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General principles for preventing high INR. Simple dental or dermatological procedures may not require interruption to warfarin therapy. If necessary, warfarin therapy can be withheld 5 days before elective surgery, when the INR usually falls to below 1.5 and surgery can be conducted safely.
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General principles for preventing high INR • Simple dental or dermatological procedures may not require interruption to warfarin therapy. • If necessary, warfarin therapy can be withheld 5 days before elective surgery, when the INR usually falls to below 1.5 and surgery can be conducted safely. • General principles for preventing high INR • • Avoid high loading doses of warfarin, • • Potential warfarin–drug interactions need to be considered. • • Aim for an INR level that balances the therapeutic goal with risk factors of bleeding on an individual basis. • • Avoid frequent dose adjustments. • • Avoid excessive increases in dose when INR drifts below target INR range.
Dramatic increase in number of patients receiving OAC • Interindividual variation (environmental and genetic) • Incidence of warfarin associated haemorrhage :fatal haemorrhage 1%/Y. • Reversal :seriousness of bleeding ,balance against thrombotic risk and speed and completeness of reversal • Options include simple dose omission ,vitamin K & factors replacement • FFP is less effective in correction of coagulopathy ,volume overload & slow infusion rate than PCCs • PCCs are also subjected to virus inactivation
PCCs • PCCs are intermediate purity pooled plasma products • only HTDEFIX is licensed in UK for warfarin reversal • PCCs, (‘‘four factor concentrates’’), OR low VII (three) • Amounts of protein C and S • Optimum dose not established. • INR 2–3.9, 25 U/kg; INR 4–5.9, 35 U/kg; INR . 6, 50 U/kg. • Thrombogenicity, exacerbation of DIC are dose related problems, • The current cost in the UK is around 25 pence/unit (total cost for a single treatment for a 70 kg individual £437 -£875. • More expensive than the cost of FFP. ( unit of produced from UK plasma currently costs about £30). • FFP that is methylene blue treated or produced from non-UK plasma is more expensive.)
On the basis of the current evidence, a PCC plus IV vitamin K is the treatment of choice for patients with major haemorrhage. • A dose of 30 U/kg (regardless of INR) • Combination of PCC and FFP covers period before vitamin K1 has reached its full effect. • Vitamin K1 is essential for sustaining the reversal achieved • Pre- and postoperative management of anticoagulation. bridging therapy. • Prolonged immobility ,AF index event requiring anticoagulation occurred more than 3 months prosthetic valves VTE within the preceding 3 months • Unfractionated heparin 24 hours preceding surgery