What do you need to remember during a massive blood transfusion?

At first thought, this seems like an obvious answer: Give blood! However, the amount of blood that a person receives during a massive blood transfusion can cause a set of complications that needs to be addressed concurrently.

To remember the principles involved with managing a patient requiring a massive blood transfusion, remember the acronym ’REPLACE’:

What is a Massive Blood Transfusion?

A massive blood transfusion can be defined as follows:

• The transfusion of an adult’s blood volume within 24 hours - this can also be defined as having to administer more than 10 units of red blood cells in 24 hours, or the anticipated need to do so.
• The transfusion of half an adult’s blood volume in 4 hours - this can also be defined as the loss of over 150 mL of blood per minute.

(NBA 2011; Lifeblood 2021)

The average blood volume is approximately 70 mL/kg for adults of ideal body weight (Red Cross 2020).

Causes of Massive Blood Loss Requiring Transfusion

Massive blood transfusions are required in cases of severe haemorrhage such as trauma, ruptured aortic aneurysm, surgery and pregnancy complications (Lifeblood 2021).

Principles of Massive Blood Transfusion

General Principles

The goals of massive blood transfusion management are to:

• Recognise blood loss early
• Maintain tissue perfusion and oxygenation by restoring blood volume and haemoglobin
• Stop bleeding, including through early surgical or radiological intervention
• Manage coagulopathy through the appropriate use of blood component therapy.

(Lifeblood 2021)

Practical Management Tips

• Establish wide bore intravenous access early
• Ensure adequate access to pre-warmed fluids to maximise the restoration of circulating volume
• Maintain close communication with key personnel including blood bank, haematology and surgical teams
• Regular laboratory investigations including full set of bloods will require good communication between the treating team and pathology to prevent delays.

(Nickson 2020b)

REPLACE

Replacement of Intravascular Volume Loss

Excessive bleeding causes a loss of intravascular volume and circulating haemoglobin, resulting in decreased perfusion of the vital organs. This eventually leads to hypovolaemic shock (Taghavi & Askari 2020).

The general rule of thumb is that intravascular volume should be replaced by what has been lost. In a bleeding patient, we should replace with blood.

Crystalloid filling may be considered in order to dilute the blood and help circulate it around the body, but a 1:1 ratio of blood to crystalloid is no longer advocated due to adverse outcomes such as oedema, compartment syndrome and acute lung injury (NBA 2011). If synthetic colloids are used, limit them to a maximum of 1.5 L in 24 hours (Nickson 2020b).

Exsanguination Cessation

Attempting to replace the blood that is being lost is futile if the bleeding is not stopped. Contact key personnel such as the blood bank, interventional radiology or the surgical team as soon as possible (Nickson 2020b).

If the bleeding is internal, there needs to be an urgent surgical intervention to find the source and control it (ANZCOR 2021).

Permissive Hypotension

Read: Permissive Hypotension for Trauma Below the Neck

Permissive hypotension is a non-aggressive fluid resuscitation technique where the patient is intentionally under-resuscitated in order to keep their blood pressure lower than normal physiologic levels. This aims to ensure blood pressure is low enough to prevent exsanguination but high enough to maintain perfusion (Das et al. 2021; Nickson 2020a).

Permissive hypotension of 80-100 mmHg systolic is usually recommended until the bleeding has been controlled, as adding more force behind the bleed is only going to worsen it (NBA 2011).

It’s important to note that permissive hypotension is contraindicated in traumatic brain injury as reduced perfusion pressure can lead to secondary brain injury (NBA 2011).

Furthermore, note that the safe low threshold for systolic blood pressure and the maximum safe duration for permissive hypotension are both unknown (NBA 2011).

Low Body Temperature Management

Hypothermic people have a slower heartrate, decreased myocardial contractility and impaired uptake of oxygen by the cells, leading to worsening shock. It is easier to keep a patient warm than trying to warm them up. Use a blood warmer to administer the blood where possible and remember to put an active warming blanket on the person, aiming for a temperature of more than 35 degrees celsius (NBA 2011).

Acidosis Management

Each unit of blood contains approximately 15 mmol of hydrogen ions. As the kidneys are only able to eliminate approximately 1 mmol/kg of hydrogen ions a day, acidosis can occur with massive blood transfusions if the kidneys are unable to keep up with the buffering and removal.

Each unit of blood has a base deficit of 20 mmol/L to 40 mmol/L depending on the age of the bag, with a base deficit reducing the ability of the body to buffer a worsening acidosis. While the aim during a massive blood transfusion is to maintain a pH of > 7.2, the metabolic acidosis will eventually rectify itself once the bleeding has been controlled.

Coagulopathy Management

There are various blood products and adjuncts that can be administered to help slow the bleeding, including:

• Fresh Frozen Plasma (FFP) that contains all the coagulation factors in normal concentrations and promotes coagulation of blood along the intrinsic, extrinsic and common pathways - administer 15 mL/kg if the international normalised ratio (INR) is more than 1.5.
• Platelets that help to form a stabilised clot by binding with fibrin fibres - administer one adult therapeutic dose if platelets are less than 50,000 mCL.
• Cryoprecipitate that contains mostly fibrinogen, factor 8, factor 13 and von Willebrand factor - administer 3 to 4 grams if the fibrinogen is less than 1.0 g/L.
• Tranexamic acid (TXA), which is an antifibrinolytic that works to counteract the degrading effects that plasmin has on fibrin, thereby preserving stabilised fibrin to participate in the clotting process for longer. The recommendation is a loading dose of 1 gram over 10 minutes, followed by an infusion of 1 gram over the next 8 hours.
• Protamine, which helps reverse the effects of heparin if the bleeding is thought to be a result of a heparin-induced coagulopathy.
• Vitamin K, which helps to activate factors 2, 7, 9 and 10 if the bleeding is thought to be a result of a warfarin-induced coagulopathy.

(NBA 2011; Nickson 2019)

Electrolyte Derangement Management

Each unit of blood contains citrate that works to prevent blood clotting by binding to ionised calcium, impeding the clotting cascade significantly. The liver converts citrate to bicarbonate, thereby releasing calcium ions to facilitate the clotting ability of the blood. However, a massive blood transfusion overwhelms this process.

For this reason, calcium needs to be replaced to maintain an ionised calcium level of more than 1.1 mmol/L (NBA 2011).

Massive Transfusion Protocols

Some patients will require the activation of a massive transfusion protocol. This refers to the rapid administration of large amounts of blood products in fixed ratios (usually 1:1:1) for the management of haemorrhagic shock. It may vary per facility and protocol but is usually when at least six units of PRBC are required. The frequency and type of monitoring of blood results will also be stipulated in a massive transfusion protocol (Farkas 2021).

A massive transfusion protocol template is available here in the National Blood Authority’s Patient Blood Management Guidelines.

Complications Associated with Management of Massive Blood Loss

Safe transfusion practice and appropriate patient monitoring are essential in avoiding complications and addressing any transfusion reactions.

The management of massive blood loss itself also has a variety of potential complications, including:

• Disseminated intravascular coagulopathy (DIC)
• Fluid overload
• Electrolyte and metabolic disturbance, including hyperkalaemia and hypokalaemia
• Citrate-toxicity
• Hypothermia
• Transfusion-related lung injury (TRALi)
• Delayed transfusion reaction
• Transmission of infections.

(Nickson 2020b)

Patient Blood Management

No discussion of blood transfusion should take place without an adequate understanding of patient blood management (PBM).

PBM is based on the view that ‘the best and safest blood for most patients is their own circulating blood’ (ACSQHC 2022).

The three principles of PBM are to:

• Optimise the patient’s own blood by identifying factors that might lead to a blood transfusion
• Minimise blood loss
• Optimise tolerance of anaemia without resorting to a blood transfusion (if possible).

(ACSQHC 2022)

For more information on PBM, see the Blood Management NSQHS Standard.

Read: National Safety and Quality Health Service Standards (NSQHSS) Explained

Cell Salvage Programs

One method of reducing exposure to blood that is not the patient’s is through cell salvage, a process that involves collecting, processing and re-infusing the patient’s own red blood cells. This not only reduces the risk of transfusion reactions but also decreases the risk of the patient receiving the wrong blood due to errors (NBA 2014).

Cell salvage is part of good patient blood management.

Conclusion

There are numerous considerations that need to be taken during a massive blood transfusion in order to prevent adverse outcomes for the patient.

The acronym REPLACE can be used to remember these key management principles. Additionally, good communication, and maintaining safe transfusion practices and patient blood management principles are essential.

See the following Ausmed articles for further information on blood transfusion procedures:

• Monitoring and Assessing a Patient Receiving A Blood Transfusion
• Blood Transfusion Reactions