CASE: 65 yo lady, has colon ca, admitted today, scheduled to have surgery in 3 days. What’s her risk for DVT?
- High, why? multiple risk factors: age, gender, cancer, hospitalisation, immobility
- Use caprini risk assessment tool to objectively asses the risk of DVT
How to prevent DVT?
- Early mobilization: going to the bathroom, walking in the hallway
- Mechanical prophylaxis:
- Elastic stockings are not that effective -> associated w\ skin abrasion
- Intermittent pneumatic compression devices
- Anticoagulants: heparin;
- LMWH: smaller, selected molecules with homogenous size -> predictable absorption
- Unfractionated: heterogenous, different sizes -> absorption is unpredictable
- Aspirin is not used for DVT prophylaxis
- Advantages of LMWH over unfractionated -> used once per day, less risk of heparin-induced thrombocytopenia (HIT)
- For DVT prophylaxis, both types of heparin are given SQ:
- LMWH -> 40 mg daily
- Unfractionated -> 5000 units TID
- Start DVT prophylaxis at admission
- Hold DVT prophylaxis 12 hrs pre-op
- Resume DVT prophylaxis 8 hrs post-op (homeostasis occurs 6-8 hours after cutting)
- Continue for the duration of hospitalization for most pts
- Extend if cancer + orthopaedic (hip\knee replacement) surgery patients -> 4 weeks (up to 35 days)
- Before giving anticoagulants -> asses the risk of bleeding; active bleeding, gastric ulcer, intracranial haemorrhage, INR (>1.5 is a risk), APTT, ptt count (<50,000 is a risk)
- If high risk of bleeding -> use mechanical prophylaxis (intermittent pneumatic compression)
- IVC filter:
- Lowers the risk of PE, but has a higher risk of DVT
- Indications: prev recent PE where you can’t use anticoagulants during procedure -> use it temporarily to cover that period
CASE: 3 days post-op, pt comes w\ SOB and hypoxia. What to do?
- H&P, may include Wells score for PE
- D-dimer is not recommended (has high negative predictive value in low clinical suspicion pts)
- Do spiral CT
- If high clinical suspicion, we can give heparin until we get the result of CT (w\ low risk of bleeding)
- Treatment dose of heparin for PE?
- Enoxaparin: 1 mg\kg\12 hrs
- Unfractionated: using protocol -> 80 units bolus, followed by 18 units/kg/hr
- Very imp to reach anticoagulation as soon as possible -> failure -> recurrence
- This is why using Enoxaparin is preferred -> the dose of 1 mg\kg\12 hrs is predictable and therapeutic
- But using unfractionated heparin -> we need to use a protocol to reach therapeutic aptt; otherwise, it might take some time
Other cardioembolic events in surgical pts:
- Stroke (risk is A fib -> 6% per yr)
- Acute limb ischemia
- Mesenteric ischemia
Side note:
- Pt is taking aspirin -> hold it 7 days pre-op (depends on procedure, if small -> no need to stop it)
- Pt is taking Plavix -> hold it 5 days pre-op (higher risk of bleeding)
Caprini score:
Download the PDF version: here
References:
- Dr Aldorzi’s lecture
