trial

OBJECTIVE

To evaluate the impact of pathogen-reduced (PR) platelet transfusions on blood products requirement for clinical practice.

BACKGROUND

PR platelets are increasing in use as standard blood products. However, few randomised trials have evaluated their impact on bleeding control or prevention. Furthermore, PR platelets recirculate less than untreated platelets.

METHODS

A subgroup study of the randomised clinical trial EFFIPAP compared three arms of platelet preparations (PR: P-PRP/PAS, additive solution: P-PAS and plasma P-P arms respectively). The subgroup of acute leukaemia patients, in their chemotherapy induction phase, included 392 patients (133 P-PRP/PAS arm, 132 P-PAS arm and 130 P-P arm). Blood requirements were analysed across over periods of 7 days.

RESULTS

The number of platelet transfusions per week was significantly higher in the P-PRP/PAS group 2.3 [1.6-3.3] compared to the control groups 1.9 [1.3-2.8] and 2.0 [1.3-3.0] for P-P and P-PAS groups respectively (p < 0.0001). However, the total number of platelets transfused per week was not different. The number of red blood cell concentrates (RBC) transfusion per week did not differ either.

CONCLUSION

In a homogeneous group of patients, platelet pathogen reduction resulted in an increased number of platelet units transfused per week while having no impact on the total number of platelets transfused or the number of RBC transfusion; resulting to an average requirement of 2 RBC and 2-3 platelets transfusions per week of marrow aplasia.

The treatment of acute lymphoblastic leukemia in Jehovah's Witnesses and patients who cannot accept blood products

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Jehovah's Witnesses and patients who cannot accept blood products diagnosed with acute lymphoblastic leukemia can be a clinical challenge.

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Chemotherapy can and should be safely used for induction therapy in this population.

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Blinatumomab and nelarabine are agents with novel mechanisms of action that are minimally myelosuppressive.

Jehovah's Witnesses cannot accept blood products based upon religious beliefs, and when they present with acute leukemia, the ideal treatment strategy can be controversial. We present six cases of Jehovah's Witnesses with acute lymphoblastic leukemia and show that complete remission can be achieved without using anthracycline in 83% (5/6) of patients. We also report, for the first time in this population, that the use of agents with novel mechanisms of action, such as blinatumomab and nelarabine, is associated with minimal myelosuppression and can produce durable responses, with 2 of 6 patients still alive in CR3 at 4.9 and 6.6 years.

Transfusion thresholds for guiding red blood cell transfusion

BACKGROUND

The optimal haemoglobin threshold for use of red blood cell (RBC) transfusions in anaemic patients remains an active field of research. Blood is a scarce resource, and in some countries, transfusions are less safe than in others because of inadequate testing for viral pathogens. If a liberal transfusion policy does not improve clinical outcomes, or if it is equivalent, then adopting a more restrictive approach could be recognised as the standard of care.  OBJECTIVES: The aim of this review update was to compare 30-day mortality and other clinical outcomes for participants randomised to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all clinical conditions. The restrictive transfusion threshold uses a lower haemoglobin concentration as a threshold for transfusion (most commonly, 7.0 g/dL to 8.0 g/dL), and the liberal transfusion threshold uses a higher haemoglobin concentration as a threshold for transfusion (most commonly, 9.0 g/dL to 10.0 g/dL).

SEARCH METHODS

We identified trials through updated searches: CENTRAL (2020, Issue 11), MEDLINE (1946 to November 2020), Embase (1974 to November 2020), Transfusion Evidence Library (1950 to November 2020), Web of Science Conference Proceedings Citation Index (1990 to November 2020), and trial registries (November 2020). We  checked the reference lists of other published reviews and relevant papers to identify additional trials. We were aware of one trial identified in earlier searching that was in the process of being published (in February 2021), and we were able to include it before this review was finalised.

SELECTION CRITERIA

We included randomised trials of surgical or medical participants that recruited adults or children, or both. We excluded studies that focused on neonates. Eligible trials assigned intervention groups on the basis of different transfusion schedules or thresholds or 'triggers'. These thresholds would be defined by a haemoglobin (Hb) or haematocrit (Hct) concentration below which an RBC transfusion would be administered; the haemoglobin concentration remains the most commonly applied marker of the need for RBC transfusion in clinical practice. We included trials in which investigators had allocated participants to higher thresholds or more liberal transfusion strategies compared to more restrictive ones, which might include no transfusion. As in previous versions of this review, we did not exclude unregistered trials published after 2010 (as per the policy of the Cochrane Injuries Group, 2015), however, we did conduct analyses to consider the differential impact of results of trials for which prospective registration could not be confirmed.   DATA COLLECTION AND ANALYSIS: We identified trials for inclusion and extracted data using Cochrane methods. We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two review authors independently extracted data and assessed risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as being in the 'restrictive transfusion' group and those randomly allocated to the higher transfusion threshold as being in the 'liberal transfusion' group.

MAIN RESULTS

A total of 48 trials, involving data from 21,433 participants (at baseline), across a range of clinical contexts (e.g. orthopaedic, cardiac, or vascular surgery; critical care; acute blood loss (including gastrointestinal bleeding); acute coronary syndrome; cancer; leukaemia; haematological malignancies), met the eligibility criteria. The haemoglobin concentration used to define the restrictive transfusion group in most trials (36) was between 7.0 g/dL and 8.0 g/dL.  Most trials included only adults; three trials focused on children. The included studies were generally at low risk of bias for key domains including allocation concealment and incomplete outcome data. Restrictive transfusion strategies reduced the risk of receiving at least one RBC transfusion by 41% across a broad range of clinical contexts (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.53 to 0.66; 42 studies, 20,057 participants; high-quality evidence), with a large amount of heterogeneity between trials (I² = 96%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.99, 95% CI 0.86 to 1.15; 31 studies, 16,729 participants; I² = 30%; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (all high-quality evidence)). High-quality evidence shows that the liberal transfusion threshold did not affect the risk of infection (pneumonia, wound infection, or bacteraemia). Transfusion-specific reactions are uncommon and were inconsistently reported within trials. We noted less certainty in the strength of evidence to support the safety of restrictive transfusion thresholds for the following predefined clinical subgroups: myocardial infarction, vascular surgery, haematological malignancies, and chronic bone-marrow disorders.

AUTHORS' CONCLUSIONS

Transfusion at a restrictive haemoglobin concentration decreased the proportion of people exposed to RBC transfusion by 41% across a broad range of clinical contexts. Across all trials, no evidence suggests that a restrictive transfusion strategy impacted 30-day mortality, mortality at other time points, or morbidity (i.e. cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. Despite including 17 more randomised trials (and 8846 participants), data remain insufficient to inform the safety of transfusion policies in important and selected clinical contexts, such as myocardial infarction, chronic cardiovascular disease, neurological injury or traumatic brain injury, stroke, thrombocytopenia, and cancer or haematological malignancies, including chronic bone marrow failure.  Further work is needed to improve our understanding of outcomes other than mortality. Most trials compared only two separate thresholds for haemoglobin concentration, which may not identify the actual optimal threshold for transfusion in a particular patient. Haemoglobin concentration may not be the most informative marker of the need for transfusion in individual patients with different degrees of physiological adaptation to anaemia. Notwithstanding these issues, overall findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds between the range of 7.0 g/dL and 8.0 g/dL. Some patient subgroups might benefit from RBCs to maintain higher haemoglobin concentrations; research efforts should focus on these clinical contexts.

Ensuring the Safety of Hospitalized Oncology Patients During a Pandemic

Patients with hematologic malignancies present a unique set of circumstances during the COVID-19 pandemic; they are at increased risk of complications and death from COVID-19 infection, but the treatment of their cancer cannot be delayed. This article highlights some of the practice changes made by an inpatient hematology/oncology advanced practice provider team at a large academic institution in Philadelphia, Pennsylvania, at both a hospital-wide and service level. Practice changes have included restructuring the rounding process, imposing visitor restrictions, adjusting blood transfusion parameters, and implementing creative communication approaches to keep patients and families informed while practicing medicine under stringent new guidelines. Low COVID-19 infection rates at this particular hospital demonstrate that, while these changes were difficult, they were successful in preventing transmission of COVID-19 and keeping both patients and providers safe.

Anemia-Induced Bleeding in Patients with Platelet Disorders

Anemia is not only a consequence of bleeding, but also a modifiable risk factor for bleeding in patients with thrombocytopenia or platelet function defects. In this review we outline the mechanism of anemia-induced bleeding in patients with platelet disorders, which involves a disturbance in normal red blood cell (RBC) rheology and reduced platelet margination to the endothelial surface due to a decrease in RBC mass, leading to impaired primary hemostasis and bleeding. Biologically, anemia reduces the mass of RBCs in the central column of flowing blood through a vessel resulting in fewer platelets coming into contact with the endothelial surface at the periphery of the flowing blood column. Thus, anemia results in impaired primary hemostasis. Von Willebrand factor (vWF) is another component of primary hemostasis and vWF deficiency, especially a deficiency of the highest vWF multimers, can also manifest with bleeding when concomitant anemia occurs. Clinically, patients at greatest risk for anemia-induced bleeding include patients with hematological malignancies in whom anemia and thrombocytopenia occur as a result of the underlying disease or the myelotoxic effects of treatment; patients with renal insufficiency with uremic thrombocytopathy and hypoproliferative anemia; and patients with inherited or acquired bleeding disorders affecting primary hemostasis (eg, Bernard-Soulier syndrome, von Willebrand disease) with chronic blood loss and iron deficiency anemia. Underlying abnormalities of any components of primary hemostasis plus concomitant anemia may result in major bleeding disorders; therefore, correction of remediable abnormalities-most notably, correction of the anemia- would be expected to have important clinical benefit. In this review we discuss how the correction of the anemia may lead to improvement of bleeding outcomes in patients with a primary hemostatic defect, supported by evidence from animal models, clinical trials and clinical experience.

Outpatient intensive induction chemotherapy for acute myeloid leukemia and high-risk myelodysplastic syndrome

To improve patient quality of life and reduce health care costs, many conditions formerly thought to require inpatient care are now treated in the outpatient setting. Outpatient induction chemotherapy for acute myeloid leukemia (AML) may confer similar benefits. This possibility prompted a pilot study to explore the safety and feasibility of intensive outpatient initial or salvage induction chemotherapy administration for adults with AML and high-risk myelodysplastic syndrome (MDS). Patients with no significant organ dysfunction and a treatment-related mortality (TRM) score corresponding to a day 28 mortality rate of <5% to 10% were eligible for study. Patients were treated as outpatients with daily evaluation by providers and only admitted to the hospital if mandated by complications. Twenty patients were consented, and 17 were treated. Eight patients received initial induction chemotherapy and 9 received salvage induction chemotherapy. Fourteen patients completed induction chemotherapy administration in the outpatient setting (82.4%; exact 95% confidence interval [CI], 55.8-95.3). Three patients were admitted during the course of chemotherapy administration, 2 for neutropenic fever and 1 for grade 3 mucositis. No patients died within 14 days of the initiation of induction chemotherapy (exact 95% CI, 0-22.9). Results of this pilot study suggest it is feasible to complete outpatient induction chemotherapy in select patients with AML and high-risk MDS. A team including nurses, social workers, medical providers, and pharmacists was key to the successful implementation of outpatient induction.

Differences among hemoglobin thresholds for red blood cell transfusions in patients with hematological diseases in teaching hospitals: a real world data in Japan

A hemoglobin (Hb) threshold level of 7 g/dL has been proposed for red blood cell (RBC) transfusion in patients with chronic anemia in the Japanese guideline since 2005. However, Hb thresholds for hematological diseases in clinical practice and factors responsible for higher Hb thresholds remain unclear. Hb thresholds were collected for patients with hematological diseases from 32 Japanese teaching hospitals. Uni- and multivariate analyses were used to analyze relationships between Hb threshold level and various patient and hospital factors. In total, 4996 units of RBC were transfused to 1054 patients with hematological diseases in 2421 transfusions. Median age was 68 years. Myelodysplastic syndrome was the most frequent diagnosis. Overall median Hb threshold level was 6.9 g/dL. Multivariate linear regression analysis detected the following variables associated with Hb threshold level: hospital; cardiovascular disease; symptomatic anemia; and hematopoietic stem cell transplantation. Hospital was the most significant factor. Collectively, median Hb threshold level in clinical practice in Japan was similar to the guidelines. Higher Hb threshold level depended on the hospitals at which the transfusions were performed as well as patient condition. Educational approaches directed toward hospitals may be useful to promote transfusion guidelines.

Restrictive versus liberal transfusion strategies in patients with malignant neoplasm -a meta-analysis of randomized controlled trials

BACKGROUND

Transfusion strategies are involving the survival and prognosis of patients with malignant neoplasm and the rational utilization of medical resources, but there are still controversy between different transfusion strategies. The aim of this article is to compare the benefit and harm of restrictive and liberal red blood cell(RBC) transfusion strategies in patients with malignant tumors.

METHODS

We searched articles in the databases of PubMed, Cochrane Library, Web of Science, Embase and major conference proceedings, identified all randomized controlled trials (RCTs) and compared restrictive transfusion strategies with those that are liberal until MARCH 18, 2019. We used risk ratio (RR) and and 95 % confidence interval (95 %CI) to calculate the results of dichotomous variables, and the study heterogeneity was assessed by using the I² statistics. Also, we did sensitivity analysis and quality assessment.

RESULTS

Restrictive transfusion policies appear to have no effect on all-cause mortality (RR 1.33; 95 % CI 0.74-2.38; P = 0.34), compared with liberal policies. 2 trials including 498 patients were included of renal replacement therapy (RR 1.38; 95 % CI, 0.73-2.59; P = 0.32; I² = 0%). Myocardial infarction (RR 1.17; 95 % CI, 0.33-4.1; P = 0.81; I² = 0%) and ICU readmission were also mentioned in these articles (RR 1.19; 95 % CI, 0.7-2.04; P = 0.52; I² = 0%). However, the RR of hospital length can't be evaluated.

CONCLUSION

Restrictive transfusion strategies were not associated with all-cause mortality and other clinical outcomes in malignant tumors, and may be more suitable for patients' quality of life and medical economy than liberal.

RBC Transfusion Strategies in the ICU: A Concise Review

OBJECTIVES

To critically assess available high-level clinical studies regarding RBC transfusion strategies, with a focus on hemoglobin transfusion thresholds in the ICU.

DATA SOURCES

Source data were obtained from a PubMed literature review.

STUDY SELECTION

English language studies addressing RBC transfusions in the ICU with a focus on the most recent relevant studies.

DATA EXTRACTION

Relevant studies were reviewed and the following aspects of each study were identified, abstracted, and analyzed: study design, methods, results, and implications for critical care practice.

DATA SYNTHESIS

Approximately 30-50% of ICU patients receive a transfusion during their hospitalization with anemia being the indication for 75% of transfusions. A significant body of clinical research evidence supports using a restrictive transfusion strategy (e.g., hemoglobin threshold < 7 g/dL) compared with a more liberal approach (e.g., hemoglobin threshold < 10 g/dL). A restrictive strategy (hemoglobin < 7 g/dL) is recommended in patients with sepsis and gastrointestinal bleeds. A slightly higher restrictive threshold is recommended in cardiac surgery (hemoglobin < 7.5 g/dL) and stable cardiovascular disease (hemoglobin < 8 g/dL). Although restrictive strategies are generally supported in hematologic malignancies, acute neurologic injury, and burns, more definitive studies are needed, including acute coronary syndrome. Massive transfusion protocols are the mainstay of treatment for hemorrhagic shock; however, the exact RBC to fresh frozen plasma ratio is still unclear. There are also emerging complimentary practices including nontransfusion strategies to avoid and treat anemia and the reemergence of whole blood transfusion.

CONCLUSIONS

The current literature supports the use of restrictive transfusion strategies in the majority of critically ill populations. Continued studies of optimal transfusion strategies in various patient populations, coupled with the integration of novel complementary ICU practices, will continue to enhance our ability to treat critically ill patients.

Reducing the red blood cell transfusion threshold from 8·0 g/dl to 7·0 g/dl in acute myeloid leukaemia patients undergoing induction chemotherapy reduces transfusion rates without adversely affecting patient outcome

BACKGROUND AND OBJECTIVES

Red blood cell (RBC) transfusions are needed by almost every acute myeloid leukaemia (AML) patient undergoing induction chemotherapy and constitute a cornerstone in supportive measures for cancer patients in general. Randomized controlled trials have shown non-inferiority or even superiority of restrictive transfusion guidelines over liberal transfusion guidelines in specific clinical situations outside of medical oncology. In this study, we analysed whether more restrictive RBC transfusion reduces blood use without affecting hard outcomes.

MATERIALS AND METHODS

A total of 352 AML patients diagnosed between 2007 and 2018 and undergoing intensive induction chemotherapy were included in this retrospective analysis. In the less restrictive transfusion group, patients received RBC transfusion for haemoglobin levels below 8 g/dl (2007-2014). In the restrictive transfusion group, patients received RBC transfusion for haemoglobin levels below 7 g/dl (2016-2018). Liberal transfusion triggers were never endorsed.

RESULTS

A total of 268 (76·1%) and 84 (23·9%) AML patients fell into the less restrictive and restrictive transfusion groups, respectively. The less restrictive transfusion group had 1 g/dl higher mean haemoglobin levels, received their first RBC transfusions earlier and needed 1·5 more units of RBC during the hospital stay of induction chemotherapy. Febrile episodes, C-reactive protein levels, admission to the intensive care unit, length of hospital stay as well as response and survival rates did not differ between the two cohorts.

CONCLUSION

From our retrospective analysis, we conclude that a more restrictive transfusion trigger does not affect important outcomes of AML patients. The opportunity to test possible effects of the more severe anaemia in the restrictive transfusion group on quality of life was missed.

Transfusion strategies in non-bleeding critically ill adults: a clinical practice guideline from the European Society of Intensive Care Medicine

OBJECTIVE

To develop evidence-based clinical practice recommendations regarding transfusion practices in non-bleeding, critically ill adults.

DESIGN

A task force involving 13 international experts and three methodologists used the GRADE approach for guideline development.

METHODS

The task force identified four main topics: red blood cell transfusion thresholds, red blood cell transfusion avoidance strategies, platelet transfusion, and plasma transfusion. The panel developed structured guideline questions using population, intervention, comparison, and outcomes (PICO) format.

RESULTS

The task force generated 16 clinical practice recommendations (3 strong recommendations, 13 conditional recommendations), and identified five PICOs with insufficient evidence to make any recommendation.

CONCLUSIONS

This clinical practice guideline provides evidence-based recommendations and identifies areas where further research is needed regarding transfusion practices and transfusion avoidance in non-bleeding, critically ill adults.

Liberal Versus Restrictive Red Blood Cell Transfusion Thresholds in Hematopoietic Cell Transplantation: A Randomized, Open Label, Phase III, Noninferiority Trial

PURPOSE

Evidence regarding red blood cell (RBC) transfusion practices and their impact on hematopoietic cell transplantation (HCT) outcomes are poorly understood.

PATIENTS AND METHODS

We performed a noninferiority randomized controlled trial in four different centers that evaluated patients with hematologic malignancies requiring HCT who were randomly assigned to either a restrictive (hemoglobin [Hb] threshold < 70 g/L) or liberal (Hb threshold < 90 g/L) RBC transfusion strategy between day 0 and day 100. The noninferiority margin corresponds to a 12% absolute difference between groups in Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) score relative to baseline. The primary outcome was health-related quality of life (HRQOL) measured by FACT-BMT score at day 100. Additional end points were collected: HRQOL by FACT-BMT score at baseline and at days 7, 14, 28, 60, and 100; transplantation-related mortality; length of hospital stay; intensive care unit admissions; acute graft-versus-host disease; Bearman toxicity score; sinusoidal obstruction syndrome; serious infections; WHO Bleeding Scale; transfusion requirements; and reactions to therapy.

RESULTS

A total of 300 patients were randomly assigned to either restrictive-strategy or liberal-strategy treatment groups between 2011 and 2016 at four Canadian adult HCT centers. After HCT, mean pre-transfusion Hb levels were 70.9 g/L in the restrictive-strategy group and 84.6 g/L in the liberal-strategy group (P < .0001). The number of RBC units transfused was lower in the restrictive-strategy group than in the liberal-strategy group (mean, 2.73 units [standard deviation, 4.81 units] v 5.02 units [standard deviation, 6.13 units]; P = .0004). After adjusting for transfusion type and baseline FACT-BMT score, the restrictive-strategy group had a higher FACT-BMT score at day 100 (difference of 1.6 points; 95% CI, -2.5 to 5.6 points), which was noninferior compared with that of the liberal-strategy group. There were no significant differences in clinical outcomes between the transfusion strategies.

CONCLUSION

In patients undergoing HCT, the use of a restrictive RBC transfusion strategy threshold of 70 g/L was as effective as a threshold of 90 g/L and resulted in similar HRQOL and HCT outcomes with fewer transfusions.

Audit of red blood cell transfusion in patients with acute leukemia at a tertiary care university hospital

BACKGROUND

Red blood cell (RBC) transfusion support is essential in patients with acute leukemia (AL). A restrictive RBC transfusion approach is assumed to be safe for most individuals with AL. The aim of this audit was to assess RBC transfusion appropriateness in AL patients at an academic center.

STUDY DESIGN AND METHODS

RBC transfusions in acute lymphoblastic leukemia and acute myeloid leukemia patients of all ages between January 1, 2013, and March 31, 2019, were analyzed for adherence to evidence-based criteria. Transfusion appropriateness was compared among ordering specialties, patient locations, and hematologic diagnoses. Pretransfusion hemoglobin was compared between categories. Overtransfusion rates were also analyzed. Descriptive statistics and categorical and numerical tests were employed to determine statistical significance.

RESULTS

A total of 510 RBC transfusions were received by 133 AL patients in the departments of internal medicine, hematology, and pediatrics. Overall, 84.5% were appropriate according to established criteria. Internal medicine was the ordering department with the highest rate of appropriateness (88.1%). The outpatient clinic was the location with the highest adherence (85.9%), whereas the intensive care unit had the lowest (70%; p = 0.03). The reasons for most appropriate and inappropriate transfusions were asymptomatic anemia with a hemoglobin below (60.6%) or above (69.6%) 7 g/dL in patients without cardiac disease, respectively. Overtransfusion was present in 22% of episodes.

CONCLUSION

RBC transfusion in AL patients reflected good adherence to guidelines. However, continuing education in transfusion medicine and prospective chart auditing are needed to improve adherence to established guidelines.

Treatment of acute leukaemia in adult Jehovah's Witnesses

Since Jehovah's Witness (JW) patients diagnosed with leukaemia refuse blood transfusions, they are often denied intensive chemotherapy for fear they could not survive myeloablation without blood transfusion support. Treatment of JW patients with acute leukaemia is challenging and carries a higher morbidity and mortality; however, the refusal of blood products should not be an absolute contraindication to offer multiple treatment modalities including haematopoietic stem cell transplantation. In this review we discuss their optimal management and describe alternative modalities to blood transfusions to provide sufficient oxygenation and prevent bleeding.

The impact of recipient factors on the lower-than-expected hemoglobin increment in transfused outpatients with hematologic diseases

BACKGROUND

Patients with cancer or chronic hematologic disorders frequently receive red blood cell (RBC) transfusions. Based on long-standing assumptions, each RBC unit is thought to increase recipient hemoglobin by 1 g/dL, but smaller increments can occur. A better understanding of recipient factors affecting hemoglobin increments could help providers manage these patients.

METHODS

Data were collected as a part of the observational Red Cells in Outpatients Transfusion Outcomes (RETRO) study of outpatients with hematologic or cancer-related diagnoses. Hemoglobin was measured before transfusion and 30 minutes after transfusion. A classification and regression tree (CART) analysis was performed to identify statistically significant associations with clinical variables. A corresponding prediction equation was developed and validated using linear regression.

RESULTS

A total of 195 participants had both pre- and posttransfusion hemoglobin values for analysis. The median age was 66 years, and patients received one (73%) or two (27%) RBC units during the transfusion episode. The overall median change in hemoglobin was 0.6 g/dL per RBC unit. Both CART analysis and linear regression identified the following significant predictors of hemoglobin increment: number of units received (positive correlation), patient estimated circulating blood volume (negative correlation), pretransfusion hemoglobin (negative correlation), and patient age (negative correlation).

CONCLUSION

In this study of outpatients with hematologic disease, most patients had a hemoglobin increment of less than 1 g/dL/unit. Recipient-specific factors influenced the hemoglobin increment at 30 minutes, and providers should consider circulating blood volume, pretransfusion hemoglobin, and recipient age, when developing patient-specific RBC transfusion plans for this unique cohort.

Therapeutic impact of red blood cell transfusion on anemic outpatients: the RETRO study

BACKGROUND

Patients with cancer or other diagnoses associated with chronic anemia often receive red blood cell (RBC) transfusion as outpatients, but the effect of transfusion on functional status is not well demonstrated.

STUDY DESIGN AND METHODS

To estimate the effect of transfusion on functional status and quality of life, we measured 6-minute walk test distance and fatigue- and dyspnea-related quality-of-life scores before and 1 week after RBC transfusion in 208 outpatients age ≥50 with at least one benign or malignant hematology/oncology diagnosis. To account for potential confounding effects of cancer treatment, patients were classified into two groups based on cancer treatment within 4 weeks of the study transfusion. Minimum clinically important improvements over baseline were 20 meters in walk test distance, 3 points in fatigue score, and 2 points in dyspnea score.

RESULTS

The median improvement in unadjusted walk test distance was 20 meters overall and 30 meters in patients not receiving recent cancer treatment. Fatigue scores improved overall by a median of 3 points and by 4 points in patients without cancer treatment. There was no clinically important change in dyspnea scores. In multiple linear regression analysis, patients who maintained hemoglobin (Hb) levels of 8 g/dL or greater at 1 week posttransfusion, who had not received recent cancer treatment, and who did not require hospitalization during the study showed clinically important increases in mean walk test distance.

CONCLUSIONS

Red blood cell transfusion is associated with a modest, but clinically important improvement in walk test distance and fatigue score outcomes in adult hematology/oncology outpatients.

Single versus double-unit transfusion: Safety and efficacy for patients with hematologic malignancies

OBJECTIVES

Although hemoglobin thresholds for red blood cell (RBC) transfusion have decreased, double-unit RBC transfusion practices persist. We studied the effects switching from predominantly double-unit to single-unit RBC transfusions had on utilization and clinical outcomes for malignant hematology patients.

METHODS

Retrospective chart review compared malignant hematology patients before and after implementing single-unit RBC transfusion policy. Hemoglobin threshold was 8.0 g/dL for both groups. RBC utilization metrics included number of RBC units transfused, RBC units transfused per admission, and number of transfusion episodes. Clinical outcomes included length of stay, 30-day mortality, and outpatient RBC transfusion 30-days post-discharge.

RESULTS

Baseline hemoglobin was similar in both groups. The single-unit group was transfused with fewer RBC units per admission (5.1 vs 4.5, P = 0.01) than the double-unit group, but had more transfusion episodes per admission (4.1 vs 2.7, P < 0.001). After implementing single-unit policy, a 29% reduction in RBC utilization was observed. Mean hemoglobin at discharge was lower in the single-unit group (8.9 vs 9.5 g/dL, P = 0.005). No significant differences in length of stay or 30-day mortality were observed.

CONCLUSION

Transfusing malignant hematology patients with single RBC units is safe and efficacious. Electronic provider order systems facilitating RBC transfusion requests provide excellent adherence to transfusion policy.

TACO and TRALI: biology, risk factors, and prevention strategies

Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion-related morbidity and mortality. These adverse events are characterized by acute pulmonary edema within 6 hours of a blood transfusion and have historically been difficult to study due to underrecognition and nonspecific diagnostic criteria. However, in the past decade, in vivo models and clinical studies utilizing active surveillance have advanced our understanding of their epidemiology and pathogenesis. With the adoption of mitigation strategies and patient blood management, the incidence of TRALI and TACO has decreased. Continued research to prevent and treat these severe cardiopulmonary events is focused on both the blood component and the transfusion recipient.

Shifting ground and gaps in transfusion support of patients with hematological malignancies

The transfusion support of hematological malignancies considers 2 dimensions: the quantity of what we order (in terms of triggers, doses, targets, and intervals), and the special qualities thereof (with respect to depths of matching and appropriate product modifications). Meanwhile, transfusion-related enhancements in the quantity and quality of life may not be dose dependent but rather tempered by unintended patient harms and system strains from overexposure. Evidence and guidelines concur in endorsing clinically noninferior conservative red blood cell (RBC) transfusion care strategies (eg, triggering at hemoglobin <7-8 g/dL and in single-unit doses for stable, nonbleeding inpatients). However, the unique subpopulation of patients with hematological malignancies who are increasingly managed on an outpatient basis, and striving at least as much for quality of life as quantity of life, is left on the edges of these recommendations, with more questions than answers. If a sufficiently specific future wave of evidence can satisfy the concerns (and contest the assumptions) of the remaining proponents of liberalism, and if conservatism is broadly adopted, savings may be potentially immense. These savings can then be reinvested to address other gaps and inconsistencies in RBC transfusion care, such as the best achievable degrees of prophylactic antigen matching that can minimize alloimmunization-related service delays and reactions.

Red blood cell transfusion policy: a critical literature review

The issue of the most appropriate red blood cell transfusion policy has been addressed by a number of randomised controlled trials, conducted over the last decades, comparing the effects on patients' outcome of restrictive blood transfusion strategies (transfusing when the haemoglobin concentration is less than 7 g/dL to 8 g/dL) vs more liberal ones (transfusing when the haemoglobin concentration is less than 9 g/dL to 10 g/dL) in a variety of clinical settings. In parallel, various systematic reviews and meta-analyses have tried to perform pooled analyses of the data from these randomised controlled trials and their results have been utilised by scientific societies to provide recommendations and guidelines on red blood cell transfusion thresholds. All these aspects will be critically discussed in this narrative review.

Clinical trials evaluating red blood cell transfusion thresholds: An updated systematic review and with additional focus on patients with cardiovascular disease

BACKGROUND

Several new trials evaluating transfusion strategies in patients with cardiovascular disease have recently been published, increasing the number of enrolled patients by over 30%. The objective was to evaluate transfusion thresholds in patients with cardiovascular disease.

METHODS

We conducted an updated systematic review of randomized trials that compared patients assigned to maintain a lower (restrictive transfusion strategy) or higher (liberal transfusion strategy) hemoglobin concentration. We focused on new trial data in patients with cardiovascular disease. The primary outcome was 30-day mortality. Specific subgroups were patients undergoing cardiac surgery and with acute myocardial infarction.

RESULTS

A total of 37 trials that enrolled 19,049 patients were appraised. In cardiac surgery, mortality at 30days was comparable between groups (risk ratio 0.99; 95% confidence interval 0.74-1.33). In 2 small trials (n=154) in patients with myocardial infarction, the point estimate for the mortality risk ratio was 3.88 (95% CI, 0.83-18.13) favoring the liberal strategy. Overall, from 26 trials enrolling 15,681 patients, 30-day mortality was not different between restrictive and liberal transfusion strategies (risk ratio 1.0, 95% CI, 0.86-1.16). Overall and in the cardiovascular disease subgroup, there were no significant differences observed across a range of secondary outcomes.

CONCLUSIONS

New trials in patients undergoing cardiac surgery establish that a restrictive transfusion strategy of 7 to 8g/dL is safe and decreased red cell use by 24%. Further research is needed to define the optimal transfusion threshold in patients with acute myocardial infarction.

Blood use in hematologic malignancies: a nationwide overview in Sweden between 2000 and 2010

BACKGROUND

Patients with hematologic malignancies receive large numbers of blood transfusions, and transfusion practices for this patient group are increasingly being scrutinized by randomized controlled trials. However, no studies so far have presented current transfusion statistics on a population level for this patient group.

STUDY DESIGN AND METHODS

A retrospective descriptive study was conducted that was based on the Scandinavian Donations and Transfusions Database (SCANDAT2), which includes data on all blood donations and transfusions in Sweden and Denmark since the 1960s. Incident cases of hematologic malignancies were identified in the Swedish Cancer Register between 2000 and 2010. Cases were divided into nine patient groups based on diagnosis.

RESULTS

A total of 28,693 patients were included in the cohort. Overall, the transfusion pattern varied depending on diagnosis and age. Patients with aggressive and acute diagnoses generally received more transfusions with immediate decline in transfusion incidence after diagnosis, whereas chronic diagnoses generally maintained more stable, but lower, transfusion incidence. In general, patients with leukemia received more transfusions than patients with lymphoma, and patients with acute leukemia as well as patients that had undergone allogeneic stem cell transplantations received the most transfusions. Within 2 years after diagnosis, patients with acute myeloid leukemia diagnosed at ages 0 to 65 years received on average between 30 to 40 red blood cell transfusions and platelet transfusions, respectively, corresponding to direct material costs close to 200,000 SEK (23,809 USD).

CONCLUSION

Results from this population-based overview of blood use in hematologic malignancies showed high variability depending on diagnosis and age.

Position paper on management of iron deficiency in adult cancer patients

INTRODUCTION

Disorders of iron metabolism are commonly seen in onco-hematological clinical practice. Iron-deficiency anemia and cancer-associated anemia are usually treated with supportive therapies. Optimal management of these conditions are discussed in this perspective paper. Areas covered: A position paper discussing a number of hot topics on anemia in cancer patients is presented. The main areas covered by experts in the field are: definitions, prevalence and consequences of anemia and iron deficiency, incidence of anemia resulting from targeted therapies, importance of anemia diagnosis and monitoring, evaluation of iron status before and during treatment, role of transfusions and erythropoiesis-stimulating agents, management of iron deficiency with or without anemia, parenteral iron supplementation, role of new oral iron formulations, safety and cost issues regarding different iron compounds and administration routes. Expert commentary: Despite the availability of newer therapeutic options for its management, anemia still represents a major complication of treatment in cancer patients (surgery, chemotherapy, radiotherapy, targeted therapies), aggravating physical impairment, and negatively affecting general outcome. The view expressed by the panelists, attendees of the 4th Mediterranean Course on Iron Anemia, summarizes what they consider optimal clinical practice for screening, diagnosis, treatment and monitoring of iron deficiency and anemia in cancer patients.

Impact of red blood cell transfusion strategies in haemato-oncological patients: a systematic review and meta-analysis

Haemato-oncological patients receive many red blood cell (RBC) transfusions, however evidence-based guidelines are lacking. Our aim is to quantify the effect of restrictive and liberal RBC transfusion strategies on clinical outcomes and blood use in haemato-oncological patients. A literature search, last updated on 11 August 2016, was performed in PubMed, EMBASE (Excerpta Medica Database), Web of Science, Cochrane, CINAHL (Cumulative Index to Nursing and Allied Health Literature) and Academic Search Premier without restrictions on language and year of publication. Randomized controlled trials and observational studies that compared different RBC transfusion strategies in haemato-oncological patients were eligible for inclusion. Risk of bias assessment according to the Cochrane collaboration's tool and Newcastle-Ottawa scale was performed. After removing duplicates, 1142 publications were identified. Eventually, 15 studies were included, reporting on 2636 patients. The pooled relative risk for mortality was 0·68 [95% confidence interval (CI) 0·46-1·01] in favour of the restrictive strategy. The mean RBC use was reduced with 1·40 units (95% CI 0·70-2·09) per transfused patient per therapy cycle in the restrictive strategy group. There were no differences in safety outcomes. All currently available evidence suggests that restrictive strategies do not have a negative impact regarding clinical outcomes in haemato-oncological patients, while it reduces RBC use and associated costs.

Restrictive versus liberal red blood cell transfusion strategies for people with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without haematopoietic stem cell support

BACKGROUND

Many people diagnosed with haematological malignancies experience anaemia, and red blood cell (RBC) transfusion plays an essential supportive role in their management. Different strategies have been developed for RBC transfusions. A restrictive transfusion strategy seeks to maintain a lower haemoglobin level (usually between 70 g/L to 90 g/L) with a trigger for transfusion when the haemoglobin drops below 70 g/L), whereas a liberal transfusion strategy aims to maintain a higher haemoglobin (usually between 100 g/L to 120 g/L, with a threshold for transfusion when haemoglobin drops below 100 g/L). In people undergoing surgery or who have been admitted to intensive care a restrictive transfusion strategy has been shown to be safe and in some cases safer than a liberal transfusion strategy. However, it is not known whether it is safe in people with haematological malignancies.

OBJECTIVES

To determine the efficacy and safety of restrictive versus liberal RBC transfusion strategies for people diagnosed with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without a haematopoietic stem cell transplant (HSCT).

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and non-randomised trials (NRS) in MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1982), Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 6), and 10 other databases (including four trial registries) to 15 June 2016. We also searched grey literature and contacted experts in transfusion for additional trials. There was no restriction on language, date or publication status.

SELECTION CRITERIA

We included RCTs and prospective NRS that evaluated a restrictive compared with a liberal RBC transfusion strategy in children or adults with malignant haematological disorders or undergoing HSCT.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified six studies eligible for inclusion in this review; five RCTs and one NRS. Three completed RCTs (156 participants), one completed NRS (84 participants), and two ongoing RCTs. We identified one additional RCT awaiting classification. The completed studies were conducted between 1997 and 2015 and had a mean follow-up from 31 days to 2 years. One study included children receiving a HSCT (six participants), the other three studies only included adults: 218 participants with acute leukaemia receiving chemotherapy, and 16 with a haematological malignancy receiving a HSCT. The restrictive strategies varied from 70 g/L to 90 g/L. The liberal strategies also varied from 80 g/L to 120 g/L.Based on the GRADE rating methodology the overall quality of the included studies was very low to low across different outcomes. None of the included studies were free from bias for all 'Risk of bias' domains. One of the three RCTs was discontinued early for safety concerns after recruiting only six children, all three participants in the liberal group developed veno-occlusive disease (VOD). Evidence from RCTsA restrictive RBC transfusion policy may make little or no difference to: the number of participants who died within 100 days (two trials, 95 participants (RR: 0.25, 95% CI 0.02 to 2.69, low-quality evidence); the number of participants who experienced any bleeding (two studies, 149 participants; RR:0.93, 95% CI 0.73 to 1.18, low-quality evidence), or clinically significant bleeding (two studies, 149 participants, RR: 1.03, 95% CI 0.75 to 1.43, low-quality evidence); the number of participants who required RBC transfusions (three trials; 155 participants: RR: 0.97, 95% CI 0.90 to 1.05, low-quality evidence); or the length of hospital stay (restrictive median 35.5 days (interquartile range (IQR): 31.2 to 43.8); liberal 36 days (IQR: 29.2 to 44), low-quality evidence).We are uncertain whether the restrictive RBC transfusion strategy: decreases quality of life (one trial, 89 participants, fatigue score: restrictive median 4.8 (IQR 4 to 5.2); liberal median 4.5 (IQR 3.6 to 5) (very low-quality evidence); or reduces the risk of developing any serious infection (one study, 89 participants, RR: 1.23, 95% CI 0.74 to 2.04, very low-quality evidence).A restrictive RBC transfusion policy may reduce the number of RBC transfusions per participant (two trials; 95 participants; mean difference (MD) -3.58, 95% CI -5.66 to -1.49, low-quality evidence). Evidence from NRSWe are uncertain whether the restrictive RBC transfusion strategy: reduces the risk of death within 100 days (one study, 84 participants, restrictive 1 death; liberal 1 death; very low-quality evidence); decreases the risk of clinically significant bleeding (one study, 84 participants, restrictive 3; liberal 8; very low-quality evidence); or decreases the number of RBC transfusions (adjusted for age, sex and acute myeloid leukaemia type geometric mean 1.25; 95% CI 1.07 to 1.47 - data analysis performed by the study authors)No NRS were found that looked at: quality of life; number of participants with any bleeding; serious infection; or length of hospital stay.No studies were found that looked at: adverse transfusion reactions; arterial or venous thromboembolic events; length of intensive care admission; or readmission to hospital.

AUTHORS' CONCLUSIONS

Findings from this review were based on four studies and 240 participants.There is low-quality evidence that a restrictive RBC transfusion policy reduces the number of RBC transfusions per participant. There is low-quality evidence that a restrictive RBC transfusion policy has little or no effect on: mortality at 30 to 100 days, bleeding, or hospital stay. This evidence is mainly based on adults with acute leukaemia who are having chemotherapy. Although, the two ongoing studies (530 participants) are due to be completed by January 2018 and will provide additional information for adults with haematological malignancies, we will not be able to answer this review's primary outcome. If we assume a mortality rate of 3% within 100 days we would need 1492 participants to have a 80% chance of detecting, as significant at the 5% level, an increase in all-cause mortality from 3% to 6%. Further RCTs are required in children.

Wide variations in blood product transfusion practices among providers who care for patients with acute leukemia in the United States

BACKGROUND

Transfusion of blood products is a key component of the supportive management in patients with acute leukemia (AL). However high-quality trial evidence and clinical outcome data to support specific transfusion goals for blood products for patients with AL remain limited leading to diverse transfusion practices. The primary objective of this study was to determine the spectrum of transfusion patterns in a variety of care settings among providers who treat AL patients.

STUDY DESIGN AND METHODS

A 31-question survey queried providers caring for AL patients about the existence of institutional guidelines for transfusion of blood products, transfusion triggers for hemoglobin (Hb), platelets (PLTs), and fibrinogen in various settings including inpatient and outpatient and before procedures.

RESULTS

We analyzed 130 responses and identified divergent transfusion Hb goals in hospitalized and ambulatory patients, fibrinogen goals for cryoprecipitate transfusions, and variation in practice for use of certain PLTs and red blood cell products. The least variable transfusion patterns were reported for PLT goals in thrombocytopenia and in the setting of invasive procedures such as bone marrow biopsy and lumbar punctures.

CONCLUSIONS

This survey confirmed wide variations in blood product transfusion practices across several clinical scenarios in patients with AL. The findings emphasized the need for large prospective randomized trials to develop standardized evidence-based guidelines for blood product transfusions in patients with AL with the goal of limiting unnecessary transfusions without compromising outcomes.

Transfusion thresholds and other strategies for guiding allogeneic red blood cell transfusion

BACKGROUND

There is considerable uncertainty regarding the optimal haemoglobin threshold for the use of red blood cell (RBC) transfusions in anaemic patients. Blood is a scarce resource, and in some countries, transfusions are less safe than others because of a lack of testing for viral pathogens. Therefore, reducing the number and volume of transfusions would benefit patients.

OBJECTIVES

The aim of this review was to compare 30-day mortality and other clinical outcomes in participants randomized to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all conditions. The restrictive transfusion threshold uses a lower haemoglobin level to trigger transfusion (most commonly 7 g/dL or 8 g/dL), and the liberal transfusion threshold uses a higher haemoglobin level to trigger transfusion (most commonly 9 g/dL to 10 g/dL).

SEARCH METHODS

We identified trials by searching CENTRAL (2016, Issue 4), MEDLINE (1946 to May 2016), Embase (1974 to May 2016), the Transfusion Evidence Library (1950 to May 2016), the Web of Science Conference Proceedings Citation Index (1990 to May 2016), and ongoing trial registries (27 May 2016). We also checked reference lists of other published reviews and relevant papers to identify any additional trials.

SELECTION CRITERIA

We included randomized trials where intervention groups were assigned on the basis of a clear transfusion 'trigger', described as a haemoglobin (Hb) or haematocrit (Hct) level below which a red blood cell (RBC) transfusion was to be administered.

DATA COLLECTION AND ANALYSIS

We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two people extracted the data and assessed the risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as 'restrictive transfusion' and to the higher transfusion threshold as 'liberal transfusion'.

MAIN RESULTS

A total of 31 trials, involving 12,587 participants, across a range of clinical specialities (e.g. surgery, critical care) met the eligibility criteria. The trial interventions were split fairly equally with regard to the haemoglobin concentration used to define the restrictive transfusion group. About half of them used a 7 g/dL threshold, and the other half used a restrictive transfusion threshold of 8 g/dL to 9 g/dL. The trials were generally at low risk of bias .Some items of methodological quality were unclear, including definitions and blinding for secondary outcomes.Restrictive transfusion strategies reduced the risk of receiving a RBC transfusion by 43% across a broad range of clinical specialties (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.49 to 0.65; 12,587 participants, 31 trials; high-quality evidence), with a large amount of heterogeneity between trials (I² = 97%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.97, 95% CI 0.81 to 1.16, I² = 37%; N = 10,537; 23 trials; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (high-quality evidence)). Liberal transfusion did not affect the risk of infection (pneumonia, wound, or bacteraemia).

AUTHORS' CONCLUSIONS

Transfusing at a restrictive haemoglobin concentration of between 7 g/dL to 8 g/dL decreased the proportion of participants exposed to RBC transfusion by 43% across a broad range of clinical specialities. There was no evidence that a restrictive transfusion strategy impacts 30-day mortality or morbidity (i.e. mortality at other points, cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. There were insufficient data to inform the safety of transfusion policies in certain clinical subgroups, including acute coronary syndrome, myocardial infarction, neurological injury/traumatic brain injury, acute neurological disorders, stroke, thrombocytopenia, cancer, haematological malignancies, and bone marrow failure. The findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds above 7 g/dL to 8 g/dL.