Journal Club

February 2010

Physicians' ability to manually detect isolated elevations in leg intracompartmental pressure

Franklin D. Shuler and Matthew J. Dietz J Bone Joint Surg Am. 2010;92:361-367

Reviewed by

Dr Josh Petterwood
MBBS | Accredited Orthopaedic Registrar

Study Type

  • Cadaver study investigating the reliability of physical examination in the obtunded patient with compartment syndrome of the lower leg

Location

  • Department of Orthopaedics, West Virginia University, Morgantown, West Virginia

Funding

  • Sponsored by Stryker

Methodology

  • 4 fresh, never frozen cadavers, average age 74.5 yrs
  • Uninterrupted fluid column to each leg compartment to generate intracompartmental pressure of 20/40/60/80mmHg
  • Either deep posterior or anterior compartment then varied while remaining 3 compartments were given control pressure of 20mmHg
    • 20/40mmHg = no compartment syndrome
    • 60/80mmHg = compartment syndrome
  • 136 separate examinations by local orthopaedic residents/surgeons
  • Three questions
    • Is there a compartment syndrome?
    • In which compartment(s) is the pressure elevated, if at all?
    • Describe your examination findings as soft, compressible or firm?

Statistical analysis

  • Positive predictive value
    • where PPV equals correctly identifying an elevation in compartment pressure and the correct compartment of elevation
  • Negative predictive value
  • Sensitivity
  • Specificity
  • Comparison between groups
    • Junior residents
    • Senior residents
    • Attendings

Results

  • Overall
    • Positive predictive value – 19%
    • Sensitivity – 24%
    • Specificity – 55%
    • Negative predictive value – 63%
  • No significant difference with increasing experience
  • When investigators removed the identification of the correct compartment as a requisite for PPV and looked only at the correct identification of compartment syndrome the PPV increased to 70%.
  • Only 45% of participants described compartments elevated to 80mmHg as firm.

Discussion

  • Compartment syndrome typically considered a ‘clinical diagnosis’
    • Mostly subjective findings
    • Very difficult in the obtunded pt
    • Firmness of compartments is ‘objective’
  • Clinical exam previously shown to be unreliable (13-19%)
  • In this study palpation shown to be a very poor method of determining increases in compartment pressure (in cadavers)
  • Choice of pressures
    • Control 20mmHg
    • Compartment syndrome 60-80mmHg
    • One compartment elevated only
    • all of which have not been validated nor can be accurately applied to a clinical setting

Strengths

  • Numbers
  • Well controlled/technically performed for an in vitro study

Weaknesses

  • Cadaver study
  • Authors draw rather firm clinical conclusions from a cadaver study

Take home message

  • Cadaver study – as such no significant clinical conclusion can be drawn

But in general

  • High index of suspicion crucial in diagnosis of compartment syndrome
  • Serial examination the key
  • • Use of manometer is probably under utilised (use early)

 

Webpage Last Modified: 5 August, 2010
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