Blood Components Preparation

Introduction

-          Blood is a mixture of cells, colloids, and crystalloids.

-          Can be separated into different components:

-          Packed Red Blood Cells (pRBC)

-          Platelet Concentrate

-          Fresh Frozen Plasma

-          Cryoprecipitate

 

Component Separation Process

-          Components separated based on:

-          Relative density

-          Sediment rate

-          Size

-          Centrifugal force is applied for separation.

-          Each component is used for specific indications.

 

Importance of Component Separation

-          Maximizes the utility of one whole blood unit.

-          Provides different components for various therapeutic needs.

-          Enhances efficiency and effectiveness of blood transfusions.

 

Storage and Temperature Requirements

-          Different components have specific storage conditions.

-          Temperature requirements vary for therapeutic efficacy.

-          Proper storage is crucial for maintaining component integrity.

 

Centrifuge Process

-          Two main spins:

-          Heavy spin (e.g., 5000 G for 10-15 min)

-          Light spin (e.g., 1500 G for 5-7 min)

-          Configuration varies with manufacturer and model.

 

Automated Component Separation

-          Uses fully automated separator instruments.

-          Prepares low-volume blood components.

-          Achieves 90% recovery of whole blood platelets.

 

Red Cells Concentrate or Packed Red Blood Cells (PRBCs)

-          Obtained through centrifugation/sedimentation of whole blood.

-          Plasma is transferred to a separate bag, leaving packed red cells behind.

-          Hematocrit in packed red cell unit: 55% to 65%.

-          Reduced volume (200 ml) decreases the risk of volume overload.

 

Characteristics and Storage

-          Each unit raises hemoglobin concentration by 1 gm/dL.

-          Stored in a refrigerator/cold room at 2°C to 4°C.

-          Shelf-life: one month.

-          Essential for managing anemia and restoring oxygen-carrying capacity.

 

Indications for PRBCs

-          Anemia

-          β-thalassemia major

-          Sickle cell anemia

-          Aplastic anemia

-          Severe anemia of any cause

-          Hypovolemia due to hemorrhage

-          Blood loss during surgery

 

Fresh Frozen Plasma (FFP)

-          Plasma with anticoagulant preservative.

-          Frozen immediately at –20°C, shelf-life of 1 year.

-          Contains high levels of clotting factors.

 

Indications for FFP

-          Patients on anticoagulant drug therapy (Coumarin)

-          Antithrombin deficiency

-          Liver diseases

-          Vitamin K deficiency

-          Thrombotic thrombocytopenic purpura (TTP)

-          Disseminated intravascular coagulation (DIC)

 

Platelet Concentrate

-          Obtained from a single donor or pooled plasma.

-          Alternatively, obtained through platelet apheresis.

-          Stored at 20°C to 24°C to maintain viability.

-          Shelf-life of 5 days ensures timely utilization.

-          Platelets possess ABO antigens but lack Rh antigen expression.

 

Indications for Platelet Concentrate

-          Thrombocytopenia (platelet count <20,000/cu mm)

-          Immune-mediated

-          Secondary

-          Chemotherapy-induced

-          Due to leukemia

-          Dilutional

-          Abnormal platelet function

-          DIC

-          Bleeding disorders

 

Cryoprecipitate

-          The cold insoluble portion of plasma that precipitates when FFP is thawed between 1° to 6° C.

-          Contains concentrated Factor VIII, XIII, vWF, and fibrinogen.

 

Indications for Cryoprecipitate

-          Hemophilia

-          Factor XIII deficiency

-          Von Willebrand disease

-          Hypofibrinogenemia

 

Apheresis

-          Process of collecting anticoagulated whole blood from a donor.

-          Separation into components, retaining desired components, and returning the rest to the donor.

-          Collects various components for transfusion:

-          Platelets (Platelet apheresis)

-          Leukocytes

-          Plasma (Plasmapheresis)

-          Peripheral stem cells

-          Therapeutic apheresis to remove pathological components like cells, plasma, or plasma constituents:

-          Thrombotic thrombocytopenic purpura

-          Goodpasture syndrome

-          Guillain-Barré syndrome

 

Granulocyte Transfusion

-          Used to combat infections:

-          Neonatal sepsis

-          Chronic granulomatous disease

 

Indications for Granulocyte Transfusion

-          Agranulocytosis with a granulocyte count of less than 500/cu mm