Blood Donation and Transfusion

Overview

Every year, nearly five million Americans need blood transfusions. An estimated 43,000 pints (or units) of donated blood are used each day in the United States, and one in seven people entering the hospital needs blood. Women are critical to the country’s blood supply, since their role as caregivers sends a message that donating blood is the right thing to do. However, they are also more likely than men to be temporarily restricted from donating because of low hematocrit, or red blood cell levels if they are still menstruating.

Blood Shortages: Why Donating Blood Is Important 
Unfortunately, the country’s blood supply on occasion runs on perilously thin margins. Blood shortages occur periodically when supply doesn’t keep up with demand. But if only one more percent of the United States population would give blood, these shortages would disappear for the foreseeable future.

Shortages occur for numerous reasons, including generational differences and behaviors associated with giving blood and an increased need for blood transfusions. Blood banks work hard to make it as easy and convenient as possible to donate blood. Still, there are numerous restrictions on who can donate blood, with an estimated 62 percent of the American population unable to donate.

How Do You Donate Blood?
Donating blood is relatively simple and entirely safe, however, taking just an hour and requiring little preparation. There is little risk of adverse reaction when donating blood, and you can donate whole blood every 56 days; blood platelets every three days, up to 24 times a year. However, a few people may feel dizzy or faint during the process. In general, this can be prevented by eating a good meal and drinking a lot of fluids (not caffeine) before the donation.

Is the Blood Supply Safe?
The blood supply today is extremely safe, with the risk of catching a blood-borne disease via a transfusion miniscule. Research is underway to make the blood supply even safer via blood sterilization. Transfusions carry other risks, including the risk of receiving the wrong blood type and of contracting a rare lung condition that can be deadly.

The Blood Transfusion Process 
During a transfusion, any one of several blood components may be transfused, including blood platelets, which help blood clot; red cells, which carry oxygen; and plasma, the watery fluid that transports cells and nutrients and replaces blood volume.

What Are the Different Blood Types?
There are four types of blood—O, A, B, and AB—and each type can be positive or negative, referred to as the Rh factor. In an emergency, anyone can receive type O negative blood, regardless of his or her own blood type. Researchers have also developed medicines that may help mimic the actions of some blood parts. Throughout your life, you will undergo numerous blood tests. The most common blood test, called a complete blood count, or CBC, measures the number of white and red blood cells, your hemoglobin and hematocrit values and your platelet count. Another slew of blood tests, referred to as a comprehensive metabolic panel, provide important information about your kidneys, liver, blood sugar and blood proteins.

Facts to Know

1. Every year, nearly five million Americans need blood transfusions, while an estimated 43,000 pints of donated blood are used each day.
2. This country has a severe blood shortage.
3. It takes just an hour from start to finish to donate blood.
4. As caregivers, it is particularly important that women donate blood because it sends a signal to other family and friends that donating blood is safe, painless and appropriate.
5. Donating blood is perfectly safe, with no risk of contracting any blood-borne diseases.
6. You can donate blood every 56 days.
7. Women who still menstruate may have low iron levels that temporarily prevent them from donating blood, but they can return and donate once their iron levels return to normal.
8. The U.S. blood supply is very safe, with little chance of diseases like HIV being transmitted via blood transfusion.
9. About 85 percent of Americans have Rh-positive blood.
10. In an emergency, anyone can receive type O negative red blood cells. People with this type of blood are known as “universal donors.”Need for DonorsWhy Donate? Blood Shortages
    Unfortunately, we experience frequent blood shortages in this country. According to America’s Blood Centers, more than 43,000 pints of donated blood are used each day, and nearly five million Americans need blood transfusions annually. One in seven people entering the hospital need blood, and someone in this country needs blood every two seconds.It wouldn’t take much to improve the situation. If all current blood donors gave blood just three times a year (the average is two times a year), blood shortages would be a rare event, experts say.Major Reasons for Blood Shortages
    A major reason for the blood shortage is that even though 38 percent of the country’s population is eligible to donate blood, only about five to 10 percent does. There are three main reasons for the shrinking numbers, say experts:
    1. Changing demographics
       Since blood transfusions became commonplace in the 1950s, blood centers have depended on the World War II generation for donations. This generation is now aging and has fewer eligible donors, and Baby Boomers and the generations that follow simply don’t donate as much. Experts aren’t sure why, but suspect it may be related to differences in lifestyle, the level of altruism and the fact that the blood community may not be effectively appealing to these generations.
    2. Increasing need for blood
       As surgeries become more complex and cancer treatments more aggressive, and as people live longer, according to the American Red Cross, this country uses about six percent more blood every year.
    3. Increasing blood donor rejection rate
       Beginning with the AIDS epidemic in the early 1980s, the blood supply has gotten much safer. But that’s required turning away more and more potential donors. Today, increasingly sophisticated and sensitive tests, coupled with significantly more questions on application forms designed to weed out donors who may transmit blood-borne diseases, means there are fewer people who are able to donate blood even if they want to. For instance, people who have spent three or more months in the United Kingdom between 1980 and 1996 cannot donate blood for fear they could introduce the human version of mad-cow disease, variant Creutzfeldt-Jakob Disease (vCJD), into the blood supply.
    4. Blood products are perishable
       Red blood cells have a shelf life of 42 days, platelets just five days, so blood donations are needed every day, 365 days a year.

    Why People Don’t Give Blood
    The greatest barrier that prevents people from donating is a lack of convenience and a lack of knowledge of the importance of donating, experts say. And it is important. Every pint of donated blood saves three lives, and someone needs blood every two seconds.

    Then there are people’s perceptions about blood donation and the excuses they give for not donating. According to the American Red Cross, the most common excuses people give for not giving blood include the following:

    • I’m afraid of needles. However, most donors say they only feel a pinch.
    • I’m too busy. But most donations take less than an hour from start to finish.
    • I didn’t know there was a need for blood. Every two seconds, someone needs blood, and 43,000 units are needed each day.
    • I already gave this year. You can give blood every 56 days, and many donors give five times a year.
    • I’m afraid of AIDS. These days, it is not possible to get AIDS by donating blood because a new sterile needle is used each time.
    • I don’t have the right blood type. Every blood type is needed.
    • I can’t spare the blood. The average adult has 10 to 12 pints of blood, and donated blood is quickly replaced, usually within 24 hours.Types & Tests
    • Types of Blood
      Blood cells—red, which carry oxygen; white, which fight infection; and platelets, which help with clotting—are produced in your bone marrow. They are carried throughout your body in plasma, a pale yellow mixture of water, proteins (produced primarily in your liver) and salts.There are four main types of blood, and each type can be either Rh positive or negative:

      Blood Type	Percentage of Population
      O+	38*
      O-	7*
      A+	34
      A-	6
      B+	9
      B-	2
      AB+	3**
      AB-	1*

      Your Blood Type & What Blood You Can Receive 
      In an emergency, anyone can receive type O red blood cells. People with type O are known as “universal donors.” Type AB individuals can receive red blood cells of any ABO type. They are known as “universal recipients.” They can also give plasma to all blood types.

    • Blood TransfusionsWhen you give blood, you’re actually giving several products that can be transfused into several different people for various reasons. Blood is composed of plasma, platelets and red cells. All blood donations are processed and available for use approximately 24 to 48 hours after donation. After processing, red cells can be stored for 42 days, plasma can be frozen and stored for up to 12 months and platelets (from whole blood or by apheresis) expire after 5 days and are stored at room temperature.Blood Components & How They Are Used
      • Plasma is the watery fluid that transports cells and replaces blood volume. It is required to maintain blood pressure and assist in clotting. It also contains proteins that may help fight disease.
      • Platelets are proteins that help blood clot. They are transfused into patients undergoing transplants and those with leukemia and other cancers.
      • Red cells carry oxygen. They are transfused into patients with anemia, and those who have lost blood during surgery or trauma.

      Blood Component Use	Units*
      Automobile Accident	50 units of blood
      Bone Marrow Transplant	20 units of blood 120 units of platelets
      Heart Surgery	Six units of blood Six units of platelets
      Organ Transplant	40 units of blood 30 units of platelets 20 bags of cryoprecipitate 25 units of fresh frozen plasma

      *Average usage.

      Autologous Transfusions
      Autologous blood donation, in which you donate your own blood for use during a surgical procedure, was quite popular in the early 1980s when the risk of HIV infection was very real. But today it’s not worth doing if your community has an adequate blood supply. Although autologous donations can spare you some of the very low infectious risks of using the available blood supply, from a cost/benefit standpoint it’s a very expensive option to prevent a very few bad outcomes.

      Half of all autologous donor blood doesn’t even get used and must be discarded. Plus, even if you donate your own blood, you may still have a reaction during the transfusion. Or, your donation could get mixed up with someone else’s and used for the wrong patient.

      Overall, experts agree, the safest alternative for medically needed transfusion remains your own blood, but, in most cases, this option adds very little from a safety perspective. Still, if you want an autologous blood transfusion for your own peace of mind, all blood centers offer the option.

      Are Transfusions Necessary?
      One of the simplest ways to stretch the tight blood supply might be changing physician practices about when patients should get transfusions. A growing body of scientific literature suggests that some transfusions might not be necessary. Traditionally, most doctors have transfused patients when their hemoglobin levels drop to 10 g/dL. Today, many doctors think the decision of whether or not to transfuse should be made in the context of other factors as well, including the patient’s symptoms and overall health.

      Reducing the number of blood transfusions this way could increase the nation’s blood supply, making blood more readily available to those in need. To move hospitals in this direction, some blood centers have full-time “transfusion safety officers” who work with hospitals on these and other transfusion-related items. But patients can also play a role, say experts, by asking their doctors: “Is this transfusion necessary?”

      Risks of Blood Transfusions
      Transfusion errors pose a small but significant risk to patients, occurring at the rate of two errors a day nationwide, on average. And no one really knows how many result in death, since, until fairly recently, hospitals weren’t required to report transfusion-related errors that did not result in death. Between October 1, 2005, and September 30, 2006, the FDA received 81 reports of fatalities in patients receiving blood transfusions. Of those, eight were unrelated to the transfusion, 63 resulted from the transfusion, and the other 10 causes of death were undetermined. Yet even if it doesn’t result in death, any kind of reaction to the wrong blood can slow your recovery and increase your risk of complications.

      The primary reason for most blood-related errors is human mistakes. For instance, the sample from the patient may be mislabeled with another patient’s name before it is sent to the lab, and then the wrong unit is sent to the patient for transfusion. Or, in the heat of crisis in the emergency room, someone forgets to double-check a patient’s identity and match it with the label on the unit.

      To avoid these errors, some hospitals have begun implementing bar code systems for blood transfusions, in which nurses use a scanning wand like those used in grocery stores to make sure the code on the blood matches the code on the patient’s bracelet.

      In addition to your risk of getting the wrong blood, other risks include bacterial contamination of blood products and a condition called “transfusion-related acute lung injury,” a serious pulmonary syndrome that can lead to death if not recognized and treated appropriately. The syndrome is believed to be the third most common cause of blood transfusion-related death. There is also some concern that transfusion may affect the immune system and cause some mild immune suppression.

      For these and a multitude of other reasons—not the least of which is the chronically short blood supply—researchers have been scrambling to discover “artificial” blood products and means of maintaining blood products longer. Various types of hemoglobin carriers are being studied, but approval is unlikely in the foreseeable future because of safety concerns.