Patient with DVT on therapeutic dose of Warfarin came with complaints of breathlessness and hypotension. True statement regarding this:
High-Yield Explanation
C i.e. Maintain INR at 2 and continueRef: Harrison, 19th edition, page 755Explanation:INR Ranges When Treating with Warfarin1.5-1.9Higher rate of recurrent venous thromboembolism.<1.7Increased risk of cardioembolic stroke.2.0-3.0Warfarin is administered in doses that produce above INR.This the recommended INR while treating with warfarin.This INR is effective as higher intensity treatment and produces less bleeding.2.5-3.5Allowed in special situations like in patients with mechanical heart valves, particularly those in the mitral position or older ball and cage valves in the aortic.>4.5Increase in bleeding.Note:In a study, patients receiving long-term warfarin therapy for unprovoked venous thromboembolism demonstrated a higher rate of recurrent venous thromboembolism with a target INR of 1.5-1.9 compared with a target INR of 2.0-3.0.So, in this case patient with DVT on therapeutic dose of Warfarin came with do breathlessness, hypotension. May be he has unprovoked venous thromboembolism and recurrent venous thromboembolism, so maintain INR at 2.0 to 3.0 and continue warfarin.IMPORTANT:Warfarin induced bleedingThe INR should be maintained in the therapeutic range to minimize the risk of bleeding.In asymptomatic patients whose INR is between 3.5 and 10, warfarin should be withheld until the INR returns to the therapeutic range.If the INR is over 10, oral vitamin K should be administered, at a dose of 2.5-5 mg.Higher doses of oral vitamin K (5-10 mg) produce more rapid reversal of the INR but may render patients temporarily resistant to warfarin when the drug is restarted.Patients with serious bleeding need more aggressive treatment. These patients should be given 5-10 mg of vitamin K by slow IV infusion. Additional vitamin K should be given until the INR is in the normal range.Treatment with vitamin K should be supplemented with fresh-frozen plasma as a source of the vitamin K-dependent clotting proteins.Four factor prothrombin complex concentrates, which contain all four vitamin K-dependent clotting proteins, are the treatment of choice for:Life-threatening bleeds.Rapid restoration of the INR into the normal range in patients requiring urgent surgery or intervention,Patients who cannot tolerate the volume load of fresh-frozen plasma.