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Risk Protocol

Patients with low risk of thrombosis

For minor dental procedures it is not necessary to discontinue warfarin.
For low risk procedures where a bridging protocol is not necessary follow the protocol below:

Low risk 
4 days before surgery Stop warfarin
Organise daily INR blood tests
Night before surgery INR > 2 given 1-5mg vit K
Day of surgery INR < 1.5; operate
INR > 1.5 give FFP or defer procedure
After surgery Start usual maintenance dose warfarin on day of surgery
Consider thromboprophylaxis with LMW heparin post op.

Patients with high risk of thrombosis.

  Bridging with LMWH
(LMWH can be used for most patients and is more convenient than unfractionated heparin)		 Bridging with unfractionated heparin
(use unfractionated heparin where significant bleeding risk exists)
4 days before surgery Organise daily INR blood tests
Stop warfarin		 Organise daily INR blood tests
Stop warfarin
3 & 2 days before surgery Bridge with therapeutic dose LMWH when INR drops below 2 Stop LMWH 24h pre-op Bridge with therapeutic dose IV heparin when INR drops below 2
Night before surgery INR > 2 given 1-5mg vit K Stop heparin 4 h pre-op INR > 2 given 1-5mg vit K
Day of surgery INR < 1.5; operate INR > 1.5 give FFP or defer procedure INR < 1.5; operate INR > 1.5 give FFP or defer procedure

After surgery Start thromboprophylactic dose

LMWH 12 to 24h post op once haemostasis is secured
When haemostasis is secured, start usual dose of warfarin on the evening after surgery
Stop LMWH when INR > 2 for 48 hours		 Start heparin 12 hours after major surgery aiming for APTT 1.5x patient's normal (usually around 1000 units / hour) once haemostasis is secured.


When haemostasis is secured, start usual dose of warfarin on the evening after surgery
Check APTT 12 hours after restarting therapy
Stop IV heparin when INR >2 for 48 hours