Transfusion Flashcards
Describe the ABO blood group system, including the antigens and antibodies associated with each blood group.
ABO Blood Group System:
Type A:
Antigen: A antigen on the surface of red blood cells.
Antibody: Anti-B antibodies in the plasma.
Type B:
Antigen: B antigen on the surface of red blood cells.
Antibody: Anti-A antibodies in the plasma.
Type AB:
Antigen: Both A and B antigens on the surface of red blood cells.
Antibody: No anti-A or anti-B antibodies in the plasma.
Type O:
Antigen: No A or B antigens on the surface of red blood cells.
Antibody: Both anti-A and anti-B antibodies in the plasma.
Explain the Rh D antigen system, including the significance of the Rh D antigen in transfusion and pregnancy.
Rh D Antigen System:
Rh Positive (Rh+):
Antigen: Presence of the Rh D antigen on the surface of red blood cells.
Antibody: Rh-positive individuals do not naturally have anti-Rh D antibodies unless sensitised.
Rh Negative (Rh-):
Antigen: Absence of the Rh D antigen on the surface of red blood cells.
Antibody: Rh-negative individuals may develop anti-Rh D antibodies if exposed to Rh-positive blood (e.g., during transfusion or pregnancy).
Significance in Transfusion:
Compatibility: Rh-negative patients must receive Rh-negative blood to avoid the risk of developing anti-Rh D antibodies, which can cause haemolytic transfusion reactions.
Significance in Pregnancy:
Rh Incompatibility: If an Rh-negative mother carries an Rh-positive baby, she can develop anti-Rh D antibodies, which may lead to haemolytic disease of the newborn in subsequent pregnancies. Rh immunoglobulin (RhIg) is administered to prevent this sensitisation.
Describe the steps involved in performing a group and screen
Group and Screen:
Steps:
Obtain Blood Sample: Collect a blood sample from the patient.
Determine Blood Group: Test the blood sample to identify the ABO and Rh D blood group.
Perform Antibody Screening: Mix the patient’s serum with known red blood cells to detect any unexpected antibodies.
Purpose: Identifies the patient’s blood type and any potentially problematic antibodies
Describe the steps involved in performing a crossmatch?
Crossmatch:
Steps:
Prepare Blood Samples: Obtain a sample of the patient’s blood and the donor’s blood.
Mix and Incubate: Mix the donor’s red blood cells with the patient’s serum and incubate.
Check for Reactions: Observe for any agglutination or haemolysis, indicating incompatibility.
Purpose: Ensures that the donor blood is compatible with the patient’s blood to prevent adverse reactions.
Describe the steps involved in performing a blood transfusion
Electronic Issue:
Steps:
Enter Patient Details: Input patient information into a computerised system.
Match Blood Product: Use the system to select and match an appropriate blood product based on patient details.
Verify and Release: Confirm the match and issue the blood product electronically.
Purpose: Enhances the accuracy and efficiency of blood product matching and issuance, reducing manual errors.
Temperature control needed for blood products?
Red Blood Cells (RBCs): Stored at 1°C to 6°C.
Platelets: Stored at 20°C to 24°C with constant agitation.
Plasma: Stored at -30°C or below for long-term storage.
Cryoprecipitate: Stored at -30°C or below.
Shelf life for blood products?
Red Blood Cells: Typically up to 35 days.
Platelets: Typically up to 5 days.
Plasma and Cryoprecipitate: Shelf life varies but generally up to 1 year when frozen.
How much blood is taken in blood donation centres?
470ml (about a pint)
10%
Even though 20% is still quite safe
How often are you allowed to donate?
Every 8 weeks
Under what circumstances would mean a G&S only lasts 72 hours?
- Pregnant?
- Had a transfusion in the last 3 days
What factors increase someone’s risk of TACO?
- Heart failure
- Renal failure
- Low weight
- Previous fluids
What blood test results would indicate DIC?
Seen in burns, sepsis, hemorrhage
- Prolonged PT/APTT
- Low platelets
- Low fibrinogen
FFP would help with PT/APTT
Cryoprecipitate would replace fibrinogen
How are volunteers recruited for blood transfusion?
- Blood donation campaigns in schools, colleges and community events
- Local newspapers, TV, posters
- Offering incentives- snacks and drinks
How are volunteers screened for blood transfusion?
Health questionnaire
- Recent vaccinations
- Recent medical procedures
- Ill in the last 10 days
- Recent travel history
- History of high-risk behaviours- IV drug use, multiple sexual partners
- Hep B/Hep C
Physical examination
- Vital signs
- Weight (minimum is 50kg)
What is done in the post-donation screening of blood?
HIV
Hep B/C
Syphyllis
Zika
Blood type and cross-matching
