The catastrophic antiphospholipid syndrome (CAPS, Asherson's syndrome) develops rapidly following an identifiable triggering factor (eg infection, trauma, inadequate coagulation neoplasia, obstetric) in antiphospholipid antibody positive patients. It is most frequently encountered in patients with a primary antiphospholipid syndrome or systemic lupus erythematosus (SLE) or "lupus-like" disease (LLD). It manifests mainly with small vessel thromboses affecting organs (gastrointestinal tract, brain, heart), large vessel occlusions in one-third, manifestations of the systemic inflammatory response syndrome (SIRS), particularly the acute respiratory distress syndrome (ARDS). The mortality is high, although with early and effective therapies, including full parenteral anticoagulation, corticosteroids, plasma exchanges and IV globulins, an improvement in this high death rate has been noted recently.