Anticoagulants and regional anaesthesia

Waurick K

Abstract

Performing neuroaxial regional anaesthesia in patients receiving antithrombotic drugs requires an individual risk-benefit analysis. In particular, the patients' individual risk of thromboembolic and ischaemic complications must be taken into account when anticoagulation is interrupted. Guidelines on neuroaxial anaesthesia and anticoagulants aim to assist anaesthesiologists to decide for or against neuroaxial blockades. Compliance with the substance-specific time interval allows puncturing only when anticoagulant blood levels are as low as possible. As a rule of thumb, an interval of two half-lives between the last (prophylactic) administration (of the drug) and neuroaxial puncture is considered as an adequate safety margin. In cases of renal insufficiency or therapeutic{''} anticoagulation, the time interval should be extended to 4-5 half-lives. In addition to low-dose acetylsalicylic acid therapy, antithrombotic drugs in prophylactic dose should be paused 4-5 half-lives before neuroaxial puncture/catheter manipulation. Up to now, a neuroaxial blockade in patients receiving acetylsalicylic acid is considered safe only in combination with prophylactic low-molecular-weight heparin, unfractionated heparin, or fondaparinux. For all other anticoagulants, a central nerve block under simultaneous administration of acetylsalicylic acid should be avoided. Due to the low incidence of spinal haematoma and the (general) lack of experience, no definite conclusions about the safety of newer antithrombotic drugs like hirudins and direct oral anticoagulants can be drawn.}