Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Haematology > Haemostasis + Anti-coagulation > Flashcards

Haemostasis + Anti-coagulation Flashcards

1
Q

What does endothelium that lines blood vessels produce to stop clots and encourage flow

A 
Heparins
TFPI - natural anti-coagulant
Thrombomodulin
NO 
Prostacylin - prevent aggregation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What flows in the blood and has potential to form clots

A

Platelet
Red cell
Coagulation factors

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

What is the process of primary haemastasis when there is vessel damage

A

Vasconstriction
vWF released from damaged endothelium and binds to collagen
Platelets aggregate as exposed to sub endothelial collagen
Platelet activation by ADP receptor
GIIB/11A receptors now exposed and can bind fibrinogen
Primary platelet plug = weak
Tissue factor produced from tissue e.g. damaged vessel (physiological activator of coagulation) - extrinsic
or
Activated by sub endothelial collagen (intrinsic)
Activates coagulation proteins
Work to produce a fibrin clot - secondary haemostasis

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

What is on surface of platelets to help binding

A

GPIIb/IIa receptor

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

What do platelets bind to

A

Fibrinogen
Collagen
VWf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are platelets activated by

A

P2y12 / ADP pathway

COX pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does COX pathway produce

A

Converts arachidonic acid ->Thromboxane A2 which aids aggregation of platelets + provides surface for coagulation proteins to be activated

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

What forms stable fibrin clot (secondary haemostasis)

A

Coagulation cascade
Coagulation proteins - factor XI / IV / VII activated
Intrinsic pathway
Extrinsic pathway
Activate pro-thrombin which activates thrombin
Thrombin converts fibrinogen to fibrin to form clot

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

What happens if coagulation proteins are deficient

A

Fibrin clot won’t form

Anti-coagulants inhibit these proteins as well

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

What are natural anti-coagulants in the blood that tell clot to stop forming

A

Anti-thrombin - most important
TFPI
Protein C and S

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

What coagulation factors does anti-thrombin act on

A

Factor 10

Thrombin

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

What is fibrinolysis

A

Removal of clot

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

What endothelial cells activate plasminogen

A

t-PA

u-PA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does activated plasminogen do

A

Converts to plasmin to break down clots

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

What is left after clots broken down

A

Fibrin degradation product

e.g. D-dimer

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

What are anti-thrombotic / coagulant durgs and when are they indicated

A

Warfarin
Heparin
DOAC’s - Rivaroxaban / Edozaban / Dalbigatran

AF
VTE
Post surgery
Immobilisation
Valvular heart disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are anti-platelets

A

Clopidogrel / Prasugrel / Ticagrelor
Aspirin
Abciximab

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

What does aspirin do

A

Inhibits COX so stops production of thromboxane A2

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

What does abciximab do

A

Prevents GP IIB/ IIA from binding fibrinogen

Used less often

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

What does clopidogrel etc do

A

Prevents ADP pathway

Use in combination with aspirin

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

Who is put on antiplatelet

A 
Angina
MI
Stroke
Obesity
DM
FH
SMoking
Risk of abnormal clot
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is warfarin and what factors affected

A

Vitamin K antagonist so stops coagulation factors being produced
Hepatic metabolism by p450
1972 - 10, 9,7,2

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

How do you reverse warfarin and when

A

Vitamin K

Prothrombin complex to activate coagulation proteins if major bleed = rapid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is indication for warfarin and what is the target INR and when is it used over DOAC

A

Artificial heart valves

  • Aortic 2-3
  • Mitral 2.5-3.5

VTE
- 2.5-3.5 (higher if recurrent)
AF
- 2-3

Artificial valve / Mitral stenosis / obesity and renal failure <30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does warfarin require and what do you do if too low
Weekly INR check as narrow therapeutic range with dose adjustment If INR <2 Cover with LMWH and increase dose
26
When is warfarin CI and SE
``` Unreliable to get INR check Peptic ulcer Bleeding disorder Severe hypertension Liver disease Pregnancy as teratogenic but CAN breastfeed ``` SE Haemorrhage Teratogenic so CI in pregnancy Necrosis / purple toes
27
What do you do if INR 5-8, no bleed
Withhold dose | Start at lower dose
28
What do you do if INR 5-8, minor bleed
Stop warfarin Admit for IV vit K 1-3mg Restart when INR <5
29
What do you do if INR >8, no bleed
Stop warfarin + haematology Don't give IV K Oral vit K Restart when INR <5
30
What do you do if INR >8, minor bleed
Stop warfarin Admit urgently for IV vit K 1-3mg Restart when <5
31
What do you do if major bleed on warfarin regardless of INR
``` Stop warfarin Fluid and blood transfusion Treat cause Prothrombin complex = rapid IV Vit K 5mg Can give FFP if prothrombin not available Consider platelet replacement ```
32
What are benefits of DOAC and how do you treat bleed
Do not require monitoring Annual blood test DOAC - Add charcoal to slow absorption if recent dose - Consider specific antitode - Can give prothrombin or FFP if severe and no antitode to reverse
33
When are DOAC indicated
Prevention of VTE / stroke Preferred except in mechanical heart valves or severe MS or severe obesity Work instantly so don't require with LMWH like warfarin
34
How does rivoraxaban / abixaban work and how is it excreted
Direct factor Xa (10) inhibitor Liver No reversal agent
35
How does dapigatran work and how is it excreted
Direct thrombin inhibitor Renal Monoclonal Ab to reverse
36
When are DOAC contraindicated
Severe renal / liver Bleeding PT / APTT insensitive but gives a rough idea
37
What are options for heparin
LMWH Unfractioned heparin All activate anti-thrombin
38
What is treatment of choice for VTE
LMWH - dalteparin / anaxoparin Also used if post op or immobile as high risk of VTE as prophylaxis as quick onset and to cover till INR target
39
How does LMWH work and how can it be given
SC Inhibits factor XA only by activating anti-thrombin Monitor factor XA but not required Long action
40
How does unfractioned heparin work and how is it given
Inhibits thrombin and factor XII by activating anti-thrombin III SC or IV Rapid onset and short duration Used if high risk of bleed as can be terminated rapidly
41
How do you monitor unfractioned heparin and reverse
APTT | Protamine sulphate
42
What are SE of heparin
Bleeding Thrombocytopenia - don't give if platelets low e.g. <50 Osteoprosis Hyperkalaemia
43
What are CI to heparin
``` Bleeding disorder Low platelet - <50 Peptic ulcer Haemorrhage Severe hypertension Renal failure ```
44
What is used instead of heparin If CI due to renal and how does it work
Fondaparinux - inhibits factor XA
45
What does transexamic acid do
Binds to plasminogen and prevents conversion to plasmin
46
What blood tests are used to monitor coagulation
FBC - for platlet LFT - for liver function and albumin for synthetic D-dimer ``` Coag PT APTT Bleeding time Fibrinogen ```
47
What does PT look at - Put onto paper for OSCE
Tests factors involved in extrinsic pathway (play tennis outside) - Fibrinogen - Thrombin - 2,7,9, 10, (vit K dependent)
48
How is PT reported as and what should values be
INR - 0.8-1.2 PT - 12-13s Use to measure clotting on a regular basis as good measure of overall clotting (as factors rarely in deficiency)
49
When is INR prolonged / affected
Warfarin as more strongly affects extrinsic pathway Vit K deficiency Liver disease DIC
50
What does APTT look at
Tests factors involved in intrinsic pathway - Fibrinogen - Thrombin - 5,8, 10, 11, 12
51
What is normal APTT
30-40s
52
When is APTT increased / affected
Will be affected by overall clotting so anything that affects PT can affect APTT Also indicates issues with certain factors Factor defieincy Haemophilia A and B / acquired vWF Anti-phospholipid DIC
53
When is bleeding time prolonged | - Should be 1-6 minutes
``` Platelet issues will increase the time Thrombocytopenia Uraemia Aspirin use VWF deficiency as can't make plug TTP / ITP / HUS / DIC ```
54
What factors affect coagulation
pH Temp - hypothermia Calcium
55
How much platelets do you need for major surgery
100 - required for plug
56
When would you get purpura
<30
57
When would you get spontaneous bleeding
<10
58
Coag values warfarin / vit K deficiency
PT - prolonged APTT - normal (increased in vit K deficiency) Bleeding - Normal Platelet - normal
59
Coag values aspirin
PT - normal APTT - normal Bleeding - prolonged as stops platelet aggregating but does not affect coag so everything else normal Platelet - normal
60
Coag values heparin / NOAC
PT - normal / prolonged APTT - Prolonged as factors in extrinsic pathway Bleeding - Normal Platelet - normal
61
Coag values DIC
PT - prolonged APTT - prolnged Bleeding - prolonged Platelet - low Require platelet and clotting factors
62
Coag values Haemophilia
PT - normal APTT - prolonged as factors Bleeding - normal Platelet - normal
63
Coag values vWF
PT normal as to do with platelet not able to adhese APTT - prolonged as to do with VIII in intrinsic pathway Bleed - prolonged Platelets - normal
64
Coag values HUS / TTP / ITP
PT -normal APTT - normal Bleeding - prolonged Platelet - low Normal PT / APTT good differentiator form DIC NEVER give platelets
65
What do you do if any bleeding on anti-coagulant
``` Compress Assess haemodynaic status - BP - Basic coag bloods - FBC / U+E Get Hx of when got last dose ```
66
Surgery on warfarin
Stop 5 days before and when INR <1.5 If emergency reverse with prothrombin Restart as soon as you can
67
What drugs may increase warfarin
``` p450 inhibitor as can't break down Liver disease Anti-fungal Macrolide Ciprofloxacin Amiadarone SSRI Acute alcohol Sodium valrpoate NSAID - platelet function Sulphonamide ```
68
What drugs may decrease
``` p450 inducer Vit K Barbiturates Phenytoin Carbamazepine Cholestrolamine Rifampicin St Jon's wort Chronic alcohol Smoking ```

Haematology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions