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Evidence summaries

Transfusion Thresholds for Guiding Allogeneic Red Blood Cell Transfusion

Transfusions with allogeneic red blood cells in anaemic patients with haemoglobin thresholds above 7 g/dL to 8 g/dL is effective in decreasing the proportion of participants exposed to red blood cell transfusion by 41 % across a broad range of clinical specialities compared with a transfusion threshold of 9 g/dL to 10 g/dL, without affecting 30-day mortality or morbidity (i.e. cardiac events, stroke, infection, and thromboembolism). Level of evidence: "A"

Comment: There were insufficient data of the safety of transfusion in certain clinical subgroups, including acute myocardial infarction, chronic cardiovascular disease, neurological injury/traumatic brain injury, stroke, thrombocytopenia, cancer and haematological malignancies, including chronic bone marrow failure.

Summary

A Cochrane review [Abstract] 1 included 48 studies with a total of 21 433 subjects assessing the optimal haemoglobin threshold for the use of red blood cell (RBC) transfusions in anaemic patients (across a range of clinical specialities e.g. surgery, critical care). The restrictive transfusion threshold used 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). Restrictive strategies reduced the risk of receiving a RBC transfusion by 41 % across a broad range of clinical specialties (table T1). Overall, restrictive transfusion strategies compared with liberal transfusion strategies did not increase or decrease the risk of 30-day mortality or any of the other outcomes assessed (i.e. cardiac events, myocardial infarction, stroke, thromboembolism, pneumonia, wound infection, or bacteraemia) (table T1).

Restrictive compared with liberal transfusion protocols for guiding allogeneic red blood cell transfusion in anaemic adults and children

OutcomeRelative effect(95% CI)Assumed risk -Control - Liberal transfusion (Hb 9 g/dL to 10 g/dL)Corresponding risk - Intervention - Restrictive transfusion (Hb 7 g/dL to 8 g/dL)No of participants(studies) Quality of evidence
People receiving blood transfusionsRR 0.59 (0.53 to 0.66)815 / 1000481 / 100020 057 (42), High
30-day mortalityRR 0.99 (0.86 to 1.15)83 / 100083 / 100016 729 (31), High
Myocardial infarctionRR 1.04 (0.87 to 1.24)32 / 100033 / 100014 370 (23), High
Congestive heart failureRR 0.83 (0.53 to 1.29)35 / 100029 / 10007 247 (16), Low
Cerebrovascular accident - strokeRR 0.84 (0.64 to 1.09)17 / 100014 / 100013 985 (19), High
RebleedingRR 0.80 (0.59 to 1.09)158 / 1000126 / 10003 412 (8), Moderate
InfectionRR 0.97 (0.88 to 1.07)143 / 1000139 / 100017 104 (25), High
ThromboembolismOR 1.11 (0.65 to 1.88)15 / 100017 / 10004 201 (13), High

Clinical comments

Note

Date of latest search: 27 May 2016

    References

    • Carson JL, Stanworth SJ, Dennis JA, et al. Transfusion thresholds for guiding red blood cell transfusion. Cochrane Database Syst Rev 2021;12(12):CD002042 [PubMed]

Primary/Secondary Keywords