Title
Document Number
Version Number
Name, Date and version number of
previous document (if applicable)
Staff involved in development
Staff with overall responsibility for
development implementation and review
Development period
Date approved by Clinical Guidelines
committee
Signed by the Chair Clinical Guidelines
Committee
Anticoagulation for Invasive
Procedures in Patients on Warfarin
CG230
2
Anticoagulation for Invasive
Procedures
in Patients on Warfarin, approved
2007
Dr J M Voke & Dr D S Thompson,
Consultant Haematologists
Dr M Evans, Chief Pharmacist
Miss K Brown, Consultant Surgeon
Dr S Yogasakaran, Consultant
Anaesthetist
Dr N Simmonds, Consultant
Gastroenterologist
Miss K Brown, Chairman, Thrombosis
Committee
Up to ’07
Revision Aug- Oct ‘09
Original ‘07
Revision: November 2009
M Griffiths
Date for review
October 2011
Key words
Anticoagulation, warfarin, heparin,
enoxaparin, vitamin K, surgery,
invasive procedures
June 2009
Date document was Equality Impact
Assessed:
JV/ME/KB rev Nov 09
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ANTICOAGULATION for
INVASIVE PROCEDURES in
ADULT PATIENTS on WARFARIN
Elective Procedures on warfarin (Group A)
Elective Procedures after stopping warfarin (Group B)
Elective Procedures requiring transfer to LMW heparin (Group C)
page 1
page 2
page 2
Emergency Procedures
Endoscopic procedures (from BSG guidelines)
Bridging high risk patients with LMW heparin
Classification of thrombotic risk and bleeding risk - Appendix 1
Practical information for doctors and nurses - Appendix 2
References
Group A, B and C letters for patients
Letter requesting nurse to give LMWH injections
page 2
page 3
page 4
page 5
page 6
page 7
pages 8-10
page 11
•
These guidelines are for the use of clinical staff in the management of patients on full dose oral
anticoagulation undergoing invasive surgical procedures
•
Guidelines should be used to aid individual clinical decisions, not replace them
•
The best available evidence on which these guidelines are based, is mainly grade 2B & 2C, ie it is scientifically
weak evidence, therefore individual clinical judgement remains important.
•
The risk of thromboembolism needs to be balanced against the risk of surgical haemorrhagic complications in
each patient.
•
For major and moderate surgery, once warfarin has been stopped and the INR is less than 1.8, additional
prophylaxis according to the surgical thromboprophylaxis guidelines may be given (TED stockings and, for
some patients, intermittent pneumatic compression foot pumps) until the INR returns to the desired range.
•
If surgical complications occur, use intravenous standard heparin, not warfarin or low molecular weight heparin
(LMWH), to allow faster anticoagulant adjustment.
•
If management uncertain or high risk, discuss with Consultant Haematologist.
MANAGEMENT OF ANTICOAGULATION FOR ELECTIVE PROCEDURES*
Elective surgery should be postponed when this is safe, until full dose anticoagulation has been stopped, eg. in
patients anticoagulated for 3 - 6 months following a first episode of venous thromboembolism.
GROUP A
For procedures* with a low risk of surgical bleeding (see Appendix 1)
WARFARIN CAN BE CONTINUED
Pre-op
• Give the patient or carer a copy of the Patient Information Sheet for Group A patients (page 8)
• Patient (or carer) to inform Anticoagulant clinic (AC clinic) of procedure and date so that an extra
appointment for INR can be made a week before the procedure on the usual dose of warfarin.
• If INR >3.0, the AC clinic will reduce warfarin dose for a week before the procedure to give INR 2-3.
• Check INR on day before procedure. INR < 3 is usually acceptable.
• If the INR is above 3, ask the patient or carer to phone the consultant’s secretary for instructions.
• If INR below 3, ask the patient to bring their yellow anticoagulant booklet to the hospital on the day of
the procedure.
• If necessary, also check INR on day of procedure and proceed if INR <3.
Post-op
•
•
•
•
If warfarin has been reduced, restart at patient’s normal dose on the day of surgery.
Aim to re-establish therapeutic anticoagulation without delay
Give prophylactic enoxaparin if INR <2 in patients with high thrombotic risk (Appendix 1).
For oral haemostasis, tranexamic acid mouthwash can be used to aid surgical measures.
* Day case or Inpatient Invasive Procedures
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GUIDELINES ON THE MANAGEMENT OF ANTICOAGULATION FOR
SURGERY* when there is a high risk of surgical bleeding (Appendix 1)
GROUP B
WARFARIN TO BE STOPPED. No heparin bridging needed
as low to moderate thrombotic risk (Appendix 1)
Pre-op
• Stop warfarin 5 days before surgery*.
• Check the INR the day before surgery.
• If the INR is 1.5 or higher, repeat on the day of the procedure. Target INR for surgery in this group
should be <1.5
• If INR remains >1.5, delay surgery or consider active reversal of anticoagulation (see below Emergency Procedures)
Post-op
•
Restart patient’s normal dose of warfarin on the evening of surgery unless there has been excess
bleeding.
GROUP C
WARFARIN TO BE STOPPED. Heparin bridging needed
as high thrombotic risk (Appendix 1)
Pre-op
• Discontinue warfarin 5 days before surgery.*
• Prescribe enoxaparin to start in the morning 3 days before surgery (for doses & timing see page 4)
and arrange for the patient or carer to learn to give the injections.
• Check INR the day before surgery and, if necessary, also on the day of the procedure. See above
for INR required.
• Do not give full dose enoxaparin on the evening before the procedure.
• Prophylactic enoxaparin 40mg sc can be given 12 hours pre-op.
Post-op
• Restart patient’s normal dose of warfarin on the evening of surgery unless there has been excess
bleeding.
• After morning surgery give enoxaparin 40mg sc 6hrs post-operatively (not after 8pm).
• Restart enoxaparin the next morning, dose as per chart page 4.
• Continue enoxaparin for 3 days or until INR therapeutic again.
• If the patient remains in hospital post-op, additional INR can be checked 4 days after restarting
warfarin.
* Day case or Inpatient Invasive Procedures
EMERGENCY PROCEDURES
1.
2.
3.
4.
Stop anticoagulants unless patient is in Group A with INR <3 (see previous page).
Take blood samples for INR, FBC, cross-match & other tests if indicated.
If INR is > 1.5 and procedure requires lower INR (Groups B & C), give FFP 15ml/kg.
If INR is > 3.0 also give iv vitamin K 1mg slowly. (Anaphylaxis can occur with iv vitamin K). With
larger doses of vitamin K the patient will be refractory to warfarin for 3-4 days. If no further oral
anticoagulation is required, 5mg iv vitamin K can be given followed by daily oral vitamin K 10mg
for 3-4 days.
5. See Octaplex (prothrombin complex concentrate) guidelines if there is severe bleeding.
6. Repeat INR 20-30 minutes after the FFP or Octaplex.
7. When INR is satisfactory proceed with operation. Give post-op enoxaparin and re-establish oral
anticoagulation as described above.
If management uncertain or high risk, discuss with Consultant Haematologist.
JV/ME/KB rev Nov 09
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Luton and Dunstable Hospital
Guidelines for the management of patients on warfarin or clopidogrel undergoing
endoscopic procedures, biopsies and other invasive investigations
adapted from British Society for Gastroenterology & BCSH guidelines 2008 - Gut 2008: 57: 1332-1329
http://www.bsg.org.uk/bsgdisp1.php?id=87d6c937c883a1bf5f2a&h=1&m=00023
This page is part of ‘Guidelines on the Management of Invasive Procedures in Anticoagulated Patients’ on the L&D Intranet
Low Risk Procedure
High Risk Procedure
- Diagnostic procedures +/- biopsy of
- Polypectomy
- Liver biopsy
- ERCP with sphincterotomy
- EMR
- Dilation of strictures
- Therapy of varices
- PEG
- EUS with FNA
non-vascular tissue
- Biliary or pancreatic stenting
- Diagnostic EUS
Warfarin
Continue warfarin
- Check INR 1 week before
Clopidogrel
Continue
clopidogrel
procedure
- If INR <3 continue usual daily
dose
- If INR above 3 reduce daily
dose until INR <3
- Recheck INR before procedure
Low Risk
Condition
Low Risk Condition
- Prosthetic aortic valve
- Xenograft heart valve
- AF without valvular
disease
- >3months after VTE
Stop warfarin 5 days
before procedure
- Check INR prior to
procedure to ensure
INR<1.5
- Restart warfarin evening of
procedure with usual daily
dose
- Check INR 1-2 weeks later
at the patient’s usual clinic
High Risk
Condition
- Prosthetic mitral valve
- Any prosthetic heart
valve and AF
- AF with mitral stenosis
- <3months after VTE
- Previous VTE with
signif. thrombophilia*
- Other high risk venous
or arterial thromboembolic indications for
warfarin
Stop warfarin 5 days
before procedure
- Start LMWH** 2 days after
stopping warfarin
-Omit LMWH on the evening
before and on the day of the
procedure
- Check INR prior to procedure to
ensure INR<1.5
- Restart warfarin evening of
procedure with usual daily dose
- Continue LMWH** for 3 days
after the procedure or until INR
therapeutic
* eg antiphospholipid syndrome, antithrombin deficiency, complex
inherited thrombophilias. Discuss with Haematologist
**See next page for details of LMWH doses
JV/ME/KB rev Nov 09
Clopidogrel
Warfarin
- Ischaemic heart
disease without
coronary stent
- Cerebrovascular
disease
- Peripheral vascular
disease
High Risk
Condition
Coronary
artery stents
Liaise with
cardiologist
Stop
clopidogrel
7 days before
procedure
- Continue aspirin if
already prescribed
- If not on aspirin,
then consider
aspirin therapy
while clopidogrel
stopped
Consider stopping
clopidogrel 7 days
before procedure
if
- >12 months after
insertion of drugeluting coronary
stent
- >1 month after
insertion of bare
metal stent
Continue aspirin
Key:
EUS: endoscopic ultrasound
ERCP: endoscopic retrograde
cholangiopancreatography
EMR: endoscopic mucosal resection,
PEG: percutaneous endoscopic
gastroenterostomy,
LMWH: low molecular weight heparin
FNA: fine needle aspiration,
INR: international normalised ratio,
AF: atrial fibrillation,
VTE: venous thromboembolism
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Bridging with low molecular weight heparin (LMWH)
When patients at high risk of thromboembolism are having a high risk procedure (see green
boxes on previous page) the bridging regime below is recommended and a morning procedure
should be arranged whenever possible.
•
Stop warfarin 5 days before the procedure.
•
Always assess risk factors for bleeding as well as thrombosis before following these
recommendations.
•
Guidelines on regional anaesthesia must be followed for timing of anticoagulant doses
in relation to epidurals and regional anaesthetic injections. (Add Hyperlink to these guidelines)
LMWH recommended
Day
pre- or
postprocedure
Warfarin
Venous indication
for LT anticoagulation
(see page 5)
Prosthetic mitral valve
or other cardiac
indication (see page 5)
Day -5
No warfarin
-
-
Day -4
No warfarin
-
-
Day -3
No warfarin
Enoxaparin 40mg sc 12
hourly
Enoxaparin 1.5 mg/kg sc
once daily in the morning
Day -2
No warfarin
Enoxaparin 40mg sc 12
hourly
Enoxaparin 1.5 mg/kg sc
once daily in the morning
Day -1
No warfarin
Enoxaparin 40mg sc
12 hourly
Enoxaparin 1.5 mg/kg sc
at 8am
Day of
procedure
Restart warfarin
on evening of
procedure at
patient’s usual dose
Day 1 post
Continue daily
warfarin
Enoxaparin 40mg sc 12
hourly
Enoxaparin 1.5 mg/kg sc
once daily, in the morning
if no excessive bleeding
Day 2 post
Continue daily
warfarin
Enoxaparin 40mg sc 12
hourly
Enoxaparin 1.5 mg/kg sc
once daily in the morning
Day 3 post
Continue daily
warfarin
Enoxaparin 40mg sc 12
hourly
Enoxaparin 1.5 mg/kg sc
once daily in the morning
Day 4 post
Continue daily
warfarin
Stop LMWH
Stop LMWH
No LMWH until 6 hours post-op when
prophylactic enoxaparin 40mg sc can be given if
there has been no excessive bleeding
• Patients (or carers) should be taught to give injections themselves whenever this is possible, to
allow LMWH to be given at home before and after hospital admission, when appropriate
• For patients with renal dysfunction, see BNF Appendix A3 for enoxaparin dose adjustment
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APPENDIX 1
CLASSIFICATION OF THROMBOTIC RISK and BLEEDING RISK
THROMBOTIC RISK
if warfarin temporarily
stopped
Original clinical indication
for anticoagulants
Low to moderate
thrombotic risk no bridging needed
• 3 months since acute VTE with no significant
thrombophilia*
• AF without valve disease
• Tissue valve replacement, not in AF
• Prosthetic aortic valve, not in AF
• Other low risk venous or arterial thromboembolic
indications for warfarin
High
thrombotic risk requiring bridging
LMW heparin
• VTE within last 3 months
• Prosthetic mitral valve
• AF with
- any prosthetic valve
- mitral stenosis
- previous cardio-embolic event
• Previous VTE with significant thrombophilia*
• Other high risk venous or arterial thromboembolic
indications for warfarin
* eg antiphospholipid syndrome, antithrombin deficiency, complex thrombophilia: discuss with Haematologist.
Examples of risk of surgical bleeding
associated with invasive procedures
when patient is not on an anticoagulant or anti-platelet drug
Low risk of bleeding
High Risk of Bleeding
• Skin biopsy & excision of minor skin lumps where
pressure can be directly applied
• Banding of piles and other superficial venous procedures
• Some endoscopic procedures (page 3) including
diagnostic endoscopy +/- biopsy of non-vascular tissue,
biliary or pancreatic stenting,
diagnostic endoscopic ultrasound
•
•
•
•
Invasive surgery
Regional anaesthetic techniques
Liver biopsy
Some endoscopic procedures (page 3) including
polypectomy, ERCP with sphincterotomy,
EMR, dilation of strictures, therapy of varices,
PEG, EUS with FNA
Guidelines should be used to aid individual clinical decisions, not replace them
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APPENDIX 2
Information for Doctors & Nurses Managing Anticoagulation before and after Surgical
Procedures, Endoscopic or X-ray guided Biopsies and other Invasive Investigations.
Assessment of risk: The doctor who informs the patient that the procedure is needed must also assess
the risk of thrombosis and bleeding.
There are 3 groups, as below, with a separate Patient Information Sheet for each group.
Group A - continue warfarin as low risk of surgical bleeding due to the procedure.
Follow guidelines on page 1 for GROUP A patients.
Group B - stop warfarin for 5 days to reduce risk of surgical bleeding due to the procedure.
Follow guidelines on page 2 for Group B patients.
Group C - stop warfarin for 5 days to reduce risk of surgical bleeding due to the procedure.
Conditions listed as ‘high thrombotic risk’ are given in Appendix 1. Heparin bridging is needed for
these patients. Follow guidelines on page 2 for Group C and transfer to LMWH – dose & timing details
are given on page 4.
Prescriptions for Group C
When LMWH is required for bridging, the prescription for the appropriate pre-filled syringes of LMWH must
be given with advice about home injections at the time the procedure is agreed with the patient. The
number of syringes needed for home injection will depend on when the patient is to be admitted. Full dose
LMWH should not be prescribed for the evening before the procedure. Note the different enoxaparin doses
recommended for venous and cardiac indications (see table page 4). Doses for obese and underweight
patients must be discussed with the consultant in charge but do not usually need to be altered. See BNF
for doses for patients with renal dysfunction.
Injections at home
1. At the time the prescription is written, give an explanation for the temporary transfer from warfarin to
LMWH
2. Patients (or carers) must be asked if they would be willing to learn to give their injections at home. This
should be encouraged to avoid unnecessary admissions. Injection technique can be taught in the Day
Unit (ext 8106/7), on the ward or at the GP’s surgery. Ensure that an appropriate appointment is made
and that the patient understands where to go for training.
3. If the patient or carer cannot give injections, and early admission is impossible, arrange for a district
nurse to visit.
4. Pre-printed letters ‘Patient Information & Heparin Record Sheet for Home Treatment’ are available
from the Day Unit, the Anticoagulant Clinic Clerk or the Haematology Secretary ext 7214.
Retrieval of INR results before the procedure:
ϖ Check INR results in the patient’s own Anticoagulant record book or on ICE
ϖ The INR should be INR < 3 at the Anticoag clinic the week before a low bleeding risk procedure and
<1.5 the day before a high bleeding risk procedure.
ϖ INR requests on the day of the procedure should be labelled ‘urgent’ and samples taken and delivered
to the haematology lab as soon as the patient arrives in the ward, endoscopy unit or department.
Rarely a patient’s procedure may have to be delayed if the INR remains 1.5 or above even after
warfarin has been stopped for 5 days. In this case, check LFTs.
After the procedure
Patients who have had no excess bleeding during the procedure should restart daily warfarin on the
evening of the procedure at their usual dose (no high loading dose) unless an epidural catheter is still in
place, when warfarin should be delayed (also see Anaesthetic guidelines for timing of epidural insertion &
removal in relation to heparin injections).
For patients having bridging LMWH, check that they have the 3 days supply of LMWH injections to give at
home and that they are back on warfarin at their usual dose. Patients should attend their planned
anticoagulant clinic appointment or move their appointment forward to 1 week if there have been any
complications or changes in medicines.
JV/ME/KB rev Nov 09
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References
1.
2.
3.
4.
5.
6.
Eighth ACCP Consensus Conference on Antithrombotic Therapy. Chest 133 (6), June
2008 Supplement
Veitch A et al for the BSG & BCSH. Guidelines for the management of anticoagulant and
antiplatelet therapy in patients undergoing endoscopic procedures Gut 2008: 57(9):1322-9
British Soc for Haem Guidelines on Oral Anticoagulation. BJHaem 1998; 101: 374-387
Guidelines on oral anticoagulation (warfarin): third edition – BCSH guidelines 2005 update
BCSH guidelines, H&T Task Force, Hospital Medicine 2000, 61, 644
Baglin T et al for the BCSH. Managing bleeding and excessive anticoagulation. BJHaem
132 (3) 277, 2006
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INFORMATION FOR PATIENTS in GROUP A
Management of Warfarin
for Invasive Surgical Procedure, Biopsy or Investigation when
risk of bleeding is low and warfarin does not need to be stopped
CONTINUE WARFARIN
1. You do not need to stop warfarin before the procedure as there is a low risk of
bleeding.
2. Let the anticoagulant clinic nurses know
ϖ the date & nature of the procedure
ϖ that you do not need to stop warfarin
ϖ that you need an INR test a week before the procedure
The Anticoagulant Clinic number is 01582 497537
3. If your INR is above 3, the Anticoagulant Clinic nurse will reduce your dose for
a week before the procedure to ensure that the INR is below 3 on the day of
the procedure.
4. Bring your yellow warfarin dose record book with you when you come in for
the procedure as the doctors will want to check that your INR is below 3.
5. After the procedure, continue warfarin at your usual dose or the dose advised
by the Anticoagulant clinic nurse and keep your usual next Anticoagulant clinic
appointment.
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INFORMATION FOR PATIENTS in GROUP B
Management of Anticoagulation
for Invasive Surgical Procedure, Biopsy or Investigation
when warfarin needs to be stopped for 5 days
NO ‘BRIDGING’ HEPARIN NEEDED as risk of thrombosis is low
1. Before the procedure: you need to stop warfarin 5 days before the
operation or endoscopy.
2. You will not need heparin injections as bridging anticoagulation
3. Your surgeon or endoscopy consultant will give you a request form for
an INR test the day before the procedure (the fifth day off warfarin).
Bring the form to the Pathology Outpatient Dept for the blood test
before 2pm on the day before the procedure.
4. The result of the INR test will be checked by a doctor from the surgical
or endoscopy team. If the INR is too high (1.5 or above) they will ask
you to have another INR check on the morning of the procedure, when
your INR is likely to be lower.
5. After your procedure restart your normal dose of warfarin the same
evening and continue that dose until your next anticoagulant clinic
appointment. It takes a few days for warfarin to have its full effect so
you do not need an extra INR test in the week after your procedure.
6. Keep your usual anticoagulant clinic appointment, as recorded in your
yellow warfarin dose book.
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INFORMATION FOR PATIENTS in GROUP C
Management of Anticoagulation
for High Risk Invasive Surgical Procedure, Biopsy or Investigation
requiring BRIDGING Heparin when Warfarin stopped
1.
Before the procedure: you need to stop warfarin 5 days before the operation or
endoscopy.
2.
A prescription for heparin injections (enoxaparin) will be given to you by your hospital
doctor when you discuss the procedure. This ‘bridging’ anticoagulation is to be given for 3
days before and after the procedure. The prescription will be for pre-filled syringes of
enoxaparin
3.
Take your prescription to the hospital pharmacy and collect the enoxaparin syringes. If you
prefer to collect them from a community pharmacy, allow 2-3 days extra in case they need
to be ordered
4.
Learn how you (or your relative or carer) can give the injections at home. Phone your
General Practice nurse or the Day Unit sister (01582 718106) to arrange an appointment to
be taught how to give the injections if you have not given injections before:
5.
Bring this letter (see reverse) and the injections with you when you come for the training
session.
6.
Give your subcutaneous enoxaparin injections as advised by the doctor on the 3 days
before and the 3 days after your procedure. Patients on the once daily high dose of
enoxaparin should give it in the morning each day and no injection should be given the
evening before surgery. Patients having the lower 12 hourly dose of enoxaparin should
have a dose before 8pm on the evening before the procedure.
7.
Your surgeon or endoscopy consultant will give you a request form for an INR test the
day before the procedure (the fifth day off warfarin). Bring the form to the Pathology
Outpatient Dept for the blood test before 2pm on the day before the procedure.
8.
The result of the INR test will be checked by a doctor from the surgical or endoscopy
team. If the INR is too high (1.5 or above) they will ask you to have another INR check
on the morning of the procedure, when your INR is likely to be lower.
7. After the procedure restart your normal dose of warfarin the same evening and continue
that dose until your next anticoagulant clinic appointment. It takes a few days for warfarin to
have its full effect so you do not need an extra INR test in the week after your procedure.
8. Continue with the injections of enoxaparin as prescribed by the doctor for 3 days after the
procedure (unless there is excess bleeding) then stop the injections, continuing the
warfarin.
9.
Keep your usual anticoagulant clinic appointment, as recorded in your yellow warfarin
dose book.
JV/ME/KB rev Nov 09
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Please take this letter to the nurse when you attend for training in subcutaneous injection
technique. It is helpful if you take your injections along as well.
Date …………………………
Dear …………………………………..….
(Day Centre sister / Practice nurse / District nurse)
Patient ID
This patient is booked for (type of procedure)……………………………………………..
on (date)……………………………..
and has been asked to stop warfarin for 5 days before the procedure. Bridging heparin
(enoxaparin) injections have been prescribed for 3 days before and after the procedure.
The dose of enoxaparin is …………. mg once daily every morning subcutaneously
or 40mg every 12 hours subcutaneously (delete as required)
from (date) ……………………………
to (date) …………………………………
Thank you for teaching the patient / relative / carer to give the subcutaneous injections.
If there are any queries, please phone …………………………………….
Yours sincerely
Print name ……………………………………..
On behalf of Dr/Mr …………………..
Consultant ………………………
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