Predicting Acute Compartment Syndrome (PACS)
Condition: Acute Compartment Syndrome
MeSH terms: Compartment Syndromes; Syndrome
Study type: Interventional

Summary: 
      The long-term objective is to develop a tool to aid in making a timely and accurate diagnosis
      of acute compartment syndrome (ACS).

      The immediate objective is to develop a model to accurately predict the likelihood of ACS
      based on data available to the clinician within the first 48 hours of injury (specific
      clinical findings supplemented by muscle oxygenation measured by near-infrared spectroscopy
      (NIRS), and continuous intramuscular pressure (IMP) and perfusion pressure (PP) monitoring).

      Our primary outcome is the retrospective assessment of the likelihood of compartment syndrome
      made by a panel of clinicians using the following data:

        -  A physiologic "fingerprint" composed of continuous pressure versus time curve,
           continuous oximetry values, response of muscle to fasciotomy when performed, and serum
           biomarkers of muscle injury (CPK levels).

        -  Clinical and functional outcomes at 6 months post-injury including: sensory exam, muscle
           function, presence/absence of myoneural deficit, and patient reported function using the
           Short Musculoskeletal Function Assessment (SMFA).
    

Detailed description: 
      Specific Aim 1: Prospectively enroll and follow for 6 months a sample of 200 patients.
      Patients will receive continuous tissue perfusion monitoring using NIRS in all 4 leg
      compartments and intramuscular pressure (IMP) via indwelling catheters placed in the anterior
      and deep posterior compartments. These measures will be blinded and not provided in real time
      to treating physicians. All clinical care, including diagnosis of ACS, will be according to
      current standard-of-care practiced at each institution.

      Specific Aim 2: Convene expert panels of 5 orthopaedic surgeons experienced in the diagnosis
      and treatment of ACS to retrospectively assess the likelihood that each patient had ACS. This
      retrospective assessment will be based on a 'patient profile' summarizing data collected as
      part of this study.

      Specific Aim 3: Determine the extent to which clinicians agree in retrospective assessments
      of the likelihood of ACS.

      Hypothesis: On the basis of known clinical and functional outcome at 6 months and monitoring
      information, clinicians will agree on the likelihood of ACS in < 90% of cases.

      Specific Aim 4: Model the panel's assessment of the likelihood of ACS as a function of data
      available to the clinician within the first 48 hours of injury using a training set of the
      data. This model can then be used to compute a point estimate of the risk of ACS (and
      associated 95% confidence interval) for any given patient.

      Specific Aim 5: Assess, for patients in a test/validation data set, the performance of the
      model in predicting the panel's assessment of the likelihood of ACS.

      Hypothesis: In < 95% of the cases, the panel's assessment of the likelihood of ACS will fall
      within the 95% interval of uncertainty predicted by the model.
    

Intervention name(s): Continuous tissue perfusion monitoring by near-infrared spectroscopy (NIRS) and intramuscular pressure (IMP)
Intervention type(s): Other
Intervention description(s): Continuous monitoring of tissue perfusion using NIRS in all 4 leg muscle compartments and IMP via indwelling catheters in anterior and deep posterior compartments. These measures will not provided in real time to treating physicians. All clinical care, including the diagnosis of ACS, will be according to the current standard-of-care practiced at each institution, Clinicians may use the indwelling IMP monitor to obtain up to 2 discrete measures of IMP if they encounter a clinical situation in which they would normally measure IMP as an adjunct in their normal standard-of-care for the monitoring and diagnosis of compartment syndrome. Patients who undergo fasciotomy will also have NIRS and IMP values recorded from all 4 leg compartments immediately before and after fasciotomy.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: fasciotomy; ACS