Whole human blood

Whole human blood is the blood that is drawn directly from the body, containing all of its components without any separation or modification. It consists of plasma, red blood cells (RBCs), white blood cells (WBCs), and platelets, each of which has specific functions critical to the body’s survival and overall health.

 

Components of Whole Blood:

1. Plasma (55% of blood volume):

   • Description: Plasma is a straw-colored liquid that makes up the majority of blood's volume.
   • Function: It serves as a medium for transporting nutrients, hormones, waste products, proteins (such as clotting factors), and antibodies throughout the body. It also helps maintain blood pressure and regulate body temperature.

2. Red Blood Cells (RBCs, 45% of blood volume):

   • Description: These cells contain hemoglobin, a protein that carries oxygen from the lungs to tissues and returns carbon dioxide back to the lungs for exhalation.
   • Function: The primary role of RBCs is to transport oxygen and carbon dioxide. The concentration of RBCs in blood is crucial for adequate oxygen delivery to tissues.

3. White Blood Cells (WBCs, less than 1% of blood volume):

   • Description: These cells are part of the immune system and help the body fight infection. There are different types of WBCs, such as lymphocytes, neutrophils, monocytes, eosinophils, and basophils.
   • Function: WBCs protect the body by identifying and destroying pathogens like bacteria, viruses, and other foreign invaders.

4. Platelets (less than 1% of blood volume):

   • Description: These are small, cell-fragment particles that play a key role in clotting.
   • Function: Platelets help prevent bleeding by clumping together at sites of injury and forming clots to seal blood vessels.

Clinical Use of Whole Blood:

Whole blood is rarely used in transfusions today because specific blood components are typically needed for different medical conditions. For example:

• Red blood cell transfusions: Used in cases of anemia or significant blood loss.
• Platelet transfusions: Given to patients with clotting disorders or low platelet counts (such as in cancer patients).
• Plasma transfusions: Often used in cases of severe burns, liver disease, or clotting disorders.

However, in emergency situations where rapid volume expansion is needed, such as trauma or massive hemorrhage, whole blood may be used to stabilize the patient.

Blood Typing and Compatibility:

Whole blood contains both red blood cells and plasma, so it must be compatible with the recipient’s blood type. Blood typing is determined by the presence or absence of specific antigens on RBCs and antibodies in plasma. The ABO and Rh systems are most commonly used to ensure compatibility in transfusions:

• ABO System: Individuals can have type A, B, AB, or O blood, depending on the antigens present on their RBCs.
• Rh Factor: Blood is either Rh-positive or Rh-negative, depending on the presence of the Rh antigen.

Storage of Whole Blood:

Whole blood can be stored for about 35 to 42 days, but its components degrade over time. This is why whole blood is often separated into its individual components, which can then be stored and used separately with longer shelf lives (e.g., red blood cells can be stored for up to 42 days, and plasma can be frozen for a year).

Summary:

Whole blood plays a vital role in transporting oxygen, nutrients, and immune cells while helping maintain hemostasis. In modern medicine, it is mostly fractionated into specific components to address different clinical needs. However, in situations requiring immediate, comprehensive blood replacement, whole blood can be lifesaving.