title: Effects of lithotomy position and external compression on lower leg muscle compartment pressure.
abstract: BACKGROUND
  Case reports have suggested that externally applied pressure from antithrombosis devices may contribute to the development of compartment syndromes during extended surgery in the lithotomy position. The purpose of this study was to assess the effects of a pneumatic compression device on directly measured intracompartment pressure in the lower leg with the leg positioned in the lithotomy position.
  
  
  METHODS
  In 25 conscious, healthy men and women, the authors measured pressure within the tibialis anterior muscle compartment with the leg supine and in the lithotomy position with and without intermittent compression. Three different devices were used to keep the leg in the lithotomy position, supporting the leg either behind the knee, under the calf, or at the ankle.
  
  
  RESULTS
  The lithotomy position with support behind the calf or knee increased intracompartment pressure to 16.5+/-3.4 versus 10.7+/-5.8 mmHg supine (mean +/- SD; P < 0.05). The addition of intermittent compression decreased pressure to 13.4+/-5.1 mmHg during lithotomy (P < 0.05) and to 9.1+/-7.0 mmHg in the supine position (P < 0.05). In contrast, the lithotomy position with support near the ankle decreased intracompartment pressure to 8.7+/-5.6 versus 13.3+/-5.1 mmHg supine (P < 0.05). The addition of intermittent compression decreased pressure to 6.5+/-5.4 mmHg during lithotomy (P < 0.05) and to 10.3+/-4.7 mmHg in the supine position (P < 0.05).
  
  
  CONCLUSIONS
  These results show that the lithotomy position is associated with changes in intracompartment pressure that are dependent on the method of leg support used. Furthermore, they indicate that intermittent external compression can reduce intracompartment pressure in the lower leg. Therefore, increases in intracompartment pressure during surgery in the lithotomy position with the calf or knee supported may be one of the factors that contribute to the development of compartment syndrome. Further, use of intermittent external compression may significantly reduce this pressure increase.
authors.affiliation: Mayo Graduate School of Medicine, Department of Anesthesiology, Mayo Medical School, Rochester, Minnesota 55905, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Pfeffer
authors.forename: J R
authors.initials: JR
authors.lastname: Halliwill
authors.forename: M A
authors.initials: MA
authors.lastname: Warner
mesh_terms: D000328:Adult; D003161:Compartment Syndromes / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D011187:Posture; D011312:Pressure