-
1.
Transfusion thresholds for guiding red blood cell transfusion
Carson JL, Stanworth SJ, Dennis JA, Trivella M, Roubinian N, Fergusson DA, Triulzi D, Dorée C, Hébert PC
The Cochrane database of systematic reviews. 2021;12:Cd002042
-
-
-
Free full text
-
Full text
-
Editor's Choice
Abstract
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.
PICO Summary
Population
Adults and children across a range of clinical contexts including surgery (48 studies, n= 21,433).
Intervention
Restrictive red blood cell (RBC) transfusion threshold strategy.
Comparison
Liberal RBC transfusion threshold strategy.
Outcome
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 showed that the liberal transfusion threshold did not affect the risk of infection (pneumonia, wound infection, or bacteraemia). Transfusion-specific reactions were uncommon and were inconsistently reported within trials.
-
2.
Association between leukoreduced red blood cell transfusions and hospital-acquired infections in critically ill children: A secondary analysis of the TRIPICU study
Flatman LK, Fergusson DA, Lacroix J, Ducruet T, Papenburg J, Fontela PS
Vox sanguinis. 2021
Abstract
BACKGROUND AND OBJECTIVES Hospital-acquired infections (HAIs) are an important problem in critically ill children. Studies show associations between the transfusion of non-leukoreduced red blood cell units (RBC) and increased HAI incidence rates (IRs). We hypothesize that transfusing pre-storage leukoreduced RBC is also associated with increased HAI IR. We aim to evaluate the associations between (1) a leukoreduced RBC restrictive transfusion strategy and HAI IR, (2) leukoreduced RBC transfusions and HAI IR, and (3) the number or volume of leukoreduced RBC transfusions and HAI IR in critically ill children. MATERIALS AND METHODS This post hoc secondary analysis of the "Transfusion Requirement in Paediatric Intensive Care Units" (TRIPICU) randomized controlled trial (637 patients) used quasi-Poisson multivariable regression models to estimate HAI incidence rate ratios (IRRs) and 95% confidence intervals (CI). RESULTS A restrictive transfusion strategy yielded an IRR of 0.88 (95% CI 0.67, 1.16). The association between transfusing leukoreduced RBCs (IRR 1.25; 95% CI 0.73, 2.13) and HAI IR was not statistically significant. However, we observed significant associations between patients who received >20 cc/kg volume of leukoreduced RBC transfusions (IRR 2.14; 95% CI 1.15, 3.99) and ≥3 leukoreduced RBC transfusions (IRR 2.40; 95% CI 1.15, 4.99) and HAI IR. CONCLUSION Exposing critically ill children to >20 cc/kg or ≥3 leukoreduced RBC transfusions were associated with higher HAI IR, suggesting dose-response patterns.
-
3.
Effect of Fresh vs Standard-issue Red Blood Cell Transfusions on Multiple Organ Dysfunction Syndrome in Critically Ill Pediatric Patients: A Randomized Clinical Trial
Spinella PC, Tucci M, Fergusson DA, Lacroix J, Hebert PC, Leteurtre S, Schechtman KB, Doctor A, Berg RA, Bockelmann T, et al
Jama. 2019;322(22):2179-2190
-
-
-
Free full text
-
-
Editor's Choice
Abstract
Importance: The clinical consequences of red blood cell storage age for critically ill pediatric patients have not been examined in a large, randomized clinical trial. Objective: To determine if the transfusion of fresh red blood cells (stored ≤7 days) reduced new or progressive multiple organ dysfunction syndrome compared with the use of standard-issue red blood cells in critically ill children. Design, Setting, and Participants: The Age of Transfused Blood in Critically-Ill Children trial was an international, multicenter, blinded, randomized clinical trial, performed between February 2014 and November 2018 in 50 tertiary care centers. Pediatric patients between the ages of 3 days and 16 years were eligible if the first red blood cell transfusion was administered within 7 days of intensive care unit admission. A total of 15568 patients were screened, and 13308 were excluded. Interventions: Patients were randomized to receive either fresh or standard-issue red blood cells. A total of 1538 patients were randomized with 768 patients in the fresh red blood cell group and 770 in the standard-issue group. Main Outcomes and Measures: The primary outcome measure was new or progressive multiple organ dysfunction syndrome, measured for 28 days or to discharge or death. Results: Among 1538 patients who were randomized, 1461 patients (95%) were included in the primary analysis (median age, 1.8 years; 47.3% girls), in which there were 728 patients randomized to the fresh red blood cell group and 733 to the standard-issue group. The median storage duration was 5 days (interquartile range [IQR], 4-6 days) in the fresh group vs 18 days (IQR, 12-25 days) in the standard-issue group (P < .001). There were no significant differences in new or progressive multiple organ dysfunction syndrome between fresh (147 of 728 [20.2%]) and standard-issue red blood cell groups (133 of 732 [18.2%]), with an unadjusted absolute risk difference of 2.0% (95% CI, -2.0% to 6.1%; P = .33). The prevalence of sepsis was 25.8% (160 of 619) in the fresh group and 25.3% (154 of 608) in the standard-issue group. The prevalence of acute respiratory distress syndrome was 6.6% (41 of 619) in the fresh group and 4.8% (29 of 608) in the standard-issue group. Intensive care unit mortality was 4.5% (33 of 728) in the fresh group vs 3.5 % (26 of 732) in the standard-issue group (P = .34). Conclusions and Relevance: Among critically ill pediatric patients, the use of fresh red blood cells did not reduce the incidence of new or progressive multiple organ dysfunction syndrome (including mortality) compared with standard-issue red blood cells. Trial Registration: ClinicalTrials.gov Identifier: NCT01977547.
PICO Summary
Population
Critically ill paediatric patients between the ages of 3 days and 16 years, (n=1461).
Intervention
Red blood cells stored </=y days (Fresh red blood cell group, (n=728).
Comparison
Delivery of oldest compatible red cell units available (Standard-issue red blood cells, (n=733).
Outcome
There were no significant differences in new or progressive multiple organ dysfunction syndrome between fresh (147 of 728 [20.2%]) and standard-issue red blood cell groups (133 of 732 [18.2%]), with an unadjusted absolute risk difference of 2.0%; P = .33). The prevalence of sepsis was 25.8% (160 of 619) in the fresh group and 25.3% (154 of 608) in the standard-issue group. The prevalence of acute respiratory distress syndrome was 6.6% (41 of 619) in the fresh group and 4.8% (29 of 608) in the standard-issue group. Intensive care unit mortality was 4.5% (33 of 728) in the fresh group vs 3.5 % (26 of 732) in the standard-issue group.
-
4.
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
Estcourt LJ, Malouf R, Trivella M, Fergusson DA, Hopewell S, Murphy MF
The Cochrane Database of Systematic Reviews. 2017;((1)):CD011305.
-
-
-
Free full text
-
Full text
-
Editor's Choice
Abstract
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 m
PICO Summary
Population
Children or adults with malignant haematological disorders treated with intensive chemotherapy or radiotherapy, or both, with or without a haematopoietic stem cell transplant (6 studies).
Intervention
Restrictive red blood cell (RBC) transfusion strategy.
Comparison
Liberal RBC transfusion strategy.
Outcome
Evidence from randomised controlled trials showed that a restrictive RBC transfusion policy may make little or no difference to: the number of participants who died within 100 days (RR: 0.25); the number of participants who experienced any bleeding (RR: 0.93), or clinically significant bleeding (RR: 1.03); the number of participants who required RBC transfusions (RR: 0.97); or the length of hospital stay. It was uncertain whether the restrictive RBC transfusion strategy: decreases quality of life, or reduces the risk of developing any serious infection (RR: 1.23).
-
5.
Age of red blood cells in premature infants (ARIPI)
Fergusson DA, Hebert PC, LeBel L, Rouvinez-Bouali NG, Smyth JA, Sankaran K, Tinmouth AT, Blajchman MA, Kovacs L, Lachance C
Transfusion. 2012;52((S3)):11A-12A.. Abstract No. P3-030A.
-
6.
Effect of fresh red blood cell transfusions on clinical outcomes in premature, very low-birth-weight infants: the ARIPI randomized trial
Fergusson DA, Hébert P, Hogan DL, LeBel L, Rouvinez-Bouali N, Smyth JA, Sankaran K, Tinmouth A, Blajchman MA, Kovacs L, et al
JAMA: the Journal of the American Medical Association. 2012;308((14):):1443-51.
Abstract
CONTEXT Even though red blood cells (RBCs) are lifesaving in neonatal intensivecare, transfusing older RBCs may result in higher rates of organ dysfunction,nosocomial infection, and length of hospital stay. OBJECTIVE To determine if RBCs stored for 7 days or less compared with usual standards decreased rates ofmajor nosocomial infection and organ dysfunction in neonatal intensive care unitpatients requiring at least 1 RBC transfusion. DESIGN, SETTING, AND PARTICIPANTS Double-blind, randomized controlled trial in 377 premature infants with birthweights less than 1250 g admitted to 6 Canadian tertiary neonatal intensive careunits between May 2006 and June 2011. INTERVENTION Patients were randomlyassigned to receive transfusion of RBCs stored 7 days or less (n = 188) vsstandard-issue RBCs in accordance with standard blood bank practice (n = 189). MAIN OUTCOME MEASURES The primary outcome was a composite measure of majorneonatal morbidities, including necrotizing enterocolitis, retinopathy ofprematurity, bronchopulmonary dysplasia, and intraventricular hemorrhage, as wellas death. The primary outcome was measured within the entire period of neonatalintensive care unit stay up to 90 days after randomization. The rate ofnosocomial infection was a secondary outcome. RESULTS The mean age of transfusedblood was 5.1 (SD, 2.0) days in the fresh RBC group and 14.6 (SD, 8.3) days inthe standard group. Among neonates in the fresh RBC group, 99 (52.7%) had theprimary outcome compared with 100 (52.9%) in the standard RBC group (relativerisk, 1.00; 95% CI, 0.82-1.21). The rate of clinically suspected infection in thefresh RBC group was 77.7% (n = 146) compared with 77.2% (n = 146) in the standardRBC group (relative risk, 1.01; 95% CI, 0.90-1.12), and the rate of positivecultures was 67.5% (n = 127) in the fresh RBC group compared with 64.0% (n = 121)in the standard RBC group (relative risk, 1.06; 95% CI, 0.91-1.22). CONCLUSION In this trial, the use of fresh RBCs compared with standard blood bank practicedid not improve outcomes in premature, very low-birth-weight infants requiring atransfusion. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00326924;Current Controlled Trials Identifier: ISRCTN65939658.
-
7.
Avoiding transfusions in children undergoing cardiac surgery: a meta-analysis of randomized trials of aprotinin
Arnold DM, Fergusson DA, Chan AK, Cook RJ, Fraser GA, Lim W, Blajchman MA, Cook DJ
Anesthesia and Analgesia. 2006;102((3):):731-737.
-
8.
The use of aprotinin to reduce transfusion requirements in children undergoing cardiac surgery: a meta-analysis
Arnold DM, Fergusson DA, Chan AK, Cook RJ, Fraser GA, Lim W,, et al.,
Blood. 2004;104((11):):742a.. Abstract No. 2718.