Clinical use of anticoagulants Flashcards Preview

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Flashcards in Clinical use of anticoagulants Deck (34)
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1
Q

What is VTE?

A

Collective term for deep vein thrombosis DVT, pulmonary embolism PE.

2
Q

All patients must be assessed for their risk of VTE when?

A

On admission
After 24hr
After every clinical situation change

3
Q

Pharmacologiclal VTE prophlaxis can take the form of [3]

A
  1. UFH
  2. LMWH
  3. Fondaprinux
4
Q

What is UFH?

Why is it reserved for those unable to use LMWH or fondaparinux?

A

First pharmacological agent.
High strength heparin product (25000units/mL) means it is generally reserved for second or third line choice in those patients who cannot use LWMH or Fondaparinux.

5
Q

LMWH have been shown to be clearly superior to UFH in what situations?

A

In preventing DVT in patients undergoing orthopaedic surgery.

LMWHs should be used in preference to UFH if not other contraindications.

6
Q

What is fondaparinux?

A

Selective anti-Xainhibitor, which unlike UFH and LMWH, has not antithrombin activity.

Fondaparinux is more effective at preventing DVT in hip and knee surgeries.

Also can be used in people with a history of HIT.

7
Q

How is fondaparinuxdifferent to UFH and LMWH? (2)

A

No direct antithrombin activity

Can be used in people at risk of HIT

8
Q

How long should DVT prophylaxis continue?

A

Until patient is fully mobile and fit for discharge.

In knee, hip replacements etc maybe for 28 days post discharge.

9
Q

When would DVT prophylaxis continue for 28 days?

A

Oncology surgery, knee hip replacements etc.

10
Q

In what situations is even the slighest risk of local bleeding unacceptable?

What should be offered instead of anticoagulation?

A

Neurosurgery, ophthalmic surgery, some plastic surgery, head injury, haemorrhagic stroke.

Mechanical prevention methods.

11
Q

What VTE risk factors should we look out for? [11]

A
  1. Active cancer or cancer treatment
  2. Age >60 years
  3. Emergency care admission
  4. Dehydration
  5. Known thrombopilias
  6. Obese patients (BMI>30)
  7. One of more signif medical comorbidities such as heart disease, metabolic, endocrine, respiratory pathologies, acute infectious diseases, inflammatory conditions.
  8. personal or FH of VTE
  9. HRT
  10. Oestrogen containing contraceptives
  11. Varicose veins with phlebitis
12
Q

What bleed risk factors are there?

A
  1. Active bleeding.
  2. Acquired bleeding disorder such as acute liver failure
  3. Anticoagulant use, such as wafarin inr>2.0
  4. Lumbar puncture, epidural, spinal anaesthesia within previous 4 hrs or next 12 hrs.
  5. Acute stroke
  6. Thrombocytopenia (platelets <75 x 10^9/L)
  7. BP unctrolled >120
  8. Haemophillia
  9. von Willebrands disease
13
Q

What is von Willebrands disease?

A

(VWD) is a genetic disorder caused by missing or defective von Willebrand factor (VWF), a clotting protein. VWF binds factor VIII, a key clotting protein, and platelets in blood vessel walls, which help form a platelet plug during the clotting process.

14
Q

When should mechanical DVT prophylaxis occur?

A

Evening before surgery and continue until patient is fully mobile.

15
Q

How do the doses of enoxaparin and dalteparin for high/moderate and low risk DVT prophylaxis differ?

A

80mg enox/5000 dalt for high

40mg enox/2500 dalt for low

16
Q

Before treatment of a DVT occurs, blood should be collected for determination of what?

A

APTT
PT
Platelet count

17
Q

For who suffering from a DVT would a thombophilia screen be considered?

A

Family history of VTE
Recurrent VTE
Possibly if there is spontaneous VTE.

18
Q

As LMWH has been shown to be at least as effective and safe as an IV UFH infusion in the initial management of DVT, why would we choose LMWH over UFH?

A

LMWH has the advantage of not requiring routine laboratory monitoring and enabling management in a hospital out-patient or general practice setting in selected cases and is now the treatment of choice.

19
Q

Tinzaparin, Dalteparin and Enoxaparin are all

A

LMWH

20
Q

In the presence of renal impairment, LMWH requires what monitoring and adjustment when?

A

Requires factor Xa monitoring and possible dose adjustment if the calculated creatinine clearance <30ml

21
Q

A normal loading dose of warfarin is ________ divided between __ days.

A

15-30mg, 3 days, LOCAL PROTOCOL

INR monitored daily.

22
Q

The inital dose of warfarin should be what in the elderly?

A

Lowered

23
Q

LMWH should be giben for a minimum of how long?

A

5 days or until the INR has been >2 on two consecutive days, whichever is longer.

24
Q

Why should warfarin not be commenced alone (i.e without a LMWH)?

A

It is associated with a high rate of DVT recurrence.

25
Q

The duration of anticoagulation therapy given depends on what?

A

The risk of both recurrent VTE and bleeding.

26
Q

Graduated compression stockings should be worn for at least how long?

A

18 months, indefinitely if the post-thrombotic syndrome is present.

27
Q

What pathophysiological changes would indicate decreasing the warfarin loading dose?

A

Liver disease
Cardiac failure
Nutritional failure

28
Q

The risk of bleeding on warfarin increases significantly when the INR is >

A

5

29
Q

When reversal of anticoagulation is needed due to major/life-threatening bleeding and PCC is given alongside IV phtomenadione, what investigations need to occur?

A

FBC
APTT
INR

30
Q

If there is minor bleeding and an INR of >5,what should happen?

A

Omit Warfarin

Give IV phytomednadione 0.5-1mg

31
Q

If there is minor bleeding and an INR of <5, what should be done?

A

Clinical decision needs to be made on the benefits of stopping the anticoagulation.

32
Q

If the INR is 5.0-7.9 and there is no bleeding what should we do?

A

Omit and restart warfarin when below 5.

33
Q

If the INR is >8 but less than 12 and no bleeding?

A

Omit warfarin and give 1-5mg oral phytomenadione.

> 12 mut warfarin and give 5mg oral phytomenadione.

34
Q

Examples of PCC include

A

Beriplex
Octaplex

PCCs derived from human plasma which has been virally inactivated, and they contain coagulation factors II, VII, IX and X.