DVT prophylaxis

see also:

• Mx of lower limb DVT
• deep venous thrombosis (DVT)
• risk assessment for venous thromboembolism (VTE)
• DVT prophylaxis, anticoagulation and spinal anaesthesia or spinal cord injured patients
• DVT prophylaxis for the surgical patient
• DVT_proph_nonsurg
• DVT, PE, VTE prophylaxis and risk assessment in patients with lower leg immobilization (eg BKPOP plaster for fracture ankle)
• NHMRC NICS Stop The Clot patient information brochure (pdf)
• NSW Govt: VTE prevention - risk assessment, etc (pdf)
• Western Health DVT prophylaxis and anticoagulation guidelines including peri-operative Mx of those patients on warfarin (pdf) - intranet only

• all hospital patients should have VTE risk assessment performed
• high risk patients generally require:
  • pharmacologic prophylaxis if not C/I,
  • PLUS one mechanical prophylaxis if not C/I
• moderate risk patients generally require:
  • pharmacologic prophylaxis if not C/I
  • OR one mechanical prophylaxis if not C/I
  • PLUS early mobilisation and patient education
• low risk patients generally require:
  • no need for pharmacologic or mechanical prophylaxis
  • BUT early mobilisation and patient education should be given
• pregnant patients
  • see Qld health guidelines on DVT prophylaxis in pregnancy
  • some patients may require FULL therapeutic anticoagulation
    • requirement for anticoagulation prior to pregnancy
    • PH VTE with high risk thrombophilia
    • recurrent unprovoked VTE
    • VTE in current pregnancy
  • other patients may require prophylactic enoxaparin 40mg once daily s/c
    • for whole of pregnancy from 1st TM:
      • PH unprovoked VTE
      • recurrent provoked VTE
      • active autoimmune or inflammatory disorder
      • Medical co-morbidity: (e.g. cancer, nephrotic syndrome, heart failure, sickle cell, type I diabetes with nephropathy)
      • high VTE risk score
    • only while admitted to hospital:
      • general antenatal patients
      • ovarian hyperstimulation syndrome in 1st TM
      • any surgery
      • severe hyperemesis or dehydration
    • from 28wks gestation:
      • moderate VTE risk score

• anticoagulant:
  • enoxaparin
    • usual dose: 40 mg subcutaneous daily
    • if Creatinine Clearance < 30mL/min: 20 mg subcutaneous daily or use heparin
  • or, heparin:
    • 5,000 units subcutaneous 8-12 hourly
  • or, oral agents may be appropriate for some patients
• duration of Rx:
  • medical patients:
    • continue until acute medical condition is stable, patient is mobile or until hospital discharge
  • post-op patients:
    • THR or hip fracture surgery: 28-35 days
    • TKR surgery: 14 days
    • lower leg immobilisation: until fully mobile
    • major general surgery: up to 1 week or until fully mobile

• active haemorrhage
• severe trauma to head or spinal cord with haemorrhage within past 4 weeks
• coagulopathy
• thrombocytopaenia < 50 x x 10^9/L
• end stage liver disease with INR > 1.5
• therapeutic pharmacologic anticoagulation already in place

• intracranial haemorrhage within last 1 yr
• craniotomy in last 2 weeks
• intraocular surgery in last 2 weeks
• GIT or genitourinary tract haemorrhage in past month
• active intracranial lesions or neoplasms
• hypertensive emergency
• pos-op bleeding concerns
• use of anti-platelets eg. clopidogrel
• inherited bleeding disorder
• high falls risk

• heparin sensitivity of PH HIT
• insertion/removal of epidural catheter or spinal needle (lumbar puncture) (current or planned)
  • should be carried out ≥ 4 hours BEFORE a prophylactic dose of LMWH AND ≥ 10 hours after a previously administered dose.
• creatinine clearance <30mL/min
• acute stroke - seek advice
• neurosurgery - seek advice
• weight < 50kg - adjust dose
• weight > 100kg - adjust dose

• Mechanical methods of prophylaxis increase venous outflow and /or reduce stasis within the leg veins.(ACCP Conference on Antithrombotic and Thrombolytic Therapy 2004).
• Whilst they have been shown to reduce the risk of DVT in a number of patient groups, these methods have been studied far less extensively than anticoagulant-based options.
• Mechanical methods of prophylaxis are generally less efficacious than anticoagulant based options and are primarily recommended for patients with high bleeding risks or as an adjunct to anticoagulant-based prophylaxis for patients assessed as being at moderate to very high risk of VTE.
• The effectiveness of mechanical methods of prophylaxis is dependent upon appropriate fit and use.

• skin ulceration
• severe peripheral vascular disease (PVD or PAD)
• severe dermatitis
• lower leg trauma
• severe lower leg deformity
• recent low limb DVT (although anti-embolic stockings can be used)
• massive leg oedema or pulmonary oedema due to congestive cardiac failure
• morbid obesity where correct fitting is not possible
• peripheral neuropathy although intermittent pneumatic compression can be used
• recent skin graft
• stroke patients - avoid anti-embolic stockings

• Augment the inherent ability of the calf muscle to function as a pump in forcing blood from the venous sinuses and stimulating endogenous fibrinolytic activity (Rice 2001).
• IPC devices are available in single-chamber or multi-chamber types and provide intermittent or sequential pressure at predetermined time intervals.
• Note: Assessment of appropriate application, device function and skin integrity under the sleeve must be undertaken at least once per shift.

• Studies have generally involved full-length stockings although it is anticipated that below knee stockings should also provide a degree of protection against DVT. As there few comparative studies, no recommendation can be made with regard to the length of stockings.
• The decision on the length of stockings to be worn i.e. full-length vs. knee-high, is to be made by the Senior treating clinician or as per the treating Unit’s protocol
• Regardless of the length of GCS the following recommendations are made:

1. Ideal characteristics of GCS for DVT prophylaxis
   • Evidence of clinical efficacy
   • Pressure of 16mmHg to 20 mmHg at the ankle in the supine position with graduated compression to the knee or above
   • Note: higher pressures may be ordered for GSC ordered for the treatment of chronic venous insufficiency.
2. The use of GSC is contradicted in critical limb ischaemia
   • Avoid/use with extreme caution in the following conditions:
     • Skin diseases/dermatitis
     • Ligature of veins
     • Open ulcers
     • Severe arteriosclerosis.
3. They must be measured and fitted for the individual patient.
   • Sizing range should be suitable for a large percentage of the population and the window of coverage should be clearly defined
   • The circumference and length of each extremity must be accurately measured according to the manufacturer’s instructions.
   • The stocking should fit snugly to maximise venous return – an appropriate fit is vital to prevent stocking from rolling down and forming a constrictive rubber-band like effect.
4. They should be worn continuously during the period of immobility to the return of full ambulation.
   • The use of GCS should not impede ambulation
   • Note: Patients are at increased falls risk (risk of slipping) if not wearing appropriate footwear.
5. Assessment of appropriate application and skin integrity must be undertaken at least once every shift