title: Warfarin-induced limb gangrene in the setting of lung adenocarcinoma.
abstract: A 53-year-old man with lung adenocarcinoma developed pulmonary embolism and bilateral popliteal venous thrombosis. Treated with intravenous unfractionated heparin and discharged home on warfarin, he returned a week later with extending thrombosis. Treatment with heparin followed by warfarin was reinitiated. Twenty-four hours following the re-administration of warfarin, the patient's INR increased to 14.5. The platelet count dropped by more than 50%, and he developed venous limb gangrene of the left leg and skin necrosis of the right leg. Heparin-induced thrombocytopenia was ruled out, and coagulation studies showed a severe depletion of protein C as well as increased thrombin generation. The patient was transfused with fresh frozen plasma, and vitamin K was given. Heparin was continued, and after 4 weeks, the patient improved markedly showing only minimal necrosis of the toes. Venous limb gangrene is a major complication associated with warfarin therapy. Its pathogenesis is explained by a transient hypercoagulable state produced by protein C depletion that leads to microvascular thrombi progressing to venous limb gangrene. The present case emphasizes the importance of careful anticoagulation with heparin followed by slow initiation of low-dose warfarin, in order to minimize thrombotic complications.
authors.affiliation: Department of Medicine, Advocate Illinois Masonic Medical Center, Chicago, Illinois, USA.
authors.forename: Liviu
authors.initials: L
authors.lastname: Klein
authors.forename: Angel
authors.initials: A
authors.lastname: Galvez
authors.forename: Oana
authors.initials: O
authors.lastname: Klein
authors.forename: Juan
authors.initials: J
authors.lastname: Chediak
mesh_terms: D000230:Adenocarcinoma / Q000150:complications*; D000925:Anticoagulants / Q000009:adverse effects; D017809:Fatal Outcome; D005734:Gangrene / Q000139:chemically induced / Q000473:pathology*; D006493:Heparin / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011152:Popliteal Vein; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D011655:Pulmonary Embolism / Q000150:complications* / Q000188:drug therapy; D013927:Thrombosis / Q000150:complications* / Q000188:drug therapy; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D006493:Heparin