INVASIVE AND NON-INVASIVE MONITORING FOR COMPARTMENT SYNDROME

Abstract

The detection and treatment of acute compartment syndrome following trauma is critical if contractures, delayed fracture healing and possible amputations are to be avoided. The current standard for monitoring relies on invasive compartment pressure measurements. These require an additional procedure and cause discomfort to the patient. This prospective clinical study investigates the relationship between the intra-compartmental pressure and soft tissue oxygenation (%StO₂) measured non-invasively by near-infrared spectroscopy (NIRS) in patients at risk of acute compartment syndrome.

Adults with acute tibial or radial diaphyseal fractures were recruited on admission to the orthopaedic trauma unit. Non-invasive and invasive monitoring over anterior tibial or volar forearm compartments was carried out from admission and continued post-operatively. The differential pressure (ΔDP) was calculated as the compartment pressure subtracted from the diastolic blood pressure. The threshold for fasciotomy was a ΔDP < 30mmHg. StO₂ values were simultaneously recorded from the contralateral (uninjured) limb at the same site. All patients had the difference between the StO₂ value on the injured and uninjured sides calculated (‘StO₂ difference’).

Sixty patients with tibial fractures and 5 patients with forearm fractures were recruited. The mean age was 39 years (S.D.18 years). Fourteen patients underwent a four-compartment lower leg fasciotomy determined by a ΔDP < 30mmHg.

We have observed that the difference in StO₂ between limbs (measured non-invasively) was significantly lower in patients undergoing a fasciotomy. This suggests that NIRS is able to detect a change in oxygenation of the soft tissues in trauma patients developing an acute compartment syndrome. We are optimistic that near-infrared spectroscopy (NIRS) will be a reliable new non-invasive technique for detection of an acute compartment syndrome.