title: Can a new design of pneumatic compression device reduce variations in delivered therapy for the mechanical prophylaxis of thromboembolic disease after total hip arthroplasty?
abstract: BACKGROUND
  Compression devices have been shown to prevent thromboembolic disease. However, the pressures generated may not be the same as the ones recommended by the manufacturer. The purpose of this study is to investigate a new sequential compression device with feedback to maintain optimal therapy, and to determine whether therapy is improved with this new device.
  
  
  METHODS
  A series of 50 patients undergoing elective total hip arthroplasty at a major tertiary-care hospital with a special interest in joint replacement were enrolled prospectively. In addition to pharmacological prophylaxis for thromboembolic disease, all patients received compression from a modified device. Maximum pressures generated and the rate of pressure rise in each of the 3 compartments within the device sleeves were measured and the results compared with data from historical controls.
  
  
  RESULTS
  We considered therapy to be ideal when in a particular compression cycle all chambers of both right and left sleeves reach within 10% of their target pressures at within 10% of their target pressure rise rates. The average patient received this ideal therapy 88% of the time that the new trial sequential compression device was operating. This represents a dramatic improvement over previous devices.
  
  
  CONCLUSIONS
  The new device allows dramatically improved pressures within the device because of a feedback loop that allows dynamic control of each chamber's pressure. Improved consistency of delivery should make it easier to accurately assess the true benefits of mechanical prophylaxis with a sequential compression device.
authors.affiliation: Division of Lower Limb Reconstruction and Oncology, Department of Orthopedics, University of British Columbia, Vancouver, BC. masri@interchange.ubc.ca
authors.forename: Bassam A
authors.initials: BA
authors.lastname: Masri
authors.forename: David J
authors.initials: DJ
authors.lastname: Dunlop
authors.forename: James A
authors.initials: JA
authors.lastname: McEwen
authors.forename: Donald S
authors.initials: DS
authors.lastname: Garbuz
authors.forename: Clive P
authors.initials: CP
authors.lastname: Duncan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D004867:Equipment Design; D005260:Female; D006801:Humans; D048228:Intermittent Pneumatic Compression Devices; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors