Transfusion Medicine Chapter Quiz

Background of Transfusion Medicine

• Transfusion medicine covers blood donation, component preparation, serology, and transfusion therapy.
• The term "blood banking" has evolved into "transfusion medicine" to highlight patient care and clinical outcomes.

Blood Donor Eligibility and Regulations

• Blood donor criteria are set by the FDA to safeguard both donors and transfusion recipients.
• All blood establishments, including blood centers and transfusion services, must be FDA-registered and licensed for interstate commerce.

Blood Component Manufacturing

• Major blood components include red blood cells, platelet concentrates, fresh frozen plasma, and cryoprecipitate.
• Components are manufactured and stored to minimize functional loss and maximize patient outcomes.
• Key techniques in blood manufacturing include leukocyte reduction and pathogen reduction to decrease transmission risks.

Blood Collection and Distribution

• Blood centers are responsible for recruiting donors, collecting blood, and distributing components to transfusion services.
• Transfusion services conduct compatibility testing and provide medical support but do not typically collect blood.

Transfusion Guidelines and Recommendations

• Restrictive red cell transfusion is recommended for certain patients with a hemoglobin target of 7–8 g/dL to improve outcomes.
• Platelet transfusions are indicated for microvascular bleeding when platelet counts are critically low.

Pretransfusion Testing and Administration

• Accurate identification of blood samples and recipients is crucial to prevent acute hemolytic reactions.
• Blood component administration is highly regulated and must follow strict protocols to ensure safety.

Transfusion Reactions

• Types of transfusion reactions include:
  • Acute Hemolytic Reactions: Immediate response, often due to ABO incompatibility.
  • Delayed Hemolytic Reactions: Occur days to weeks after transfusion, related to minor antigen discrepancies.
  • Febrile Nonhemolytic Reactions: Common and usually benign, characterized by fever.
  • Allergic Reactions: Can range from mild to severe (anaphylaxis).
  • Transfusion-Related Acute Lung Injury: A serious, though rare, complication of transfusion.
  • Transfusion-Associated Circulatory Overload: May occur with rapid or large volume transfusions.

Specialized Practices

• Graft-versus-host disease prevention through irradiation of blood components.
• Leukocyte reduction decreases risks associated with human leukocyte antigens and infections like cytomegalovirus.

Conclusion

• Transfusion medicine is a critical field aimed at optimizing blood transfusion safety and effectiveness while minimizing risks to patients and donors alike.

Background of Transfusion Medicine

• Transfusion medicine covers blood donation, component preparation, serology, and transfusion therapy.
• The term "blood banking" has evolved into "transfusion medicine" to highlight patient care and clinical outcomes.

Blood Donor Eligibility and Regulations

• Blood donor criteria are set by the FDA to safeguard both donors and transfusion recipients.
• All blood establishments, including blood centers and transfusion services, must be FDA-registered and licensed for interstate commerce.

Blood Component Manufacturing

• Major blood components include red blood cells, platelet concentrates, fresh frozen plasma, and cryoprecipitate.
• Components are manufactured and stored to minimize functional loss and maximize patient outcomes.
• Key techniques in blood manufacturing include leukocyte reduction and pathogen reduction to decrease transmission risks.

Blood Collection and Distribution

• Blood centers are responsible for recruiting donors, collecting blood, and distributing components to transfusion services.
• Transfusion services conduct compatibility testing and provide medical support but do not typically collect blood.

Transfusion Guidelines and Recommendations

• Restrictive red cell transfusion is recommended for certain patients with a hemoglobin target of 7–8 g/dL to improve outcomes.
• Platelet transfusions are indicated for microvascular bleeding when platelet counts are critically low.

Pretransfusion Testing and Administration

• Accurate identification of blood samples and recipients is crucial to prevent acute hemolytic reactions.
• Blood component administration is highly regulated and must follow strict protocols to ensure safety.

Transfusion Reactions

• Types of transfusion reactions include:
  • Acute Hemolytic Reactions: Immediate response, often due to ABO incompatibility.
  • Delayed Hemolytic Reactions: Occur days to weeks after transfusion, related to minor antigen discrepancies.
  • Febrile Nonhemolytic Reactions: Common and usually benign, characterized by fever.
  • Allergic Reactions: Can range from mild to severe (anaphylaxis).
  • Transfusion-Related Acute Lung Injury: A serious, though rare, complication of transfusion.
  • Transfusion-Associated Circulatory Overload: May occur with rapid or large volume transfusions.

Specialized Practices

• Graft-versus-host disease prevention through irradiation of blood components.
• Leukocyte reduction decreases risks associated with human leukocyte antigens and infections like cytomegalovirus.

Conclusion

• Transfusion medicine is a critical field aimed at optimizing blood transfusion safety and effectiveness while minimizing risks to patients and donors alike.

Transfusion Medicine Overview

• Transfusion medicine integrates blood donation, component preparation, serology, and transfusion therapy, focusing on patient care and clinical outcomes.
• Blood banking terminology has evolved to emphasize transfusion medicine's broader scope.

Blood Component Sources and Functions

• Blood components include red blood cells, platelet concentrates, fresh frozen plasma, and cryoprecipitate.
• Leukocyte reduction helps in reducing alloimmunization and the risk of febrile reactions and cytomegalovirus transmission.
• Irradiation of blood components is critical in preventing graft-versus-host disease.
• Pathogen reduction techniques significantly lower the risk of transfusion-transmitted infections.

Blood Donation and Collection

• Blood centers are responsible for recruiting donors, collecting blood, and manufacturing blood components.
• Most hospital transfusion services rely on regional blood centers for access to blood components, rather than collecting their own.
• All blood establishments must be registered with the FDA and adhere to strict standards regarding donor eligibility and blood component manufacturing.

Pretransfusion Testing and Compatibility

• Accurate identification of pretransfusion blood samples and recipients is vital to prevent acute hemolytic transfusion reactions.
• Pretransfusion compatibility testing is conducted to ensure safe transfusions.

Blood Transfusion Guidelines

• Restrictive red cell transfusion practices, targeting hemoglobin levels of 7-8 g/dL, have demonstrated improved outcomes in specific patient groups.
• Platelet transfusions are indicated for microvascular bleeding and when platelet counts are critically low.

Adverse Reactions to Transfusion

• Various transfusion reactions include acute and delayed hemolytic reactions, febrile nonhemolytic reactions, allergic reactions, and anaphylactic reactions.
• Awareness of risks like bacterial contamination, transfusion-related acute lung injury, and transfusion-associated circulatory overload is crucial for patient safety.

Conclusion Notes

• The regulation and operational aspects of blood centers and transfusion services underscore the emphasis on safety and quality in transfusion medicine.

Plasma and Fresh Frozen Plasma (FFP)

• Plasma is extracted from whole blood and frozen for long-term storage.
• Freezing plasma at approximately −18°C preserves its quality, especially for clotting factors.
• FFP must be frozen within 8 hours of collection to maintain its effectiveness.
• Plasma labels vary based on the time and conditions before freezing:
  • PF24 if held at 4°C for up to 24 hours.
  • PF24RT24 if held at room temperature.
• FFP and its equivalents (PF24, PF24RT24) have similar coagulation factor content.
• Frozen plasma can be stored for up to 1 year at −18°C.
• Thawed plasma must be transfused within 24 hours and can be kept at fridge temperatures for up to 5 days.

Cryoprecipitated Antihemophilic Factor

• Cryoprecipitate is the insoluble component obtained after thawing FFP.
• Contains about 50% factor VIII, 20-40% fibrinogen, von Willebrand factor (vWF), and factor XIII.
• At least 80 IU of factor VIII is required per unit according to FDA regulations.
• Usually contains around 250 mg of fibrinogen.
• Primarily utilized for fibrinogen source today; historically used to treat hemophilia A.

Platelet Concentrates (PCs)

• PCs are derived from whole blood via centrifugation, leaving platelet-rich plasma.
• Must contain at least 5.5 × 10^10 platelets and stored at 20-24°C to maintain viability.
• FDA allows up to 5 days of storage with continuous agitation to prevent clumping.
• Alkalinity (pH) must remain 6.0 or above at the end of storage.
• Pools of PCs are required to achieve therapeutic doses (3.0 × 10^11 platelets) for adults.
• Pooled PCs that utilize open systems must be transfused within 4 hours.
• Apheresis platelets (single donation) also serve as an alternative source, collecting higher platelets in one session.

Leukocyte Components

• Granulocytes can be collected via apheresis and stored for up to 24 hours at room temperature.
• They require immediate transfusion for effective treatment due to decreased functionality over time.
• Donor stimulation with G-CSF is often necessary to obtain sufficient granulocyte volumes.
• Mononuclear cells can provide hematopoietic progenitor cells (HPCs) for transplantation.
• HPCs can be frozen with cryoprotective agents and thawed for use post-collection.

Leukocyte-Reduced Blood Components

• Reduction of leukocytes in RBCs and PCs minimizes transfusion complications, including febrile reactions and graft-versus-host disease.
• Universal leukocyte reduction is practiced but does not conclusively prevent all adverse effects.
• Blood components must have fewer than 5 × 10^6 residual leukocytes for RBCs and fewer than 8.3 × 10^5 for PCs.
• Prestorage leukocyte reduction prevents the accumulation of harmful biological modifiers, improving safety.
• Specific filtration devices can effectively prepare components with reduced leukocyte counts.
• Failures may occur during filtration from donors with sickle cell trait due to low oxygen tension impacts on Hb S polymerization.
• Granulocytes and HPCs cannot undergo leukocyte reduction.

Cryoprecipitated Antihemophilic Factor (Cryoprecipitate or Cryo)

• Cryoprecipitate is the cold insoluble portion obtained from thawed Fresh Frozen Plasma (FFP).
• Contains approximately 50% of factor VIII, essential for blood clotting.
• Comprises 20% to 40% of the original plasma unit's fibrinogen, crucial for clot formation.
• Also includes von Willebrand factor (vWF), involved in platelet adhesion.
• Contains factor XIII, which stabilizes blood clots.
• FDA mandates a minimum of 80 IU of factor VIII per unit of cryoprecipitate, although many centers provide higher levels.
• A single unit of cryoprecipitate typically has about 250 mg of fibrinogen, but content testing is not obligatory.
• Significantly advanced hemophilia A treatment before the advent of purified clotting factor concentrates.
• Currently used primarily as a source of fibrinogen in clinical settings.

Liquid Plasma Overview

• Liquid plasma is derived from whole-blood donations and is not subjected to freezing.
• It is stored at temperatures between 2°C to 6°C for a period of up to 5 days after the whole-blood expiration date.

Advantages of Liquid Plasma

• Readily available for transfusion during trauma cases due to the absence of thawing requirements.
• This immediate availability can be crucial in emergency situations.

Disadvantages of Liquid Plasma

• Coagulation factors that are sensitive to storage temperatures (2°C to 6°C) may reduce in concentration after 7 days of storage.
• Due to reduced coagulation factor levels, liquid plasma is specifically indicated for trauma resuscitation and not for other medical uses.