PERI - Prevention of Post-Operative VTE/DVT/PE

Question 1

Diagnosis of a DVT

Clinical Features
Wells Criteria x10
Differential Diagnosis

Answer 1

1. ) Clinical Features
   - unilateral localised pain when weight bearing
   - calf swelling or swelling of entire leg
   - tender, oedema, redness, warmth, vein distension
2. ) Wells Criteria - assessment for suspected DVT
   - whole leg swelling, swelling (>3cm), pitting oedema,
   - collateral superficial veins, localised tenderness along distribution of deep venous system
   - active cancer, previous DVT, recently bedridden or major surgery, recent immobilisation of lower limbs
   - alternative diagnosis as likely (score -2)
3. ) Differential Diagnoses
   - cellulitis, ruptured Baker’s cyst, compartment syn…
   - right sided HF, lymphoedema, venous insufficiency

Question 2

Suspected DVT: Diagnosis and Initial Management

Suspected DVT Likely
Suspected DVT Unlikely
Ultrasound Scan Positive
Ultrasound Scan Negative

Answer 2

1. ) Suspected DVT Likely - wells score 2 and above
   - proximal leg vein ultrasound scan within 4 hours, OR:
   - scan within 24hrs + D-dimer test + anticoagulation
   - D-dimer test + interim anticoagulation
2. ) Suspected DVT Unlikely - D-dimer test
   - interim anticoagulation if results will take > 4hrs
   - if D-dimer positive, treat like suspected DVT likely
   - if negative, stop anticoagulation
3. ) Ultrasound Scan Positive - diagnostic
   - diagnose DVT and offer/continue treatment
4. ) Ultrasound Scan Negative - depends on D-dimers
   - if positive D-dimers, stop anticoagulation and repeat scan 6-8 days later
   - if negative D-dimers or second USS, stop anticoagulation and think about other diagnoses

Question 3

Suspected PE: Diagnosis and Initial Management

PE Wells Score
Suspected PE Likely
Suspected PE Unlikely
CTPA Positive
CTPA Negative

Answer 3

1. ) PE Wells Score
   - 3: clinical features of DVT, most likely diagnosis
   - 1.5: HR >100, previous DVT/PE, immobilisation for >3days or surgery in previous 4 weeks
   - 1: haemoptysis, malignancy in last 6 months
2. ) Suspected PE Likely - wells score of 5 and above
   - immediate CTPA (anticoagulation while awaiting)
3. ) Suspected PE Unlikely - D-dimer test
   - interim anticoagulation if results will take > 4hrs
   - if D-dimer positive, treat like suspected PE likely
   - if D-dimer negative, stop anticoagulation
4. ) CTPA Positive - diagnostic
   - diagnose PE and offer/continue treatment
5. ) CTPA Negative
   - if DVT suspected, consider proximal leg vein USS
   - if DVT not suspected, stop any anticoagulation

Question 4

VTE Assessment/Risk Factors

VTE Risk Assessment
Patient Related Thrombosis Risk Factors
Admission Related Thrombosis Risk Factors
Patient Related Bleeding Risk Factors
Admission Related Bleeding Risk Factors

Answer 4

1. ) VTE Risk Assessment - for all surgical patients or medical patients w/ significantly reduced mobility
   - balances risk of thrombosis and bleeding to determine whether patient needs anticoagulation
2. ) Patient Related Thrombosis Risk Factors
   - age, obesity, dehydration, previous history/FH of VTE
   - active cancer, thrombophilia, varicose veins
   - oestrogen/HRT, pregnancy, <6wks post-partum
   - significant medical comorbidities: CHD, resp, metabolic, endocrine, inflammatory conditions
3. ) Admission Related Thrombosis Risk Factors
   - ↓↓↓ mobility >3days, critical care admission
   - inflammatory or intra-abdominal condition
   - hip/knee replacement, hip fracture
   - anaesthetic + surgical time >90min (60 if lower limb)
4. ) Patient Related Bleeding Risk Factors
   - active bleeding, acute stroke, use of anticoagulants
   - uncontrolled HTN (>230), thrombocytopenia
   - acquired/genetic bleeding disorders
5. ) Admission Related Bleeding Risk Factors
   - procedure w/ high bleeding risk e.g. neurosurgery, spinal surgery, eye surgery
   - lumbar puncture/epidural/spinal anaesthesia within next 12hrs or within previous 4 hours

Question 5

Pharmacological methods to prevent/treat post-operative DVT/VTE

Pharmacological Prophylaxis
Anticoagulation Treatment

Answer 5

1. ) Pharmacological Prophylaxis - heparin
   - start ASAP (within 14 hours of admission)
   - dalteparin (SC) OD, 5000 units for at least 7 days
   - given 6 hours after surgery for up to 35 days
   - LMWH should be given >4hrs after an epidural to prevent spinal haematomas
   - UFH for patients with severe renal impairment
2. ) Anticoagulation Treatment
   - DOAC (apixaban) for patients w/ confirmed DVT/PE or
   - bridging therapy with LMWH + warfarin/dabigatran
   - UFH only if renally impaired or ↑risk of bleeding

Question 6

Non-pharmacological methods to prevent post-operative DVT/VTE

Mobilisation
Mechanical Prophylaxis
Other

Answer 6

1. ) Mobilisation - keep patients moving to prevent stasis
   - pre-operative: as close as possible to time of surgery
   - post-operative: as soon as possible after surgery
2. ) Mechanical Prophylaxis - for patients w/ high risk of bleeding or an adjunct to pharmacological therapy
   - increases venous return and reduces blood stasis
   - graduated compression stockings
   - intermittent pneumatic compression
3. ) Other
   - maintain hydration
   - stop pro-thrombotic drugs e.g. COCP

Question 7

Post-Thrombotic Syndrome

What is it?
Symptoms

Answer 7

1. ) What is it? - damage to veins and valves, reducing blood carried away from the legs causing symptoms
   - can develop weeks or years after a DVT
2. ) Symptoms
   - pain, swelling, aching/cramping, heaviness in limbs
   - itching, discolouraiton, venous leg ulcers