title: The unlikely presence of deep vein thrombosis in a patient with low pretest probability and a negative D-dimer: a case report.
abstract: BACKGROUND
  Deep vein thrombosis (DVT) is commonly encountered in the emergency department. Clinical models, such as the Wells criteria, allow physicians to estimate the probability of DVT in a patient. Current literature suggests a low pretest probability combined with a negative D-dimer laboratory study rules out DVT approximately 99% of the time.
  
  
  METHODS
  This case discusses a 37-year-old male patient who had a low pretest probability and a negative D-dimer, but was found to have a DVT on Doppler ultrasound. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The astute emergency physician must not discount clinical suspicion in order to decide when radiographic imaging is warranted for a possible venous thromboembolism. New adjuncts, such as bedside ultrasonography, can also be implemented to further risk stratify patients, potentially decreasing morbidity and mortality associated with DVT.
authors.affiliation: McLaren Medical Center-Macomb, Mount Clemens, Michigan.
authors.forename: Shaun C
authors.initials: SC
authors.lastname: Ramsey
authors.affiliation: McLaren Medical Center-Macomb, Mount Clemens, Michigan.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Flaherty
mesh_terms: D000328:Adult; D002637:Chest Pain / Q000209:etiology; D003661:Decision Support Techniques; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D008297:Male; D059352:Musculoskeletal Pain / Q000000981:diagnostic imaging / Q000209:etiology; D011237:Predictive Value of Tests; D018570:Risk Assessment; D013848:Thigh / Q000000981:diagnostic imaging; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: D-dimer; Wells score; clinical decision tools; deep vein thrombosis; pretest probability