title: Direct Measurement of Tissue Oxygenation as a Method of Diagnosis of Acute Compartment Syndrome.
abstract: OBJECTIVE
  The aim of this study was to investigate the utility of direct measurement of tissue oxygenation during compartment syndrome (CS) and tourniquet-induced ischemia in a large animal model. We hypothesize that as compartment pressure (CP) rises, circulation within the compartment will decrease resulting in a decreased level of oxygen in the muscle.
  
  
  METHODS
  This study used a dog model of both CS- and tourniquet-based ischemia. In 15 animals, CS was induced in 1 hind limb with varying degrees of severity using an infusion model. Tourniquet ischemia was induced in the contralateral hind limb for varying durations. The partial pressure of oxygen (PmO2) was continuously monitored using a polarographic oxygen probe in the muscle of both hind limbs. CP was monitored in the CS limb. PmO2 and CP were analyzed after fasciotomy, performed after approximately 7 hours of warm ischemia, or release of tourniquet.
  
  
  RESULTS
  With the application of tourniquet ischemia, PmO2 fell from 38.40 to 1.30 mm Hg (P < 0.001) and subsequently rose after release of the tourniquet to 39.81 mm Hg (P < 0.001). Elevated CP induced by infusion was relieved by fasciotomy (52.04-11.37 mm Hg postfasciotomy, P < 0.001). PmO2 readings in the infusion model were significantly higher in pre-CS than during CS (31.77 mm Hg vs. 3.88 mm Hg, P < 0.001) and rebounded after fasciotomy (50.24 mm Hg, P < 0.001), consistent with hyperemic response.
  
  
  CONCLUSIONS
  Increased CP caused an observable decrease in PmO2 that was reversed by fasciotomy. PmO2 can be directly measured in real time with a polarographic tissue pO2 probe. This study is the first step of evaluating an alternative method for diagnosing acute CS.
authors.affiliation: *Department of Orthopaedic Surgery and Rehabilitation Medicine, University of Chicago Medicine and Biologic Sciences, Chicago, IL; †Department of Orthopaedic Surgery, University of California, San Francisco, CA; and ‡Department of Anesthesia, University of California, San Francisco, CA.
authors.forename: Jack W
authors.initials: JW
authors.lastname: Weick
authors.forename: Heejae
authors.initials: H
authors.lastname: Kang
authors.forename: Lawrence
authors.initials: L
authors.lastname: Lee
authors.forename: Justin
authors.initials: J
authors.lastname: Kuether
authors.forename: Xuhui
authors.initials: X
authors.lastname: Liu
authors.forename: Erik N
authors.initials: EN
authors.lastname: Hansen
authors.forename: Utku
authors.initials: U
authors.lastname: Kandemir
authors.forename: Mark D
authors.initials: MD
authors.lastname: Rollins
authors.forename: James M
authors.initials: JM
authors.lastname: Mok
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003161:Compartment Syndromes / Q000175:diagnosis* / Q000378:metabolism* / Q000601:surgery; D004285:Dogs; D000071938:Fasciotomy; D005260:Female; D018482:Muscle, Skeletal / Q000378:metabolism*; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010100:Oxygen