Too Much Blood at the Wrong Time
The American Red Cross says that in the United States, someone needs blood every two seconds, and someone needs platelets every thirty seconds. Yet the supply often runs short. About 37% of Americans are eligible to donate, but fewer than 10% of them actually give each year. In the UK the donation rate is about 4%, and in Canada it is 3.5%.
Strangely, the pattern flips during disasters. From 1988 to 2013, every national disaster brought a surplus of donations. In the first week after the September 11 attacks, about 28,700 more donations came in than in a normal week before them. Much of the extra blood given during disasters later has to be thrown away.
The reason is shelf life. Most parts of blood do not keep for long, so building up a big stockpile is hard. After the September 11 attacks, experts agreed it was better to keep a steady supply at all times than to rush collections during a crisis. Even so, US blood centers often struggle to keep even a three-day supply, and one pathologist notes that shortages regularly strike between July 4 and Labor Day.
From a Belgian Doctor to the First Blood Bank
The first transfusion that did not go straight from one person to another took place on March 27, 1914. Belgian doctor Albert Hustin performed it with a diluted blood solution. In November that same year, Argentine doctor Luis Agote used a much less diluted one. Both used sodium citrate as an anticoagulant.
In 1921, Percy Lane Oliver, secretary of the British Red Cross, set up the world's first blood donor service in London. Volunteers took physical tests to find out their blood group. The service was free and grew quickly. By 1925 it was serving almost 500 patients, and similar services soon appeared in France, Germany, Austria, Belgium, Australia and Japan.
In 1937, Bernard Fantus at Cook County Hospital in Chicago set up one of the first hospital blood banks in the United States. His lab kept donated blood refrigerated and stored, and he came up with the very term "blood bank." The world now marks World Blood Donor Day every 14 June, the birthday of Karl Landsteiner, the scientist who discovered the ABO blood group system.
Who Gets to Give, and Who Has to Wait
Before anyone donates, they answer questions about their health and get a short check. Staff look at pulse, blood pressure, body temperature and hemoglobin. Low hemoglobin is the most common reason a donor is turned away. The American Red Cross accepts levels from 12.5 g/dL for women and 13.0 g/dL for men, up to 20.0 g/dL. Weight matters too: whole blood donors there must weigh at least 50 kg.
People who cannot give right away get a deferral, not a rejection, because many of them can donate later. Pregnant women usually wait until six weeks after the pregnancy. Some places ask about travel: Canada defers people who lived in the United Kingdom, while Australia dropped that rule in July 2022. And despite a common misconception, blood from a family member is not safer. It must be treated with radiation to prevent graft-versus-host disease, which is more likely between related people.
Every donation is typed as A, B, AB or O, plus its Rh type. Type O negative is famous as the universal donor, but that label only applies to red cells and whole blood. For plasma and platelets the rule flips. AB positive is the universal platelet donor type, and both AB positive and AB negative are universal plasma donor types. Testing in the US takes at least 48 hours.
What Happens to a Donation
A single donation, called a unit, is 450 millilitres by World Health Organization standards, but the size varies by country. India uses 350 mL, and Japan uses 200 or 400 mL. The plastic bag holds sodium citrate, phosphate, dextrose and adenine, which keep the blood from clotting and preserve it for up to 42 days. Most patients need only one part of the blood, so a donation is usually split into red cells and plasma.
Another method is apheresis. A machine draws blood, keeps one part and returns the rest to the donor. Because the red cells go back, donors can give plasma or platelets much more often. In the US, plasma donors may give twice a week and could nominally donate 83 litres in a year. In Japan, the same donor could give only about 16 litres a year.
Each part has its own shelf life. Platelets last at most seven days, red cells 35 to 42 days in a fridge, and frozen plasma usually gets a one-year expiry date. The body refills, too. Plasma is replaced in 2 to 3 days, while red cells take about 36 days on average in healthy adult men. That recovery time decides how often someone can donate.
Juice, Cookies and a Porcelain Pelican
After giving, donors usually stay 10 to 15 minutes, because most reactions happen during or right after the donation. Blood centers hand out light snacks like orange juice and cookies. In one study, 2% of donors had a reaction, and most were minor. Fainting is generally the worst problem, and a bruise on the arm is the most common concern.
Countries reward donors in creative ways. In Italy, donors get the donation day as a paid day off work. In 2023, Poland gave employed donors two days off: the donation day and the day after. Polish donors who give 18 litres (men) or 15 litres (women) earn the title "Distinguished Honorary Blood Donor" and a medal. In some big Polish cities they can also ride public transport for free, and a theatre in Poznań gives them ticket discounts.
Ireland awards pins for 10, 20 and 50 donations. Donors who reach 100 are invited to a dinner and receive a small porcelain statue of a pelican, the logo of the Irish Blood Transfusion Service. Malaysia offers free outpatient and hospital care after each donation. Giving can even help the donor: for people prone to iron overload, donating blood stops toxic amounts of iron from building up.
