Wk 1- transfusion medicine

Question 0

Name five components blood can be broken up into.

Answer 0

Packed red cells
Platelets
Fresh frozen plasma
cryoprecipitate
Synthetic/recombinant coagulation factors: 8, 9, 7a, fibrinogen

Question 1

What can frozen plasma be further separated into?

Answer 1

Immunoglobulins, albumin, factor concentrates

Question 2

What are the components of cryoprecipitate?

Answer 2

This is plasma enriched in fibrinogen, vWF (With factor 8 and 13)

Question 3

What are indications for packed blood cells transfusion?

Answer 3

Symptomatic anemia

Severe acute anemia with signs and symptoms or ongoing bleeding significant obstetric or traumatic hemorrhage

Question 4

Or contraindications to pRBCs?

Answer 4

Compensated patients with chronic anemia
Patients with iron deficiency anemia
Asymptomatic anemia
Mild anemia of any cause

Question 5

Indications for platelet transfusion?

Who should get what for what numbers?

Answer 5

Thrombocytopenia or dysfunctional platelets with bleeding (or bleeding risk)

> 100: nobody unless platelet dysfunction
50 to 100: patients who are actively bleeding; neurosurgery patients preop.
10 to 50: preop patients; other patients at high risk for bleeding
<10: almost anyone

Question 6

Contraindications for platelet transfusion?

Answer 6

Useless: idiopathic thrombocytopenic purpura ITP
Transfuse platelets are destroyed as fast as patient’s own platelets are destroyed and therefore no useful increase in platelet count

Dangerous: TTP, HUS, HITT, DIC/MAHA
platelets for pathologically activated in the circulation before being cleared by the spleen.
This can lead to pathological thrombosis and adding more platelets increases the risk of thrombosis

Question 7

Indications for plasma transfusion?

Answer 7

When urgent multifactor replacement is needed
Ie. Vitamin K deficiency, warfarin overdose, DIC, liver failure

Coagulopathy NYD in a pre-op pt

Question 8

Contraindications to plasma transfusion

Answer 8

Single factor replacement

Question 9

Indications for cryo transfusion

Answer 9

fibrinogen replacement

Question 10

Contraindications to cryo replacement?

Answer 10

Hemophilia A - don’t do in Canada

Question 11

What are the Rh antigens? Can these be involved in hemolytic transfusion reactions? What kind?

Answer 11

D, C, c, E, e.

These can be involved in hemolytic transfusion reactions, and they are usually delayed reactions.

Question 12

What is unique about Rh D- specific and “other family” Antigen antibodies?

Answer 12

Only if prev exposed and D- do you build up the Ab, then next exposure do you react. Ie preg and transfusion.

Question 13

Difference btwn group and screen?

Answer 13

Group is Antigens ie ABO Rh
Screen is an antibody screen. If neg. than no clinically significant non-ABO Ag
If pos then need to run and EXTENDED Ab PANEL

Question 14

What is a cross match? How do electronic vs wet xmatch compare?

Answer 14

Checking the unit against the pt to ensure compatibility.
An electronic xmatch is a group compatibility check and is performed if there is no clin signif Ab inpt.
Full (“wet”) is when the pt serum is mixed w unit RBCs to ensure no rxn.

Question 15

What are the times for:
G and S
Ab panel
Wet xmatch
Electronic xmatch

Answer 15

30 min
2-3 hr
20-30 mins
15 min

Question 16

When to order G and S?

Answer 16

For ANYONE who gets a transfusion or might need one.

Question 17

What are the implications of doing a crossmatch? Therefore when should it be done?

Answer 17

RBCs will be specifically set aside for the pt in a separate fridge with pts name so as to make it immediately available if needed.
- therefore do it if pt will likely need transfusion in next couple of days.

Question 18

What are the necessary orders in writing for blood? (Mnemonic)

Answer 18

Up Dat Volume Please!

Urgency, Duration (to run), Volume/ quantity, Product.

Question 19

What bare standard durations for blood products?

Answer 19

RBC 3-4 hours / unit
Platelets: 1-2 hr / dose
Plasma: 1-2 hr/ unit
Cryo: go to town. (Run it in)

Question 20

What is a particular consideration for ordering blood products in an emergency?
What is the hierarchy of choice in emergency? Re non-crossmatched O- neg blood, what to think about?

Answer 20

Communicate directly the clinical urgency to the transfusion medicine lab.
1st choice: group specific blood which is xmatched
2. Group-specific blood that has not been crossmatched.
3. O- neg that is not xmatched
- girls and women of child bearing age get Rh neg. the men and postmeno women get O pos

Question 21

What does a stat G and S allow for?

Answer 21

Allows G and S to be considered for subsequent transfusions if required.

Question 22

What do you follow when txing TTP HUS?

Answer 22

Tx w plasmapharesis and follow until LDH and platelets normalize

Question 23

Generally speaking, what 3 tests are required in every RBC transfusion pt?

Answer 23

Group, screen, crossmatch.
Crossmatch is for determining if Abs found in the recipients plasma are compatible w donor RBCs. If incompatible may lead to hemolytic transfusion reaction.
Can be wet or electronic. If Pos screen or hx of prev antibodies, wet mandatory.

Question 24

What is lab test TAT? What are prolongations beyond clinically acceptable limits?

Answer 24

Lab test turnaround time.
Pre-analytical: Errors involve things that happen before the specimen is tested. I.e. Labeling error, inappropriate specimen collection, Ie if coagulation test collected in a heparinized line.
Delay in transporting collected blood back to the lab. Perhaps not enough porters, or too busy.
Analytical: actual laboratory testing error. Are relatively rare, ie if a couple forms inside a tube with an automated blood counter. Or misdiagnosis buy a pathologist on biopsy. delete in running a test because more urgent specimens are being run first.
Post-analytical delay: a test is run but there is a delay in the technologist entering the results or the pathologist reviewing the results. Often these delays reflect high workload in the hospital.