THROMBOEMBOLISM Flashcards
Types of thromboembolism
DVT
PE
VTE
Blood clot in vein
obstructs blood flow
DVT
Blood clot occurs in a deep vein
leg or pelvis
Unilateral localised pain or swelling
Typically in the calf of one leg.
Pulmonary Embolism (PE)
Blood clot detaches and travels to the lungs and blocks the pulmonary artery.
Chest pain
Shortness of breath
Risk factors of VTE
Surgery
Trauma
Significant immobility
Malignancy
Obesity
Pregnancy
Hormonal Therapy (COC or HRT)
How to diagnose VTE
D-dimer test for diagnosis
Methods of thromboprophylaxis (2)
Mechanical - graduated compression stockings
Pharmacological - anticoagulants
Mechanical thromboprophylaxis
Graduated Compression Stockings
* Wear until the patient is sufficiently mobile
Pharmacological thromboprophylaxis
Anticoagulants
Start within 14 hours of admission
Patients with risk factors for bleeding should only receive pharmacological prophylaxis when their risk of VTE outweighs their risk of bleeding
VTE Prophylaxis - surgery
Mechanical - graduated compression stockings
Pharmacological - anticoagulants
Mechanical prophylaxis - surgery
Prophylaxis should continue until the patient is sufficiently mobile or discharged from hospital
Pharmacological prophylaxis - surgery
Considered when the risk of VTE outweighs the risk of bleeding
Surgery - type of anticoagulant
LMWH - suitable in all types of general and orthopaedic surgery
Unfractionated heparin - preferred in renal impairment
Fondaparinux sodium - lower limb immobilisation or pelvis fragility fractures
Unfractionated heparin vs LMWH
if we need to stop fluidity of their blood quickly
Surgery - how long do we continue VTE prophylaxis for?
Continue for at least 7 days post-surgery, or until sufficient mobility has been re-established
28 days after major cancer surgery in the abdomen
30 days in spinal surgery
Elective hip replacement either:
LMWH for 10 days and then 75mg aspirin for 28 days
LMWH for 28 days in + stockings until discharge
Rivaroxaban
Elective knee replacement either:
75mg aspirin for 14 days
LMWH for 14 days in + stockings until discharge
Rivaroxaban
General medical patients with high risk of VTE
should be given pharmacological prophylaxis for at least 7 days or mechanical prophylaxis until mobile
VTE prophylaxis - Pregnancy high risk of VTE
If risk of VTE that outweighs the risk of bleeding
* LMWH during hospital admission
* Pregnant women: prophylaxis until no risk of VTE or till patient discharged
Women who have given birth, had a miscarriage or termination of pregnancy during the past 6 weeks →
start LMWH 4-8 hours after the event → continue for a minimum of 7 days
Pregnancy - Additional mechanical prophylaxis if immobilised →
until sufficiently mobile or discharged from hospital
Treatment of VTE: pregnancy
LMWH; unfractionated if patient is at high risk of haemorrhage (unfractionated = short half life)
VTE Treatment
Confirmed proximal DVT or PE: Apixaban or Rivaroxaban
VTE Treatment - if rivaroxaban or apixaban unsuitable
If unsuitable offer:
(LMWH) for at least 5 days followed by Dabigatran or Edoxaban
LMWH + warfarin for at least 5 days or until the INR is at least 2.0 for 2 consecutive readings, followed warfarin alone
Duration of treatment - VTE treatment
Distal DVT (calf): 6 Weeks
Proximal DVT / PE: At least 3 months (3 to 6 months for those with active cancer)
Provoked DVT / PE: Stop at 3 months if the provoking factor resolved
Unprovoked DVT / PE: 3 Months +
Recurrent DVT / PE: Longterm
Warfarin - maintain INR of 2.5
VTEs, AF, Cardioversion, MI, Cardiomyopathy
Warfarin -Maintain INR of 3.5
Recurrent VTEs or mechanical heart valves
Warfarin - major bleed
Stop warfarin - IV phytomenadione and dried prothrombin
INR >8, minor bleeding:
Stop warfarin - IV phytomenadione
INR >8, no bleeding:
Stop warfarin - oral phytomenadione
INR 5-8, minor bleeding
Stop warfarin - IV phytomenadione
INR 5-8, no bleeding:
Withhold 1-2 doses of warfarin
When should you restart warfarin?
Restart warfarin when INR <5
How often should INR be monitored?
INR should be monitored every 1-2 days in early treatment, and then every 12 weeks
Warfarin - side effects
MHRA Warning: SKIN NECROSIS AND CALCIPHYLAXIS
- Painful skin rash
Haemorrhage: Prolonged Bleeding
- Vitamin K1 (phytomenadione) antidote
Warfarin - CI
Pregnancy: Avoid in the first and third trimester
Use contraception
Warfarin - interactions
Vitamin K Rich Foods
Pomegranate and Cranberry Juice
Miconazole (OTC Daktarin oral gel)
CYP450 Enzyme Inhibitors and Inducers
warfarin interactions - Vitamin k rich foods
Avoid major changed in diet with leafy greens
Reduces efficacy of warfarin
warfarin interactions - Pomegranate and Cranberry Juice
Increases patient INR
Miconazole (OTC Daktarin oral gel)
Increases patient INR
CYP450 Enzyme Inhibitors and Inducers
Increases or decreases warfarin concentration respectively
Warfarin - Minor procedures with low risk of bleeding
Performed with an (INR) of less than 2.5
Restart warfarin within 24 hours of procedure
Warfarin - procedures where there is a risk of severe bleeding:
Stop warfarin 3-5 days before
Give Vitamin K if INR is 21.5 the day before surgery
Patients high risk of thromboembolism: bridge with LMWH → stop LMWH 24 hours before surgery → restart LMWH 48 hours after
Warfarin - emergency Surgery
If can be delayed by 6-12 hours: IV Vitamin K
If can’t be delayed by 6-12 hours: IV Vitamin K + dried prothrombin complex
