3.2 Effect of red blood cell transfusion on outcomes

3.2.1 Medical population

Evidence Statements by medical population
Evidence Statements –
medical population
Evidence Consistency Clinical impact Generalisability Applicability
ES2.1 In medical patients, the effect of a restrictive versus liberal RBC transfusion strategy on mortality is uncertain. X

ES, evidence statement; RBC, red blood cell

=B; =C; NA,not applicable (see Table 2.1)

Practice Points – medical population
PP1 RBC transfusion should not be dictated by a Hb concentration alone, but should also be based on assessment of the patient’s clinical status.
PP2 Where indicated, transfusion of a single unit of RBC, followed by clinical reassessment to determine the need for further transfusion, is appropriate. This reassessment will also guide the decision on whether to retest the Hb level.

Direct evidence is not available in general medical patients.a Evidence from other patient groups and CRG consensus suggests that, with a:

  • Hb concentration <70 g/L, RBC transfusion may be associated with reduced mortality and is likely to be appropriate. However, transfusion may not be required in well-compensated patients or where other specific therapy is available.
  • Hb concentration of 70 – 100 g/L, RBC transfusion is not associated with reduced mortality. The decision to transfuse patients (with a single unit followed by reassessment) should be based on the need to relieve clinical signs and symptoms of anaemia, and the patient’s response to previous transfusions. No evidence was found to warrant a different approach for patients who are elderly or who have respiratory or cerebrovascular disease.
  • Hb concentration >100 g/L, RBC transfusion is likely to be unnecessary and is usually inappropriate. Transfusion has been associated with increased mortality in patients with ACS.

a Recommendations and practice points for medical patients in a critical care setting will be found in the Patient Blood Management Guidelines: Module 4 – Critical Care.3 Recommendations and practice points for specific medical subgroups (ACS, CHF, cancer, acute upper gastrointestinal bleeding and chronically transfused) appear elsewhere in this module.

PP4 In patients with iron deficiency anaemia, iron therapy is required to replenish iron stores regardless of whether a transfusion is indicated.

ACS, acute coronary syndrome; CHF, chronic heart failure; CRG, Clinical/Consumer Reference Group; Hb, haemoglobin; PP, practice point; RBC, red blood cell

For the comparison of restrictive and liberal transfusion strategies in general medical patients, a Cochrane review by Carless et al (Level I) was identified.82 The review assessed data from 17 randomised controlled trials (RCTs) including mainly surgical, critical care and paediatric patients. Studies varied in their definition of restrictive and liberal policies. No difference in mortality or rate of stroke or thromboembolism was identified, but there was a reduction in in-hospital mortality, infection and cardiac events among patients transfused using a restrictive policy. As these findings were largely based on surgical patients, their generalisability to the medical population is limited.

In the absence of direct evidence to support recommendations for the general medical population, evidence from other patient groups was applied to derive a series of practice points. Decisions on whether to transfuse should take into account the absence of proven benefit, and should follow a precautionary principle. In medical patients, the aetiology of anaemia is often multifactorial; where appropriate, reversible causes should be identified and treated.

The Caring for Australasians with Renal Impairment (CARI) guidelines provide recommendations for the management of anaemia in patients with chronic kidney disease (CKD),83 while the Patient Blood Management Guidelines: Module 1 – Critical Bleeding/Massive Transfusion are appropriate for patients with decompensated upper gastrointestinal bleeding.4 Practice points and recommendations for other specific medical populations – for example, ACS, heart failure, cancer and acute upper gastrointestinal blood loss – are presented in the following sections. In addition, advice relating to the management of chronically transfused patients (including patients with thalassaemia and myelodysplasia) is presented under Question 6.