BLEEDING DISORDERS Flashcards

1
Q

When may normal hemostatic system go wrong?

A
  • failed to form platelet plug

- failed to form fibrin form

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2
Q

Why may the platelet plug fail to form?

A
  • vessel wall (missing components)
  • platelets (Reduced # or fxn)
  • VWF (hereditary d.o-AD)
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3
Q

What are some vascular abnormalities?

A
  • MARFAN’S syndrome (valves affected/ lack of collagen in vessels/ hyperflexibility)
  • ac
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4
Q

Name an acquired cause of vasculitis.

A
  • –Henoch-schonien purpura (in kids)
  • —-viral
  • —-could be ITP too
  • —presents as PR bleeding AND mucosal bleeding
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5
Q

Which vitamin deficiency results in vasculitis?

A
  • Vitamin C deficiency
  • – Scurvy
  • –particularly seen in lower limbs, fundi, chest if coughing
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6
Q

Senile purpura

A

Iary hemostasis

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7
Q

Commonest cause of acquired thrombocytopenia.

A
  • incr. DESTRUCTION of platelets

- more common in YOUNGER kids

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8
Q

WHcih 2 conditions use up platelets?

A

DIC

ITP

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9
Q

When is DIC seen

A
  • d.t MASSIVE TISSUE damage

- —-RTA/ Wrong blood transfusion/ malignancy/ OBSTETRIC complication

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10
Q

What is an automimmune cause of peripheral platelet destruction?

A

ITP: Immune thrombocytopenic Purpura
SLE

—-isoimmune (post-transfusion and neonatal)

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11
Q

Causes of platelet fxn defects.

A
  • Hereditary: surface lipoproteins missing

- Acquired (drugs - NSAIDs/ ASPIRIN/// Renal failure)

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12
Q

How does vWF def. present as?

A

Herditary or ACQUIRED

Hereditary:

  • —AUTOSOMAL dominant
  • common
  • generally mild
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13
Q

Acquired causes of thrombocytopenia?

A
  • Reduced prodn (marrow failure)

- incr. destruction

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14
Q

What could go wrong in IIary hemostasis?

A
  1. Multiple clotting factor defi. : could be used (DIC in sepsis
  2. single clottign factor deficiency (failure of prodn—hereditary= Hemophilia A (VIII)
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15
Q

WHat conditions result inmultiple clotting factors def.?

A
  • LIVER FAILURE (fatty liver disease/Iary biliary cirrhosis)
  • Vitamin K def. ( warfarin therapy) —–2, 7,9,10
  • complex coagulopathy (DIC)
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16
Q

Which clotting factors REQUIRE vitamin K for prodn?

A

FACTORS 2, 7, 9, 10

they are carboxylated by Vit K; ESSENTIAL FOR FUNCTION

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17
Q

WHere is vitk sourced from?

A
  • diet

- intestinal synthesis

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18
Q

Why are vit. K shots given to bbies?

A

—risk of hemorrhagic disease of the newborn

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19
Q

What is REQUIRED for Vit. K absorprtion?

A
  • requires bile SALTS for absorption in the UPPER intestine
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20
Q

Causes of Vit. K deficiency.

A
  • warfarin
  • obstructive jaundice
  • malabsorption
  • poor dietary intake
  • hemorrhagic disease of newborn
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21
Q

How does DIC occur?

A
  1. DUE TO MASSIVE tissue damage> Excessive and inappropriate activation of haemostatis system - exposure of TF to vascular components
  2. TO COUNTERACT 1., MICROVASCULAR thrombus formation occurs. (> tissue infarction> END organ failure)
  3. With continuous 1, and 2 > clotting factor consumption —> BRUISING, PURPURA and generalized bleeding
22
Q

LIVER DISEASE and warfarin disease appears how so in bleeding screening test?

A

-PT and APTT both LOWERS
—PT is first to lower ——V. GOOD to monitor liver disease
(VII is first to go)

23
Q

How may SEPSIS cause DIC?

A
  • DIRECT bacterial damage and hypoxia (ENDOTOXEMIA- endotoxins trigger the RELEASE of tissue factor from the monocytes)
24
Q

How may DIC be triggered in obstetric emergencies?

A

====placenta contains a HIGH amount of tissue factor or thromboplastic factors; so in placental abruption, DIC is greatly triggered

25
Q

What malignancies cause DIC? How?

A
  • —slowly, progressive develop. of DIC#
  • —ADENOCa (Bowel and prostate cancer)
  • –by release of proteolytic enzymes and expression of tissue factor
  • —more thrombotic fts
26
Q

How to treat DIC?

A
  1. treat underlying cause
  2. replacement therapy
    - platelet/ plasma/ fibrinogen (cryprecipitate) replacement
27
Q

How may bleeding in to the joints in hemophilia occur?

A

Spontaneous haemorrhages occur in tissues that are subject to MECHANICAL stress
> bleeding into joints> IRON in blood irritate the synovium
> triggers the neovascuralisation in the synovium
>easily broken vessels

28
Q

Hemophilia is associated with

A
  • LARGE and medium blood vessels
29
Q

What are the 3 types of haemophilia? And how does it indicate VIII/IX levels?

A
  • mild (<2%)
  • moderate (2-5%)
  • severe (>5%)–
30
Q

What is prolonged in haemophilia?

A
  • APTT
31
Q

What are the clinical fts of severe haemophilia?

A
  • recurrent haemarthroses (start at 2/3 years)
  • recurrent soft tissue bleeds (bruising in toddlers)
  • — prolonged bleeding after dental extraction/ surgery
32
Q

How to manage Haemophilia A?

A
  • IV Factor VIII every second day
  • self administered
  • —prevent massive bleeds
33
Q

What occurs with reccurent joint bleeds!

A
  • reccurent bleeding results in HAEMARTHROSES

- —-affects MOTIBILITY of joint!

34
Q

What is the commonest cause of PRIMARY haemostatic failure?

A

thrombocytopenia!

35
Q

How does vWF def. present as?

A

—-menorrhagia/ bleeding gums/ nose bleeds

36
Q

What is the MOST COMMON hematological manifestation of AIDS?

A

thrombocytopenia!

37
Q

Which infections causes thrombocytopenia?

A

MEASELS
AIDS
—–BOTH said to IMPAIR prodn of platelets!

38
Q

What drugs cause thrombocytopenia?

A

IMPAIRS prodn: cytotoxic drugs/ thiazides/ alcohol

Immune destruct.: Quinidine/ Heparin/ Sulfa compounds

39
Q

When may ineffective megakaryopoiesis occur?

What does this result in?

A

with MEGALOBLASTIC anaemia and paroxysmal nocturnal hemoglobinuria

—-thrombocytopenia.

40
Q

In whom is haemophilia seen in?

A

MEN

- X-linked, hereditary d.o

41
Q

Which haemophilia type is MORE common?

A
Haemophilia A  (5x more common) 
-----VIII deficiency
42
Q

What causes non-immunological destruction of platelets?

A
  1. thrombotic thrombocytopenic purpura
  2. DIC
  3. Giant hemangiomas
  4. Microangiopathic hemolytic anaemia
43
Q

What is ITP?

Best rx?

A
  • Spleen - the MAIN culprit for pathogenesis
  • —-site of anti-platelet Abs and site of DESTRUCTION of IgG coated platelets

RX: if chronic ITP= Splenectomy

44
Q

What does a bone marrow with incr. megakaryocyte, suggest ?

A
  • accelerated platelet destruction

- common to all forms of thrombocytopenia

45
Q

What is the risk of heparin?

WHy does it occur?

A
  • drug- induced thrombocytopenia (sets in 1/2 weeks after administration)
  • —seen more with UNfractionated heparin.

—d.t formation of IgG abs activating platelets !

46
Q

How is the dx of hemophilia made?

How is it treated?

A
  • using specific assays of Factor VIII and IX

- infusion of recombinant factor VIII and IX

47
Q

Why is splenomegaly a problem?

A
  • chronically enlarged spleen often removes single/ multiple elements of the blood
    > thrombocytopenia (common), anaemia, leukocytopenia
48
Q

What are the key roles of vWF?

A
  1. carrier of Factor VIII

2. binds platelets to endothelium and other platelets; def. ==> poor aggregation of platelets

49
Q

WHat is seen with the lab results of vWF disease?

A
  • raised Bleeding time

- may have slight rise in PTT (if SEVERE; factor VIII is a.w vWF)

50
Q

What occurs in Heyde’s Disease?

A
  • GI bleeding in the setting of Aortic stenosis. d.t 2 reasons:
    1. Incr. in vascular malformations in the GI tract (PRONE to bleeding)
    2. def. of vWF (HIGH sheering force through aortic stenosis UNCOILD vWF multimers; exposing it to ADAMTS13 enzyme) —basically an OVERACTIVITY of ADAMTS 13