Fri., 10/14/11 Tibia, Paper #51, 11:26 am OTA-2011
Do Intracompartmental Pressure Measurements Have a High False-Positive Rate in Diagnosing Compartment Syndrome?
Augusta Whitney, MD1; Robert V. O’Toole, MD1; Emily Hui, MPH1;
Marcus F. Sciadini, MD1; Andrew N. Pollak, MD1; Theodore T. Manson, MD1;
W. Andrew Eglseder, MD1; Romney C. Andersen, MD1; Christopher T. LeBrun, MD1;
Christopher Doro, MD2; Jason W. Nascone, MD1;
1R Adams Cowley Shock Trauma Center, Dept. of Orthopaedics,
University of Maryland School of Medicine, Baltimore, Maryland, USA;
2Dept. of Orthopaedics, University of Wisconsin School of Medicine, Madison, Wisconsin, USA
Purpose: Intracompartmental pressure measurements are frequently used to aid in the diagnosis of compartment syndrome, particularly in patients whose physical examination is equivocal or limited by altered sensorium. Despite their widespread use, little work has been done to validate the clinical use of intracompartmental pressures, particularly in identifying the false-positive rates. Our hypothesis was that there would be a high false-positive rate if the diagnosis of compartment syndrome were made based on one-time pressure measurements alone.
Methods: 48 consecutive patients with tibial shaft fractures who were not suspected of having compartment syndrome based on the attending orthopaedic surgeons’ standardized physical examination were prospectively enrolled in this study. Compartment pressure measurements were taken in all 4 compartments at a single point in time immediately after induction of anesthesia using a commercially available pressure-monitoring device. The patients’ preoperative and intraoperative blood pressures were recorded. The same standardized examination was performed by the attending surgeon postoperatively and in clinical follow-up for 6 months to demonstrate that the patients did not develop clinical evidence of compartment syndrome either acutely or late.
Results: No patients demonstrated clinical evidence of compartment syndrome postoperatively or in clinical follow-up for 6 months from the date of injury. Using the accepted criteria of a delta of 30 mm Hg from preoperative diastolic blood pressure, 35% of patients (n = 17; 95% confidence intervals (CI): 48.5%, 21.5%) qualified as meeting criteria for compartment syndrome. Raising the threshold to a delta of 20 mm Hg reduced the false-positive rate in this cohort to only 23% (n = 11; 95% CI: 34.9%, 11.1%). 21% (n = 10; 95% CI: 32.5%, 9.5%) of patients exceeded an absolute pressure value of 45 mm Hg.
Conclusion: We found there was a relatively high false-positive rate (35%) for the diagnosis of compartment syndrome in patients with tibial shaft fractures using currently accepted criteria for the diagnosis based solely on one-time compartment pressure measurements using a commercially available pressure-monitoring device. To our knowledge, this is the first prospective study to use rigorous methodology to demonstrate the false-positive rate in patients not suspected of compartment syndrome using this technique. These data suggest that reliance on one-time intracompartmental pressure measurements alone may substantially overestimate the true rate of compartment syndrome and raises concern that use of intracompartmental pressure measurement as a tool to diagnose compartment syndrome may lead to unnecessary fasciotomies.
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.