title: Apparent heparin resistance form elevated factor VIII in a patient with postoperative deep venous thrombosis. A case report.
abstract: BACKGROUND
  During the puerperium, heparin levels, rather than the adjusted partial thromboplastin time test, can be used to identify heparin resistance and guide heparin therapy.
  
  
  METHODS
  A patient receiving heparin for deep venous thrombosis had artifactual resistance to heparin, with a short adjusted partial thromboplastin time due to elevation of factor VIII. Heparin assay revealed a heparin level above the therapeutic range.
  
  
  CONCLUSIONS
  Direct measurement of heparin concentration and factor VIII activity should be performed when heparin resistance is suspected.
authors.affiliation: Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: F D
authors.initials: FD
authors.lastname: Cirisano
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: J S
authors.initials: JS
authors.lastname: Greenspoon
mesh_terms: D000328:Adult; D004351:Drug Resistance; D005169:Factor VIII / Q000378:metabolism*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000097:blood; D006493:Heparin / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D007044:Hysterectomy; D010314:Partial Thromboplastin Time; D010921:Placenta Accreta / Q000601:surgery*; D011183:Postoperative Complications / Q000188:drug therapy*; D011247:Pregnancy; D015912:Thrombolytic Therapy; D013924:Thrombophlebitis / Q000097:blood / Q000188:drug therapy*
chemical_list: D005343:Fibrinolytic Agents; D005169:Factor VIII; D006493:Heparin