1
Q
What is considered a prolonged BMBT?
A
> 4mins in dog
2mins in cat
2
Q
What conditions can cause prolonged BMBT?
A
- Thrombocytopathia
- vWD
- Vessel injury
- NSAIDs/aspirin
3
Q
Do GA/sedation affect BMBT?
A
Yes, mildly
4
Q
What two types of vWD does vWF:Ag differentiate between?
A
Type I & type III.
Type II will have a normal vWf:Ag test.
5
Q
What does platelet function analyzer (PFA-100) assess?
A
Platelet adhesion
6
Q
What type of vWD does vWF:CBA help diagnose?
A
- Type II
- Measuring how much vWF bound to collagen.
- vWF:Ag to vWF:CBA ratio >2
- Lower vWF CBA as less bound to collagen as lack large multimers
7
Q
What conditions cause normal platelets, normal PT with elevated PTT?
A
- Hemophilia A/B
- Factor XII (Hageman) deficiency
- Liver disease
- DIC
- Hypofibrinogenemia
Also factor X, II, I deficiencies.
Other contact deficiencies (HMW kininogen, pre-kallikrein)
8
Q
ACT can be prolonged in patients with thrombocytopenia & thrombopathy. True or false.
A
True. The platelets in the tube provide the lipid surface for binding > therefore could be prolonged falsely.
9
Q
What type of protein is fibrinogen? Where is it produced? What pathway is it a marker of?
A
- Acute phase protein
- Liver
- Common pathway
10
Q
Is FDPs or D-dimers more specific for hypocoaguloability & why?
A
- D-dimers
- Degradation products of cross-linked fibrin (meaning clot actually formed), not soluble form, fibrinogen always in blood & could be converted by plasmin to FDPs w/o thrombin involvement
11
Q
What effect does RBC & Plt count have on TEG?
A
- Anemia > hypercoagulopathy on TEG
- Low platelets > hypocoagulable on TEG
12
Q
Does thrombocytosis cause hypercoagulability?
A
No
13
Q
What conditions can cause acquired hyperfibrinolysis?
A
- Liver failure
- Angiostrongylus vasorum (lungworm)
- DIC
- Cavitary effusions
- Acute traumatic coagulopathy
14
Q
What are the 3 broad disorders of primary hemostasis?
A
- Thrombocytopenia
- Thrombocytopathia
- Vasculitis/endothelial disruption
15
Q
What are conditions that can cause acquired thrombocytopathia?
A
- Ehrlichia
- FeLV
- Envenomation
- Liver disease
- Neoplasia
- Uremia
- Aspirin
16
Q
What are the 3 forms of vWD in dogs? Describe key features.
A
- Type 1= all multimers present but decreased number
- Type 2= large multimers absent
- Type 3= all multimers are absent
17
Q
What is vWF found? What is main source?
A
- Subendothelial matrix, in platelets, circulating in plasma
- Endothelium (lesser Plt)
18
Q
Where can desmopressin stimulate release of vWF from?
A
Endothelium (from Weibel-Palade bodies)
19
Q
What is the most important multimer size of vWf for Plt adhesion & aggregation?
A
Large
20
Q
What are examples of conditions that can cause vasculitis?
A
Endotoxin, NMSF, Leishmania, FIP, HW, heatstroke, immune-mediated dz & neoplasia.
21
Q
What is the co-factor for vWF that is also low in vWD?
A
- Factor VIII
- Bound together in circulation
22
Q
Why can vWD cause prolonged PTT in some dogs?
A
- Factor VIII deficiency as is a bound co-factor.
- <30% vWF levels (severe cases only)
23
Q
Type 1 is the most common form of vWD. What breed? Clinical severity?
A
- Dobermans
- Variable
24
Q
What breed for type 2 vWD? Clinical severity?
A
- German Shorthair/Wirehair Pointer
- Severe
25
What breed for type 3 vWD? Clinical severity?
- Scottish Terrier, Shetland Sheepdog
- Severe
26
What is normal vWf:Ag?
Normal= 70-180%
Borderline= 50-69%
Abnormal= 0-49%
27
What is difference between extrinsic vs intrinsic platelet disorders?
Extrinsic= outside platelet (e.g. vWF), Plt normal
Intrinsic= problem with Plt itself
28
What are in general broad causes of inherited intrinsic Plt function disorders?
- Storage pool/granules
- Receptors
- Signal transduction
- Procoagulant expression
29
Bernard-Soulier syndrome. Defect? Breed? Clinical significance?
Test?
- Extrinsic. macrothrombocytopenia
- GPlb/V/IX receptor deficiency > platelet adhesion
- Cocker Spaniel
- Severe bleeding
- DNA test
30
Glanzmann thombasthenia.
Defect? Breed? Clinical significance?
- Absence/deficiency GPllb-IIIa (integrin receptor/fibrinogen) on platelets
- Plt aggregation
- Great Pyrenees & Otterhounds
- Spont mucosal bleeding
31
Scott syndrome. Defect? Breed? Clinical significance? Test?
- Plt function changes meaning can't act as a surface for coagulation (impaired Plt membrane PS externalization & decreased prothrombinase activity)
- German Shepherd
- Bleeding like a coagulopathy (epistaxis, post-op etc.)
- DNA test
32
P2Y12 receptor disorder. Defect? Breed? Clinical significance? Test?
- Impaired binding ADP to Plt
- Greater Swiss Mountain dog
- Post-op bleeding
- DNA test
33
Ca1DAG-GEFI. Defect? Breed? Clinical significance? What test?
- Signal transduction problem
- GPIIb-IIIa unable to change conformation (become high affinity) > less fibrinogen binding/Plt adhesion
- Basset Hound, Landseer & Spitz
- Spont mucosal bleeding
- DNA test
34
Delta-storage pool disease. Defect? Breed? Clinical significance?
- Granule deficiency of ADP
- American Cocker Spaniel
- Post-op bleeding
35
Why do dogs with cyclic neutrophila have bleeding tendancies?
Absent platelet dense granules
36
What is the mutation in CKCS that causes macrothrombocytopenia? What % of this breed have?
- Beta1-tubulin
- 90% (~50% carriers, %50 affected)
37
What mutation causes May-Hegglin anomoly in Pugs?
MYH-9 gene, encoding non-muscle myosin heavy IIA > macrothrombocytopenia & leukocyte inclusions
38
What factor deficiency causes hemophilia A? What type of inheritance?
- Factor VIII
- X-linked recessive
- Males
39
What factor deficiency causes hemophilia B? What type of inheritance? What breed of cat?
- Factor IX
- X-linked recessive
- British Shorthair
40
What thought inherited secondary hemostatic disorder can Greyhounds suffer from?
Hyperfibrinolysis
41
What disease is desmopressin indicated for? What is MOA?
- vWD
- Release of endothelium & factor VIII for storage
- Only increases a little (10%>17%), give 30mins prior to sx
42
What does cryoprecipitate contain? What disease is it helpful for?
- FFP concentrating fibrinogen, factor VIII, vWF, fibronectin
- vWD
- Hemophilia A
43
What is contained in fresh whole blood?
- pRBCs
- Fibrinogen
- Factor VIII
- wWF
44
What does FFP contain? What is indicated for?
- All factors (even labile factors V & VIII)
- All factor deficiences, DIC, vWD
45
What antifibrinogenic drugs can be used in Greyhounds with hyperfibrinolysis syndrome?
- TXA
- Aminocapropic acid
46
Where do antifibrinogenic drugs work at?
- Bind C-terminal lysine sites on plasminogen
47
What do you have to use caution with antifibrinolytic drugs if using for renal hemorrhage?
Clot formation causing intra-renal or ureteral obstruction
48
When can antifibrinolytic acids be helpful?
After minor procedures. epistaxis, gingival bleeds
49
What does cryosupernatant contain? What conditions if it helpful for?
- What is left behind after cryptoprecip removed- Vit K depend factors, AT, albumin.
- Hemophilia B, factor II, VII, IX, XI deficiencies
50
How are platelets released into circulation?
Megakaryocytes fragment
51
Where is thrombopoetin produced?
Liver
52
Where is fibrinogen produced?
Liver
53
How is the intrinsic vs extrinsic coagulation pathways activated?
1. Intrinsic= direct collagen contact
2. Extrinsic= Tissue factor release
54
What is PFA-100 measuring? What can affect it?
- Platelet function
- Anemia, thrombocytopenia, Plt clumping, cardiac disease, uremia
55
What can also affect (increase) vWF:Ag concentrations?
Inflammatory disease, sepsis, pregnancy
56
Is there a genetic test for vWD?
Yes but more for screening for breeders than diagnosis.
57
How do you diagnose the hemophilias
- Prolonged PTT/ACT, normal PT, normal fibrinogen
- FVIIIC:C or FIX:C
58
What PT/PTT pattern is seen with vit-K dependent factor deficiency?
Increased PT, PTT, ACT
59
What conditions can cause elevated PT & PTT? How can FDPs/D-dimers help?
- Hepatic failure, DIC
- Normal FDPs/D-dimers= as above + rodenticide, factor deficencies
60
What conditions can cause normal PT & elevated PTT?
- Hepatic failure (early)
- DIC (early)
- vWD
- Hemophilia
61
What conditions can cause elevated PT & normal PTT?
- Rodenticide toxicity
- Early hepatic failure
62
What conditions can cause normal Plt, PT & PTT but patient bleeding?
Measure FDPs/D-Dimers > if abnormal, consider patient was treated w/ anti-fibrinolytic drug. If normal, do PFA-100.
63
What is the test called for fibrinogen? What are other things that can affect it?
- Clauss method
- If low > hypofibrinogenemia or dysfibrinogenemia.
- False decrease= anticoagulants, increase in FDPs, hypoalbuminemia, factor XIII deficiency or amyloidosis
- Elevation= inflammation/infection as APP
- Truly low with DIC & hepatic failure.
64
What do FDPs simply mean?
Plasmin activity
65
D-dimers mean fibrinolysis occurred in the last ____ hours?
5
66
What is TEG simply?
Global assessment of hemostasis from beginning of clot formation to fibrinolysis. Only measures coagulation, not blood stasis/endothelium.
67
What is the most common type of thromboemboli in IMHA dogs?
Pulmonary
68
What is the cut off platelet level for starting clopidogrel in IMHA, PLN etc.
If > 30,000
69
How can inflammation cause activation of coagulation system?
Pro-inflammatory cytokines & endotoxins > induced TF expression
70
Where is tissue factor found?
- Subendothelial when endothelium disrupted
- Monocytes & endothelium if activated by inflammation/infection
71
What hemostatic abnormalities would DIC cause?
- Thrombocytopenia
- Prolonged PT/PTT
- Elevated D-dimers
- Hypofibrinogenemia
- RBC fragmentation
- Low AT
72
Is hemophilia A or B more common?
A
73
What are normal factor activity levels for hemophilia?
50-150%
6-20% mild, mod 2-5%, severe <2%
74
Does desmopressin increase VIII in dogs like it does in humans?
No
75
Hemophilic dogs/cats can develop factor VIII or IX inhibitors with repeated transfusions. True or false.
True
76
What is the platelet life span in circulation?
6-10 days
77
Can PFA-100 detect dogs with vWD?
Yes, type 1 dogs with level <35%
78
Do cats get VWF?
Yes but rarely, only 2x reported cases.
79
What is MOA of platelet dysfunction with Chediak-Higashi syndrome?
Test?
- Lack of dense granules & deficiency of other agonists
- Characteristic granules in leucocytes on smear & in melanocytes (skin bx)
80
How long does platelet rich plasma?
~6d but if IMTP only few hours
81
What does frozen plasma contain?
Same as FFP but not labile factors V & VIII
82
What does whole blood lose once stored vs fresh?
- Platelets
- vWF, factors V, VIII
- Mainly just RBCs left
83
How much does ~40-45ml/kg of FFP raise g/dL albumin?
0.5-1g/dL
SAIM General Exam
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