dvt_proph
Table of Contents
DVT prophylaxis
see also:
introduction
- 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
- 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
Pharmacologic prophylaxis
- anticoagulant:
-
- 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
C/I to pharmacologic prophylaxis
absolute C/I
- 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
relative C/I
- 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
special considerations
- 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 DVT prophylaxis in adults
- 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.
C/I to mechanical prophylaxis
- skin ulceration
- 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
Intermittent pneumatic compression devices
- 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.
Graduated compression stockings (GCS)
- 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:
- 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.
- 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.
- 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.
- 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.
- Assessment of appropriate application and skin integrity must be undertaken at least once every shift
dvt_proph.txt · Last modified: 2026/01/18 08:57 by gary1