title: Management of primary care patients with suspected deep vein thrombosis: use of a therapeutic dose of low-molecular-weight heparin to avoid urgent ultrasonographic evaluation.
abstract: BACKGROUND
  Out of hospital management of patients with suspected deep vein thrombosis (DVT) can be problematic. The accuracy of clinical prediction rules in the primary care setting may be inadequate, D-dimer testing may not be available, and the cost-effectiveness of urgent ultrasonographic evaluation is uncertain.
  
  
  OBJECTIVE
  The purpose of this study was to determine the efficacy and safety of an empiric single therapeutic dose of low-molecular weight heparin (LMWH) in the time interval preceding ultrasound investigation in patients presenting to primary care physicians (PCPs) for suspicion of DVT.
  
  
  METHODS
  Consecutive patients with suspected DVT who presented to the office of a PCP outside regular thrombosis center working hours were enrolled. All eligible patients received a single therapeutic dose of LMWH (100 anti-Xa IU kg(-1) weight) and were scheduled to undergo clinical and instrumental evaluation at the thrombosis center the morning after. Clinical events were documented after a 3-month follow-up.
  
  
  RESULTS
  A total of 534 consecutive patients with suspected DVT were included in this study; of these 102 patients had subsequent diagnosis of DVT. We detected no episodes of pulmonary embolism, major bleeding, or death during the 18-h window between the administration of LMWH and objective evaluation. Of the 432 patients in whom diagnosis of DVT was subsequently excluded, only three (0.7%; CI: 0.2-2.0%) developed venous thromboembolic events during the 3-month follow-up period.
  
  
  CONCLUSIONS
  Empiric treatment with a single therapeutic dose of LMWH is effective and safe for outpatients with suspected DVT initially managed in a primary care setting. This strategy has the potential to reduce the need for urgent diagnostic imaging.
authors.affiliation: Emergency Department, Thrombosis Center, Hospital of Piacenza, Via Taverna 49, 29100 Piacenza, Italy. d.imberti@ausl.pc.it
authors.forename: D
authors.initials: D
authors.lastname: Imberti
authors.forename: W
authors.initials: W
authors.lastname: Ageno
authors.forename: F
authors.initials: F
authors.lastname: Dentali
authors.forename: M
authors.initials: M
authors.lastname: Giorgi Pierfranceschi
authors.forename: E
authors.initials: E
authors.lastname: Croci
authors.forename: D
authors.initials: D
authors.lastname: Garcia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010346:Patient Care Management / Q000379:methods*; D011320:Primary Health Care; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy*
chemical_list: D006495:Heparin, Low-Molecular-Weight