VTE
14/10/10
OHOA
SP Notes
- may contribute to up to 12% of deaths in ICU
- importance of asymptomatic DVT uncertain -> if seen on Doppler then significantly higher chance of embolism
- even small PE’s may be tolerated poorly by the critically unwell
RISK FACTORS
Major (relative risk 5-20) - SLOMMM
Surgery – major abdominal/pelvic, hip/knee replacements, post ICU
Lower limb problems - #, varicose veins
Obstetrics – late pregnancy, C/S, puerperium
Malignancy – abdominal/pelvic, advanced/metastatic
Mobility – hospitalization, institutional care
Miscellaneous – previous VTE
Minor (relative risk 2-4) - COM
Cardiovascular – congenital heart disease, CHF, HT, superficial venous thrombosis, CVL
Oestrogens – OCP, HRT
Miscellaneous – COPD, neurological disability, occult malignancy, thrombotic disorder, long distance travel, obesity, other (IBD, nephrotic syndrome, dialysis, myeloproliferative disorders, paroxysmal nocturnal haemoglobinuria, Bechet’s diseas)
Thrombophillia’s
- Factor V Leiden mutation
- Prothombin gene mutation (G20210A)
- Hyperhomocysteinaemia
- Antiphospholipid antibody syndrome (lupus anti-coagulant & anti-cardiolipin antibodies)
- Deficiency of antithrombin III, protein C or protein S
- High concentrations of factor VIII or XI
- Increased lipoprotein (a)
-> test in those < 50years with recurrent or a strong FHx
MANAGEMENT
- many different strategies
- risk should be considered
- reviews and recommendations are widely published -> data quality is low
- but good placebo controlled RCT’s are rare
Non-pharmacological
- TED stockings (simple, widespread use, effective for low risk patients)
- hydration (physiological basis only)
- intermittent pneumatic compression (recommended but limited evidence, useful where anticoagulation contraindicated)
- passive mobilisation (not well studied)
- early mobilisation (not well studied)
- minimisation of intraoperative duration
- optimal cardiac output
- clinical and imaging surveilance
- elective insertion of an IVC filter (risk associated, only recommended in high risk patients)
Pharmacological
- regional anaesthesia (low quality data)
- adequate analgesia
- aspirin 100-300mg OD
- heparin 5000IU SC BD
- enoxaparin 40mg SC OD (20mg OD if has renal impairment, similar or better than heparin, with less thrombocytopaenia, only slight increase in bleeding)
- IV heparin titrated to an APTT of 60-80 seconds
- petasaccharides (new, showing promise)
- hirudin (new, showing promise)
- dextran (old, not used)
- warfarn (less frequently used)
- other controversies include cost-benefit and side-effect profiles
EVIDENCE
- DVT happen in ICU
- rate with prophylaxis = 6%
- LMWH as good as SC heparin BD
MY APPROACH
- routinely used non-pharmacological techniques (SCD’s, TEDS, hydration, physio)
- LMWH 40mg SC or 20mg SC in renal failure (OD dosing, heparin not superior, bleeding not an issue, cheap), possible trend to decreased PE – PROTECT trial).
Jeremy Fernando (2010)