Blood conservation

There are different techniques that may eliminate the need for transfusion which involve the identification and correction of anaemia, use of haemostatic agents, decrease blood sampling and blood salvage techniques.

For surgical patients, blood conservation begins at the time of the patient’s surgical booking and continues through the operation and into the recovery process.

Preoperative blood conservation techniques

The preoperative assessment for anaemia, optimising haemoglobin level and bleeding risk are key components of blood conservation strategies. Refer to Anaemia and haemostasis management for further information.

Before and after an operation, restricting phlebotomy to essential tests only and taking smaller samples (microsampling) can limit the amount of non-surgical blood loss.

Lifeblood can only provide autologous blood collection for exceptional circumstances including for patients with a rare blood group or multiple red cell antibodies whose transfusion requirements can’t be met with allogeneic blood.

Preoperative autologous blood collection:

• Reduces the risk of allogeneic red cell transfusion but increases the risk of receiving any red cell transfusion (allogeneic and autologous).
• Increases the risk of preoperative anaemia which is associated with worse outcomes (than those who were not anaemic preoperatively).
• Results in excessive wastage, with a significant percentage of autologous units discarded.
• Results in generally higher costs on balance than the value of reported benefits of the actual autologous collection.
• Carries some of the same risks of allogeneic blood, e.g. bacterial contamination, clerical and human errors including incorrect transfusion and, febrile reactions.

Intraoperative blood conservation techniques

The Patient Blood Management Guidelines: Module 2 supports the following intraoperative strategies for blood conservation:

• prevention of hypothermia (Grade A)
• appropriate patient positioning
• deliberate induced hypotension in specific surgeries (Grade C)
• acute normovolaemic haemodilution (Grade C)
• cell salvage (Grade C)
• haemostasis analysis (Grade C)
• use of medications such as tranexamic acid (Grade A, B)
• meticulous operative technique, and
• topical haemostatic agents.

Postoperative blood conservation techniques

In select clinical settings, postoperative cell salvage is recommended as a blood conservation strategy (Grade C). This technique involves the collection of a patient’s postoperative blood loss into a wound drain. It’s then returned to the patient via a filter, either washed or unwashed depending on the equipment used.

Close patient observation and monitoring to identify episodes of uncontrolled bleeding and readiness to return to theatre to control bleeding is important in blood conservation.

Medical blood conservation techniques

If a patient requires therapy for anaemia, thrombocytopenia or coagulopathy, transfusion should not be a default decision. Instead, the decision on whether to transfuse should be carefully considered, taking into account the full range of available therapies, and balancing the evidence for efficacy and improved outcome against the potential risks.

Identification and treatment of reversible causes of anaemia, particularly iron deficiency in patients with chronic heart failure, is vital. The routine use of erythrocyte stimulating agents (ESAs) is not recommended in many patient groups, but may be cautiously used in others.

Where a red cell transfusion is indicated, a single unit should be followed by clinical assessment to determine the need for further transfusion.

The National Blood Authority Patient Blood Management Guidelines: Modules 2, 3, 4, 5 and 6 which focus on Perioperative, Medical, Critical Care, Obstetrics and Maternity and Neonatal and Paediatric patients respectively, provide recommendations and practice points on blood conservation strategies.