Perioperative management of patients receiving vitamin K antagonists

Abstract

Purpose: As the number of patients taking vitamin K antagonists (VKA) is growing, the clinician is increasingly faced with having to make decisions regarding anticoagulation therapy before, during and immediately after surgery. In this article we review the indications for VKA and assess their use in the perioperative period based on available pharmacological and clinical data.Source: An on-line computerized search of Medline was conducted limited to English and French language articles. The bibliographies of relevant articles and additional material from other published sources were retrieved and reviewed.Principal findings: Assessment of patients taking VKA who need surgery must include three factors: 1) the indication for anticoagulation, which determines the thromboembolic risk; 2) the pharmacokinetics of VKA, which determine the moment at which treatment should be discontinued; and 3) the type of surgery, which determines the hemorrhagic risk. Some patients will need to stop VKA treatment and start a substitution or "bridging" anticoagulant therapy, such as unfractionated heparin or low molecular weight heparin, prior to and after surgery. In patients requiring emergency surgery, prothrombin complex concentrate can be used to improve coagulation and is preferable to, although more expensive than fresh frozen plasma.

Periprocedural and medium-term antithrombotic strategies in patients with an indication for long-term anticoagulation undergoing coronary angiography and intervention

“…In general, however, the periprocedural antithrombotic treatment appears to have been carried out in our population according to the current recommendations for patients on VKA treatment undergoing invasive procedures [8][9][10][11], although some variability within same classes of indication was observed ( Table 2). This finding may be accounted for by the heterogeneous thromboembolic risk profile of patients with atrial fibrillation, in whom in fact, the highest treatment variability was observed ( Table 2).…”

“…The available information on the periprocedural treatment mostly derives from small studies [4][5][6][7] or practice guidelines [8][9][10][11] and overviews [12] on the management of patients receiving vitamin K antagonists (VKA) undergoing invasive procedures in general (i.e. surgery, dental extraction, endoscopic examination or treatment, pacemaker implantation, etc.…”

Management of surgical patients receiving anticoagulation and antiplatelet agents

“…‘Bridging therapy’ is the administration of an appropriate form of heparin while the oral anticoagulation is discontinued. In recent years, bridging has been procured mainly using LMWH, and only occasionally with intravenous UFH14, 18–20, 29. LMWH is started once the INR is less than 2·0 after the cessation of warfarin.…”

Urgent reversal of vitamin K antagonist therapy

“…Other adverse effects are nausea, diarrhoea and anaemia. Also worth mentioning is skin necrosis at the initiation of therapy due to the rapid decrease in protein C and S initiating a hypercoagulable state and formation of thrombi in subcutaneous fat 8 …”