title: Comparison of three intermittent pneumatic compression systems in patients with varicose veins: a hemodynamic study.
abstract: OBJECTIVE
  Previous studies have demonstrated the hemodynamic impact of sequential leg compression, compared to uniform compression. The aim of this study was to compare the hemodynamic effectiveness of three compression devices: 1) circumferential sequential gradient compression (CSG); 2) a posterior uniform compression device (PU) and a posterior sequential rapid gradient inflation device (PSR).
  
  
  METHODS
  
  
  
  METHODS
  open, controlled trial. Thigh length sleeves were tested in 12 patients with primary bilateral varicose veins.
  
  
  METHODS
  the three devices were tested in the semirecumbent position.
  
  
  METHODS
  augmented flow velocity and volume flow, including the total and peak volume of blood expelled per hour during compression, were measured using duplex scanning. Refilling time was determined from velocity recordings of the common femoral vein. All values were expressed as median and interquartile range with P values obtained using the Mann-Whitney U-test.
  
  
  RESULTS
  Compared to the median baseline flow, all three devices increased flow during compression by 2.5-3 times (P<0.0001). The cycles per hour for the three devices CSG, PSR and PU were 78 (70-88), 60 and 60, respectively; the duplex effective compression time was 11, 12 and 6 s, respectively; single cycle volume expelled during compression was 105, 85 and 45 mL (P<0.005), respectively; the total volume expelled per hour was 7 800, 5 200 (P<0.028) and 3 300 (P<0.005) mL/hr, respectively; peak velocity increased (P<0.001) from baseline of 12 cm/s to 38 cm/s for the CSG, 33 cm/s for the PU and to 68 cm/s for the PSR.
  
  
  CONCLUSIONS
  The highest volume expelled per hour during compression was observed with the CSG and the lowest with the PSR. This was due to increased volume per cycle and more compression cycles over time, because of the CSG device's sensing of refill time. Although the peak velocity with the PSR was high, it was associated with reduced expelled volume, because of its short compression period. The PU occupied an intermediate position. The relative effectiveness of the three devices in deep vein thrombosis prevention should be tested in future studies.
authors.affiliation: The Vascular Noninvasive Screening and Diagnostic Centre, London, UK. mauragriffin@dsl.pipex.com
authors.forename: M
authors.initials: M
authors.lastname: Griffin
authors.forename: S K
authors.initials: SK
authors.lastname: Kakkos
authors.forename: G
authors.initials: G
authors.lastname: Geroulakos
authors.forename: A N
authors.initials: AN
authors.lastname: Nicolaides
mesh_terms: D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D048228:Intermittent Pneumatic Compression Devices; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D016896:Treatment Outcome; D014648:Varicose Veins / Q000628:therapy*