AntiCoagulation Management

CreatedNovember 11, 2020

Last UpdateMay 1, 2022

Ross Hanrahan

¹ ² ³ ⁴ ⁵ ⁶

STEP 1: Determine if Anticoagulant Needs to be Stopped

Some minor procedures may proceed without interruption of anticoagulation.

Examples of Procedures Which May Proceed Without Interruption of Anticoagulation
Minor dental procedures (removal of 1-3 teeth) Removal of minor skin lesions Incision of superficial abscesses Cataract surgery Cystoscopy/ gastroscopy/ colonoscopy without biopsy ERCP without sphincterotomy

Examples of Procedures Which May Proceed Without Interruption of Anticoagulation

Minor dental procedures (removal of 1-3 teeth)
Removal of minor skin lesions
Incision of superficial abscesses
Cataract surgery
Cystoscopy/ gastroscopy/ colonoscopy without biopsy
ERCP without sphincterotomy

Patients on warfarin should have their INR checked to exclude excessive anticoagulation.

Warfarinised patients undergoing dental procedures with an INR > 2.2 may benefit from tranexamic mouthwash. See protocol in therapeutic guidelines

In patients taking rivaroxaban, dabigatran or apixaban, avoid undertaking the procedure during time of peak drug effect.

Rivaroxaban: 2-3 hours post ingestion
Dabigatran: 2 hours post ingestion
Apixaban: 2-3 hours post ingestion

Discuss with surgical team if there is uncertainty regarding the need to withhold anticoagulation.

STEP 2: Consider Benefit of Delaying Surgery

Patients at high thrombotic risk due to a transient cause may benefit from delay of surgery until the thrombotic risk has fallen. High thrombotic risk that will not reduce with time (eg mechanical heart valves) will not benefit from surgical delay. In patients with an urgent indication for surgery the risks and benefits of delay should be weighed.

Senior advice should be sought before postponement of planned surgery.

Recommended Minimum Duration of Anticoagulation Before Interruption for Surgery
Arterial Thromboembolism	At least ONE MONTH where possible
Venous Thromboembolism	At least THREE MONTHS where possible
Mechanical / Bioprosthetic Heart Valve Implantation	At least THREE MONTHS where possible

Recommended Minimum Duration of Anticoagulation Before Interruption for Surgery
Arterial Thromboembolism	At least ONE MONTH where possible
Venous Thromboembolism	At least THREE MONTHS where possible
Mechanical / Bioprosthetic Heart Valve Implantation	At least THREE MONTHS where possible

STEP 3: Assess Surgical Bleeding Risk

Consider the risks and consequences of bleeding for the specific procedure planned for this patient.

Minor residual anticoagulant effect may be acceptable in certain procedures, but dangerous in others.

Interventions with LOW Bleeding Risk
Endoscopy with biopsy Prostate, breast or bladder biopsy Non-coronary angiography Pacemaker insertion Laparoscopic cholecystectomy Abdominal/ inguinal hernia repair Arthroscopy Carpal tunnel repair Dilation and curettage Skin cancer excision

Interventions with LOW Bleeding Risk

Endoscopy with biopsy
Prostate, breast or bladder biopsy
Non-coronary angiography
Pacemaker insertion
Laparoscopic cholecystectomy
Abdominal/ inguinal hernia repair
Arthroscopy
Carpal tunnel repair
Dilation and curettage
Skin cancer excision

Interventions with HIGH Bleeding Risk
Liver or kidney biopsy Some endoscopic procedures: Biliary sphincterotomy Treatment of varices Thoracic or abdominal surgery major orthopaedic surgery Cardiac Surgery Neurosurgery Cancer surgery TURP

Interventions with HIGH Bleeding Risk

Liver or kidney biopsy
Some endoscopic procedures:
- Biliary sphincterotomy
- Treatment of varices
Thoracic or abdominal surgery
major orthopaedic surgery
Cardiac Surgery
Neurosurgery
Cancer surgery
TURP

STEP 4: Determine Time to Cease Anticoagulant

Therapeutic Dose Anticoagulants

Warfarin

Withhold Before Surgery	Day Before Surgery, Check INR	If Vit K Given on Day Befoire Surgery, Recheck INR Immediately Pre-Operatively
Stop Warfarin 5 Days Before Surgery	If INR still > 1.5, Give 1mg IV Vit K	If INR still > 1.5 (Neurosurgery 1.3), Give 30U/kg Prothrombinex
Active warfarin related bleeding may also warrant consideration of FFP

Pre-Operative Warfarin Management
Withhold Before Surgery	Stop Warfarin 5 Days Before Surgery
Day Before Surgery, Check INR	If INR still > 1.5, Give 1mg IV Vit K
If Vit K Given on Day Before Surgery, Recheck INR Immediately Pre-Operatively	If INR still > 1.5 (Neurosurgery 1.3), Give 30U/kg Prothrombinex
Active warfarin related bleeding may also warrant consideration of FFP

Direct Oral AntiCoagulants

CLEARANCE OF DIRECT ACTING ORAL ANTICOAGULANTS IS RENAL DEPENDENT. CHECK CREATININE CLEARANCE ON A RECENT EUC

	Creatinine Clearance > 50ml/min⁷
	Period to Withhold Anticoagulant Before Surgery
	Low Risk of Surgical Bleeding	High Risk of Surgical Bleeding	Neuraxial Procedure
Rivaroxaban (Xarelto)	Withhold 24 hours (Last dose Day -2)	Withhold 2-3 Days (Last dose Day -3 or Day -4)	Withhold 3 Days (Last dose Day -4)
Dabigatran (Pradaxa)	CrCl ≥ 80: Withhold 24 hours (Last dose Day -2) CrCl 50-80: Withhold 24-48 hours (Last dose Day -2 or Day -3)	CrCl ≥ 80: Withhold 2 Days (Last dose Day -3) CrCl 50-80: Withhold 2-3 Days (Last dose Day -3 or Day -4)	CrCl ≥ 80: Withhold 3 Days (Last dose Day -4) CrCl 50-80: Withhold 4 Days (Last dose Day -5)
Apixaban (Eliquis)	Withhold 24 hours (Last dose Day -2)	Withhold 2-3 Days (Last dose Day -3 or Day -4)	Withhold 3 Days (Last dose Day -4)

Creatinine Clearance > 50ml/min⁸
Period to Withhold Anticoagulant Before Surgery
Rivaroxaban (Xarelto)
Low Risk of Surgical Bleeding	Withhold 24 hours (Last dose Day -2)
High Risk of Surgical Bleeding	Withhold 2-3 Days (Last dose Day -3 to Day -4)
Neuraxial Procedure	Withhold 3 days (Last dose Day -4)

Dabigatran (Pradaxa)
Low Risk of Surgical Bleeding	CrCl ≥ 80: Withhold 24 hours (Last dose Day -2) CrCl 50-80: Withhold 24-48 hours (Last dose Day -2 to Day -3)
High Risk of Surgical Bleeding	CrCl ≥ 80: Withhold 2 Days (Last dose Day -3) CrCl 50-80: Withhold 2-3 Days (Last dose Day -3 or Day -4)
Neuraxial Procedure	CrCl ≥ 80: Withhold 3 Days (Last dose Day -4) CrCl 50-80: Withhold 4 Days (Last dose Day -5)

Apixaban (Eliquis)
Low Risk of Surgical Bleeding	Withhold 24 Hours (Last dose Day -2)
High Risk of Surgical Bleeding	Withhold 2-3 Days (Last dose Day -3 to Day -4)
Neuraxial Procedure	Withhold 3 Days (Last dose Day -4)

	Creatinine Clearance 30-49ml/min⁹
	Period to Withhold Anticoagulant Before Surgery
	Low Risk of Surgical Bleeding	High Risk of Surgical Bleeding	Neuraxial Procedure
Rivaroxaban (Xarelto)	Withhold 48 hours (Last dose Day -3)	Withhold 3 Days (Last dose Day -4)	Withhold 3 Days (Last dose Day -4)
Dabigatran (Pradaxa)	Withhold 2-3 Days (Last dose Day -3 to Day -4)	Withhold 4 Days (Last dose Day -5)	Withhold 5 Days (Last dose Day -6)
Apixaban (Eliquis)	Withhold 2 Days (Last dose Day -3)	Withhold 3 Days (Last dose Day -4)	Withhold 4 Days (Last dose Day -5)

Creatinine Clearance > 30-49ml/min¹⁰
Period to Withhold Anticoagulant Before Surgery
Rivaroxaban (Xarelto)
Low Risk of Surgical Bleeding	Withhold 48 hours (Last dose Day -3)
High Risk of Surgical Bleeding	Withhold 3 Days (Last dose Day -4)
Neuraxial Procedure	Withhold 3 Days <(Last dose Day -4)

Dabigatran (Apixaban)
Low Risk of Surgical Bleeding	Withhold 2-3 Days (Last dose Day -3 to Day -4)
High Risk of Surgical Bleeding	Withhold 4 Days (Last dose Day -5)
Neuraxial Procedure	Withhold 5 Days (Last dose Day -6)

Apixaban (Eliquis)
Low Risk of Surgical Bleeding	Withhold 2 Days (Last dose Day -3)
High Risk of Surgical Bleeding	Withhold 3 Days (Last dose Day -4)
Neuraxial Procedure	Withhold 4 Days (Last dose Day -5)

Prophylactic Dose Anticoagulants

	Last Dose PRIOR to Neuraxial Procedure	First Dose AFTER Neuraxial Procedure
Rivaroxaban 10mg PO Daily	Withhold 22-26 hours If CrCl < 50 or dose > 10mg/day extend to 44-65 hours	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose rivaroxaban accidentally given while epidural still in, wait 22-26 hours before removing epidural
Dabigatran 150-220mg PO Daily	Withhold 34 hours	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose dabigatran accidentally given while epidural still in, wait 34-36 hours before removing epidural
Apixaban 2.5mg PO BD	if 2.5mg/day withhold 26-30 hours If 5mg/day or Cr ≥ 133µmol/L and < 80yo or < 60kg withhold 40-75 hours	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose apixaban accidentally given while epidural still in, wait 26-30 hours before removing epidural
PROPHYLACTIC Dose Enoxaparin 40mg SC Daily	Withhold 12 hours	Withhold 12 hours Extend to 24 hours if traumatic puncture Epidural can remain in situ during prophylactic LMWH provided dosing no more frequent then q24h Withhold LMWH 12 hr before epidural removal Wait 4 hours after epidural removal before LMWH dose
THERAPEUTIC Dose Enoxaparin 1mg/kg SC BD	Withhold 24 hours	For therapeutic dosing delay first post-operative dose until at least 24 hours after needle/ catheter placement. Subsequent LMWH dosing should occur at least 4 hours after catheter removal. Note that therapeutic dose LMWH may be resumed 24 hours after low bleeding risk surgery, and 48-72 hours after high-bleeding risk surgery

Rivaroxaban
Prophylactic Dose	10mg PO Daily
Last Dose PRIOR to Neuraxial Procedure (based on 2 drug half lives)	Withhold 22-26 hours If CrCl < 50, extend to 44-65 hours
First Dose AFTER Neuraxial Procedure	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose rivaroxaban accidentally given while epidural still in, wait 22-26 hours before removing epidural

Dabigatran
Prophylactic Dose	150-220mg PO Daily
Last Dose PRIOR to Neuraxial Procedure (based on 2 drug half lives)	Withhold 36 hours If Renal Function Normal
First Dose AFTER Neuraxial Procedure	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose dabigatran accidentally given while epidural still in, wait 34-36 hours before removing epidural

Apixaban
Prophylactic Dose	2.5mg PO BD
Last Dose PRIOR to Neuraxial Procedure (based on 2 drug half lives)	if 2.5mg/day: withhold 26-30 hours If 5mg/day or Cr ≥ 133µmol/L and < 80yo or < 60kg: withhold 40-75 hours
First Dose AFTER Neuraxial Procedure	Withhold 6 hours after neuraxial procedure Extend to 24 hours if traumatic puncture Remove epidural catheter at least 6 hours prior to first dose If prophylactic dose apixaban accidentally given while epidural still in, wait 26-30 hours before removing epidural

PROPHYLACTIC Dose Enoxaparin
Prophylactic Dose	40mg SC Daily
Last Dose PRIOR to Neuraxial Procedure (based on 2 drug half lives)	Withhold 12 hours
First Dose AFTER Neuraxial Procedure	Withhold 12 hours Extend to 24 hours if traumatic puncture Epidural OK provided dosing no more frequent than q24h Withhold LMWH 12 hr before epidural removal Wait 4 hours after epidural removal before LMWH dose

THERAPEUTIC Dose Enoxaparin
Therapeutic Dose	1mg/kg SC BD
Last Dose PRIOR to Neuraxial Procedure	Withhold 24 hours
First Dose AFTER Neuraxial Procedure	For therapeutic* dosing delay first post-operative dose until at least 24 hours after needle/ catheter placement. Subsequent LMWH dosing should occur at least 4 hours after catheter removal.* Note that therapeutic dose LMWH may be resumed 24 hours after low bleeding risk surgery, and 48-72 hours after high-bleeding risk surgery

Neuraxial Anaesthesia and Anticoagulation
Neuraxial Anaesthesia / Spinal puncture under the effect of anticoagulation carries a risk of spinal or epidural haematoma and long term paralysis. Drug pharmacokinetics should be taken into consideration, and appropriate laboratory tests considered. Factors that may increase this risk include: use of indwelling epidural catheters concomitant use of other drugs affecting haemostasis (NSAIDs, platelet inhibitors, other anticoagulants) a history of traumatic or repeated epidural or spinal punctures a history of spinal deformity or spinal surgery 2018 ASRA Guidelines allow prophylactic dose enoxaparin to be administered while an epidural catheter remains in situ, provided that enoxaparin is dosed no more frequently than once every 24 hours. Epidurals should be removed prior to commencement of anticoagulation with BD enoxaparin, therapeutic dose enoxapain, or a direct oral anticoagulant at any dose

Neuraxial Anaesthesia and Anticoagulation

Neuraxial Anaesthesia / Spinal puncture under the effect of anticoagulation carries a risk of spinal or epidural haematoma and long term paralysis. Drug pharmacokinetics should be taken into consideration, and appropriate laboratory tests considered.

Factors that may increase this risk include:

use of indwelling epidural catheters
concomitant use of other drugs affecting haemostasis (NSAIDs, platelet inhibitors, other anticoagulants)
a history of traumatic or repeated epidural or spinal punctures
a history of spinal deformity or spinal surgery

2018 ASRA Guidelines allow prophylactic dose enoxaparin to be administered while an epidural catheter remains in situ, provided that enoxaparin is dosed no more frequently than once every 24 hours. Epidurals should be removed prior to commencement of anticoagulation with BD enoxaparin, therapeutic dose enoxapain, or a direct oral anticoagulant at any dose

STEP 5: Consider Bridging Anticoagulation

Bridging and the New Oral Anticoagulants

Bridging and the New Oral Anticoagulants (rivaroxaban, dabigatran, apixaban)

Bridging and the New Oral Anticoagulants

DUE TO THEIR RELATIVELY RAPID OFFSET AND ONSET OF ACTION, INTERRUPTION OF DIRECT ORAL ANTICOAGULANTS DOES NOT USUALLY REQUIRE BRIDGING.

Consider Bridging Anticoagulation in Patients on DOACs if:
Pre-Operatively	Pre-Operatively
In patients with particularly high thromboembolic risk Note that the newer anticoagulants are contraindicated for use in patients with prosthetic heart valves. These patients should be anticoagulated with warfarin.	Where prolonged interruption of oral intake is anticipated (ie ileus) Where a high risk of bleeding favours initial anticoagulation with a more readily reversible agent (such as UFH)

Consider Bridging Anticoagulation in Patients on DOACs if:

Pre-Operatively

In patients with particularly high thromboembolic risk

Note that the newer anticoagulants are contraindicated for use in patients with prosthetic heart valves. These patients should be anticoagulated with warfarin.

Where prolonged interruption of oral intake is anticipated (ie ileus)
Where a high risk of bleeding favours initial anticoagulation with a more readily reversible agent (such as UFH)

Bridging for Patients on Warfarin

Atrial Fibrillation

PATIENTS ANTICOAGULATED FOR ATRIAL FIBRILLATION SHOULD BE RISK STRATIFIED ACCORDING TO THEIR THROMBOEMBOLIC RISK

Patients with Valvular Disease or Prior CVA/TIA are always considered High Risk
Other patients may be stratified with the CHA₂DS₂–VASc Score

	Risk Criteria	Pre-Operative Bridging	Post-Operative Bridging
High Risk	Associated Valvular Heart Disease History of Arterial Thromboembolism CHA₂DS₂-VASc: 7-9	Heparin Infusion or Therapeutic Dose Enoxaparin	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis
Moderate Risk	CHA₂DS₂-VASc: 5-6	Bridging Usually Not Required
Low Risk	CHA₂DS₂-VASc: 0-4	No Bridging Required

High Risk
Risk Criteria	Associated Valvular Heart Disease History of Arterial Thromboembolism CHA₂DS₂-VASc: 7-9
Pre-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin
Post-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis

Moderate Risk
Risk Criteria	CHA₂DS₂-VASc: 5-6
Pre-Operative Bridging	Bridging Usually Not Required
Post-Operative Bridging	Bridging Usually Not Required

Low Risk
Risk Criteria	CHA₂DS₂-VASc: 0-4
Pre-Operative Bridging	No Bridging Required
Post-Operative Bridging	No Bridging Required

Mechanical Heart Valves (and Bioprosthetic Heart Valves within 1st Three Months)

	Pre-Operative Bridging	Post-Operative Bridging
Patients at Low Risk of Thrombosis Bileaflet mechanical aortic valve and No Risk Factors*	Withhold warfarin 48‐72 hours pre procedure, and allow INR to fall < 1.5	Restart warfarin 24 hours post-procedure
	Heparin Bridging Usually Not Required in This Group Discussion with patient’s cardiologist is recommended
Patients at High Risk of Thrombosis Mechanical Mitral Valve or any Risk Factors*	Heparin Infusion ceased 6‐8 hours pre‐operatively	Heparin Infusion commenced as soon as bleeding risk acceptable
Risk Factors: Mitral or Tricuspid Valve replacement, More than one mechanical valve, Atrial Fibrillation, Previous Thromboembolism, Left Ventricular Dysfunction, Hypercoagulable Condition, Older‐generation Thrombogenic Valves (ball and cage, tilting disc)

Patients at Low Risk of Thrombosis Bileaflet mechanical aortic valve and No Risk Factors*
Pre-operative Bridging	Withhold warfarin 48‐72 hours pre procedure, and allow INR to fall < 1.5
Post-operative Bridging	Restart warfarin 24 hours post-procedure
Heparin Bridging Usually Not Required in This Group Discussion with patient’s cardiologist is recommended

Patients at High Risk of Thrombosis Mechanical Mitral Valve or any Risk Factors*
Pre-operative Bridging	Heparin Infusion ceased 6‐8 hours pre‐operatively
Pre-operative Bridging	Heparin Infusion commenced as soon as bleeding risk acceptable
Risk Factors: Mitral or Tricuspid Valve replacement, More than one mechanical valve, Atrial Fibrillation, Previous Thromboembolism, Left Ventricular Dysfunction, Hypercoagulable Condition, Older‐generation Thrombogenic Valves (ball and cage, tilting disc)

Venous Thromboembolism

	Pre-Operative Bridging	Post-Operative Bridging
VTE within ONE month of surgery which cannot be delayed	Heparin Infusion or Therapeutic Dose Enoxaparin	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis
VTE within ONE month of surgery which cannot be delayed	Consider IVC Filter insertion in selected cases. Consult Haematology.
VTE within 2-3 months of surgery which cannot be delayed	Prophylactic Dose Enoxaparin	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis
VTE more than 3 months before surgery	Prophylactic Dose Enoxaparain	Prophylactic Dose Enoxaparain

VTE within ONE month of surgery which cannot be delayed
Pre-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin
Post-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis
Consider IVC Filter insertion in selected cases. Consult Haematology.

VTE within 2-3 months of surgery which cannot be delayed
Pre-Operative Bridging	Prophylactic Dose Enoxaparain
Post-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis

VTE more than 3 months before surgery
Pre-Operative Bridging	Prophylactic Dose Enoxaparain
Post-Operative Bridging	Prophylactic Dose Enoxaparain

Arterial Thromboembolism (CVA/ TIA/ Acute Embolic Limb Ischaemia/ Systemic Emboli)

	Pre-Operative Bridging	Post-Operative Bridging
ATE within ONE month of surgery which cannot be delayed	Heparin Infusion or Therapeutic Dose Enoxaparin	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis
ATE more than a month before surgery	Prophylactic Dose Enoxaparin	Prophylactic Dose Enoxaparin

ATE within ONE month of surgery which cannot be delayed
Pre-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin
Post-Operative Bridging	Heparin Infusion or Therapeutic Dose Enoxaparin commence within 12-24 hours if adequate surgical haemostasis

ATE more than a month before surgery
Pre-Operative Bridging	Prophylactic Dose Enoxaparain
Post-Operative Bridging	Prophylactic Dose Enoxaparain

STEP 6: Determine Bridging Anticoagulant Dose

Unfractioned Heparin (UFH) Infusion

Pre-Operatively

Commence Heparin once INR < 2.0 (for patients bridging from warfarin).

Confirm normal APTT prior to commencement of heparin

Check APTT after 6 hours and adjust infusion rate according to hospital protocol

Post-Operatively

Discuss with surgical team once operation complete to determine desired starting time and whether loading dose desired.

Heparin infusion should be recommenced at rate determined during pre‐operative heparinisation.

Omit loading dose if preferred by surgical team.

If on warfarin commence at patients usual dose on evening of surgery. Overlap warfarin and heparin therapy for at least 5 days and until INR is therapeutic for > 2 days prior to ceasing heparin.

Therapeutic Heparin (UFH) Infusion

Pre-Operatively

Bridging Therapy with THERAPEUTIC dose enoxaparin should begin once INR is sub‐therapeutic. This will typically be around 36 hours after ceasing warfarin and 3 days prior to surgery.

Creatine Clearance > 30ml/min	Creatine Clearance 10-30ml/min	Creatine Clearance < 10ml/min
Enoxaparin 1mg/kg SC BD (max 120mg BD) or Enoxaparin 1.5mg/kg SC once daily (max 180mg)	Enoxaparin 1mg/kg once daily	Use IV Unfractionated Heparin
In patients ≥ 120kg BD Enoxaparin dosing is preferable to single daily dosing (ie 120mg BD rather than 180mg daily)

Creatine Clearance > 30ml/min
Enoxaparin 1mg/kg SC BD (max 120mg BD) or Enoxaparin 1.5mg/kg SC once daily (max 180mg)

Creatine Clearance 10-30ml/min
Enoxaparin 1mg/kg once daily

Creatine Clearance < 10ml/min
Use IV Unfractionated Heparin

In patients ≥ 120kg BD Enoxaparin dosing is preferable to single daily dosing (ie 120mg BD rather than 180mg daily)

Creatine Clearance > 30ml/min

Enoxaparin 1mg/kg SC BD
(max 120mg BD)
or
Enoxaparin 1.5mg/kg SC once daily
(max 180mg)

Creatine Clearance 10-30ml/min

Enoxaparin 1mg/kg once daily

Creatine Clearance < 10ml/min

Use IV Unfractionated Heparin

In patients ≥ 120kg BD Enoxaparin dosing is preferable to single daily dosing (ie 120mg BD rather than 180mg daily)

Therapeutic dose enoxaparin should be ceased 24 hours prior to operation.

Post-Operatively

Discuss with surgical team once operation complete to determine desired starting time.

If on warfarin commence at patients usual dose on evening of surgery. Overlap warfarin and enoxaparin therapy for at least 5 days and until INR is therapeutic prior to ceasing heparin.

Prophylactic Heparin (UFH) Infusion

Pre-Operatively

Bridging therapy with prophylactic enoxaparin should begin once INR is sub‐therapeutic. This will typically be around 36 hours after ceasing warfarin and 3 days prior to surgery.

Enoxaparin Thromboprophylaxis Dosing in Obesity¹¹
Weight	< 50kg	50 - 100kg	100 - 150kg	> 150kg
Dose	20mg daily	40mg daily	40mg BD	60mg BD

Enoxaparin Thromboprophylaxis Dosing in Obesity¹²
Weight	Dose
< 50kg	20mg daily
50 - 100kg	40mg daily
100 - 150kg	40mg BD
> 150kg	60mg BD

Prophylactic dose enoxaparin should be ceased 12 hours prior to operation.

Post-Operatively

Discuss with surgical team once operation complete to determine desired starting time. Typically 6‐12 hours post surgery, increased to 24 hours in patients at high risk of peri‐operative bleeding.

If on warfarin commence at patients usual dose on evening of surgery.

Overlap warfarin and enoxparin therapy for at least 5 days and until INR is therapeutic for > 2 days prior to ceasing heparin.

STEP 7: Recommence Oral Anticoagulation Post‐Operatively

The timing for recommencement of oral anticoagulation post‐operatively is a surgical decision, and takes into account the risk and
consequences of surgical site bleeding, balanced with the thromboembolic risk.

	Suggested Period to Withhold Anticoagulant After Surgery
	Low Risk of Surgical Bleeding	High Risk of Surgical Bleeding	Important Considerations
Rivaroxaban Dabigatran Apixaban	Withhold 1 Day Post-op	Withhold 2 Days Post-op	Full anticoagulation effect established within hours, eliminates need for post‐operative bridging anticoagulation. However, difficult to reverse anticoagulation effect if surgical bleeding develops.
Warfarin	Plan to Recommence Warfarin 12-24 Hours Post-op		Delayed onset of effect may require bridging therapy (See step 5)

Suggested Period to Withhold Anticoagulant After Surgery
Rivaroxaban/ Dabigatran/ Apixaban
Low Risk of Surgical Bleeding	Withhold 1 Day Post-op
High Risk of Surgical Bleeding	Withhold 2 Days Post-op
Important Considerations Full anticoagulation effect established within hours, eliminates need for post‐operative bridging anticoagulation. However, difficult to reverse anticoagulation effect if surgical bleeding develops.

Warfarin
Plan to Recommence Warfarin 12-24 Hours Post-op
Important Considerations Delayed onset of effect may require bridging therapy (See step 5)

References

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AntiCoagulation Management

STEP 1: Determine if Anticoagulant Needs to be Stopped

STEP 2: Consider Benefit of Delaying Surgery

STEP 3: Assess Surgical Bleeding Risk

STEP 4: Determine Time to Cease Anticoagulant

Therapeutic Dose Anticoagulants

Warfarin

Direct Oral AntiCoagulants

Prophylactic Dose Anticoagulants

STEP 5: Consider Bridging Anticoagulation

Bridging and the New Oral Anticoagulants

Bridging and the New Oral Anticoagulants (rivaroxaban, dabigatran, apixaban)

Bridging and the New Oral Anticoagulants

Bridging for Patients on Warfarin

Atrial Fibrillation

Mechanical Heart Valves (and Bioprosthetic Heart Valves within 1st Three Months)

Venous Thromboembolism

Arterial Thromboembolism (CVA/ TIA/ Acute Embolic Limb Ischaemia/ Systemic Emboli)

STEP 6: Determine Bridging Anticoagulant Dose

Unfractioned Heparin (UFH) Infusion

Pre-Operatively

Post-Operatively

Therapeutic Heparin (UFH) Infusion

Pre-Operatively

Post-Operatively

Prophylactic Heparin (UFH) Infusion

Pre-Operatively

Post-Operatively

STEP 7: Recommence Oral Anticoagulation Post‐Operatively

References