Transfusion Medicine

Question 1

Concept of blood component therapy

Answer 1

Centrifuge bag of donated whole blood and separate into parts…each component cn go to a different patient

Question 2

Whole blood

Answer 2

Contains everything that came from the donor

RBCs, WBCs, platelets, proteins (including coag factors)

Question 3

Total bag volume and temp

Answer 3

slightly greater than 500 mL

4C fridge

Question 4

Indication for transfusion of whole blood

Answer 4

Only one is to treat patients who are experiencing massive bloodloss

This is rarely done

Question 5

Benefits of whole blood transfusion

Answer 5

RBC replaces patients lost RBCs so increases O2 capactiy

Plasma portion replaces lost intravascular blood volume and prevents CV collapse

Question 6

Limitations of Whole Blood

Answer 6

Not a good source for platelets due to fridge
Not a good source for coagulation factors (especially 5 and 8) due to fridge
Capable of transmitting infectious dzs

Question 7

RBC volume and storage

Answer 7

Same number of RBCs as wholeblood
225 to 350 mL
4 C fridge

Question 8

Indication to transfuse RB

Answer 8

Increase RBC mass…and increase O2 carrying capacity in the anemic patient

Question 9

Decision to transfuse anemic patient with packed cells depends on

Answer 9

HgB and Hct of patient - if HgB less than 7 or HcT less than 21% (general)
Clinical situation - more important…symptomatic may need transfusion regardless of count…if not symptomatic, may want to withold, even if counts are low

Question 10

Hematologic response to packed cells

Answer 10

Transfusion of one unit should increase HgB by 1 and HcT by 3%

Question 11

Limitations of packed cells

Answer 11

Not a good source for platelets or coagulation factors

Capable of transmitting infection

Question 12

LRBC

Answer 12

Leukocyte reduced RBCs….99.9% of leukocytes removed by passing blood through special filter

Question 13

Indication for transfusion and how it is commonly used

Answer 13

Same as RBCs (packed cells)
Commonly used in patients prone to febrile non-hemolytic transfusion reactions (FNHTRs)…occur in patients with ABs against foreign antigens present on membranes of leukocytes that are present within donated blood…produces fever and chills

LRBC is BEST blood component to prevent FNHTRs

Question 14

LRBC limitations and advantage

Answer 14

Besides preventing FNHTRs, prevents CMV transmission

Limitations same as packed cells

Question 15

WRBCs

Answer 15

Washed RBCs…removal of all plasma

Question 16

Indication for transfusion of WRBCs and how commonly used

Answer 16

Same as packed cells
Best to use in anemic patient with history of allergic transfusion reactions (ATR) to human plasma proteins…clinical manifestations are anaphylaxis to hives

Question 17

LImitations of WRBCs

Answer 17

Not a good source for platelets or coag factors

Capable of transmitting dz

Question 18

PC aka RDP including storage and volume

Answer 18

Platelet concentrate (random donor platelet)
Derived form oneunit of WB and is platelets in 50 mL plasma...stored at room temp

Question 19

Indications for RDP trnasfusion

Answer 19

Thrombocytopenic or has throbocytopathy (aspiriin use could cause)

Question 20

Guidelines for transfusing thrombocytopenic patients

Answer 20

If bleeding or about to go to surgery AND platelet<50,000 consider PC transfusion

If not bleeding AND platelet count less than 10,000, consider PC transfusion…prophylactic transfusion will prevent hemorrhage in brain

Question 21

DOse and response to RDP

Answer 21

1PC/10kg body weight

1 PC shoud increase platelets by 5,000 to 10,000

Question 22

Disadvantage of RDP

Answer 22

Infectious dz

Question 23

Apheresis platelet

Answer 23

Number of platelets equivalent to 6 units of PC

Question 24

FFP with storage

Answer 24

Fresh frozen plasma

Plasma of 1 unit of WB separated and frozen within 8 hours…then thawed in 37 degree water bath when need

Question 25

FFP advantage

Answer 25

Quick freeze preserves ALL coag factors...even 5 and 8

Question 26

Indication for FFP transfusion

Answer 26

Tx of bleeding patients who have multiple coag factor deficiencies (cirrhosis, DIC)...offers coag factor replacement

Question 27

Effectiveness of FFP therapy

Answer 27

Evaluated by comparison of pre and post PT and PTT

Question 28

Disdvantage of FFP

Answer 28

Infectious dz

Question 29

Cryo aka AHF

Answer 29

Cryoprecipitate aka cryoprecipitated antihemophilic factor

Question 30

AHF formed when

Answer 30

FFP thawed at 4C...precipitate removed and then frozen...thawed and pooled before use

Question 31

AHF rich in

Answer 31

Clotting factors - Fibronogen (factor 1), von Willebrand (vWF), factor 8, and factor 13

Question 32

Indication for AHF transfusion

Answer 32

``` Bleeding patient deficient in one of factors it includes Von Willebrands dz (vWF) Hemophilia A (Factor 8 def) Factor 13 def (rare) Fibrinogen def ```

Question 33

Cryo is most appropriate

Answer 33

Blood componenet to be used for these dz

Question 34

Cryo disadvantage

Answer 34

Infectous dz

Question 35

Blood derivatives

Answer 35

Drugs derived from human plasma | Albumin, Immune globulin, Rh immune globulin, Factor 8 concentrate

Question 36

Hemolytic transfusion txns

Answer 36

RBC membranes contain carbs and proteins which functon as antigens in transfusion setting

Question 37

Acute hemolytic transfusion reactions

Answer 37

AHTR Within 4 hours of transfusion uncommon

Question 38

Mech of AHTRs

Answer 38

IgM ABs in recipients bloodstream activate complement...donor RBCs hemolyse intravascularly

Question 39

Most common cause of AHTR and almost always due to

Answer 39

Human error | IgM Abs directed against donor ABO red cell antigens

Question 40

Signs of AHTRs and tx

Answer 40

Fever, pain at IV site, hemoglobinemia and uria, renal failure due to excess plasma hemoglbin in renal tubules, hypotnesion/schock/DIC due to released RBC stroma, hyperkalemia due to release of K from hemolyses donor RBCs, death STOP transfusion and seek supportive care

Question 41

DHTR

Answer 41

Fairly common | 5-21 days after

Question 42

DHTR mech

Answer 42

IgG antibodies get phagocytosed by liver and spleen (extravascular hemolysis)...positive Coombs test helps diagnose

Question 43

Why do DHTRs occur

Answer 43

Offending AB is too low to detect in recipient

Question 44

ABs of DHTRs directed against

Answer 44

Non-ABO antigens | Maybe Rh antigen

Question 45

Symptoms and signs of DHTR and tx

Answer 45

Mild, possibly asymptomatic Fever Jaundice Possibly none, monitor Hb and Hct

Question 46

How to prevent DHTR in future

Answer 46

Blood bank staff can ID antibody in patient's post trnasfusion blood specimen courtesy of response

Question 47

Infectious agents to be concerned of

Answer 47

``` HIV 1/2 HTLV 1/2 HBV (highest risk) HCV West nile virus (lowest risk) ```