Hemostasis Defects Flashcards Preview

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Flashcards in Hemostasis Defects Deck (66)
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1
Q

What factors does protime (PT) measure?

A

II, VII, X, V and fibrinogen

The extrinsic and lower part of the coagulation cascade.

2
Q

What is a normal PT?

A

9-12 seconds

3
Q

Because the PT is dependent upon the potency of the material that i used to start the reaction in the laboratory what must it be compare to?

A

International normalized ration (INR)

4
Q

What is a normal INR?

A

1.0

5
Q

What are two of the most common causes of abnormal PT?

A

Deficiency of vitamin K dependent factors (VII, X, II) or

Inadequate liver funciton

6
Q

What would warfarin do to the PT?

A

Increase PT

7
Q

What does the PTT measure?

A

The procoagulant activity of the entire pathway, but it is more sensitive to deficiencies of the higher numbered factors especially XI, VIII, and IX

8
Q

What is PTT not effective in measuring?

A

Factor VII

9
Q

What can prolong the PTT?

A

Heparin or acquired anticoagulants such as fibrin split products

Patients with hemophilia

10
Q

What is a normal PTT?

A

25-32 seconds

11
Q

What is PT used to monitor?

What is PTT used to monitor?

A
  • Warfarin

- Heparin

12
Q

What does thrombin time measure?

A

The procoagulant activity of fibrinogen and is also very sensitive to the anticoagulant effect of heparin or fibin split products.

13
Q

What is the normal range of thrombin time?

A

12-18 seconds

14
Q

What does the bleeding time measure?

A

Platelet and vessel initeraction as well as the number and the function of platelets.

15
Q

What is a normal bleeding time?

A

2-9 minutes

16
Q

What will cause an increase in bleeding time?

A

Severe decrease in platelet count

von Willebrand disease

abnormalit in platelet function

OTHER FACTOR DEFICIENCIES DO NOT PROLONG THE BLEEDING TIME

17
Q

What is PFA-100?

A

Platelet function analyzer that can perform an in vitro bleeding time

18
Q

What is most common cause of a severe bleeding tendency?

A

Hemophilia A (Factor VIII deficiency)

19
Q

Hemophilia B is characterized as a deficiency of what coagulation factor?

A

Factor iX

20
Q

What is the inheritance pattern of both Hemophilia A and Hemophilia B?

A

X-Linked
Females are carriers
Men are affected

21
Q

Which test is prolonged in Hemophilia A and B?

A

PTT

22
Q

What is the genetic defect is seen in 40% of Hemophilia A patients?

A

Inversion on the long arm of the X chromosome

23
Q

Less than 1% factor activity is considered a severe hemophilia. What are the symptoms of someone with less than 1% factor activity?

A

Spontaneous hemorrhaging into their joints, muscles, soft tissues, retroperitoneal space and CNS.

Continuous bleeding into the joints leads to very severe arthritis

24
Q

Between 2%-5% factor activity is considered to by a moderate hemophilia. What are the symptoms of someone with moderate hemophilia?

A

It usually takes some degree of trauma to cause bleeding in these patients

25
Q

> 10% factor activity is considered a mild hemophilia. What are the symptoms of someone with >10% factor activity?

A

Only bleed after trauma and do not develop the chronic joint disease

They are usually diagnosed after a bad traumatic even ot after a bad result from surgery

26
Q

Female carriers can express anywhere from 30-100% factor activity, but at what percent are they symptomatic carriers?

A

30%

27
Q

Factor XI deficiency usually express >5% factor activity. Are they spontaneous bleeders?

A

No usually

28
Q

What is the inheritance pattern of Factor XI deficiency?

A

Autosomal recessive

29
Q

What patient population is Factor XI deficiency common in?

A

Ashkenazi Jews

30
Q

What test time is usually prolonged in Factor XI deficiency?

A

PTT

31
Q

When is Factor XI deficiency most commonly diagnosed?

A

Post-operative hemorrhage

32
Q

What test time is usually prolonged in Factor VII deficiency?

A

JUST PROTIME

33
Q

What is the inheritance pattern of Factor VII deficiency?

A

Autosomal disease: Homozygous severe but heterozygous still affected.

34
Q

What are the two functions of von Willebrand protein?

A
  1. Adhere platelets to exposed collagen at the wound site.

2. Carrier of Factor VIII

35
Q

What two tests are prolonged in von Willebrand’s Disease?

A

PTT

Bleeding time

36
Q

What is type I von Willebrand’s disease?

A

Deficiency of normal von Willebrand protein

37
Q

What is type II von WIllebrand’s disease?

A

Presence of an abnormal protein

38
Q

DDAVP (arginine vasoprressin is very effective in treating which type of von Willebrand’s disease?

A

Type I

39
Q

What is the inheritance pattern of von Willebrand’s disease?

A

Autosomal dominant

40
Q

What are some symptoms of von Willebrand’s disease?

A

Bleeding from mucosal mebranes, and nose bleeds, GI bleeds and menorrhagia

They also bleed after surgery

41
Q

Acquired Factor VIII inhibitor is an extremely rare acquired factor inhibitors seen in postpartum or advanced age patients.
How does this acquired disease present?
What test is prolonged?

A
  • Soft tissue and muscle bleeding, and usually marked hematomas of their skin or mucosal bleeding
  • Abnormal PTT only. Which will not correct after two hours of incubation.
42
Q

What is the prognosis for Aquired Factor VIII inhibitor?

A

Although the disease has a 25% mortality due to bleeding it has an EXCELLENT long-term prognosis since most patients respond to immune suppression.

43
Q

Name some very rare acquired inhibitors that can be seen.

A

Inhibitors to von Willebrand protein
Factor II inhibitors
Factor V inhibitors

44
Q

Where are most coagulation factors synthesized?

A

Liver

45
Q

What are the factors that are especially lowered due to liver disease?

A
Factor V
Factor II
Factor VII
Factor IX
Factor X 
Fibrinogen
46
Q

What tests are prolonged in liver disease?

A

PT
Relatively less prolonged PT
Thrombin time may also be prolonged

47
Q

In liver disease you should always make sure that there is not a component of ____________ deficiency

A

Vitamin K

48
Q

Vitamin K is obtained from the diet. What two circumstance cause vitamin deficiency?

A

No oral intake and broad spectrum antibiotics

49
Q

A 16 year old patient is brought into the emergency room by his parents. He is unconscious and his parents report that he suffers from depression and that they found a box of d-Con by his bed. They show you the box that has an upside-down rat on it. Based on your knowledge of rat poison you know that this patient will need what type of therapy? Besides charcoal and gastric lavage blah blah blah

A

Vitamin K therapy for many months

50
Q

What two tests are decreased in disseminated intravascular coagulation?

A

Fibrinogen level is decreased

Platelet count is low

51
Q

Fibrin cleavage products, fibrin degradation products and D-dimer can be measured in DIC. These products can inhibit two tests. Which two tests?

A

PTT&raquo_space;>it being prolonged

TT»».it being prolonged.

52
Q

What two factors are consumed in DIC?

A

Factor VIII and Factor V

53
Q

How is DIC distinguished from liver disease just based on the labs?

A

Liver disease PT is prolonged a lot more than PTT

DIC: PTT is increased relatively much more than the protime

54
Q

Define thrombosis

A

Formation and propagation of clot within the vasculature

55
Q

Thrombosis occurs due to some combination of what three factors?

A

Stasis
Inflammation
Vessel wall injury

56
Q

What factors create a hypercoagulable state?

A

Chronic damage to vessel walls
Excess of procoagulant factors
Deficiency of anticoagulant facotrs
Fibrinolytic activity

57
Q

Name four risk factors for thrombosis

A
  1. A thrombotic episode in the absence of a defined precipitating condition
  2. Recurrent episodes of throbosis, or throbosis at an early age and is otherwise health
  3. A severe, life threatening thrombosis, or thrombosis at an unusual site
  4. Family history of thrombosis
58
Q

Is it appropriate to search for an underlying hemostatic defect that can contribute to a “hypercoagulable state”?

A

Yeah

59
Q

Lupus anticoagulant is
rare or common?
congenital or acquired?

A

Common acquired abnormality

60
Q

What is the pathogenicity of Lupus anticoagulant?

A

IgG antibody which reacts against phospholipid in the platelet membrane or endothelial cell

61
Q

What test is prolonged in lupus anticoagulant?

A

Prolongs the PTT

62
Q

What are some symptoms of lupus anticoagulant?

A

Deep vein throbosis, pulmonary embolism, thrombotic strokes and recurrent miscarriage due to thrombotic disease of the placental blood

63
Q

Is PTT corrected when normal plasma is mixed with the plasma from a patient with lupus anticoagulant?

A

no

64
Q

What are the most common familial congenital condition which cause hypercoagulable syndromes?

A

Deficiencies of

  • antithrombin (AD)
  • protein C (AD)
  • protein S (AD)
  • resistance to protein C (Factor V Leiden)
65
Q

What are the symptoms of someone who has homozygous deficiencies in either protein C or S?

Heterozygous

A

Fetal at birth

Presents after puberty with recurrent venous thrombotic disease

66
Q

Mutation in Factor V causes it not to inactivated by ________.

Which patient population are heterozygous states common?

A

Protein C

Europeans