Abstract
The activated clotting time (ACT) may be an unreliable monitor of coagulation for patients with the antiphospholipid syndrome. We describe a patient with antiphospholipid syndrome in whom adequate anticoagulation during cardiopulmonary bypass was confirmed by monitoring both the ACT and anti-factor Xa levels. The cardiopulmonary bypass was uneventful, and there were no thrombotic or bleeding complications. The use of anti-factor Xa levels provided confirmation of adequate anticoagulation (and reversal of anticoagulation) that was not possible using the ACT alone.
