Overview of Blood Donation
Blood donation is a critical part of healthcare across the globe. Every year, people give over 100 million units of blood. This donated blood can save lives, helping patients in surgery, dealing with accidents, facing long-term illnesses, and fighting cancer. Patients with specific health conditions, like hereditary hemochromatosis (an iron overload disorder) and polycythemia vera (a bone marrow disease), also benefit from giving blood.
The practice of blood donation has an interesting history. In the early 20th century, a scientist called Karl Landsteiner identified different blood groups, leading to the standard practice of matching blood types during transfusion. However, there were challenges in preserving donated blood and preventing blood clotting once it was taken from a donor. In the early days, transfusions needed to happen directly from the donor to the recipient. This made it hard to manage on a large scale, as it required the donor and the patient receiving the blood to be in the same place at the same time. This system wasn’t very flexible and became a big problem during World War I, where soldiers were dying from wounds that could have been treated with a timely blood transfusion.
The war created a need to find a way to store and deliver blood effectively. This led to some important discoveries. Firstly, adding a substance called citrate to donated blood prevented it from clotting. Secondly, adding glucose helped the red blood cells (the cells that carry oxygen in your blood) to survive for several weeks under refrigeration. A breakthrough came in 1917 when Captain Oswald Hope Robertson of the US Army discovered a way to “bank” blood. Mixing group O blood with glucose, he managed to store this blood mix. This was a big step forward, moving from “direct” to “indirect” blood donation, and meant donors didn’t have to be in the same place or time as the patients. This made blood donation and transfusion much more practical and useful.
Why do People Need Blood Donation
Blood donations are usually used for two main reasons: to help with anemia and to replace blood lost suddenly. The medical term often used for blood donation is “therapeutic phlebotomy.” This technique can also be useful for treating a few specific health conditions. For example, therapeutic phlebotomy is recommended for people with hereditary hemochromatosis, a condition that leads to too much iron in the body, or other disorders related to blood cell production like polycythemia and porphyria.
Sometimes, when a person is about to have surgery, they might donate their own blood to be used during or after the operation. This process is known as “autologous donation”. This practice was common in the 1980s and 1990s when people were more concerned about diseases such as HIV and hepatitis C being transmitted through blood transfusions. Health professionals might recommend patients who are likely to need a blood transfusion during or after surgery to donate their own blood about 72 hours before the procedure. However, this option isn’t available for patients with a suspected bacterial infection or conditions that put them at high risk.
Thanks to improved safety measures in how blood is donated, handled, tested, and transfused, the risk of infections like HIV and hepatitis C being passed on through blood transfusions is now much lower, so autologous donation is less common now. It could still be a beneficial option for people with common “alloantibodies”, a kind of immune system protein, that could make it hard to find matching blood from donations. Autologous donation also helps conserve donated blood supplies, decreases the risk of the body reacting negatively to donated blood, reduces or eliminates the risk of catching transfusion-related diseases, and may make some people feel more comfortable accepting a blood transfusion.
Another source of blood for transplantation is umbilical cord blood, which is obtained at the time of a baby’s birth and stored in specialized cord blood banks for future use. This blood has a much higher percentage of hematopoietic stem cells (cells responsible for producing blood) than normal blood, making it an excellent candidate for stem cell transplants.
When a Person Should Avoid Blood Donation
When it comes to giving blood, not everyone is eligible to be a donor. The organization known as American Association of Blood Banks (AABB) makes these rules, which they update occasionally, and made available online for anyone curious. The Food and Drug Administration (FDA) also has additional details on blood donations.
The AABB has set certain criteria that a person must meet to donate blood. This includes being at least 16 years old (although it might be older in some states), weighing at least 110 pounds or 50kg, and not suffering from unchecked high blood pressure, diabetes, or anemia. It’s also important for the person to be in generally good health and feeling well at the time of donation. If a person’s blood pressure is too high (above 180/100 mmHg) or too low (below 90/50 mmHg), they cannot donate blood. Generally, it is advised that donors should have stable blood pressure without any negative effects for at least three months before donating blood.
A common reason for not being able to donate blood is having low hemoglobin, which is a part of the blood that carries oxygen in your body. This can happen in one out of ten potential donors, often because they aren’t getting enough iron in their diet. In the US, the minimum allowed levels of hemoglobin for donating blood are 13.0 g/dL for men and 12.5 g/dL for women. Since a significant amount of iron is lost each time a person donates blood, this could potentially prevent you from donating again.
To help your body recover after donating blood, the AABB recommends waiting 8 weeks or 56 days before donating again. Though, if someone donates 2 units of blood at once, they should wait 16 weeks. This time frame might not be enough for some people to regain their lost iron, meaning they could get deferred for having low hemoglobin if they try to donate again. Taking iron supplements might help to rebuild iron stores quicker. If a person gets deferred because of low hemoglobin, especially if they are men or women after menopause, they might have an underlying health issue causing anemia and should see their primary care provider for further evaluation.
Certain medications can harm potential unborn babies if given to someone who’s pregnant. This doesn’t necessarily stop you from being able to donate blood forever. A few examples of these medications include thalidomide, finasteride, and retinoids. One specific medication, etretinate, is extremely harmful to unborn babies and can leak out of fatty tissue into the bloodstream over time. If someone’s taken this medication, it’s strongly discouraged for that person to donate blood. The restrictions differ by country: for example, in Japan, a person has to stop taking etretinate for at least 2 years before becoming eligible to donate blood, but in the United States, the United Kingdom, and Quebec, it’s a permanent restriction. For thalidomide and finasteride, the waiting period is 1 month.
Additional reasons for deferral from blood donation include men who’ve had sex with a new partner, or more than one partner, and have had anal sex within the past three months, people who’ve had or have syphilis or gonorrhea, sex workers, people who’ve recently gotten tattoos or piercings, people on antiretroviral therapy for preventing HIV, and anyone who’s been exposed to blood through a transfusion, needle stick, or intravenous recreational drugs. Moreover, anyone with solid organ cancers must wait 1 to 5 years after they’re cured and symptom-free before they’re eligible to donate.
There are other situations in which people are not allowed to donate blood. This includes if someone has HIV, has taken medication for HIV, has had a blood or blood marrow-related cancer, suffered from hepatitis since turning 11, has been infected with parasites responsible for babesiosis or Chagas disease, has taken etretinate for psoriasis (a skin disease), has been identified as having risk factors for a brain disease known as variant Creutzfeldt-Jakob disease (CJD), or has blood relatives suffering from this disease. Additional risk factors for CJD include living for 3 months or more in the United Kingdom from 1980 to 1996, receiving a blood transfusion in the United Kingdom or France from 1980 until now, or living in Europe for 5 years from 1980 till now.
Blood donations are carefully tested for a variety of infectious diseases. They check for hepatitis B, hepatitis C, HIV-1 and HIV-2, a virus called HTLV that can cause leukemia and nerve disorders, syphilis, as well as DNA and RNA of several other diseases. If a donor tests positive for any of these infections, they are not allowed to donate blood. That said, it’s worth noting that some infections might not be detected because they’re too low in level or aren’t tested due to cost, availability, and prevalence. The list of diseases screened for is growing, which is leading to higher costs per donation event and limiting the number of eligible donors.
A newer development in blood donation is something called pathogen reduction or inactivation. This is a proactive approach that purges potential disease-causing agents from the blood donation. The most common method currently used to limit infections associated with transfusions is testing blood for specific disease-causing agents and then either purging the units of blood that test positive or temporarily barring those donors. In contrast, pathogen reduction targets all genetic material to prevent infections transmitted by transfusions. However, this method hasn’t been universally adopted in blood banks yet because the systems for doing so are still being developed and tested.
Equipment used for Blood Donation
When you go to donate blood, the healthcare providers will need a specific set of tools and equipment to ensure the process is safe and successful. Here’s the equipment they’ll use:
* Blood pressure cuffs: These help them monitor your blood pressure.
* Thermometers: This is used to check your body temperature.
* Scales: These are used to check your weight. This is important as there are certain weight requirements for donors.
* Donor chairs and tables: These are to help you feel comfortable during the donation process.
* Blood collection monitors or mixers: These machines ensure that the blood is collected and mixed safely.
* Blood bag tube sealers: This tool is used to seal the bag that collects your blood.
* Blood transportation boxes: These are specifically designed to transport donated blood.
* Blood bank refrigerators: They keep the blood donations at a specific temperature to preserve them.
* Tourniquet: This band is used to help make your veins more visible.
* Blood collection mixer and weigher: It’s a machine to mix the blood properly and weigh it.
* Bandages: Necessary to cover the needle site after donating.
* Cotton balls or gauze: Used for cleaning the area of injection and covering it post-donation.
* Needles, 16G or 18G: These are the sizes of the needles used for the donation process.
* Drinks and snacks for donors: After donating blood, it’s important to hydrate and eat something.
* Chlorhexidine gluconate (2%) and isopropyl alcohol solution (70%): Used to clean the skin before the needle is inserted.
* Labels: Labels are important to keep track of whose blood is in each bag.
* Pens: Used to fill out forms and label blood bags.
* Hemoglobin analyzer: A machine that checks the iron level in your blood before donation.
* Apheresis machine: This is only necessary if you’re donating plasma or platelets, not whole blood. This machine separates the blood components.
Who is needed to perform Blood Donation?
Staff who collect blood for donations are often specially trained and certified individuals known as phlebotomists. To become a phlebotomist, one must usually have a high school diploma and complete 1 to 2 months of both classroom learning and practical training. After this, they receive a certification confirming they are qualified to draw blood.
Besides phlebotomists, there are other people involved in the blood collection process. These individuals might have different types of medical training, such as being a licensed vocational nurse, a registered nurse, or an emergency medical technician. These are all healthcare professionals with different skill sets who can also be trained in collecting blood.
Preparing for Blood Donation
Before giving blood, it’s recommended that donors get plenty of rest, eat a full meal, and drink lots of non-alcoholic, non-caffeinated drinks. After donating blood, they should avoid heavy lifting, consuming alcohol, and smoking for a few hours to allow their body to recover properly.
How is Blood Donation performed
Firstly, the person who is donating blood goes through a health check. This includes questions about their health, a check of their overall wellness, vital signs like their heart rate and body temperature, and a simple finger-prick test to measure their hemoglobin levels (a substance in our blood that carries oxygen).
After passing the health check, the blood donor will move to a special table or chair where the blood will be collected. The healthcare professional will clean the area inside the donor’s elbow using a mixture of 2% chlorhexidine gluconate and 70% isopropyl alcohol. This is done to kill any germs and prevent infection. They will then insert a sterile needle into a vein inside the elbow to collect the blood.
In some cases, when the vein inside the elbow can’t be easily accessed, other prominent veins might be used, such as veins on the back of the hand. The person donating blood is kept under continuous watch during the process. The blood collected goes into a bag that contains a medication to prevent clotting, and is regularly mixed mechanically. Once the bag has collected about a pint of blood (450 mL), the needle is removed, and pressure is applied to the area to stop any bleeding.
The process of separating certain components like platelets or plasma from the whole blood is called apheresis. The rest of the blood is then returned to the donor’s body. This procedure needs two tubes connected to a machine that separates the blood, and it requires the use of both arms. Apheresis usually lasts around 1 hour, longer than a regular blood donation, which usually takes about 10 to 15 minutes.
Possible Complications of Blood Donation
When you get a blood donation, it’s done by a phlebotomist. They’re trained professionals who know how to select the right people to give blood, how to keep everything sterile, and how to manage the whole donation process. Some people might have side effects from giving blood, but these are usually rare and not serious.
The most common issue is a small pooling of blood under the skin (known as a hematoma) when the needle is removed. This can be prevented by putting pressure and a cold pack on the area. Although these are usually small and don’t cause serious issues, very rarely they can cause damage to nearby tissues, so it’s important to watch them closely.
The second most common problem after a blood donation is fainting (clinically known as syncope). This can happen because of a sudden drop in blood pressure or not having enough fluid in the body. During a fainting episode, donors may feel weak, sweaty, dizzy, or look pale. If this starts to happen, the donation process is stopped or paused, and steps are taken to help the donor feel better. Fainting can also happen after the donation, so it’s a good idea for donors to rest and replenish fluids with food and drinks afterward. It’s also advised to avoid alcoholic or caffeinated drinks for a few hours after donating. Slowly going from lying to sitting to standing can also help prevent fainting.
Some factors can increase the risk of these side effects, like being a first-time donor, being young, or being female. While fainting isn’t usually harmful, there is a risk of injury from falling, so it’s important to rest before and after the donation. Nausea and vomiting are not common, but they can happen and, if so, donation is temporarily paused.
Other less common risks include low iron, low platelet count, low white blood cell count, and high levels of a substance called citrate in the blood. Donating your own blood for yourself (known as autologous donation) can lead to low blood count, losing the donated blood due to unexpected events, and sometimes even delayed essential treatments.
Even though there are some risks, donating blood is generally safe and a lot of people do it to help others. Donors can greatly contribute to the health care of others and save lives.
What Else Should I Know About Blood Donation?
Donating blood and the process of transferring it to someone else, which is called a transfusion, are incredibly important for healthcare today. Many people’s lives are saved each year thanks to these procedures. The big challenge is having enough blood to go around, as it can’t be stored for very long, and products made from blood also have a short lifespan. For example, over 24 million whole blood units and products made from blood are used every year just in the United States.
Our ability to keep the blood supply going depends completely on people volunteering to donate their blood. Lately, finding donors has become more challenging due to new rules about who can give blood because of concerns over infections, new and better ways to screen donated blood, finding new viruses and bacteria, and changing requirements for who can donate. All these changes have made the pool of potential donors smaller. Efforts are being made to manage our blood supply better and use it more efficiently, and these strategies have helped ensure we make the most of the blood donations we receive.
