title: Prospective study on the usefulness of lung scan in patients with deep vein thrombosis of the lower limbs.
abstract: BACKGROUND
  Asymptomatic pulmonary embolism (PE) is a common finding in patients with deep venous thrombosis (DVT) of the lower limbs, but the usefulness of seeking for silent PE in patients with acute DVT has not been evaluated.
  
  
  METHODS
  This was a prospective study involving consecutive patients with acute symptomatic proximal DVT (confirmed by objective methods) and no clinical suspicion of PE. All patients underwent chest X-ray, ventilation-perfusion lung scan and arterial blood gases on admission, and received anticoagulant therapy. Those with scintigraphic evidence of PE underwent repeated lung scan and blood gases 7 days later. The aim of the study was to assess how many patients with silent PE develop symptoms while on heparin therapy, and in how many of them such symptoms are due to recurrent PE.
  
  
  RESULTS
  946 consecutive patients with acute, proximal DVT had no contraindications to full-dose anticoagulant therapy. Baseline lung scan revealed high-probability defects (silent PE) in 200 (21%). Seven of these 200 patients had symptomatic recurrences during the 7-day study period, and an inferior vena cava filter was inserted. Besides, 6 patients developed PE symptoms, but no new perfusion defects were found on repeated scan. They switched to coumarin therapy, and they did not develop any further complications.
  
  
  CONCLUSIONS
  Lung scan in patients with symptomatic DVT and no clinical suspicion of PE may be useful, since some patients with silent PE may develop symptoms while on heparin therapy. Without a baseline scintigraphy all these patients would have been considered to have recurrent PE, and vena cava interruption could have been performed.
authors.affiliation: Hospital Universitari Germans Trias i Pujol de Badalona, Servei de Medicine Internal, Spain. mmonreal@ns.hugtip.scs.es
authors.forename: M
authors.initials: M
authors.lastname: Monreal
authors.forename: J
authors.initials: J
authors.lastname: Ruiz
authors.forename: M
authors.initials: M
authors.lastname: Fraile
authors.forename: M
authors.initials: M
authors.lastname: Bonet
authors.forename: E
authors.initials: E
authors.lastname: Davant
authors.forename: J
authors.initials: J
authors.lastname: Muchart
authors.forename: V
authors.initials: V
authors.lastname: Vallejos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000494:pharmacology; D001784:Blood Gas Analysis; D005260:Female; D005500:Follow-Up Studies; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D007866:Leg / Q000098:blood supply; D008168:Lung / Q000098:blood supply / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D011877:Radionuclide Imaging; D012008:Recurrence; D015996:Survival Rate; D020246:Venous Thrombosis / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology
chemical_list: D000925:Anticoagulants; D006493:Heparin