Update notice: Chapters 3, 4, 5, 6 have been redrafted. Please refer to Change Notification 12 - 2010.
3.7 Volume of donation
Whole Blood: A donation of 450 mL±10% is required to ensure the final red cell component meets specification. No more than 15% of the estimated blood volume should be taken during any one donation. In general 470–475 mL of blood, excluding samples, is collected into the main pack.
Attention must be paid during apheresis to the extra-corporeal volume (ECV) in order to avoid rendering the donor significantly hypovolaemic. Consideration must be given to the following factors:
donor weight and estimated blood volume
type of apheresis procedure: intermittent flow or continuous flow
donor's haematocrit: this influences volume of plasma collected during any one cycle of an intermittent flow procedure (see Appendix III).
For any single apheresis procedure, the final collection volume should not exceed 15% of the total blood volume (TBV) excluding anticoagulant (see Appendix l).
During apheresis procedures the ECV should not exceed 15 % TBV (excluding anticoagulant). Some procedures may result in a total ECV of as much as 1 litre. The procedure may need to be adjusted to suit each individual donor's safety tolerance limits. Special considerations should be given during intermittent flow apheresis procedures (see Appendices I, II and III). TBV can be estimated using the Nadler formula (see Appendix I) (4).
ECV is the total volume of blood and plasma removed from the donor at any time. It includes all blood and plasma in collection packs and contained within the machine harness (volumes contained within collection harness can be obtained by reference to manufacturers' manuals).
Anticoagulant ratio during collection influences the volume of anticoagulant in collected plasma, e.g. anticoagulant in 1:12 ratio forms 14% of the final volume collected in a donor with haematocrit of 45% (see Appendix II).
3.8 Medical history of donors
General considerations
All donors should clearly understand any information and questionnaire presented to them and must sign an appropriate document which also attests to their consent for the blood to be taken, tested and used for the benefit of patients. Any condition declared shall be discussed with the clinician in attendance at the blood collection session unless clear, unequivocal instructions regarding the responses are available to the member of staff conducting the questioning.
For the details of information to be supplied to and obtained from donors see Chapter 5.
Donors whose serum or plasma or cells are to be used for laboratory, as opposed to therapeutic, purposes shall be submitted to the same routine as other donors, but some decisions regarding their suitability to donate may be different (e.g. treatment with certain medications, or on the basis of their medical history). When this is the case, secure mechanisms must be in place to ensure that the donation cannot be released for clinical purposes.
Individuals currently undergoing medical investigations or who have been referred for a specialist opinion or are on a hospital waiting list should normally be deferred. If, however, the condition or potential condition concerned would not of itself be a contraindication to donation they may be able to donate.
Donors taking part in clinical trials cannot be accepted until their involvement in the trial has finished, or the designated clinical support team member has examined the trial protocol and agreed that donors participating in that trial can be accepted. A 'clinical trial' normally implies that the donor is participating in an intervention programme – usually taking a drug or a potential drug which may be either active or a placebo. Participating in questionnaires does not constitute a clinical trial.
All donors should be made aware that recipients are at risk from transfusion, and shall be asked to report any illness that develops within 14 days of donation.
Information about either the donor or the donation which becomes available after the blood or any derivative has been issued or transfused, and which is, or may be, relevant to the safety of that blood for transfusion, should be reported to the appropriate individual e.g. consultant in charge of the hospital blood transfusion laboratory. Donor confidentiality must be respected.
The member of staff carrying out the donor assessment must confirm they have done so by signing the donation record. Any reason for deferral, whether temporary or permanent, must be explained to the donor and recorded.