Blood Transfusion and Blood Groups (ABO and Rh system)

Carl Landsteiner discovered ABO blood groups in 1900, for which he won the Nobel Prize in 1930. The AB blood group was discovered by Decastello and Sturli in 1902. 

• Blood groups are determined by the presence or absence of specific proteins, called antigens and antibodies, in the blood.

The Rh (Rhesus)  factor is a specific protein found on the surface of red blood cells. The name comes from its discovery in the Rhesus monkey, where it was first identified. The presence or absence of the Rh factor is used to classify blood as either Rh-positive (Rh +ve) or Rh-negative (Rh -ve).

• Rh Positive (Rh +ve): Indicates the presence of the Rh factor.
• Rh Negative (Rh -ve): Indicates the absence of the Rh factor.

Each of the four main blood groups (A, B, AB, and O) can be either Rh positive or Rh negative, resulting in a total of eight different blood groups.

When a person experiences significant blood loss, such as from an accident or injury, blood transfusion is often necessary to replace the lost blood. Blood transfusion is carried out to compensate for the blood shortage in the body. This is called a blood transfusion.

• During surgical operations, blood transfusions are performed to maintain the required blood volume and support vital functions.
• Patients suffering from conditions like anaemia, thalassaemia, or cancer may also require blood transfusions to restore healthy blood levels.
• Blood transfusion is a process used to compensate for blood shortages in the body, ensuring that the organs receive enough oxygen and nutrients.
• This medical procedure is critical for saving lives and supporting patients' recovery during or after severe blood loss or treatment for chronic conditions.

• Blood banks collect blood from healthy donors using a standardised and safe method.
• The collected blood is then processed, tested, and prepared for use in medical treatments or emergencies.
• Blood from donors is supplied to patients in need, such as those undergoing surgeries, trauma care, or suffering from medical conditions requiring transfusions.
• If the blood is not needed immediately, it can be stored in a refrigerator under controlled conditions to maintain its quality and usability.
• Blood can be preserved for a certain number of days, ensuring that it is available for future use when required.

A blood donor is a person who voluntarily gives their blood to help others who need it for medical reasons, such as surgeries, injuries, or illnesses. 

• Blood donors must meet certain health and age criteria to ensure the safety of both the donor and the recipient.
• Typically, donors should be in good health, of a certain minimum age (usually 16 or 18, depending on regulations), and meet weight requirements. 
• One blood donation can potentially save up to three lives, as components like red cells, platelets, and plasma can be separated and used for different patients.

Donation Process:

• The process involves a health screening, a blood type check, and the safe collection of blood using sterile equipment.
• The entire donation procedure is generally quick and safe, lasting about 10-15 minutes, with additional time for recovery.

Types of Donations:

1. Whole Blood Donation: The most common type, where a pint of whole blood is collected. One pint is approximately 473 millilitres (mL), which is about half a liter. This is the standard amount collected during a typical whole blood donation.
2. Platelet Donation: Platelets are collected separately and used for patients undergoing treatments like chemotherapy.
3. Plasma Donation: Plasma is separated and collected, often used for burn or trauma patients.

A blood recipient is a person who receives blood through a transfusion, often needed for medical emergencies, surgeries, or treatments of certain health conditions. 

1. A person with blood group 'O' is referred to as the universal donor because they can donate blood to individuals of any blood group.
2. A person with blood group 'AB' is called the universal recipient because they can receive blood from any blood group without adverse reactions.

Blood transfusion is performed only after matching the donor and recipient blood groups to ensure safety. Blood groups are hereditary, meaning they are passed down from parents to their children through genes. 

• The compatibility of blood groups is essential for safe transfusions, as mismatched transfusions can be life-threatening.
• If a transfusion is carried out without proper blood group matching, it can cause severe and potentially fatal reactions in the recipient.
• Blood donation is a selfless and life-saving act, often required in critical situations like accidents, excessive bleeding, childbirth (parturition), and surgeries.
• A person who donates blood today may themselves become a recipient in the future, highlighting the importance of maintaining an adequate blood supply.