Prevention Of Blood Loss And Blood Transfusion In Surgery

Introduction

Blood transfusion is the introduction of whole blood or blood components into the blood stream of an individual.
Transfusion should be used appropriately because its use is not without complications and untoward effects.
Several techniques and manoeuvres are available to help minimize blood loss at surgery, and hence minimize blood transfusion.
Use of simple techniques to minimize blood loss at surgery

Techniques

1. Elevation of site of surgery
2. Pressure (digital and sponge)
3. Electrocautery
4. Clipping and ligature
5. Surgical glues (e.g. fibrin glue)
6. Tourniquets (elastic bandage or pneumatic, useful in limbs, remember tourniquet time, remember to remove before closure of skin wound)

Blood and its commonly used components:

• Whole blood
• Packed red cells
• Fresh frozen plasma
• Clotting factor concentrates
• Platelet concentrate

Basic principles of blood transfusion:

Appropriate use

• Adequate evaluation before transfusion to ascertain the indication, amount and
  component required
• Screening for communicable diseases (HIV, hepatitis, etc.) before transfusion
• Adequate grouping and cross-matching before transfusion
• Store under at appropriate temperature
• Use blood fractions whenever possible to avoid wastage
• Use autologous blood whenever possible to minimize risk of transfusing communicable
  diseases
• Transfusion is not a substitute for
  meticulous and appropriate surgical techniques

Indications for blood transfusion

• To replace lost blood volume
• Haemorrhage from trauma and other forms of blood loss
• Operative haemorrhage
• To improve oxygen carrying capacity
• Various types of anaemias
• To replace clotting factors
• Some liver diseases
• Deficiency states

Complications

Early complications:

• Immune reactions
• ABO incompatibility
• Rhesus incompatibility
• Febrile reactions
• Allergic reactions
• Reactions to plasma proteins

Biochemical complications:

• Hyperkalaemia
• Citrate toxicity (hypocalcaemia)
• Haemoglobinaemia

Infective complications:

• Bacteraemia
• Transfusion of parasites (e.g. malaria)
• Transfusion of viruses (HIV, Hepatitis B, C, D)

Physical complications:

• Volume overload
• Air embolism
• Hypothermia

Complications of massive blood transfusion:

Massive transfusion refers to the single transfusion of 50 – 100% of the equivalent of an individual\’s blood volume in less than 24 hours.

• 2.5 – 5 litres in adults and 40-80 ml/kg body weight in children

The complications are related to:

• Volume overload
• Transfusion of old blood
• Electrolyte derangements (especially potassium and calcium)
• Transmission of infections

Delayed complications:

• Haemosiderosis
• Post transfusion purpura

Autologous transfusion

Transfusion of the patients\’ own blood

Advantages

• Reduced risk of transmitting communicable diseases
• Overcomes the problem of shortage of blood

Types and methods

1. Pre-deposit blood

• Usually best, done in conjunction with haematology staff
• The patient donates one unit of blood at a time (e.g. weekly) several weeks before the elective surgery
• Following donation, the patient is given haematinics, and sometimes erythropoietin to enhance bone marrow function; the blood is stored for later use

2. Pre-operative isovolaemic haemodilution

Just before elective surgery, 1 – 2 units of
blood are taken from the patient and
replaced by volume expanders such as
Ringer\’s lactate, sodium chloride 0.9%, or
colloid.
The blood taken is transfused intraoperatively after all haemostasis has
been secured

3. Intraoperative blood salvage

Appropriate for patients undergoing laparotomy or thoracotomy for haemorrhage into these cavities (e.g. traumatic haemothorax, splenic injury, ectopic gestation)

• The blood is collected in an appropriate blood bag and then transfused using a blood giving set with filter
• Special salvage equipment may be available sometimes
• Contaminated blood must not be transfused

Contraindications to autologous transfusion

• Pregnancy
• Chronic medical conditions
• Cancer
• Situations where the blood may have become contaminated (this is for intraoperative blood salvage)
• Children:

Other sources of blood

Umbilical cord blood

• Alternatives to blood transfusion.
• Since blood transfusion is attended by several untoward effects and complications, efforts are continuously being made to identify alternatives to transfusion.
•  Most of these are experimental at the moment and are not practicable in the clinical setting