Laser Doppler flowmetry in the diagnosis of chronic compartment syndrome

Chronic compartment syndrome (CCS) is usually considered to be due to ischaemia of muscle. We have attempted to use the direct measurement of muscle blood flow for diagnosis since the assessment of intracompartmental pressure does not provide accurate knowledge of the vascular state. We recorded simultaneously continuous measurements of the laser Doppler flow (LDF) in muscle and the intracompartment pressure (ICP) after exercise in seven patients with CCS, and in seven control subjects. The mean ICP was 74.1 +/- 4.4 mmHg in CCS patients and 24.2 +/- 3.4 mmHg in control subjects one minute after exercise, decreasing to 34.6 +/- 2.3 mmHg and 15.0 +/- 1.6 mmHg at 20 min, respectively. The LDF was 0.80 +/- 0.11 arbitrary units (AU) in control subjects and 1.09 +/- 0.14 AU in CCS patients one minute after exercise, and 0.41 +/- 0.11 AU and 0.27 +/- 0.04 AU, respectively, at the end of the recovery period. The ICP showed a progressive decrease over time in both groups. The LDF decreased sharply during the first minutes of recovery in control subjects, but in patients with CCS there was a delayed hyperaemic peak with blood flow reaching 0.84 +/- 0.10 AU at nine minutes as against 0.33 +/- 0.06 AU for control subjects (p < 0.01). The ICP increased in both control subjects and CCS patients after exercise with no clear cut-off point between the groups. By contrast, changes in muscle blood flow over time were clearly different between control subjects and patients with CCS. For this reason, LDF should be investigated further as a technique for the diagnosis of CCS.