Voluntary blood donation is a procedure that can help save the lives of others. According to the American Red Cross, in the United States, donor blood is required every two seconds, and a single blood donation may save the lives of three people. As medical technologies advance, the demand for donor blood and blood products continues to grow steadily.
What happens when I give blood?
Donating blood is a straightforward procedure that is completely safe for healthy adults and is conducted under sterile conditions. However, understanding exactly what will happen before, during, and after the process can help new donors prepare.
The 4-step process of becoming a new donor
The process of donating blood and blood by-products can be divided into four stages:
Registration
Before arranging the first appointment to donate blood, potential donors must first register with either a local blood bank or drive or with a centralized blood donation service, depending on their jurisdiction. This will likely include answering some basic screening questions to ensure that they are eligible to donate blood. Eligibility is based on the following criteria:
- The potential donor should be in good physical health and feeling well at the time of donation
- Should weigh at least 110 pounds
- Has not donated blood in the preceding 12 weeks if male or 16 weeks if female
- Is aged 17 years or older. In some areas, donors may be aged 16 years if they have parental consent to donate.
Males can donate blood more frequently as they tend to have higher iron levels and higher platelet counts. Males also tend to have lower levels of certain antibodies in their blood, because of complex interactions between sex hormones and immune functioning. Although this means that adult males produce weaker immune responses than females, it means their blood products have wider applicability.
Currently, blood donation sites are open and receiving donations, despite the COVID-19 pandemic. Additional precautions are in place and include:
- Taking the temperature of donors at their arrival at a donation appointment,
- Asking donors not to attend a donation appointment if they have experienced coronavirus-related symptoms if they or anyone in their household has been asked to self-isolate,
- Asking those who have tested positive for COVID-19 to wait for a minimum of 28 days after symptom resolution or testing positive before donating.
Health screening
Before each donation, potential donors will be given a short physical assessment and be asked to provide details of their medical history. To ensure that the individual can safely donate blood, a short physical examination including taking the donor’s pulse, temperature, and blood pressure will be completed before each donation.
Additionally, a finger prick test will be completed to ensure the donor has sufficient hemoglobin (iron levels) in their blood. If the results of the finger prick test are borderline, a larger sample may be taken and tested at the donation center.
In all cases, potential donors will complete a private health screening to ensure it is safe for them to donate, and that their donation is safe to be used. Again, the criteria vary by jurisdiction, but in general:
- People who are HIV or HTLV positive HIV, carry hepatitis B or C, have ever tested positive for syphilis, or have ever injected or been injected with non-prescribed drugs should never donate blood products.
- Those who have worked as a sex worker, men who have had oral or anal intercourse with another man, or women who have had sexual contact with a man or men who had had intercourse with a man should wait for three months before donating.
- People who have had a tattoo, piercing, or acupuncture should also wait for three months before donating.
- People who have had sexual intercourse with a partner who may be HIV/HTLV positive, a hepatitis B or C carrier, have tested positive for syphilis, or ever injected non-prescribed drugs should also wait for three months before donating.
Blood samples are also taken from potential donors to screen donations for a wide variety of infectious diseases.
Providing the donation
After all the initial checks have been satisfactorily completed, donors are taken to provide their blood donation. This is usually completed whilst lying down, with a blood pressure cuff placed on the arm to maintain a small amount of pressure during the collection process. Donors are also advised to apply muscle tension (usually by clenching and unclenching the fist) to maintain blood pressure.
A phlebotomist will examine the arm to identify a suitable vein. The area of the skin around the vein will be cleaned using an antiseptic wipe to kill all normal bacteria on the skin. Once the insertion of the needle into the vein is complete, the donor should feel comfortable throughout the session, with no pain or discomfort.
The total amount of blood that is collected is about one pint, which takes between five and ten minutes to collect. Throughout this time, an agitator scale constantly weighs and measures the donation, and stops automatically when the full sample has been collected.
After donation, the phlebotomist will remove the needle and apply a sterile dressing to the collection site. It is advised that donors keep the dressing on for a minimum of six hours and avoid pushing or lifting with the arm used during donation.
After donating
Donors are provided with aftercare instructions and contact details in the event of any problems after the appointment. They are asked to remain at the donor center for approximately ten minutes to restore energy before leaving and to allow staff to monitor donors for adverse reactions. Most sites provide refreshments to help rehydration.
Donors are asked to apply light but continuous pressure to the venipuncture site while remaining in the refreshment area.
References:
- Redcrossblood.org. (2019). Home Page. [online] Available at: https://www.redcrossblood.org/.
- Revised Recommendations for Reducing the Risk of Human Immunodeficiency Virus Transmission by Blood and Blood Products Guidance for Industry. (2015). [online] . Available at: https://www.fda.gov/media/92490/download.
- NHS Blood Donation. (n.d.). What happens on the day. [online] Available at: https://www.blood.co.uk/the-donation-process/what-happens-on-the-day/.
- Klein, S., Flanagan, K. Sex differences in immune responses. Nat Rev Immunol 16, 626–638 (2016). https://doi.org/10.1038/nri.2016.90
Further Reading