3. Blood clots Flashcards

1
Q

xfTypes of venous thromboembolism

A
  1. Deep vein thrombosis
  2. Pulmonary embolism (life-threatening)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Deep vein thrombosis symptoms

A
  • Swollen veins
  • Hard and sore veins
  • Unitlateral pain in legs
  • Warm and red skin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pulmonary emobolism symptoms

A
  • Chest pain
  • Dyspnoea
  • Coughing up blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Groups whom require VTE prophylaxis

A
  • Immobility
  • Obesity BMI >30
  • Malignancy
  • First-degree relative
  • Pregnancy, post-partum
  • Oestrogens
  • Combined oral contraceptives
  • Personal history
  • Thrombophilic disorders
  • Varicose veins with phlebitis

C

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

Factors that increase a patient’s risk of bleeding

A
  • Acute stroke
  • Anticoagulants
  • Sytolic hypertension
  • Thrombocytopenia
  • Bleeding disorders: liver failure, haemophilia, von willebrands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Thromboprophylaxis treatment

A

Two types

1. Pharmacological
2. Mechanical

1. Pharmacological
* DOAC oral
~7 days in general surgery
~28/30 days in major cancer surgery and spinal surgery respectively
* Heparin (parenteral)
Alternatively: Fondaparinux

Unfractionated heparin is offered in renal impairement

2. Mechanical
If Pharmacological interventions usuitable, mechanical can be used. Worn until mobile

  • Pneumatic compression - inflatable sleeved worn on the legs
  • Anti-embolic stockings
    Should NOT be offered in acute stroke and legs conditions such as peripheral arterial disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Hip and Knee replacement thromboprophylaxis

A
  • For 35 days in hip replacement
    LMWH + aspirin (10 days with further 38 days) OR LMWH + anti-embolism stockings
    OR rivaroxaban
  • For 14 days in knee replacement
    OR low dose aspirin for 14 days OR LMWH for 14 days WITH anti-embolism stockings
  • OR rivaroxaban

Apixaban or dabigatran can be used alternatively

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

Thromboprophylaxis and Venous thromboembolism treatment in pregnancy

A

Thromboprophylaxis:
LMWH + Pneumatic compression (if immbolised, alternatively: anti-embolism stockings)

Venous thromboembolism:
LMWH (unfractionated heparin if there is an increased risk of bleeding)

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

Venous thromboembolism treatment

A

Apixaban or Rivaroxaban

  • For at least 3 months (or up to 6 months in active cancer, as cancer increases likelihood of developing blood clots)
  • For unprovoked causes e,g combined oral contracepeptives, pregnant, leg cast: Around 3 months
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Anticoagulants mechanism of action

A

Factor Xa Inhibitors:
* Oral DOAC: Apixaban, Edoxaban, Rivaroxaban
* Fondaparinux
* Heparins

Thrombin (Factor lla) inhibitiors
* Dabigatran
* Heparins:

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

Common errors associated with oral and parenteral anticoagulants

A

Dose
Wrong dose and duration
Wrong rate or frequency of parenteral anticoagulants

Drug-interaction
Duplication of therapy
Co-prescribing NSAID

Monitoring
Inadequate monitoring
Monitoring errors (lab values, vital signs)

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

Heparin uses and forms

A

Unfractionated heparin
Preferred if patient has HIGH risk of bleeding OR renal impairement (as it has a short half life so its effects can quickly be stopped, when discontinuing treatment)

LMWH e.g
tinzaparin
enoxaparin
dalteparin
It is Long-acting
lower risk of osteoperosis and thrombocytopenia

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

Heparin side effects

A
  • Bleeding
    Antidote: protamine
  • HyPERkalaemia
    Heparins block aldosterone secretion in the renin-angiotensin system = hyperkalaemia

Patients with chronic kidney disease
Patients who have diabetes mellitus are at a higher risk of this

  • Heparin-induced thrombocytopeonia
    If this occurs, heparin should be STOPPED
    Signs: skin allergy, thrombosis, reduced platelet count ~30%
  • Osteoporosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Heparin interactions

A
  • Increased risk of HypERkalaemia, when taken with hyperkalaemic drugs:
    ACE inhibitors/ARBs, aldosterone anatagonists e.g spiranolactone, Ciclosporin and tracrolimus, NSAID, potassium-sparing diuretic, potassium supplement, trimethoprim
  • Increased risk of bleeding when taken with:
    Anitcoagulants e.g warfarin, DOAC’s, antiplatelets, SSRI’s NSAID, Venlafaxine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Warfarin mechanism of action

A

Antagonises Vitamin-K

It takes 48-72 hours to work

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

Warfain indications

A

For venous thromboembolism and preventing a stroke in atrial fibrillation

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

Warfarin dose

A

Maintenance dose: 3-9mg daily
If a dose is missed, should take it as soon as they remember

0.5mg WHITE
1mg BROWN
3mg BLUE
5mg Pink

For isolated calf DVT: 6 weeks
Provoked VTE (by surgery, pregnancy, combined oral contraceptives): 3 months
Unprovoked VTE: 3+ months

18
Q

Warfarin and pregnancy

A

Warfarin is teratogenic

Females of child-bearing age must take precautions

19
Q

Warfarin monitoring

A

INR is meased every 12 weeks
unless there is a change in the clinical condition

TARGETS:
2.5: VTE, AF, MI, cardioversion, artificial valves
3.5:Recurrent VTE if on anticoagulant
Can afford to be within 0.5 units of targets

Warfarin can cause Calciphylaxis (calcium accummulating in small blood vessels of fat and tissue). Patients must reprt painful skin rash

More likely to occur in patients with end-stage renal disease. consider stopping.

20
Q

Warfarin bleeding rules

A

If there is no bleeding
INR 5.0-8.0: Withold 1-2 doses of warfarin
INR>8.0: Oral phytomenadione

If there is bleeding
INR 5.0-8.0 OR INR>8.0: IV phytomenadione

Bleeding rules:
Patients must report nose bleeds >10mins, cuts that don’t stop bleeding, red urine, blood in vomiting, tarry stools, severe headaches, seizures

21
Q

Warfarin counselling

A

Patients should be given a yellow booklet and an anticoagulant alert card (shown to doctors and dentists before procedures)

Food interactions:
Green, leafy, vegetables (should eat similar amounts regularly)
Alcohol binge increases risk of bleeding
Cranberry juice increases risk of bleeding

OTC interactions:
Miconazole, NSAID, Vitamin E and K supplements

  • Avoid contact sports
  • Use a soft toothbrush to avoid bleeding gums
22
Q

Warfarin before surgery

A

Warfarin should be stopped 5 days before surgery
BUT
If patients are at a high risk of VTE, they can temporarily take a LMWH - bridging

If warfarin has not been stopped, in an emergency, IV phytomenadione can be used

23
Q

Warfarin interactions

A
  • Interacts with drugs that also cause bleeding as a side effects:
    Anticoagulants, Anti-platelet, SSRI’s, venlafaxine, tetracycline
  • NSAIDs and warfarin interact
    NSAIDs have a higher affinity for albumin than warfarin, displaces warfarin = more free warfarin in the blood = increased risk of bleeding
  • Interacts with cytochrome P450 inhibitors = reduce warfarin metabolism = more warfarin in blood
    Amiodarone, Azole antifungals, clarithromycin, erythromycin, metronidazole, quinolones, cranberry juice
  • Interacts with cytochrome P450 inducers = increase warfarin metabolism = less warfarin in blood
    Carbamazepine, Phenobarbital, Rifampicin, St John’s Wort
24
Q

DOAC’s special conditions

A

Used for venous thromboembolism and for non-valvular AF

  • Rivaroxaban - taken with food, only DOAC licensed to be crushed
  • Dabigatran - comes in a special container, must be kept in the original container. It has a 4 month expiry
  • Apixaban
  • Edoxaban*

DOAC’S End in ban or tran

25
DOAC's dose
Simpler dosing regimen, same dose is taken everyday. Do not require regular monitoring A missed dose is more than 6 hours, however as their effect only lasts for 12-24 hours, this means the anticoagulant effect is reduced or delayed when the dose is missed
26
DOAC side effects and counselling (+antidotes)
Patients must carry their alert card at all times **Side effects:** * Bleeding Caution in patients with renal impairement as DOAC's are renally cleared. These patients have a higher risk of bleeds. These patients should be monitored. **Antidote for dabigatran:** idarucizumab **Antidote for apixaban, rivaroxaban:** andexanet alfa Patiets must report signs of bleeding and read the PIL
27
DOAC Contra-indications
DOAC's should not be to patients with: * Prosthetic heart valves * Antiphospholipid syndrome * Patients already on other anticoagulants
28
Rivaroxaban doses for VTE prevention
**VTE prevention:** Replacement: 10mg OD Replacing hip: 35 days Replacing knee: 14 days **For recurring VTE:** 10mg OD for 6 months+ **Patients at high risk:** 20mg OD
29
Rivaroxaban doses for VTE treatment, stroke prevention and atherothrombotic event prevention
* **VTE treatment:** 15mg BD up to 20mg BD for 21 days * **Stroke prevention in non-valvular AF**: 20mg OD * **Prevention of atherthrombotic events:** 2.5mg BD It is the only DOAC that does this ## Footnote Rivaroxaban can also be used for secondary prevention after a cardiovascular events
30
Apixaban VTE prevention dose
**VTE prevention:** **Replacement of the hip:** 2.5mg BD for 32-38 days **Replacement of the knee:** 2.5mg BD for 10-14 days **For patients who have recurrent VTE:** 2.5mg BD
31
Apixaban dose for VTE treatment and stroke prevention in non-valvular AF
**VTE treatment:** 5-10mg BD for 7 days **For stroke prevention in non-valvular AF:** 5mg BD or 2.5mg BD (if the person is 80+, <61kg, creatnine ≥ 133)
32
Edoxaban dose for VTE prevention and treatment, and for stroke prevention in non-valvular AF
Edoxaban doses are determined by weight **For VTE prevention** **For VTE treatment** **For stroke prevention in non-valvular AF:** 30mg OD If the person is above 61kg+: 60mg OD
33
Dabigatran dose for VTE prevention
**For hip replacement:** 220mg OD for 35 days **For knee replacement**: 220mg OD for 14 days **If the patient is 75years+, is taking amiodarone, or verapamil:**150mg OD
34
Dabigatran dose for VTE treatment and for stroke prevention in non-valvular AF
**For VTE treatment** **For stroke prevention in non-valvular AF:** 150mg BD If the patient is **75years+**, **has moderate renal impairement**, is **at risk of bleeding**: 110-150mg BD If the patient is **80years+**, is taking **verapamil**: 110mg BD
35
DOAC interactions
* **Interacts with cytochrome P450 inhibitors = reduce warfarin metabolism = more warfarin in blood** Amiodarone, Azole antifungals, clarithromycin, erythromycin, metronidazole, quinolones, cranberry juice * **Interacts with cytochrome P450 inducers = increase warfarin metabolism = less warfarin in blood** Carbamazepine, Phenobarbital, Rifampicin, St John's Wort * **Interacts with drugs that also cause bleeding as a side effects:** Anticoagulants, Anti-platelet, SSRI's, venlafaxine, tetracycline
36
What is arterial thrombosis
A blood clot forms in an artery, blocks blood supply to the heart and brain **Types**: * **Ischaemic** Ischaemic (including transient ischaemic stroke) when blood supply is cut off to the brain: Caused by atherosclerosis, Thromboembolism * **Haemorrhagic:** When a weak blood vessel that surrounds the brain bursts, spilling blood into the surrounding tissues Also known as a intracerebral haemorrhage caused by a very high blood pressure
37
Symptoms of a stroke
act FAST F - Facial weakness in one side A - Arm weakness, paralysis on one or both sides of the body S - Slurred speech, difficulty breathing T - Time TO CALL 999
38
Treatment of an ischaemic stroke (including TIA)
* **Clopidogrel** (alternatively dypyridamole MR + aspirin) or aspirin alone * **High-intensity statin** (even if blood cholesterol is normal as most strokes are caused by atherosclerosis * **Anti-hypertensive** (NOT a beta-blocker unless they are taking it for another condition) * Patients with atrial-fibrillation should be reviewed for anti-coagulant)
39
Treatment of an haemorrhagic stroke
* **Offer an antihypertensive** as haemorrhagic strokes are commonly caused by high blood pressure * **NO statin, NO aspirin, NO anticoagulant should be offered**
40
Antiplatelet mechanism of action
Lowers platelet aggregation and inhibits thrombus formation in arteries
41
List of antiplatelets
**Secondary CVD prevention** * Low-dose aspirin (75mg OD) * Clopidogrel * Dipyridamole (30-60mins before food, MR - after food and MR capsules are in "special container" to be discareded after 30 days/6weeks depending on manufacturer) **Glycoprotein llb/lla inhibitor** * Cangrelor * Prasugrel * Ticagrelor * Tirofiban