Path Heme/Onc/ Blood Bank Flashcards
1
Q
What are four steps of pretransfusion testing?
A
- ID blood and paperwork
- ABOD typing
- Ab screen
- Crossmatch donor RBC and recipient serum
2
Q
ABO abs are naturally occurring Ig___ and (do/do not) require prior exposure.
A
IgM
do not
3
Q
What do IgM abs of ABO do?
A
fix complement and cause intravascular hemolysis causing an immediate transfusion reaction
4
Q
Rh/D abs (are/are not) naturally occuring abs and (do/do not) require prior exposure).
A
are not
do
5
Q
Rh abs are of Ig___ and cause…
A
IgG
delayed hemolytic transfusion rxn and hemolytic disease of the newborn
6
Q
Rh abs may cause (intravascular/extravascular) hemolysis.
A
they do not fix complement so would only cause extravascular hemolysis
7
Q
What causes Hemolytic Disease of the Fetus/Newborn?
A
hemolysis in fetus from Mom’s IgG that crossed the placenta
8
Q
What are symptoms of HDFN?
A
anemia hypoxic injury to fetus hydrops fetalis (d/t circulatory failure, severe generalized edema) hyperbilirubinemia as newborn kernicterus
9
Q
What is kernicterus?
A
when the BBB is suboptimal due to prematurity or immunocompromization, unconjugated bilirubin that is very lipid soluble is able to enter the brain causing acquired metabolic encephalopathy -> cerebral edema; yellow staining on autopsy
10
Q
What is the MCC of HDNF?
A
ABO incompatibility
11
Q
What is the most severe cause of HDFN?
A
Rh incompatibility
12
Q
What does RhIg (Rhogam) treat and when would I give it to someone?
A
Prevents HDNF by preventing antibody production in the mom
give to Rh- mom at 28 weeks gestation and then again within 72 hours of giving birth
13
Q
This typing looks at pt serum and reagent cells
A
Reverse Typing/ Back Type
14
Q
This typing looks at pt cells and reagent sera
A
Forward Typing/Front Type
15
Q
What kind of typing tells me what antigens are on pt cells?
A
Forward Typing
16
Q
What king of typing tells me which ABO abs are present in pt serum?
A
Reverse Typing
17
Q
What is the universal recipient blood type?
A
AB +
18
Q
What is the universal donor blood type?
A
O -
19
Q
What test determines if there are any in vivo abs attached to RBCs? What conditions is this test used in?
A
Direct Antiglobulin (Coomb’s) Test - DAT
HDFN
AI hemolytic anemia
transfusion rxn
20
Q
What test detects in vitro attachment of Ig or Complement and what is it used for?
A
Indirect Antiglobulin (Coomb’s) Test - IAT
Ab screening and crossmatching - detect unexpected Abs in pt serum; look for clinically significant Ab (IgG, activated above 37C, and Kell, Kidd, Rh)
21
Q
What is crossmatching?
A
confirming ABO typing; may detect other abs; done at room temp unless Ab screen is abnl
22
Q
What kind of typing is used in emergencies?
A
uncrossmatched: O+ or O-
takes about 5 min to prep
23
Q
Who gets O- blood?
A
females still of childbearing age
24
Q
You’re about to go into surgery, you really don’t think you will need blood for the pt, but want to have some on hand just in case. What are you going to order?
A
Type and screen only
25
You're about to go into surgery, this dude's a bleeder and you know you'll need at least a few transfusions. What are you ordering?
Type and crossmatch
26
One unit of packed RBC will increase hgb and hct how much?
hgb will go up 1g/dl
| hct will increase by 3%
27
How long can you store packed RBCs?
store up to 42 days at 1-6C
28
What is an indication for leukocyte depleted RBCs?
to decrease risk of febrile non-hemolytic transfusion reaction
to decrease CMV risk
to decrease HLA autoimmune rxn
29
Frozen, deglycerolized RBCs are for who? How long can they be stored this way?
rare blood types - Bombay
military
can be stored up to 10 years if at -65C
30
Who really needs to have washed RBCs? What does this remove from the RBCs?
for IgA deficient pt
| removes platelets, plasma, and 90-99% of WBCs
31
Pts at risk for GVHD get what type of blood transfusion products?
irradiated blood products to prevent WBC replication and engraftment
32
A single donor of platelets gives the collection via...
apheresis
33
When a pt does not respond to a platelet transfusion, what adjustment should be made?
HLA matched single donor platelets - one of the few times there is reason for a directed donation
34
If you are washing blood products, how quickly must they be used after washing?
4 hours
35
What are two things that are not indications for platelet transfusion? why are these not indicated?
TTP/HUS or HIT
| due to increased risk of thrombosis
36
Platelets don't have to be crossmatched to be transfused, but it is generally best if they are...
ABOD identical
37
What is the expected response of a single donor unit or pooled 6-pack of platelets?
increases platelet count by about 30-60k
38
How long do transfused platelets normally live? What would shorten their lifespan?
normally about 6-7 days
| shorter if complicated with sepsis, DIC, alloimmunization, hypersplenism, or immune thrombocytopenia purpura (ITP)
39
FFP must be frozen how quickly? Is there another kind?
within 8 hours or within 24 hours is considered FP24
40
FFP and FP24 have all coagulation factors, but FP24 has slightly less of these two factors
Factor V and Factor VIII
41
How long will it take FFP to thaw prior to transfusion?
about 30 min
42
What are four indications for FFP?
1. PT or PTT is >1.5x normal with risk of bleeding
2. bleeding in pt with liver disease
3. bleeding due to warfarin OD
4. Deficient in any of Factors II, V, X, XI
43
What are the only products if pt is deficient in Factors II, V, X, XI?
FFP or FP24
44
What is the cold, insoluble form of plasma remaining after FFO has been thawed?
Cryoprecipitate (Antihemophilic Factor)
45
Cryoprecipitate contains what percent of Factor VIII and fibrinogen of original plasma?
50%
| 20-40%
46
What four things does cryoprecipitate contain?
Factor VIII
fibrinogen
vWF
Factor XIII
47
What are three indications for use of cryoprecipitate?
hypo or afibrinogenemia
Factor XIII deficiency
burn or trauma pts
48
What is now used to tx von Willebrand Disease and Hemophilia A?
Factor VIII Concentrate (Antihemophilic Factor - AHF)
49
What Factor treats Hemophilia B?
Factor IX
50
What hgb range should you consider transfusing PRBCs? When would a pt be symptomatic?
6-10 consider
<6 is probably a symptomatic pt
>10 rarely needs transfusion
51
Why would I never add lactated ringers to blood products?
contains calcium and could cause clotting
52
Why would I never add D5W to blood products?
clumping and hemolysis
53
What is intravascular hemolysis almost always due to? What transfusion reaction is this associated with?
almost always due to ABO incompatibility (IgM)
| found in Acute Hemolytic Transfusion Reaction
54
24 hours after a transfusion, the pt is having an anamnestic response to RBC antigens. What is happening and what is the Reaction called?
extravascular hemolysis due to abs v transfused RBCs in a Delayed Hemolytic Transfusion Reaction
55
What are the most common abs that implicate a delayed reaction?
anti-D
Jka (Kidd)
E
K (Kell)
56
What would have to happen in order for a transfusion reaction to be considered Febrile Non-hemolytic Transfusion Reaction?
pt's temp increases 1C or 1.8F during or within 2 hours of transfusion, not a/w another cause
57
What causes Febrile Non-hemolytic Transfusion Reaction?
pt abs v donor WBC, platelets, or cytokines that accumulated in stored blood
58
Allergic Reaction is a common transfusion reaction that is due to a response to donor's....
plasma proteins
59
An anaphylactic reaction to a transfusion most often occurs when...
there is a severe IgA deficiency in the recipient and the recipient has made abs to IgA
60
What causes TRALI?
caused by abs in donor plasma to recipient HLA class I or granulocyte ags
61
Who is likely to have more abs produced and circulating?
multiparous women and prior transfusion recipients
62
Your pt has received a blood transfusion less than 6 hours ago and has been developing pulmonary edema. Pt is SOB, hypoxic, tachycardic, febrile, hypotensive, and becoming cyanotic. This pt has...
What is their most likely prognosis?
TRALI
| most get better in 24 hours
63
What is the MCC of transfusion related fatality?
TRALI
64
Your pt has a Hgb of 6 and is symptomatic. You have decided to transfuse quickly to bring them back up. You know this may put the pt at risk for TACO. What are the signs and symptoms of TACO and who most often would be at higher risk for TACO?
afebrile, hypertension, cyanosis, cough, SOB, rales, tachy, looks like CHF
elderly and children at higher risk
65
How do you prevent GVHD?
give irradiated blood products
66
If a transfused pt gets hyperkalemia, what is this most likely from? What age is this more likely to be problematic?
due to leak of K+ from donor RBC while in storage
| neonates - so neonates get the freshest units
67
Hypothermia is a risk with massive transfusion, but how should you NOT warm up units?
do NOT use hot water to warm RBC units as the RBCs will lyse
68
Bacterial contamination in a transfusion infection is usually due to...
poor phlebotomy technique
69
I should only ever add ________________ to blood products
0.9% NaCl - normal saline
70
After injury to a vessel, reflex vasoconstriction occurs due to a neurogenic mechanism and it is augmented by...
transient local secretion of endothelin
71
In primary hemostasis, what two factors get things going with Adhesion?
subendothelial collagen and vWF
72
In the Activation part of Primary Hemostasis, what happens to platelets? Where are sites of coagulation complex assembly?
platelets undergo shape change
phospholipids bind Ca2+ and are sites
73
What are the main triggers of activation of platelets?
Thrombin and PAR (protease activated receptors)
74
How do platelets and RBCs aggregate in primary hemostasis?
conformational change allows binding to fibrinogen; concurrent activation of thrombin stabilizes plug
75
What is the irreversible part of aggregation of platelets?
thrombin activation and stabilization - irreversible platelet contraction
76
Secondary Hemostasis includes....
| and is initiated by...
local activation of coagulation cascade
intrinsic and extrinsic pathways
fibrin polymerizes to form hemostatic plug
initiated by exposure of tissue factor (TF)
77
What is the most important of all coagulation factors?
thrombin
78
What are 5 functions of thrombin?
1. converts fibrinogen to fibrin
2. activates factors V, VII, XI, XIII
3. activates platelets through PAR
4. is pro-inflammatory
5. Anti-coag effects in uninjured vessels
79
What is a main player of counter-regulatory mechanisms so that clotting is not over done? What does this do?
activation of fibrinolytic system via tPA
converts plasminogen to plasmin, proceeds to break down fibrin
80
What inhibits free plasmin?
alpha2-antiplasmin inhibitor
81
How is clotting initiated in vitro compared to in vivo?
in vitro: add phospholipids, calcium, and either negatively charged substance or a source of TF
in vivo: TF, amplified by FB loops
82
When testing for hemostasis, what plasma is used? What color are these tubes? What is the correct ratio to use?
citrated plasma, blue top tubes, 9:1 ratio of blood to anti-coag
83
What pathways will PT evaluate?
extrinsic and common pathways
84
What are two big reasons to use PT evaluation?
monitor warfarin or screen for Vit-K dependent deficiencies
85
What is INR for?
it is a calculated value with PT result, ISI of reagent, and MRI - used to standardize monitoring of warfarin
86
APTT screens what pathways?
intrinsic and common pathways
87
What is the MCC of prolonged APTT in hospitalized pts?
heparin
88
APTT is able to pick up most factor deficiencies except for which one?
Factor VII deficiency is not picked up by this test
89
What is the most sensitive test that will be prolonged if heparin is present? What test is used to monitor heparin?
most sensitive: TT
| PTT used to monitor
90
Measuring the time it takes to convert fibrinogen to fibrin is a test called what?
thrombin time (TT)
91
Which clotting factor is in highest concentration in the plasma?
fibrinogen level
92
What can cause a false low of fibrinogen level?
heparin
93
FDP mainly look at degradation of what two things?
fibrin and fibrinogen
94
D-dimers have a high NPV and look most closely at
cross-linked fibrin degradation
95
This test measures capillary integrity and platelet function but is a poor predictor of risk..
bleeding time
96
Both PTT and PT are prolonged. You decide to add heparinase. PT remains prolonged so you are going to do a mixing study.
What deficiencies are we thinking if PT eventually normalizes?
Factor deficiencies of I, II, V, VII, X
97
Both PTT and PT are prolonged. You decide to add heparinase. PT remains prolonged so you are going to do a mixing study.
What are we thinking if PT initially decreases, but then remains prolonged?
Factor V inhibitor
98
Both PTT and PT are prolonged. You decide to add heparinase. PT remains prolonged so you are going to do a mixing study.
This doesn't seem to have made any difference and PT is still prolonged. What are we thinking?
Inhibitor (e.g. specific factor inhibitor, rare)
99
Both PTT and PT are prolonged. You decide to add heparinase. PTT remains prolonged so you are going to do a mixing study.
PTT normalizes, so we are going to measure factors....
Factors VIII, IX, XI, XII
100
Both PTT and PT are prolonged. You decide to add heparinase. PTT remains prolonged so you are going to do a mixing study.
PTT initially decreases, but then remains prolonged. My biggest concern is...
Factor VIII Inhibitor
101
Both PTT and PT are prolonged. You decide to add heparinase. PTT remains prolonged so you are going to do a mixing study.
Well, that did nothing and PTT has remained prolonged. I am thinking we need to check...
inhibitor,
| most likely Lupus anticoagulant
102
What is the MC inherited bleeding disorder?
von Willebrand Disease
103
What does vWF do?
carries Factor VIII and is a ligand for GPIB receptor - allows adhesion
104
What will be the biggest symptom clue in vWD?
mucocutaneous bleeding
105
What is the MC type of vWD?
Type 1: heterozygous or partial quantitative deficiency
106
What is the most severe type of vWD?
Type 3: rare, homozygous, complete or severe deficiency
plasma Factor VIII will be decreased greatly
looks like hemophilia A
107
Why is vWD difficult to diagnose? What test could you do if you have a very skilled technician?
lab values may be normal, esp. during pregnancy
can try bleeding time test
108
What disease has a decrease in Factor VIII?
Hemophilia A
109
What will the blood timed test look like in a dx of Hemophilia A?
prolonged PTT
| nl PT, TT, and BT
110
What can I use to tx hemophilia A?
vasopressin if mild or Factor VIII concentrate for more severe
111
Will I see hemophilia A in males or females?
males only - Xlinked
112
What is the key ssx of hemophilia A?
bleeding into joints or muscle, hemophilic arthropathy
113
Hemophilia B is a deficiency in...
It can be treated with...
Its inheritence is...
Factor IX
tx with Factor IX concentrate
Xlinked
114
Most other hereditary bleeding conditions are rare and have this inheritance pattern
autosomal recessive
115
The MCC of acquired bleeding disorders is
liver disease
often d/t decreased synthesis of clotting factors, esp Vit K dependent, synthesis of abnl clotting factors, hypo or dysfibrinogenemia, and chronic DIC
116
Vitamin K dependent factors are...
II, VII, IX, X, protein C, protein S
117
What is the difference between hemostasis and thrombosis?
hemostasis is naturally occurring and keeps blood in fluid state while localizing a clot to the site of injury
thrombosis is pathologic and is clotting in an uninjured vessel
118
What three things are involved in the balance of homeostasis? What population is this balance harder to maintain?
vascular wall integrity
platelets
coagulation cascade
difficult to maintain in premature infants
119
These people should have a complete thrombophilia w/u
people with any event under the age of 50;
| anyone with an unprovoked clotting event
120
Virchow's triad includes what three things that predispose people to thrombosis?
1. endothelial injury
2. hypercoagulability
3. abnl blood flow
121
What is the MC inherited thromboembolic disorder?
Factor V Leiden
122
What are the three MC RF for venous thrombembolism?
Factor V Leiden
Prothrombin gene mutation
Increased Factor VIII
123
What does the mutation in Factor V Leiden do?
activates Factor V resistance to proteolytic action of activated protein C
124
What is the increase in risk of VTE for pt with homozygous Factor V Leiden?
80x increased risk VTE
125
How would I screen for Factor V Leiden?
APCR - activated protein C resistance
126
What gene is concerned with prothrombin gene mutation? What is the result?
G20201A
increases prothrombin levels, increasing risk of VTE by 2-6x
incrases TAFI, causing clots to remain longer
127
What three deficiencies cause increased risk of DVT in legs and mesenteric veins?
protein C, protein S, and antithrombin deficiencies
128
What two deficiencies are a/w warfarin induced skin necrosis?
protein C and protein S deficiencies
129
Anti-phospholipid antibody syndrome is also known as what? What was this generally associated with?
Lupus anticoagulant syndrome
a/w SLE, prolonged APTT, and paradoxical thrombophilia
130
What happens in APA/LA?
IgG, IgM, or IgA abs as a result of AI dz, infection, or drugs are directed against phospholipid protein complexes
131
What are 2 broad categories of APA?
```
anticardiolipin abs (ACA)
lupus anticoagulant (LA)
```
132
What are some ssx of APA?
recurrent miscarriages
cardiac valve regurgitation
recurrent thrombosis
thrombocytopenia
133
What tests can be done with concurrent tx, event, or immediately after cessation of tx?
APCR
Homocysteine
ACA
Molecular tests for Factor V Leiden and prothrombin gene
