[Surgery in patients treated with anticoagulation during emergency and elective interventions]

Patients under oral anticoagulation with coumarin derivatives have a variable perioperative thromboembolic risk which necessitates continuation of their thromboembolic prophylaxis during elective and emergency surgery. Because of their better handling unfractionated heparin and low-molecular-weight heparins are used most often for this purpose. The overlapping effect of coumarin and heparin therapy requires a close daily monitoring of the clotting inhibition (partial thromboplastin time, thromboplastin time, thrombin time). In elective surgery coumarin therapy is interrupted 2-3 days preoperatively; in emergency cases vitamin K or fresh frozen plasma have to be substituted. Patients under heparin therapy or prophylaxis are easier to handle, because the effect of heparin disappears in a few hours after stopping the treatment. In the immediate postoperative phase the heparin application is interrupted for 6 h because of increased bleeding risk. It is important to take into account additional risk factors like the underlying disease, disturbances of platelet function, liver diseases and renal insufficiency.