ABO Incompatibility is the Most Important Complication of Blood Product Transfusion
Administering the wrong blood type in error (with the risk of ABO incompatibility) is the most serious outcome of blood transfusion. 1 This complication takes precedence over haemostatic breakdown, hepatitis, and HIV due to its potential for immediate and life-threatening consequences.
Why ABO Incompatibility is Most Critical
ABO incompatibility reactions occur when blood containing incompatible ABO antigens is transfused to a recipient with preformed antibodies against those antigens. This leads to:
- Brisk complement-mediated lysis of red blood cells 2
- Rapid onset of potentially fatal reactions
- High mortality risk even with small volumes of incompatible blood 3
Pathophysiology and Clinical Impact
When ABO-incompatible blood is transfused, several dangerous pathophysiological cascades are triggered:
- Complete complement activation leading to intravascular hemolysis
- Formation of anaphylatoxins
- Systemic inflammatory response syndrome from cytokine release
- Activation of the kinin system and intrinsic clotting cascade
- Disseminated intravascular coagulation
- Disruption of microcirculation leading to renal failure and shock 4
Prevention of ABO Incompatibility
Most incidents of ABO incompatibility are due to failure of final identity checks between the patient and the blood to be transfused 1. Prevention requires:
Proper Identification Protocols
- Patient must be positively identified with four core identifiers:
- First name
- Last name
- Date of birth
- Patient identification number 1
Bedside Checking Process
- Check component next to patient against prescription
- Compare compatibility label with patient identification
- Verify blood group and component donation number
- Visually inspect blood component for abnormalities
- Check expiry date and time 1
Staff Training
- All staff involved in blood administration must be trained and competency-assessed
- Follow local policy regarding one- or two-person bedside checks 1
Monitoring for Transfusion Reactions
Clinical observations should include:
- Heart rate
- Blood pressure
- Temperature
- Respiratory rate
Signs of a transfusion reaction include:
- Tachycardia
- Rash
- Breathlessness
- Hypotension
- Fever 1
Management of Suspected Reactions
If a transfusion reaction is suspected:
- Stop the transfusion immediately
- Contact the laboratory
- Consider administration of antihistamines, steroids, or intramuscular/intravenous adrenaline if life-threatening 1
Comparison with Other Transfusion Complications
While hepatitis, HIV, and haemostatic breakdown are serious complications:
- Infectious disease transmission (hepatitis, HIV) has been dramatically reduced through advances in laboratory testing, pathogen reduction, and donor qualification 5
- Haemostatic breakdown, while concerning, typically develops more gradually and allows time for intervention
- ABO incompatibility can cause immediate, severe, and potentially fatal reactions even with small volumes of incompatible blood 3
Special Considerations
- Platelet transfusions can also cause ABO incompatibility reactions due to plasma content 6
- Transfusion-associated graft-versus-host disease is rare but usually fatal; it can be prevented through irradiation of blood products 1
- Bacterial contamination of platelets is a significant risk but can be mitigated through pathogen reduction technologies 1
ABO incompatibility remains the most feared complication of transfusion despite progress in other areas of transfusion safety 5, making it the most important complication to prevent through rigorous adherence to identification protocols and checking procedures.