Since first used in 2009, non-vitamin K oral anticoagulants (NOAC) have gained world-wide acceptance. Two groups of NOAC are currently used: the direct thrombin antagonist dabigatran and three direct factor Xa antagonists apixaban, edoxaban, and ricaroxaban. With their increasing use for prevention of thromboembolism, the probability increases that NOAC-pretreated patients are admitted to emergency departments or intensive care units.The clinical challenge in NOAC preanticoagulated patients is to adequately cope with the given anticoagulated status of such patients. Because of their short half-life, many patients will be adequately treated with a "wait and see" approach, and surgeries and interventions are postponed until anticoagulant activities have totally subsided. In the few cases where immediate action is mandated, based on appropriate risk assessments it can be decided either to take the increased hemorrhagic risk of early intervention or to transfuse factor concentrates like PPSB or FEIBA which can safely reverse the anticoagulant activities of the three factor Xa antagonists (and potentially also of dabigatran). Recently a humanized Fab antibody fragment for dabigatran, idarucizumab, has been introduced onto the market, that can immediately reverse the anticoagulant effects of dabigatran. For the reversal of dabigatran, idarucizumab is therefore the drug of choice.In addition, in some specific indications of emergency and intensive care medicine, the primary use of a NOAC can be considered advantageous. Such indications are early cardioversion in patients admitted for new episodes of atrial fibrillation and patients with acute pulmonary embolism. For the widespread use of low-molecular-weight heparins in such indications, however, the decision to use a NOAC for anticoagulant therapy is frequently postponed to the treatment phase when the stabilized patient is already treated on the general ward.
Keywords: Blood coagulation; Dabigatran; Factor Xa inhibitors; Hemorrhage; Idarucizumab.