Crossmatch A Request Against A Unit

A crossmatch is the final compatibility check between a specific recipient and a specific unit of blood before that unit can be reserved for them. On the Crossmatch bench you pick an open request, choose a candidate unit, record whether they are compatible, and sign the verdict. A signed-Compatible crossmatch is what makes a unit reservable; nothing leaves the fridge for a patient without one.

Two terms first. TTI stands for transfusion-transmissible infection — the infectious-disease markers (HIV, hepatitis B and C, syphilis, malaria and so on) screened on every donation; a TTI-cleared unit is one whose donation passed that panel and was released from quarantine. An eSign PIN is your 6-digit electronic signature, separate from your login password.

Who / when: the lab scientist or blood bank officer at the immunohaematology bench, when an open transfusion request needs a unit matched to it.

We will follow Ifeoma, a blood bank officer working the crossmatch bench.

The main path

1. Lab Scientist / Blood Bank Officer — open Blood Bank → Crossmatch. The left panel, “Open Requests”, lists requests awaiting a crossmatch, ordered by urgency. Click the request you are working to select it; its existing crossmatches (if any) appear on the right.
2. Lab Scientist / Blood Bank Officer — with the request selected, press “Record Crossmatch”. In the “Record Crossmatch” dialog, open the “Candidate Unit” picker. It lists only TTI-cleared, Available units of the requested component — a unit that has not cleared its infectious-disease panel never appears here. Each option shows the unit, its group and its expiry. Ifeoma picks one.
3. Lab Scientist / Blood Bank Officer — set the “Method” (for example AHG/Coombs), set the “Result” to “Compatible” or “Incompatible”, and add an optional “Phase” note (IS / 37°C / AHG). Press “Record”. Veona confirms “Crossmatch … recorded. Sign it out to apply.” — the verdict is a draft until you sign it.
4. Lab Scientist / Blood Bank Officer — in the crossmatch table on the right, press “Sign Out” on your new row. The “Sign Out Crossmatch” dialog explains the consequence: a signed Compatible result reserves the unit and notifies the requesting clinician. Enter your 6-digit eSign PIN and press “Sign Out”.
5. Lab Scientist / Blood Bank Officer — on a Compatible sign-out, Veona advances the request to “Crossmatching”, makes the unit reservable for this request, and sends the requesting clinician a content-free “crossmatch ready” notice with a bell alert. The row now shows your signature.

Note

Only TTI-cleared, Available units of the requested component are offered as candidates. That filter is deliberate: you should never be able to crossmatch a unit that has not passed its infectious-disease screen, or one that is already reserved or issued to someone else.

Tip

Signing a crossmatch — Compatible or Incompatible — raises the bb.crossmatch charge against the recipient’s bill, because the compatibility test is billable work whether or not the unit matched. The charge is priced from your facility’s tariff, captured once per signed crossmatch, and only emitted because the record is signed.

Caution

An unsigned crossmatch reserves nothing. Recording a Compatible result is not enough — until you sign it out, the unit cannot be reserved at the Issue Desk and the clinician is not notified. The signature is what turns a bench result into an actionable, auditable verdict.

Other ways this goes

Compatible signed — the unit is reserved and the clinician is told

1. Lab Scientist / Blood Bank Officer — sign out a “Compatible” verdict with your PIN. The request advances to “Crossmatching”, the candidate unit becomes reservable for this request (its formal Available→Reserved reservation is then taken at the Issue Desk), and the requesting clinician receives the content-free “crossmatch ready” notice plus a bell alert.
2. Lab Scientist / Blood Bank Officer — the unit now carries a signed-Compatible verdict for this recipient, ready to be reserved and issued.

Incompatible signed — the unit is excluded

1. Lab Scientist / Blood Bank Officer — set “Result” to “Incompatible” and sign it out with your PIN. Veona confirms the unit is excluded from this request.
2. Lab Scientist / Blood Bank Officer — the incompatible unit will not be offered for reservation against this recipient. Record and sign a crossmatch against a different candidate unit to find a compatible one. (The compatibility test still raised its bb.crossmatch charge — the bench work was done.)

Only TTI-cleared, Available units are candidates

1. Lab Scientist / Blood Bank Officer — if the “Candidate Unit” picker reads “No cleared available units”, there is no unit of that component that is both TTI-cleared and free to reserve.
2. Lab Scientist / Blood Bank Officer — clear a donation’s TTI panel so its units release into stock, or move a cleared unit in from another facility, then return to the bench and crossmatch.

What happens next

A signed-Compatible crossmatch hands the recipient off to the Issue Desk: there a scientist reserves the unit (the auditable Available→Reserved step) and then issues it as an eSigned cold-chain checkout. The requesting clinician, already notified that blood is ready, can expect the unit to follow. An incompatible result simply rules that unit out and the search continues. Every verdict you signed stays on the record under your name.

Follow the trail

• Previous: Raise A Transfusion Request
• Next: Reserve And Issue The Unit
• Related: Clear The Donation TTI Panel (Release Gate) · Run The Recipient Antibody Screen · Move Units Between Network Facilities