For patients who are shocked and anaemic red cell transfusion to increase the circulating red cell mass can relieve clinical features that are caused by insufficient oxygen delivery (PMID 14556774, 9504576). Circulating blood volume must be corrected with other fluids (PMID 15163774, 12535407, 11279761). Mortality rates are high in patients who do not receive blood.
A randomised trial in ICU patients suggested that transfusion of red cells to achieve a higher haemoglobin concentration target appears to offer no benefit over more conservative transfusion to achieve a lower target Hb concentration. The exception to this may be patients with cardiovascular disease. Table 7.4 shows a recent evidence-based national clinical transfusion guideline for transfusion of red cells in acute anaemia
Germany Haemotherapy Guidelines downloadable from the bottom of the page.
Table 7.4 Evidence based national clincal transfusion guideline for transfusion of red cells in acute anaemia
Reproduced from: cross sectional guidelines for therapy with blood components and plasma derivatives, 4th revised edition 2009. Bundesaertztekammer (German Medical Association)
|The decision on transfusion for each patient should take account of that patient’s haemoglobin (Hb) concentration, capacity to compensate for acute anaemia, and risk factors
|Hb concentration alone is not an adequate measurement of oxygen supply. If the patient is hypovolaemic the Hb concentration does not correctly reflect the red cell mass in an individual patient and it may be necessary to deviate from the recommendations below
|range of haemoglobin concentration
|capacity to compensate: risk factors
|recommendation on red cell transfusion
|strength of recommendation *
|< 6 g/dl (3.7mmol/l)
|> 6-8 g/dl (3.7-5 mmol/l
|adequate compensation: no risk factors
|limited compensation: risk factors such as coronary artery disease, cardiac insufficiency, cerebrovascular insufficiency
|symptoms of anaemic hypoxia or decompensation (physiologic transfusion trigger) eg tachycardia, hypotension, ECG ischemia, lactic acidosis
|> 8-10 g/dl (5.0-6.2 mmol/l
|symptoms of anaemic hypoxia or decompensation (physiologic transfusion trigger) e.g. tachycardia, hypotension, ECG ischemia, lactic acidosis
|> 10g/dl (6.2 mmol/l)
Neonatal ICU patients
Transfusion of red cells to achieve a higher haemoglobin concentration target in patients who require transfusion appears to offer no benefit over more conservative transfusion to achieve a lower target Hb concentration (PMID 19117884). Target haemoglobin levels used in the key randomised controlled clinical trial depended on the age and condition of the infant.
In countries where thalassaemia is still prevalent, it can account for a large proportion of the clinical requirement for red cell transfusion. In many countries, as a result of successful prevention programmes, most cases are now in older individuals. Red cell transfusions are typically given at two to four weekly intervals to maintain a mean Hb around 12g/dl. The aim is to fully relieve the symptoms of anaemia and suppress the patient’s own increased abnormal red cell production in the marrow (ineffective erythropoiesis). This is the cause of the skeletal abnormalities and spleen enlargement seen in under-treated patients. All patients need iron chelation therapy to prevent progressive and ultimately fatal organ damage (PMID 18413891).
Symptomatic anaemia patients with haematological malignancies or solid tumours:
The local clinical management protocol should define the range within which a patient’s haemoglobin should be maintained. A suggested arbitrary guide is to maintain Hb at not less than 9.0g/dl. As a result of complications associated with the use of erythropoetin in patients with cancer, guidelines in a number of countries now discourage or restrict its use in this situation (PMID 16705125).