DVT & PE Flashcards
Provoked vs unprovoked DVT
Provoked: associated with transient RF eg. immobility, surgery, trauma, pregnancy, COCP, HRT
Unprovoked: occurs in absence of transient RF eg. no RF or RF that can’t be removed - active cancer, thrombophlebitis - increased risk of recurrence
DVT risk factors
Ongoing RF:
1) History of DVT
2) Cancer
3) > 60y
4) Overweight
5) Male
6) HF
7) Illness, infection
8) Thrombophilia
9) Inflammation - vasculitis, IBD
10) Varicose veins
11) Smoking
Temporary RF:
1) Recent major surgery
2) Recent hospitalisation
3) Recent trauma
4) Chemo
5) Immobility
6) Travel > 4h
7) Trauma to a vein (IV catheter)
8) COCP / HRT
9) Pregnancy and postpartum
10) Dehydration
Post-thrombotic syndrome
Chronic venous HTN causing limb pain, swelling, hyperpigmentation, dermatitis, ulcers, gangrene, lipodermatosclerosis
Affects 50% within 2y of DVT of lower limbs
Heparin-induced thrombocytopenia (HIT)
Occurs 5-7 days after initial exposure to heparin, but can occur < 1 day if previously exposed
2-level DVT Well’s score
Do not use in pregnancy or 6 weeks postpartum
1 point for:
1) Active cancer - on treatment, within the last 6m, or palliative
2) Paralysis, paresis or recent plaster immobilisation of the legs
3) Recently bedridden for >= 3 days or major surgery within the last 12 weeks requiring general or regional anaesthesia
4) Localised tenderness along deep venous system (calf)
5) Entire leg swollen
6) Calf swelling by > 3cm compared to other leg
7) Pitting oedema confined to symptomatic leg
8) Collateral superficial veins (non-varicose)
Take away 2 points if alternative cause at least as likely as DVT
> = 2 - DVT is likely
Management of likely DVT (2-level Wells score >= 2)
1) Proximal leg vein USS with results within 4h
2) If USS cannot be done within 4h -
- D-dimer test
- then interim therapeutic anticoagulation
- and leg USS with results within 24h
Management if unlikely DVT (2-level Well’s score <=1)
1) D-dimer with result available within 4h
2) If cannot get d-dimer result within 4h:
- offer interim therapeutic anticoagulation whilst awaiting result
- take d-dimer blood test before starting anticoagulation as it can affect result
D-dimer positive:
- offer leg USS with result within 4h, if not available within 4h offer interim therapeutic anticoagulation with result within 24h
D-dimer negative:
- Stop intermin therapeutic anticoagulation and consider alternative Dx
1st line interim therapeutic anticoagulation and baseline tests
Apixaban or rivaroxaban
If DOAC unsuitable:
- LMWH for at least 5 days followed by dabigatran or edoxaban
- or LMWH with warfarin for at least 5 days
Baseline tests:
- FBC, U&E, LFT, PT, APTT
- do not wait for results before starting anticoagulation treatment, but review and act of them within 24h of starting
Management of confirmed DVT
1) Anticoagulation:
- specialist decides duration, but usually >= 3 months
- INR 2-3
2) Unprovoked DVT:
- investigate for cancer if not already diagnosed - FBC, U&E, LFT, PT, APTT, examination
- offer thrombophilia testing
3) Do not offer graduated compression stockings to prevent post-thrombotic syndrome of VTE recurrence after a proximal DVT (elastic stocking can be used for leg symptoms after DVT)
4)
Thrombophilia testing in unprovoked DVT
Only if planning to stop anticoagulation treatment:
1) Antiphospholipid antibodies
2) Hereditary thrombopbilia if they had unprovoked DVT + a 1st degree relative had DVT/PE
Tests can be affected by anticoagulants, therefore seek specialist advice
DVT and travelling:
Incidence of DVT
Risk factors
High vs moderate vs low risk & advice
Annual incidence of DVT 1/1000 - increased 2-3 fold after flights > 4h
High risk of travel-related DVT if:
1) Active cancer
2) Previous travel related DVT with no temporary RF
3) Previous unprovoked VTE
4) Major surgery in past 4 weeks
5) > 1 RF for DVT
Other RF for travel related DVT:
1) FH DVT/PE
2) > 60y
3) < 1.6m or > 1.9m - shorter people experience seat edge pressure to popliteal area / taller people have less leg room
4) Inherited blood clotting abnormality thrombophilia
5) Limited mobility
6) BMI > 30
7) Polycythaemia
8) HF, recent MI, severe infection, IBD
9) COCP/HRT
Advice if moderate risk: 1 RF which is not hight risk
- Graduated compression stockings providing 15-30mmHg of pressure at the ankle (class 1 or flight socks) - remember to check ABPI if any signs of PAD and can’t use if < 0.8
Advice if at high risk:
- postpone travel
- if essential LMWH can be considered in addition to GCS, given before departure
Advice post hip/knee replacement
1) Avoid long-haul flight for 3 months
2) It may be possible to fly short haul at 6 weeks
Advice if fracture in plaster case
1) Short flights <2h > 24h
2) longer flight > 2h > 48h
3) if travel essential before these limits - cast needs to be slit along full length prior to travel and then be reapplied once arrived
Advice for long haul travel if recent DVT
< 2 weeks Ince diagnosis - specialist advice
Taking anticoagulants for >= 2 weeks:
- low risk of further VTE
- advice on general measures to reduce risk
- consider GCS
Indications to prescribe graduated compression stockings
Class 1 (14-17mmHg): (flight socks OTC cheaper)
- superficial or early varicose veins
- varicose veins during pregnancy
Class 2 (18-24mmHg): (can also get class 2 flight socks OTC)
- varicose veins of medium severity
- treatment & prevention of recurrence of leg ulcers
- mild oedema
- varicose veins during pregnancy
Class 3 (25-35mmmHg):
- Gross varicose veins
- post-thrombotic venous insufficiency
- gross oedema
- treatment and prevention of recurrent of leg ulcers
2 prescription charges for a pair
