5.10 Donor adverse events - Collection of a blood or component donation

5.10.1: Definitions

Donor Adverse Event (DAE)

An event where harm occurs to a donor as a result of the blood donation process.

Serious Donor Complication (SDC)

A DAE which is graded at Grade 3 or above using the Severity Grading Tool.

Serious Adverse Event of Donation (SAED)

A DAE which meets the previous severity criteria agreed by the UK Blood Services.

A DAE which is graded as either an SDC or an SAED meets the Medicines and Healthcare products Regulatory Agency (MHRA) definition of a Serious Adverse Reaction:

"An unintended response in a donor or in patient associated with the collection or transfusion of blood or blood components that is fatal, life-threatening, disabling, incapacitating, or which results in, or prolongs, hospitalisation or morbidity."

5.10.2: DAE classification, investigation, and reporting

DAEs are classified according to the categories included in the Standard for Surveillance of Complications Related to Blood Donation (SSCRBD), available from the Donor Haemovigilance section of the Association for the Advancement of Blood & Biotherapies (AABB) website.

In 2023/24, the UK Blood Services agreed to implement the validated donor severity grading criteria developed by the AABB Donor Haemovigilance Working Group and endorsed by the International Society of Blood Transfusion (ISBT), the International Haemovigilance Network (IHN) and the European Blood Alliance (EBA) [Townsend, 2020]. The Severity Grading Tool for Donor Adverse Events is available on the AABB Donor Haemovigilance page. This records the severity of donor adverse events by Grades 1–5, with 1 through 5 being roughly associated with mild, moderate, severe, life-threatening and death. Further details of DAE classification, grading and assignment of imputability scores are given below (see 5.10.3 to 5.10.5).

Management of all SDCs or SAEDs should include appropriate incident investigation to ensure that proper preventative and corrective actions are implemented. This supports optimal learning from reported incidents.

The Blood Safety and Quality Regulations 2005 (BSQR) mandate that blood establishments report serious adverse events or reactions, including those which occur in donors. Each Blood Service is therefore required to submit an annual report to the MHRA covering any DAE which are classified as SDCs. During the transition period for introduction of the Severity Grading Tool, Services may alternatively choose to report using the previous SAED categories (see 5.10.6).

Blood Services must also ensure that:

• All DAEs are documented and reported according to standard procedures.
• For DAEs which are Grade 3–5 (or identified as SAEDs), written procedures are in place documenting expected donor follow-up.
• Processes are in place for investigation of appropriate DAE. This should include those of Grade 3–5 or SAEDs. Any investigation should apply human factors and systems thinking principles. Lessons learnt should be shared widely.

The care of all donors at blood collection venues should incorporate research-based therapeutic interventions to reduce the risk of adverse events of donation.

Blood Services are encouraged to collect all DAE data in a format which will allow analysis of DAE trends over time both within and between services (benchmarking). This will also enable monitoring of the effectiveness of any interventions to reduce event rates.

A summary of the serious donor adverse events reported in the UK Blood Services is included in the donor haemovigilance chapter in each Annual SHOT Report available from the SHOT website.

5.10.3: Classification of Donor Adverse Events

The following classification codes and descriptions are based on the AABB Standard for Surveillance of Complications Related to Blood Donation.

Code: A

Complications mainly arising from local symptoms

Code: A.1

Complications mainly characterised by the occurrence of blood outside the vessels

• Haematoma (bruise)
• Arterial puncture
• Delayed bleeding (rebleeding)

Code: A.2

Complications mainly characterised by pain

• Nerve injury/irritation
• Other painful arm

Code: A.3

Localised infection/inflammation

Code: A.4

Other major blood vessel injury

• Deep vein thrombosis
• Arteriovenous fistula
• Compartment syndrome
• Brachial artery pseudoaneurysm

Code: B

Complications mainly with generalised symptoms: vasovagal reactions

• Without loss of consciousness
• With loss of consciousness
• Recording of the additional subcategories below is recommended.
• With or without injury
• Occurring at the donation site or after the donor has left the donation site

Code: C

Complications related to apheresis

• Citrate reaction
• Haemolysis
• Air embolism
• Infiltration (only relevant for procedures using volume replacement)

Code: D

Allergic reactions

• Allergy
• Generalised allergic reaction / anaphylaxis

Code: E

Other serious complications related to blood donation

Major cardiovascular event such as acute cardiac symptoms, myocardial infarction, cardiac arrest, transient ischaemic attack, cerebrovascular accident, death

Code: F

Other complications

Systemic reactions or complications which do not fit into any of the categories listed above

5.10.4: Donor Adverse Event Severity Grading

The following severity grades and criteria are based on the AABB Severity Grading Tool for Blood Donor Adverse Events.

Grade 1

Did not require intervention from an external healthcare practitioner (HCP)

AND Duration ≤2 weeks

AND No limitation on activities of daily living (ADL)

AND Resolved with no or minimal intervention

Grade 2

Required intervention from an external HCP, no hospitalisation

OR Duration >2 weeks and ≤6 months

OR Limitations on ADL ≤2 weeks

Grade 3

Not life-threatening

AND any of the following:

• Hospitalisation
• OR Duration >6 months
• OR Limitations on ADL >2 weeks
• OR Require surgery
• OR Other serious complications (Category E)

Grade 4

Immediate medical intervention required to prevent death

Grade 5

Death

When assessing DAEs, assign the highest applicable severity grade. The Severity Grading Tool should be referenced for guidance on specific DAE categories.

5.10.5: Donor Adverse Event Imputability Scoring

Imputability, in the context of blood donation, means the likelihood that a DAE can be attributed to the donation. Imputability is scored according to the criteria below based on the SHOT Definitions (2023).

Score: N/A

Imputability: Not assessible.

Definition: When there is insufficient data for imputability assessment.

Score: 0a

Imputability: Excluded.

Definition: When there is conclusive evidence, beyond reasonable doubt, for attributing the adverse reaction to causes other than the blood or blood components or where the evidence is clearly in favour of alternative causes.

Score: 0b

Imputability: Unlikely.

Definition: When there is conclusive evidence, beyond reasonable doubt, for attributing the adverse reaction to causes other than the blood or blood components or where the evidence is clearly in favour of alternative causes.

Score: 1

Imputability: Possible.

Definition: When the evidence is indeterminate for attributing the adverse reaction either to the blood or blood component or where there may be alternative causes.

Score: 2

Imputability: Likely/probable.

Definition: When the evidence is clearly in favour of attributing the adverse reactions to the blood or blood component.

Score: 3

Imputability: Certain.

Definition: When there is conclusive evidence, beyond reasonable doubt, attributing the adverse reactions to the blood or blood component.

5.10.6: Serious Adverse Events of Donation

Prior to implementation of the Severity Grading Tool, DAEs were classified as Serious Adverse Events of Donation (SAEDs) if they fell into 1 of the categories listed below. Mapping of SAED categories to the new classification and grading system is also shown. Note that if reporting under SAED criteria, fewer adverse events will be included.

During the transition phase for introduction of the Severity Grading Tool, services may continue to use SAED classifications for reporting of serious adverse reactions to SABRE and SHOT.

Code: 01

SAED category:

Death within 7 days of donation

Mapped to new system:

Any category, Grade 5

Code: 02

SAED category:

Hospital admission within 24 hours of donation

Mapped to new system:

Any category, Grade 3 or 4

Code: 03

SAED category:

Injury resulting in a fracture within 24 hours of donation (including fractured teeth)

Mapped to new system:

B, Grade 3

Code: 04

SAED category:

Road traffic collision within 24 hours of donations

Mapped to new system:

B*, Grade 3 or 4

(* if due to vasovagal reaction)

Code: 05a

SAED category:

Problems relating to needle insertion persisting for more than 1 year (this mainly includes suspected or confirmed nerve and tendon injuries)

Mapped to new system:

A (usually A.2), Grade 3

Code: 05b

SAED category:

Problems relating to needle insertion requiring hospitalisation/intervention (this mainly includes vascular complications)

Mapped to new system:

A (usually A.4), Grade 3 or 4

Code: 06

SAED category:

Acute coronary syndrome diagnosed within 24 hours of donation

Mapped to new system:

E, Grade 3 or 4

Code: 07

SAED category:

Anaphylaxis (component donation)

Mapped to new system:

D, Grade 3 or 4

Code: 08

SAED category:

Haemolysis (component donation)

Mapped to new system:

C, Grade 3 or 4

Code: 09

SAED category:

Air embolism (component donation)

Mapped to new system:

C, Grade 3 or 4

Code: 10

SAED category:

Other event related to donation resulting in:

• Hospital admission,
• Intervention, or
• Disability or incapacity lasting more than 1 year and not included above

Mapped to new system:

F, Grade 3 or 4

References

Townsend M, Kamel H, Van Buren N, Wiersum-Osselton J, Rosa-Bray M, Gottschall J, Rajbhandary S (2020). Development and validation of donor adverse reaction severity grading tool: enhancing objective grade assignment to donor adverse events. Transfusion, 60(6):1231–1242. https://doi.org/10.1111/trf.15830