title: Pressures Under 3.8cm, 5.1cm, and Side-by-Side 3.8cm-Wide Tourniquets.
abstract: BACKGROUND
  Applications of wider tourniquet are expected to occlude arterial flow at lower pressures. We examined pressures under 3.8cm-wide, 5.1cm-wide, and side-by-side-3.8cm-wide nonelastic strap-based tourniquets.
  
  
  METHODS
  Ratcheting Medical Tourniquets (RMT) were applied mid-thigh and mid-arm for 120 seconds with Doppler-indicated occlusion. The RMTs were a Single Tactical RMT (3.8cm-wide), a Wide RMT (5.1cm-wide), and Paired Tactical RMTs (7.6cm-total width). Tightening completion was measured at one-tooth advance past arterial occlusion, and paired applications involved alternating tourniquet tightening.
  
  
  RESULTS
  All 96 applications on the 16 recipients reached occlusion. Paired tourniquets had the lowest occlusion pressures (ρ < .05). All pressures are given as median mmHg, minimum-maximum mmHg. Thigh application occlusion pressures were Single 256, 219-299; Wide 259, 203-287; Distal of Pair 222, 183-256; and Proximal of Pair 184, 160-236. Arm application occlusion pressures were Single 230, 189-294; Wide 212, 161-258; Distal of Pair 204, 193-254, and Proximal of Pair 168, 148-227. Pressure increases with the final tooth advance were greater for the 2 teeth/cm Wide than for the 2.5 teeth/cm Tacticals (ρ < .05). Thigh final tooth advance pressure increases were Single 40, 33-49; Wide 51, 37-65; Distal of Pair 13, 1-35; and Proximal of Pair 15, 0-30. Arm final tooth advance pressure increases were Single 49, 41-71; Wide 63, 48-77; Distal of Pair 3, 0-14; and Proximal of Pair 23, 2-35. Pressure decreases occurred under all tourniquets over 120 seconds. Thigh pressure decreases were Single 41, 32-75; Wide 43, 28-62; Distal of Pair 25, 16-37; and Proximal of Pair 22, 15-37. Arm pressure decreases were Single 28, 21-43; Wide 26, 16-36; Distal of Pair 16, 12-35; and Proximal of Pair 12, 5-24. Occlusion losses before 120 seconds occurred predominantly on the thigh and with paired applications (ρ < .05). Occlusion losses occurred in six Paired thigh applications, two Single thigh applications, and one Paired arm application.
  
  
  CONCLUSIONS
  Side-by-side tourniquets achieve occlusion at lower pressures than single tourniquets. Additionally, pressure decreases under tourniquets over time; so all tourniquet applications require reassessments for continued effectiveness.
authors.forename: Piper L
authors.initials: PL
authors.lastname: Wall
authors.forename: Jacob
authors.initials: J
authors.lastname: Weasel
authors.forename: Mary
authors.initials: M
authors.lastname: Rometti
authors.forename: Sarah
authors.initials: S
authors.lastname: Birkholz
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Gildemaster
authors.forename: Lisa
authors.initials: L
authors.lastname: Grulke
authors.forename: Sheryl M
authors.initials: SM
authors.lastname: Sahr
authors.forename: Charisse M
authors.initials: CM
authors.lastname: Buising
mesh_terms: D001132:Arm; D004867:Equipment Design; D017276:Friction; D006470:Hemorrhage / Q000628:therapy*; D006801:Humans; D011312:Pressure; D013848:Thigh; D014111:Tourniquets