Disorders of Hemostasis - Ex 6 Flashcards Preview

724 Clin Path > Disorders of Hemostasis - Ex 6 > Flashcards

Flashcards in Disorders of Hemostasis - Ex 6 Deck (22):
1

Vascular and platelet abnormalities - CS

Petechial hemorrhages

2

Coagulation disorders - CS

Large hemorrhages:
- subcutaneous
- body cavities
- hemarthrosis (bleeding into joint spaces)

3

Vascular disorders

Increased vessel fragility and/or defective sub endothelial collagen

4

Acquired vascular disorders

Vasculitits (including envenomation)

Cushing's Syndrome

Scurvy

5

Lab Results - Vascular Disorders

Bleeding time: P
ACT: N
APTT: N
PT: N
QF: N
PLT: N to decreased (consumption)

6

Thrombocytopenia:

<50,000/ul

<10,000/ul

<50,000ul --> increased bleeding secondary to trauma

<10,000ul --> spontaneous bleeding

7

First rule out of thrombocytopenia

Artefact: platelet clump
(esp in cats)

8

Thrombocytopenia - decreased production

Causes

1. Infectious agents (Ehrlichia)

2. Neoplasia (myelophthisis)

3. Drugs (estrogen)

9

Thrombocytopenia - increased destruction

Causes

**Primary Immune-mediated**

Seen with IMHA

10

Lab Results - Thrombocytopenia

Bleeding time: P
ACT: N --> P
APTT: N
PT: N
QF: N

11

Platelet Dysfunction - Acquired

Causes

NSAIDS (most common!!)


Others:
Myeloma proteins
FDPs
Uremia
Phenothiazines

12

Lab Results - Platelet Dysfunction

BT: P
ACT: N
APTT: N
PT: N
QF: N
vWF: N
PLT: N

13

Platelet Dysfunction - Inherited

von Willebrand disease! (Type 1 is most common)

vWF on sub endothelium binds to platelets --> lack of vWF --> platelets cannot bind and form clot

14

How do we measure vWF?

Measured immunologically (Ag)

15

Types of vWD

Type 1:
- dec vWF:Ag
- dec all multimers
**most common

Type 2:
- dec vWF:Ag
- dec all multimers, esp high MW
**more severe than type 1

Type 3:
- vWF:Ag = undetectable
**defect in the gene --> most severe form

16

Lab Results - vWD

BT: P
ACT: N --> P
APTT: N --> P
PT: N
QF: N
vWF: dec to absent

17

Coagulation Disorders (Inherited) - Factors IX and VIII:C

IX - Dog, cat (severe bleeding)

VIII:C - dog, cat, sheep, horse (variable bleeding)

18

Coagulation Disorders (Acquired) - Vit K and Hepatic Failure

1. Dec Vit K
- vit K antagonists (rodenticides)
- bile duct obstruction
- malabsorption
- dietary vit k deficiency

2. Hepatic failure
- decreased production of factors

19

Lab Results - Vit K antagonism/deficiency

BT: N
ACT: P
APTT: P
PT: P
QF: N
vWF: N

20

Lab Results - Hepatic Failure

BT: N
ACT: P
APTT: P
PT: P
QF: Dec
vWF: N

21

Combined Disorders

DIC
- thrombocytopenia
- coagulopathy

22

Lab Results - DIC

BT: P
PLT: Dec
ACT: P
APTT: P
PT: P
QF: P
FDPs: Inc
D-dimers: Inc

***Everything is abnormal!