Pfeffer SD, Halliwill JR, Warner MA.
Effects of lithotomy position and external compression on lower leg muscle
compartment pressure.
Anesthesiology 2001 Sep;95(3):632-6

Mayo Graduate School of Medicine, Department of Anesthesiology, Mayo Medical
School, Rochester, Minnesota 55905, USA.

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.