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Deferral Reasons Explained

Undoubtedly, blood donors have an altruistic feeling. They have a strong desire to save lives. The South African National Blood Service (SANBS) salute you all. However, in the process of donating blood some blood donors may be deferred from donating blood for various genuine reasons, writes Dr Robert Crookes, Transfusion Medical Consultant for SANBS.

Blood transfusion is a cornerstone of modern medical practice. Patients in hospital, who depend on a blood transfusion as part of their medical treatment need to be assured that the blood that they receive will improve their wellbeing and will not harm them in any way.

The Blood Services in South Africa adhere to the highest international quality standards and go to extraordinary lengths to ensure that the blood that is procured from blood donors is as safe as possible, and is free from any infection, or medication, that may in any way be detrimental to the health of the recipient.

SANBS has an obligation to protect the health of its blood donors as well as protect the health of the recipient of the blood (the patient).

Transfusion Medicine is a medical discipline. The reasons that individuals are temporarily deferred, or indefinitely excluded from donating blood, are evidence-based.

For example, a donor may question why he/she is deferred from donating blood because her weight was less than 50Kg.

Reason: The amount of blood that any person has in their circulation is directly proportional to their weight. With each blood donation, 480ml to 500ml of blood is withdrawn. An acute blood loss of more than 15% of total blood volume may be associated with a significant drop in blood pressure and even clinical shock.

Blood Services internationally have therefore defined 50Kg as a safe minimal weight, for regular blood donation.

Again, another blood donor may question his/her deferral from donating blood after they have taken iron supplements.

Without knowing the medical reason for iron supplement in a particular donor’s case, a general comment can be that whenever a person is diagnosed as being iron deficient, the reason for the iron deficiency should always be determined.

A unit of blood (500ml) contains approximately 250mg of iron. In general, it will take approximately 4-6 weeks for the iron that is lost in a blood donation to be made up from the diet.

Any person who has been diagnosed with iron deficiency must first complete a full course of iron supplementation and must be sure that their iron reserves have been replenished, before continuing to donate blood.

The medication that a blood donor is taking may alter the function of certain blood components and may adversely affect the patient who receives the blood transfusion.

If a blood donor is deferred from donating blood after taking ‘painkillers’ the night before it is because an anti-inflammatory medication as well as medication that contains asprin or asprin-like compounds has a profound effect on the function of blood platelets.

Blood platelets, for transfusion to patients who are experiencing severe haemorrhage, are routinely prepared from donations of whole blood.

Blood donors who have taken anti-inflammatory medication within 24 hours of a whole blood donation (or have taken aspirin or aspirin-like medication within three days of a blood donation) must please be sure to inform the Blood Service staff.

Taking this medication prior to donating blood will severely affect the ability of transfused platelets to stop bleeding in the recipient. It will render the platelet transfusion clinically ineffective.

It would be negligent of the Blood Service to provide blood platelets from donors who have recently taken this type of medication.

The SANBS professional nurses are trained and knowledgeable on who may or may not donate blood.

The professional nurse at the blood donor clinic is expected to give a logical, reasoned explanation to any person who is being deferred from donating blood.

South Africa has pioneered the concept and practice of voluntary unpaid blood donation and, as a result, has a proud record of an exceptionally safe and reliable blood supply.

All blood donors who have contributed, and who continue to play a part in this life saving endeavour, are to be thanked and congratulated.

SANBS has sound reasons for the strict acceptance and deferral criteria that are applied to prospective blood donors. Hopefully, blood donors will consider the rationale for being deferred from donating blood and continue to donate blood when is it safe for them and for the recipient, to do so.