List the steps involved in pre-transfusion testing
- Sample collection: request form; collection; appropriate sample
- ABO & Rh(D) grouping
- Ab screen (& ID if required)
- Select appropriate donor
- Cross-match
- Transfusion
Explain the importance of the date/time of collection and phlebotomist signature on the sample tube and request form for TS samples
- Info. required to identify recipients details
2. Must be Signed by person collecting that the sample tube & request form is labelled w/ appropriate identifiers
Explain the scenarios where samples for TS testing are valid for 72 hours, and 7 days
- If patient not transfused or pregnant in past 3 months = sample is valid for 7 days from collection
- If patient has been transfused or preg. in past 3 months = sample is valid for 72 hours (3 days) from collection [bc inc. risk for amnestic response]
Explain why we perform an antibody screen
- to detect clinically sig. Ab that may be present in patient’s plasma
- need to know to avoid haemolysis from giving donor blood that has Ag specific twds recipient’s Ab (avoid HTR or HDNB)
how one is an Ab screen performed?
- use Ab screening cell panel
- Patient’s plasma reacted against screening cells from different O doners to detect which Ab patient has w/ the Rh(D) groups & other Ag groups
- IAT @ 37ºC
- Postitve screen: ≥1 positive rxn in any cells (/tests)
- Negative screen: no agglutination rxn in any cells
Explain the characteristics of the cells used in an antibody screen
- come from different O donors: not deal w/ A, B, A,B Ag
- Have Ag from Rhesus, Kell, Duffy, Kidd, MNS, Lewis, Lutheran
- Have R1R1 (CDe) & R2R2 (cDE)
=> to detect clinically sig. Ab in patients plasma to any of those Ag
You perform an antibody screen; there is no reaction with the three cells and the reactions are validated with AHG control cells. What is your interpretation of these results?
negative screen = patient as no an Ab
Explain donor RBC selection in individuals with and without antibodies.
- If possible, donor RBC should match recipient’s ABO & Rh(D) group
- If recipient has a clinically Sig. Ab. give then a cell that NOT express that Ag
- If Ab is present & not clinically sig. can use IAT cross-match compatible cells (ie neg Ab screen for CSig. Ab)
Explain when it is appropriate to perform cross-matches by IS and IAT
- IS: ABO compatibility. Only when patient has NEVER had a clinically sig. Ab detected in their plasma (no previous exposure)
- IAT: ABO compatibility & compatibility w/ other blood groups. Use if patients HAS had a Clinically sig. Ab in their plasma (had previous exposure = not want amnestic response)
Requirements for ABO grouping
- ABO grouping
- Rh(D) grouping
- Confirm Hx records
What is the group and hold?
aka group & screen
- Ab screen & STOP pre-transfusion test
- If patient’s having complications continue w/ crossmatch = have blood ready for patient
- Neg Ab screen & no Hx of CSig. Ab=> IS crossmatch
- Pos Ab screen & have CSig. Ab => Ab ID & IAT crossmatch
Name of guidelines AUstralia & New Zealand must follow in their transfusion labs.
ANZSBT guidelines for transfusion & immunohaematology laboratory practice.
ANZSBT: Aus & NZ Society of blood transfusion
Requirements for transfusion in emergency
- Provide O Rh(D) neg E neg & K neg blood initially
- Provide group-specific blood ASAP - when done blood group test
- Complete pre-transfusion test ASAP
• 10 min: ABO Rh(D) group
• 30 min: Ab screen & cross match (*if Ab screen is neg can do crossmatch w/ IS given patient not have Hx of CSig. Ab, but if pos. -> Ab ID & Xmatch w/ IAT) - Labelled
