title: Deep vein thrombosis during prolonged mechanical ventilation despite prophylaxis.
abstract: OBJECTIVE
  To determine the prevalence of deep vein thrombosis (DVT) among patients requiring prolonged mechanical ventilation in the intensive care unit.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Medical intensive care unit of a university-affiliated urban teaching hospital.
  
  
  METHODS
  Patients requiring mechanical ventilation for >7 days.
  
  
  METHODS
  All patients admitted to the medical intensive care unit requiring prolonged mechanical ventilation underwent duplex ultrasonography of their lower extremities and upper extremities every 7 days. The main outcome identified was the presence of DVT. Secondary outcomes included hospital mortality, hospital and intensive care unit lengths of stay, and the occurrence of pulmonary embolism.
  
  
  RESULTS
  A total of 110 patients requiring mechanical ventilation for >7 days were enrolled. Prophylaxis against DVT was employed in 110 of the patients (100%). A total of 26 patients (23.6%) developed DVT. Patients with DVT were statistically more likely to have underlying malignancy (30.8% vs. 8.3%; p =.004) and longer durations of central venous catheterization (26.9 +/- 22.2 days vs. 14.5 +/- 12.1 days; p =.024) compared with patients without DVT. There were no statistically significant differences in hospital mortality or lengths of stay in the hospital and intensive care unit for patients with and without DVT. Patients documented to have DVT by using duplex ultrasonography had a statistically greater frequency of subsequent pulmonary embolism during their hospitalization (11.5% vs. 0.0%; p =.012).
  
  
  CONCLUSIONS
  The occurrence of DVT is common among patients requiring prolonged mechanical ventilation in the intensive care unit setting despite the use of prophylaxis measures. These data suggest that alternative strategies for the prevention of DVT should be evaluated. Additionally, early detection methods should be considered to reduce the potential morbidity associated with untreated DVT in this high-risk population.
authors.affiliation: Pulmonary and Critical Care Division, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Emad H
authors.initials: EH
authors.lastname: Ibrahim
authors.forename: Manuel
authors.initials: M
authors.lastname: Iregui
authors.forename: Donna
authors.initials: D
authors.lastname: Prentice
authors.forename: Glenda
authors.initials: G
authors.lastname: Sherman
authors.forename: Marin H
authors.initials: MH
authors.lastname: Kollef
authors.forename: William
authors.initials: W
authors.lastname: Shannon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000209:etiology; D012121:Respiration, Artificial / Q000009:adverse effects*; D013997:Time Factors; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control