title: D-dimer in the diagnostic workup of suspected pulmonary thrombo-embolism at high altitude.
abstract: BACKGROUND
  Pulmonary thrombo-embolism (PTE) is relatively common in high altitude areas where radiological diagnostic facilities are usually not available. So this study was undertaken to use the results of D-dimer assay to determine the need for imaging studies in patients suspected of having PTE at high altitude.
  
  
  METHODS
  A total of 101 patients at an altitude of > 3,000 m suspected of having PTE were evacuated. D-dimer and imaging studies were carried out to confirm the diagnosis.
  
  
  RESULTS
  A total of 101 patients suspected of having PTE underwent D-dimer level estimation and imaging studies for PTE. Sixty-eight of these had negative findings) on D-dimer assay. All these patients with negative findings on D-dimer assay had negative findings on pulmonary imaging studies also. So this test is very sensitive with very high negative predictive value (NPV). Whereas, 17 out of 33 patients positive for D-dimer, had positive findings on imaging studies, indicating a relatively less specific test.
  
  
  CONCLUSIONS
  Clinical assessment in combination with D-dimer assay can be used for timely differentiation of PTE from other conditions such as high altitude pulmonary oedema (HAPO) especially at isolated high altitude areas/military posts, so that patients could be evacuated as early as possible by fastest means to save the precious lives and in hospital settings this test identifies patients to whom anticoagulant therapy should not be given or patients who should not be subjected to invasive imaging tests.
authors.affiliation: Senior Advisor (Pathology & Neuropathology), Base Hospital, Delhi Cantt. - 10.
authors.forename: Kr
authors.initials: K
authors.lastname: Rathi
authors.affiliation: Medical Officer (Pathology), Military Hospital, Jabalpur.
authors.forename: Vikram
authors.initials: V
authors.lastname: Uppal
authors.affiliation: Graded Specialist (Medicine), Military Hospital, Kamptee.
authors.forename: Nm
authors.initials: N
authors.lastname: Bewal
authors.affiliation: Graded Specialist (Radiology), Command Hospital (CC), Lucknow.
authors.forename: Debraj
authors.initials: D
authors.lastname: Sen
authors.affiliation: Deputy Commandant, AFMSD, Mumbai.
authors.forename: Anurag
authors.initials: A
authors.lastname: Khanna
keywords: D-dimer test; PTE