Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

basic oral and dental care > haemostasis and anaemia > Flashcards

haemostasis and anaemia Flashcards

1
Q

What is normal haemostasis?

A
  1. Localised vasoconstriction at injury site
  2. Platelet adhesion to vessel wall and formation of platelet aggregation/plug
  3. Coagulation cascade activation—> fibrin formation (reinforces plug)
  4. Fibrinolytic system activation which digests plug, reestablishing vascular patency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are platelets?

A 
Small non-nucleated cells
Fragments of megakaryocyte cytoplasm
140-350 x10^9/l
<20- spontaneous bleeding
>80- haemostatic
Thrombocytopenia- reduced
Thrombocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is primary haemostasis?

A

Present w purpura, bruising, bleeding from cuts, heavy periods, surgical bleeding
~inv vessel wall, platelets and Von Willebrand factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is secondary haemostasis?

A

Present w joint and muscle haematomas and surgical bleeding, bruising not prominent
~inv coagulation cascade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How should a patient w a bleeding disorder be managed?

A

History- bruising? bleeding after minor injury/extractions/surgery? epistaxis? menorrhagia? family history? drugs (eg. aspirin, warfarin, cytotoxics)? alcohol?

Examination- ecchymoses? purpura? haemarthrosis? damaged joints? anaemia? signs of liver disease? splenomegaly?

Investigations- full blood count? clotting screen (PT, APTT, fibrinogen)? bleeding time/PFA?

Treatment- depends on diagnoses 
Haemophilia A- FVIII concentrate
Haemophilia B- FIX concentrate
Thrombocytopenia- platelet transfusion
Warfarin overdose- Vit K
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some bleeding terms?

A 
Menorrhagia- heavy menstrual periods
Epistaxis- nose bleed
Haemoptysis- coughing blood
Haematemesis- vomiting blood
Haematuria- blood in urine
Malaena- black stool (bleed in upper GIT)
Ecchymoses- bruises
Purpura- purple blood spots
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does PFA stand for?

A

Automated platelet function analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some inherited vascular bleeding disorders?

A

Hereditary haemorrhagic telangiectasia

Ehlers-Danlos syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is Ehlers-Danlos syndrome?

A

V flexible joints

Stretchy and fragile skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is hereditary haemorrhagic telangiectasia?

A

Arteriovenous malformations
Regular nosebleeds
Red/purple spots/lines under skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are coagulation factor disorders?

A

Haemophilia A and Haemophilia B= x linked

Von Willebrand disease- autosomal dominant

Others- autosomal recessive, deficiciency of fibrinogen or factors II, V, VII, X, XI, XIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the frequency of bleeding disorders?

A

Haemophilia A- 1:5000
Haemophilia B- 1:25000
VWD- 1:1000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Haemophilia?

A

A- factor VIII deficiency
B- factor IX deficiency

Identical clinical features
Sex linked inheritance

Sites of bleeding- joints, muscles, post trauma, post op

Severity-
<1%- severe
1-5%- moderate 
5-50%- mild
50%-150%- normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is haemophilia treated?

A

Mild Haem A- desmopressin (releases factor VIII from endothelium)

All severities- factor VIII/IX concentrate- UK recombinant products

Plasma derived products- risk of infection, all products virally inactivated since 1985

Haemophiliacs treated before 1985 (HIV 30%, Hep B 5%, Hep C 98%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Von Willebrand Disease?

A

Autosomal dominant
3 main types (many subtypes)
Milder than haemophilia
Clotting factor + platelet abnormality

Sites of bleeding- bruising, cuts, gums, epistaxis, menorrhagia, post op, post trauma

Treatment-
~desmopressin (DDAVP)
~intermediate purity (plasma derived) factor VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What tests should be done for Haem A?

A

Factor VIII- low

APTT- prolonged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What tests should be done for Haem B?

A

Factor IX- low

APTT- prolonged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What tests should be done for VWD?

A

Factor VIII- low
VW factor- low
BT- Prolonged
APTT- Prolonged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some inherited platelet disorders?

A

Affecting number-
MYH-9 related thrombocytopenia
32 other inherited causes of it

Affecting function-
Glanzmann’s thrombasthenia
Storage pool disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is thrombosis?

A

Blood coagulation in a vessel

Arterial-
~high pressure, platelet rich
~eg. MI, stroke
~treat- anti platelet drugs

Venous-
~low pressure, fibrin rich
~eg. deep vein thrombosis, pulmonary embolism
~treat- anticoagulants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are risk factors for venous thrombosis?

A

Acquired-
~age, previous VTE, surgery/trauma, immobility, obesity, cancer/serious illness, pregnancy, the pill, hormone replacement therapy

Inherited thrombophilia-
~antithrombin deficiency (1:3000), protein C deficiency (1:300), protein S deficiency (1:300), factor V Leiden mutation (1:20), prothrombin G20210A condition (1:75)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are risk factors for arterial thrombosis?

A

Smoking, obesity, hypertension, diabetes mellitus, older age

Not inherited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are some aquired vascular bleeding disorders?

A 
Senile purpura
Scurvy (Vit C deficiency)
Steroid purpura (long term use)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are causes of thrombocytopenia?

A

Failure to produce-
~Vit B12 or folate deficiency
~disease infiltrates bone marrow
~radiation, cytotoxic therapy

Increased consumption-
~immune thrombocytopenia
~disseminated intra vascular coagulation
~HIV infection

Hypersplenism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is immune thrombocytopenia?

A

Children- usually follows acute infection, self limiting so not treated

Adults- unclear cause, chronic, treat if bleeding

Diagnosis- exclude other causes of thrombocytopenia, bone marrow exam

Treatment- steroids, IV immunoglobulin, splenectomy, thrombopoietin receptor analogues

26
Q

What is desseminated intravascular coagulation (DIC)?

A

Breakdown of haemostatic balance
Simultaneous bleeding and micro vascular thrombosis
Life threatening

Causes- sepsis, obstetrics, malignancy

Treat- remove cause, give plasma/platelets if bleeding

27
Q

What is the platelet distribution like in a person w splenomegaly?

A

Normal- 30% spleen, 70% circulating

Splenomegaly- 60-90% spleen, 10-40% circulating

28
Q

What are some aquired platelet function abnormalities?

A

Antiplatelet drugs- aspirin, Clopidogrel, prasugrel- irreversible action
(prasugrel more rapid and consistent inhibition than Clopidogrel)

Renal disease- increased bleeding(anaemia, thrombocytopenia/uraemia/treat w desmopressin or dialysis)/thrombotic risk (nephrotic syndrome- aquired antithrombin deficiency)

Liver disease (reduced clotting factors, hypersplenism, portal hypertension, dysfibrinogenemia, increased fibrinolysis)

DIC

29
Q

What happens with a Vit K deficiency?

A

Vit K synthesises factors II, VII, IX, X
Fat soluble vitamin
Must have shot at birth due to deficiency
Obstructive jaundice- narrowed/blocked bile duct

Maifests as prolonged PT
Vit K given via IV

30
Q

What drugs may be the causes of aquired bleeding disorders?

A

Antiplatelet drugs (aspirin)
Anticoagulants (heparin/warfarin)
Steroids- tissues thin causing bleeding/bruising
Drugs affecting liver, kidneys, bone marrow

31
Q

What are some antiplatelet drugs?

A

Aspirin
Clopidogrel
Prasugrel
Ticagrelor

32
Q

What are some anticoagulants?

A

IV- unfractionated heparin

Subcutaneous- low molecular weight heparin

Oral- warfarin, dabigatran, rivaroxaban, apixaban, edoxaban, vit K antagonists* (96% warfarin, 4% acenocoumarol)

*used more over other oral

33
Q

What is heparin?

A 
Glycosaminoglycan
Binds to antithrombin and increases its activity
Indirect thrombin inhibitor
Not absorbed via gut
Continuous infusion
Monitor w APTT

Low molecular weight- less variation in dose, weight adjusted dose, once daily, Renault excreted, for treatment and prophylaxis

34
Q

What is warfarin?

A

99% plasma protein bound
Inhibits II, VII, IX, X
Peak effect- 3-4 days after start
4-5 days after stop- still affected

Side effects- bleeding, embryopathy

Measured by INR
Dose based on INR

For DVT/PE- 2-3 dose

Freq of monitoring depends on stability of INR, must be measured before surgery

35
Q

Why are direct oral anticoagulants advantageous?

A 
Oral
No monitoring
Standard dosing
No alcohol/food interactions
V few drug interactions
Short half life (10-15hrs)

However, more expensive than warfarin

36
Q

What is vaccine induced immune thrombosis and thrombocytopenia?

A 
4-16 days after Astra Zeneca
18-65 years
Cerebral or portal vein thrombosis
Thrombocytopenia 
1:100000
25-30% mortality
37
Q

What is anaemia?

A

Haemoglobin conc below normal range
Males- <125g/l
Females- <115g/l

38
Q

How is the normal haemoglobin range measured?

A

Measure Hb in normal range
Work out mean and SD
Normal range is mean +/- 2SD
Different in men and women

39
Q

What are symptoms of anaemia?

A

Fatigue, reduced exercise tolerance, shortness of breath
Postural hypotension, dizziness, palpitations
Angina
Heart failure

40
Q

What are signs of anaemia?

A 
Pallor
Tachycardia 
Heart murmurs
Koilonychia- iron deficiency (dish shaped nails, brittle, soft)
Angular stomatitis
Glossitis- B12/folate deficiency
41
Q

How do you diagnose anaemia?

A

Full blood count-
~Haemoglobin and it’s mean cell volume
~White cell count
~Platelet count

42
Q

What is a normal mean cell volume?

A

82-96 fl

Anaemia-
Microcytic- <82
Normocytic- 82-96
Macrocytic- >96

43
Q

What causes microcytic anaemia?

A

Due to iron deficiency, thalassaemia (inherited RBC disorder) or anaemia of chronic disease (rarely)

44
Q

What causes macrocytic anaemia?

A

Due to Vit B12/folate deficiency

Macrocytosis w/o anaemia-
~liver disease
~hypothyroidism
~alcohol

45
Q

What causes normocytic anaemia?

A

Acute bleeding
Congenital/acquired haemolysis (RBCs destroyed)
Aplastic anaemia (RBCs not produced in marrow)
Anaemia of chronic disease

46
Q

What causes iron deficiency?

A

Reduced intake (rare in UK)
Increased requirements in pregnancy/childbirth/malabsorption/coeliac disease
Chronic blood loss- menorrhagia/GI blood loss (due to oesophageal web?- Patterson-Kelly syndrome)

47
Q

How do you diagnose iron deficiency?

A

Full blood count-
Reduced Hb and MCV

Serum Ferritin- blood test

Bone marrow/liver biopsy- to see tissue iron stores

48
Q

How do you investigate iron deficiency?

A

History- bleeding somewhere? Black stool? Stool consistency? Appetite? Weight loss? Abdominal pain? Freq/clots/attendance barrier of periods?

Examination- lymph nodes? masses in abdomen? rectal examination?

Ferritin
Gastroscopy/colonoscopy- ulcers? Polyps?

49
Q

How do you treat iron deficiency?

A

Treat cause

Ferrous sulphate 200mg oral daily, until Hb normal and then 3 months to rebuild stores

50
Q

What is B12 and folate deficiency?

A

Needed for haematopoiesis/DNA synthesis of all cells

Deficiency causes magaloblastic anaemia- precursors of RBCs become really large in marrow
~macrocytic anaemia (high MCV)
~leukopenia
~thrombocytopenia

51
Q

How do we get B12?

A

Dietary- bacteria/animal products
Absorption- intrinsic factor from stomach binds w B12 and is absorbed in terminal ileum as complex (intrinsic factor produced by parietal cells)
Body storage- 4 years

52
Q

What causes B12 deficiency?

A

Lack of intrinsic factor
Pernicious anaemia (autoimmune disorders- antibodies prohibit binding between intrinsic factor and B12)
Gastrectomy
Failure of absorption in terminal ileum due to resection, Crohns, TB, lymphoma etc
Diets- vegans?

53
Q

What happens if someone has B12 deficiency?

A 
Macrocytic anaemia
Megaloblasts in marrow
Pancytopenia- low Hb, WBCs and platelets
Affects all body cells
Neuropathy- memory loss? Altered personality? Dementia? Peripheral neuropathies? Ataxia?
54
Q

What is pernicious anaemia?

A

Autoimmune disorder
Usually affects elderly
Achlorhydria- absence of hydrochloric acid in gastric secretions
Autoantibodies against intrinsic factor- blocks binding
Associated w other autoimmune disorders- hypothyroidism, vitiligo

55
Q

How is B12 deficiency diagnosed?

A

Serum B12- blood test

In pernicious anaemia-
~intrinsic factor antibodies (50%)
~parietal cell antibodies (80%)

56
Q

How is B12 deficiency treated?

A 
Parenteral hydroxycobalamin- intramuscular, 1mg every 2 days initially
Give before folate if also deficient
Reticulocyte (young RBC) response
Risk of hypokalaemia- monitor potassium
1mg every 3 months for life
57
Q

How do we get folate?

A

Dietary- fresh fruit/veg
Absorbed in proximal intestine
Low body stores- easily depleted
Need 100micrograms

58
Q

What causes folate deficiency?

A

Dietary
Malabsorption- coeliac disease
Increased requirements- pregnancy, haemolysis, some drugs (eg. Folate antagonists)

59
Q

How is folate deficiency treated?

A

Oral folate 5mg tablet daily

Works for all causes inc malabsorption

60
Q

What are haemolytic anaemia?

A

HEREDITARY
~RBC membrane defect eg. Hereditary spherocytosis
~Abnormal RBC metabolism eg. G6PD/pyruvate kinase deficiency
~Hb abnormalities eg. Sickle cell disease

ACQUIRED
~Auto/allo-immune eg. Rhesus disease
~RBC fragmentation syndromes
~infections

61
Q

What do sickle cell disease?

A

Autosomal recessive
Afro-Caribbean population
Single point mutation. (Alanine changes to thymine)
Heterozygous patients protects from malaria
Painful vaso-occlusive sickle cell crises
Crises precipitated by infection/cold/hypoxia etc
Diagnose- FBC, sickle cell test and Hb electrophoresis

basic oral and dental care (49 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions