Do one-time intracompartmental pressure measurements have a high false-positive rate in diagnosing compartment syndrome?
BACKGROUND
Intracompartmental pressure measurements are frequently used in the diagnosis of compartment syndrome, particularly in patients with equivocal or limited physical examination findings. Little clinical work has been done to validate the clinical use of intracompartmental pressures or identify associated false-positive rates. We hypothesized that diagnosis of compartment syndrome based on one-time pressure measurements alone is associated with a high false-positive rate.


METHODS
Forty-eight consecutive patients with tibial shaft fractures who were not suspected of having compartment syndrome based on physical examinations were prospectively enrolled. Pressure measurements were obtained in all four compartments at a single point in time immediately after induction of anesthesia using a pressure-monitoring device. Preoperative and intraoperative blood pressure measurements were recorded. The same standardized examination was performed by the attending surgeon preoperatively, postoperatively, and during clinical follow-up for 6 months to assess clinical evidence of acute or late compartment syndrome.


RESULTS
No clinical evidence of compartment syndrome was observed postoperatively or during follow-up until 6 months after injury. Using the accepted criteria of delta P of 30 mm Hg from preoperative diastolic blood pressure, 35% of cases (n = 16; 95% confidence interval, 21.5-48.5%) met criteria for compartment syndrome. Raising the threshold to delta P of 20 mm Hg reduced the false-positive rate to 24% (n = 11; 95% confidence interval, 11.1-34.9%). Twenty-two percent (n = 10; 95% confidence interval, 9.5-32.5%) exceeded absolute pressure of 45 mm Hg.


CONCLUSIONS
A 35% false-positive rate was found for the diagnosis of compartment syndrome in patients with tibial shaft fractures who were not thought to have compartment syndrome by using currently accepted criteria for diagnosis based solely on one-time compartment pressure measurements. Our data suggest that reliance on one-time intracompartmental pressure measurements can overestimate the rate of compartment syndrome and raise concern regarding unnecessary fasciotomies.


METHODS
Diagnostic study, level II.
From R Adams Cowley Shock Trauma Center (A.W., R.V.O., E.H., M.F.S., A.N.P., T.T.M., W.A.E., R.C.A., C.L., J.W.N.), Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland; and Department of Orthopaedics (C.D.), University of Wisconsin School of Medicine, Madison, Wiconsin.
Augusta
A
Whitney
Robert V
RV
O'Toole
Emily
E
Hui
Marcus F
MF
Sciadini
Andrew N
AN
Pollak
Theodore T
TT
Manson
W Andrew
WA
Eglseder
Romney C
RC
Andersen
Christopher
C
Lebrun
Christopher
C
Doro
Jason W
JW
Nascone
D000328:Adult; D000868:Anterior Compartment Syndrome / Q000175:diagnosis* / Q000209:etiology; D015331:Cohort Studies; D016001:Confidence Intervals; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000379:methods; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011312:Pressure; D011446:Prospective Studies; D011859:Radiography; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013978:Tibial Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult