Christopher J Doro1, Thomas J Sitzman, Robert V O'Toole. 1. From the University of Wisconsin School of Medicine and Public Health (C.J.D., T.J.S.), Madison, Wisconsin, and the R Adams Cowley Shock Trauma Center (R.V.O.), Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland.
Abstract
BACKGROUND: Compartment syndrome is difficult to diagnose, particularly in patients who are not able to undergo adequate clinical examination. Current methods rely on pressure measurements within the compartment, have high false-positive rates, and do not reliably indicate presence of muscle ischemia. We hypothesized that measurement of intramuscular glucose and oxygen can identify compartment syndrome with high sensitivity and specificity. METHODS: Compartment syndrome was created in 12 anesthetized adult mixed-sex beagles, in the craniolateral compartment of a lower leg, by infusion of lactated Ringer's solution with normal serum concentration of glucose. The contralateral leg served as a control. Hydrostatic pressure, oxygen tension, and glucose concentration were recorded with commercially available probes. Compartment syndrome was maintained for 8 hours, and the animals were recovered. Two weeks later, compartment and control legs underwent muscle biopsy. Specimens were reviewed by a blinded pathologist. RESULTS: Within 15 minutes of creating compartment syndrome, glucose concentration and oxygen tension in the experimental limb were significantly lower than in the control limb (glucose, p = 0.02; oxygen, p = 0.007; two-tailed t test). Intramuscular glucose concentration of less than 97 mg/dL was 100% sensitive (95% confidence interval [CI], 73-100%) and 75% specific (95% CI, 40-94%) for the presence of compartment syndrome. Partial pressure of oxygen less than 30 mm Hg was 100% sensitive (95% CI, 72-100%) and 100% specific (95% CI, 69-100%) for the presence of compartment syndrome. Pathology confirmed compartment syndrome in all experimental limbs. CONCLUSION: Our results show that intramuscular glucose concentration and partial pressure of oxygen rapidly identify muscle ischemia with high sensitivity and specificity after experimentally created compartment syndrome in this animal model.
BACKGROUND: Compartment syndrome is difficult to diagnose, particularly in patients who are not able to undergo adequate clinical examination. Current methods rely on pressure measurements within the compartment, have high false-positive rates, and do not reliably indicate presence of muscle ischemia. We hypothesized that measurement of intramuscular glucose and oxygen can identify compartment syndrome with high sensitivity and specificity. METHODS: Compartment syndrome was created in 12 anesthetized adult mixed-sex beagles, in the craniolateral compartment of a lower leg, by infusion of lactated Ringer's solution with normal serum concentration of glucose. The contralateral leg served as a control. Hydrostatic pressure, oxygen tension, and glucose concentration were recorded with commercially available probes. Compartment syndrome was maintained for 8 hours, and the animals were recovered. Two weeks later, compartment and control legs underwent muscle biopsy. Specimens were reviewed by a blinded pathologist. RESULTS: Within 15 minutes of creating compartment syndrome, glucose concentration and oxygen tension in the experimental limb were significantly lower than in the control limb (glucose, p = 0.02; oxygen, p = 0.007; two-tailed t test). Intramuscular glucose concentration of less than 97 mg/dL was 100% sensitive (95% confidence interval [CI], 73-100%) and 75% specific (95% CI, 40-94%) for the presence of compartment syndrome. Partial pressure of oxygen less than 30 mm Hg was 100% sensitive (95% CI, 72-100%) and 100% specific (95% CI, 69-100%) for the presence of compartment syndrome. Pathology confirmed compartment syndrome in all experimental limbs. CONCLUSION: Our results show that intramuscular glucose concentration and partial pressure of oxygen rapidly identify muscle ischemia with high sensitivity and specificity after experimentally created compartment syndrome in this animal model.