Skeletal-muscle necrosis was evaluated in previously pressurized canine
compartments using technetium-99m stannous pyrophosphate and classic
histological criteria. Intracompartmental necrosis was quantitated in the
anterolateral muscle compartment of each dog by uptake of 99mTc stannous
pyrophosphate using the contralateral anterolateral compartment as an
internal control. Representative specimens of muscle were sampled in
experimental and control legs of each dog and were analyzed by qualitative
histological techniques. Muscle necrosis was assessed in compartments
forty-eight hours after pressurization to levels of ten to 120 millimeters
of mercury for eight hours in thirty-seven dogs. In another dog, neither
anterolateral compartment was pressurized so that both compartments acted
as control muscle. The results in these experiments identify a threshold
pressure level (thirty millimeters of mercury) and duration (eight hours)
at which significant muscle necrosis occurs at normal blood pressure. Our
findings imply that a quantitative relationship exists between
incorporation of 99mTc stannous pyrophosphate and the level of
intracompartmental pressure. This uptake technique, however, is not
suitable for diagnosing compartment syndrome in patients with a threatened
compartment syndrome. We suggest that intracompartmental pressure
measurements by the wick-catheter technique, in conjunction with clinical
findings, offer the best means for diagnosing compartment syndrome.
CLINICAL RELEVANCE: Significant muscle necrosis associated with an
impending compartment syndrome occurs at a threshold intracompartmental
pressure of thirty millimeters of mercury after eight hours. Since time
variables are often unknown in suspected compartment syndromes, fasciotomy
is recommended when intracompartmental pressure exceeds thirty millimeters
of mercury in a patient with normal blood pressure. The use of this
threshold pressure level as an indication for fasciotomy requires a device
for measuring intracompartmental pressure such as the wick catheter.