ASiT Yearbook 2011 - The Association of Surgeons in Training

ASiT EXECUTIVE
Thromboprophylaxis 3_Layout 1 29/03/2011 12:58 Page 4
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continue for 28-35 days and include one of the
following:
• LMWH (or UFH in patients with renal failure),
started at admission, stopping 12 hours before
surgery, and re-starting 6-12 hours after surgery
• Fondaparinux sodium, starting 6 hours after surgical
closure 3
D. NICE Guidelines 3
The February 2010 NICE guidelines on reducing the risk
of venous thromboembolism gives specific guidance
relating to elective hip and knee replacement, hip
fracture surgery, and plaster casts. Routine
thromboprophylaxis for patients undergoing upper limb
surgery is not recommended. Whilst the guidance for
hip fractures and plaster casts are discussed elsewhere
in this article, the recommendations for elective hip and
knee surgery are as follows:
Mechanical thromboprophylaxis should be started on
admission choosing from GCS (thigh or knee length),
IPCD (thigh or knee length), and FID. This should be
continued until the patient no longer has significantly
reduced mobility. Chemical thromboprophylaxis should
include one of the following:
• Rivaroxaban, starting 6-10 hours after surgery,
continuing for 5 weeks for hip surgery, and 2 weeks
for knee surgery
• LMWH, starting 6-12 hours after surgery (UFH for
patients with renal failure)
• Fondaparinux sodium, starting 6 hours after surgical
closure providing haemostasis has been established
• Dabigatran etexilate, starting 1-4 hours after surgery
E. Foot and Ankle Surgery and Plaster Casts
In the 2010 NICE guidelines routine thromboprophylaxis
for upper limb surgery is not routinely
recommended, and although recommendations for
spinal surgery exist, there is overlap with neurosurgery
and any discussion on thromboprophylaxis in this
context is beyond the scope of this article. Although
foot and ankle surgery is not specifically referred to in
the guidelines, it does come with a VTE burden and falls
under the “other orthopaedic surgery” section of the
guidelines. In this section one should offer mechanical
(GCS/IPCD/FID) and chemical (LMWH/UFH) thromboprophylaxis
based on an assessment of inclusion criteria.
Those criteria specific to foot and ankle surgery would
include surgical and anaesthetic time exceeding 90
minutes; expected significant reduction in mobility; and
one or more of the following risk factors:
• Active cancer or cancer treatment
• Age over 60 years
2
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• Critical care admission
• Dehydration
• Known thrombophilias
• Obesity (BMI over 30 kg/m2)
• One or more significant medical co-morbidities
(such as heart disease, metabolic, endocrine or
respiratory
Plaster casts are used in a wide variety of patients in
trauma & orthopaedics. There are those who do not
require surgery, those who are being protected in cast
after trauma, and after elective foot and ankle surgery.
The period of immobilization is also varied ranging from
six weeks to three months. The asymptomatic and
symptomatic DVT risk in this group of patients has been
reported as between 4-40%. The 2010 NICE guidelines
regarding plaster casts are identical to those for “other
orthopaedic surgery” 3 . Batra et al 2006, conducted a
survey of thromboprophylaxis practice for lower limb
injuries in plaster casts across 70 randomly selected
hospital across the UK. 62% of departments did not use
thromboprophylaxis in this group, only 11% of
departments risk-stratified this group, and 99% were
unaware of any guidelines concerning this topic 15 .
In contrast Chipperfield and Redfearn 2007, conducted
a random survey on the use of thromboprophylaxis
amongst 71 foot and ankle consultants. 94% of foot and
ankle surgeons prescribed LMWH to their postoperative
patients in plaster, and 65% continued this for
out-patients. The duration of treatment ranged from
ten days to the entire duration of cast immobilization.
This practice far exceeds the NICE guidelines 16 .
Conclusion
The choice of thromboprophylactic methods used in
trauma and orthopaedic surgery depends upon surgeon
preferences, individual patient characteristics and
choices, and national guidelines that are based upon an
extensive review of various studies and RCTs. For
surgeons in training, it is important to have an
understanding of what thromboprophylactic methods
are available, their mechanism of action, when to use
them, and problems associated with their use. Further
guidelines will be available from the British Orthopaedic
Association in the near future.
References
1 Sachdeva A, Dalton M, Amaragiri SV, Lees T. Elastic
Compression Stockings for Prevention of Deep Vein
Thrombosis. Cochrane Database of Systematic Reviews 2010,
Issue 7
2 Hui ACW, Heras-Palou C, Dunn I, Triffitt PD, Crozier A,
Imeson J, Gregg PJ. Graded Compression Stockings for
Prevention of Deep Vein Thrombosis after Hip and Knee
Replacement. J Bone Joint Surg (Br) 1996; 78-B: 550-4