How much do you actually know about Blood Donation?

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Blood donation is the process of drawing 450mL of whole blood from a healthy person for the purposes of transfusing blood products into a patient in need of those products.

Medical technologists have to assess many areas before drawing this unit of blood. The blood donation process includes:

  • Determining the donor’s hematocrit (blood level) and blood group (blood type);
  • Determining (via interview or questionnaire) if the person is healthy enough and fits the criteria to donate,
  • Acquiring patient’s consent for drawing and testing blood;
  • Drawing unit and samples required for testing.

Blood types:

Before delving into the blood donation process, allow me to ensure that everyone is fully educated on the eight (8) major blood groups and exactly who can give and receive what types. Here is a helpful chart that provides this information:

Blood TypeYou can give blood toYou may receive blood from
A +A +, AB +A +, A -, O +, O –
A –A +, A -, AB +, AB –A -, O –
B +B +, AB +B +, B -, O +, O –
B –B +, B -, AB +, AB –B -, O –
AB +AB +All blood types
AB –AB +, AB –AB -, A -, B -, O –
O +O +, A +, B +, AB +O +, O –
O –All blood typesO –


As depicted by the above table, the universalrecipient (the person who can receive from any blood type) is AB positiveand the universal donor (the person who can donate to any blood type)isO negative. However, both blood types are very rare. According to the American Red Cross, the rate is only 4% in the black population. The most popular blood type donated is O positive (found in 47% of the black population).

Types of donors:

There are mainly two types of donors: Voluntary donors and Donors who are asked to donate for family or friends. Generally, medical technologists prefer the voluntary donors, as they tend to be the healthier set. When “forced” to donate for a family member or friend, the donor is generally not prepared and might have smoked, drunk alcohol or been on medication. They would likely not know the process and therefore most likely would not fit the criteria established.  At JNF Hospital, it is our goal to achieve at least 30% voluntary donation. However, at present we would be lucky to have reached 5%.

Blood type and Hematocrit:

When donating blood, the medical technologist would first determine the donor’s blood group and blood level. It is imperative that the donor understands that if donating for a specific patient, while it is helpful to know the patient’s blood type, it is NOT necessary. The blood being taken from that donor is merely a replacement, and not necessarily given to that particular patient. Once the blood is taken, it is coded and therefore difficult for the technologist to determine what unit was taken for what patient. Also, processing of the unit takes approximately one week, by which time the patient would have already needed the unit requested.

For the purposes of donating blood, the donor’s blood level must be over a certain level (36% for females, 39% for males). This is to ensure that after the blood is drawn, the patient will not becomeanemic.


After verifying that the donor’s blood type is needed and that the blood level is sufficient, the donor is carried into a secluded room where vitals (such as blood pressure, pulse, temperature, weight) are taken and a number of questions are asked. Some questions are geared towards keeping the donor well, and some are to protect the patient receiving the blood. They are as follows:

Questions to safeguard donors:

Have you eaten for the day?

  • Are you hypertensive/diabetic?
  • Do you have any other chronic or acute medical conditions such as sickle cell anemia, heart problems, liver diseases etc.?
  • Are you pregnant?

Questions to safeguard the patient:

  • Are you currently on medication?
  • Have you ever tested positive for sexually transmitted diseases?
  • Do you participate in illegal drug use?
  • Have you recently travelled to a malaria endemic country?
  • Have you been to jail in the past year?
  • Have you had a tattoo or piercings in the past year?
  • Do you participate in high-risk sexual activity such as sex with more than one partner without a condom, prostitutes, homosexuals or bisexuals?

The most commonly asked questions by the prospective donor are “what is the purpose of asking about going to jail and recent tattoo and piercings?” Firstly, whilst in jail, men may participate in sexual acts (whether consensual or not). This would put them in the ‘at risk’ group for HIV and other STDs. With regard to the tattoo and piercings, the donor may have been infected with a used needle and would therefore be exempted for one(1) year,according to the window period in which these infections may not be detected.

After the donor is questioned to the satisfaction of the medical technologist, the donor is told that the blood drawn will be tested for HIV 1&2, Hepatitis B and C, HTLV 1&2 (a virus similar to HIV which attacks the T-lymphocytes)and Syphilis. The donor then has to give written consent for this process along with the technologist (for confidentiality); it’s like a contract. If any results return positive, the donor is notified to see their doctor, and the laboratory will also notify the doctor.

Blood Drawing Process:

The blood drawing process lasts about five to ten (5-10) minutes depending on the flow of blood. It is the medical technologist’s duty to ensure that the donor is conscious and as comfortable as possible. If at anytime the donor asks to stop the process, feels discomfort, or is in pain, the blood drawing process ceases. The donor bag is labeled with the blood group, collection date and expiration date, along with a number assigned to the unit. It is atthis time that the samples for testing are also drawn. At the end of the process, the donor is asked to abstain from heavy lifting for the remainder of the day and to drink lots of water to help build back up fluid lost.


The blood donated has multiple uses and one unit can go a long way. That unit can be separated into Packed Cells, Plasma, or even Platelets.

Some Uses of Packed Cells:

  • For pregnant patients who have lost a lot of blood via delivery/cesarean section.
  • Accident victims who have lost a lot of blood.
  • Gunshot wound victims who are actively and profusely bleeding.
  • Patients undergoing major surgeries such as hysterectomies or amputations.
  • Patients with chronic diseases which may cause gradual blood loss such as End Stage Renal failure or various cancers (eg. colon)
  • Internal bleeding patients (Upper Gastro Intestinal Bleeding)

Some uses ofPlasma:

  • Patients who have lost a lot of fluid and nutrients due to an open wound bleed (this is used along with Packed Cells)
  • Patients with clotting factor deficiencies

Some uses for Platelets:

  • Patients with viruses that decrease the platelet count (Leptospirosis, dengue etc)
  • Patients with genetic platelet deficiencies.

Therefore, one unit donated can be given to an anemic patient as packed cells, a patient with clotting problems as fresh plasma, or a patient with extremely low platelets in the form of just platelets. Of course, every product has its expiry date. Whole blood or packed cells expire in thirty-five (35) days. Plasma, which is separated and taken off within twenty-four (24) hours, is frozen and lasts one year. Platelets must be separated immediately and last one (1) day.

As mentioned before, it takes approximately one (1) week to complete all testing on the unit before it is ready for use. If for any reason a unit is positive for any of the tests, the unit is immediately discarded.


There are a few myths surrounding blood donation which all technologists would love ‘to get the rid of’. Here are a few:

  • Women cannot donate: All genders can donate, as long as the person is over the age of eighteen (18) and under seventy (70) years of age. Sixteen (16) years olds can donate once the parent orguardian of that child provides written consent. It is advised that if the female donoris currently on her menses/’seeing her period’she may return at a later date, due to the amount of blood lost during menstruation, which may leave her a bit lethargic.
  • Donors with tattoos and piercings cannot donate. Once the patient has passed the one (1) year mark of receiving the tattoo or piercing/s, the donor is indeed welcomed.
  • Blood donation is extremely painful: The medical technologists at the JNF Hospital try to make this process as pain-reduced as possible and try to make the donor as comfortable and at peace as possible.


Once a donor has donated,he/she is encouraged to return as a volunteer donor within the next three (3) months (within this time the blood lost would have had sufficient time to build back up). This allows not only the Blood Bank to keep a healthy stock of blood to be used on demand, but it also serves as a free health check for the donor.

With this being said,readers who fit the above-mentioned criteria are encouraged to become volunteer donors. The Blood Bank hours are from 8:30 a.m. to 1:30 p.m. Monday to Friday.  Blood drives are also held throughout the year, and are advertised on radio.So listen out for our next blood drive, and don’t hesitate to play your part in saving a life! 

Submitted by, 

Ms. Sasskya Archibald

Medical Technologist, JNF Hospital

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