Tranfusion Medicine

Question 1

what are the complications of massive transfusion?

Answer 1

1) alkalosis ( citrate converts to bicarb)
2) citrate load = hypoCa, increased Qtc
3) dilutional coagulopathy
4) hypothermia

Question 2

What are transfusion goals for hgb, plts, INR and fibrinogen?

Answer 2

1) Hgb above 70
2) Platelets: above 50, or above 100 in head injury
3) INR below 1.5 - recall that high INR times means youre taking awhile to clot
4) Fibrinogen over 1 - you want high clotting factors available

Question 3

most common cause of heartattack in adults following massive transfusion?

Answer 3

Hypothermia casing VFib - give procainamide

Question 4

what are you orderng when you ask for blood group?

Answer 4

the ABO group of the patient

Question 5

what infectious agents do they screen blood for?

Answer 5

HCV, HIV, Syphilis, Hep B and C, West Nile, HTLV 1 and2, RH status

Question 6

what does it mean to get blood screened, as in group and screen?

Answer 6

Screen means the recipient patient is screen for Abs in their blood, usually made in a previous pregnancy or transfusion. This is important because they may have factors present that are independent of their blood group and more related to previous exposures - stuff we need to know about. Its like taking a history just of their blood

Question 7

Crossmatch means what?

Answer 7

it means you check that the donor and recipient bloods do not interact. This can be done physically by mixing the two, or a computer can project if there is going to be an issue. There is also a third time of crossmatching…

Question 8

what are the three types of crossmatching one can do?

Answer 8

1) Antiglobulin Crossmatch - see other card
2) Immediate Spin Crossmatch - mix the two together and await agglutination reaction
3) Computer crossmatch - computer assists in the crossmatch process

Question 9

What does an antigobulin crossmatch consist of?

Answer 9

This is a full and complete crossmatch where you do three tests

a) mix the two ( immediate spin method)
b) then incubate the two to see if there is a delayed reaction
c) do an indirect antoglobulin test

Question 10

what is a direct coombs test?

Answer 10

should be doesn if you suspect a transfusion reaction.
You add rabbit serum Abs to the suspected sample. They only latch on if there are RBC-Ab complexes already present, telling you there is a transfusion reaction.

Question 11

why should you not warm blood in a microwave?

Answer 11

doesnt say in the manual, seems unsafe/ high risk for microbes

Question 12

When should you think about transfusion ( beyond hgb level)

Answer 12

The rule is Hgb under 80/symptomatic with 2+ of following:

1) estimated/anticipated loss of 750cc or 15% blood volume
2) SBP drop 30 pts from baseline
3) DBP drop under 60 ( recall cardiac perfusion depends on diastolic flow
4) tachy/ anuria/oliguria (sigs of dryness)
5) evidence of MI ( demand MI)
6) cognitive change

Question 13

What hemocrit change will 1 U PRBCs give you?

Answer 13

increase by 3 %

Question 14

When should you consider platelet transfusion?

Answer 14

Platelet goals depend on the patient/ surgery. Aim for

1) 50+ - major surgery
2) 30+ minor surgery
3) 10+ at any time
4) if you’ve given 10 U pRBCs
5) epidural/spinal - 50+

Question 15

What does one unit of platelets get you?

Answer 15

its pooled, so likely actually from 5 donors and should raise plts by 15 pts

Question 16

RH -ve women, should they be worried about platlets?

Answer 16

YES! RH +ve platelets means she needs rhogam

Question 17

What are contraindications to giving platelets?

Answer 17

1) TTP
2) HIT
3) PTP - post transfusion purpura
4) Dont give in VWD - the platelets are dysfunctional and thats fine don’t touch it

Question 18

Why do platelets have more microbe growth associated?

Answer 18

they are stored at room temp so bacterial contamination can be an issue

Question 19

Why cant renal failure patients have platelet transfusion?

Answer 19

Renal failure gives you baseline dysfunctional platelets so actually the best think is desmopressin ( DDAVP) +/- Cryo +/_ pRBCS

Question 20

How does desmopressin work?

Answer 20

it makes endothelial cells at the area of the cut release clotting factors that help the dysfunctional platelets eg of VWD function

Question 21

What the hell is FFP and why do we care?

Answer 21

FFP - Fresh frozen plasma is a liquid taken from whole blood and contains ++ clotting factors. This is given if the INR is getting high ( above 1.5, indicating a long coagulation time) or abnormal PTT

Question 22

When should you give FFP?

Answer 22

1) massive transfusion
2)DIC
3) Liver failure
4) warfarin - it reverses it by giving the person back the vit K dependent factors
5)

Question 23

What are the two ways to reverse warfarin?

Answer 23

1) give vit K - will work in 2-24 hours to change their INR aka their coag time
2) FFP - works instantly

Question 24

What is the typical dose of FFP?

Answer 24

2 units, given in a volume of 250 cc

Question 25

What is cryoprecipitate?

Answer 25

a concentrated subset of coag factors, like a smaller form of FFP

Question 26

What does cryo contain?

Answer 26

factor 8, fibrinogen, fibronectin, factor 13, and vWF - there are all the cold insoluble proteins (aka hot soluble)

Question 27

when do you give cryo/ indications?

Answer 27

1) bleeding in a uremic patient ( remember their platelets are dysfunctional so we give them clotting help in a different way)
2) Hemophilia A - they dont have factors
3) VWD is Desmopressin not working
4) Hypofibinogenemia - aka fibrinogen is below 1

Question 28

what is the typical dose and volume?

Answer 28

10 units of cryo are given in 15ccs usually over 10 mins

Question 29

Albumin - indications to transfuse

Answer 29

Give for Oncotic Volume:

1) post paracentesis of 5L
2) Spontaneous Bacterial Pertonitis? for whatever reason
3) hepatorenal syndrome - the liver stops producing albumin in stress because it switches to CRP/ acute phase reactants
4) plasma exchange -

Question 30

when should you NOT give albumin?

Answer 30

1) hypovolemia - crystalloid is just as good
2) Hypoalbuminemia - use crystalloid
3) burns
4) capillary leak / sepsis -crystalloid instead
5) Cardiac surgery-
6) ascites - albumin + lasix doesn’t work