Increasing Patient Comfort and Compliance: The Bridging Anticoagulation Clinic strives to provide the highest quality of care to patients who require temporary interruption of warfarin therapy. An important component of optimizing patient care is minimizing patient discomfort with perioperative administration of short-acting anticoagulants (LWMH or UFH) used for bridging therapy, which, in turn, may optimize patient compliance with this treatment. This issue is especially relevant for patients who are receiving out-of-hospital treatment with LMWH or UFH because about 85% of such patients will be taught to self-administer this medication. This study seeks to determine if there is less discomfort and bruising associated with self-injection of LMWH than with UFH.