Continual near-infrared spectroscopy monitoring in the injured lower limb and acute compartment syndrome: An FDA-IDE trial

Aims The aim of this study was to evaluate near-infrared spectroscopy (NIRS) as a continuous, non-invasive monitor for acute compartment syndrome (ACS). Patients and Methods NIRS sensors were placed on 86 patients with, and 23 without (controls), severe leg injury. NIRS values were recorded for up to 48 hours. Longitudinal data were analyzed using summary and graphical methods, bivariate comparisons, and multivariable multilevel modelling. Results Mean NIRS values in the anterior, lateral, superficial posterior, and deep posterior compartments were between 72% and 78% in injured legs, between 69% and 72% in uninjured legs, and between 71% and 73% in bilaterally uninjured legs. In patients without ACS, the values were typically > 3% higher in injured compartments. All seven limbs with ACS had at least one compartment where NIRS values were 3% or more below a reference uninjured control compartment. Missing data were encountered in many instances. Conclusion NIRS oximetry might be used to aid the assessment and management of patients with ACS. Sustained hyperaemia is consistent with the absence of ACS in injured legs. Loss of the hyperaemic differential warrants heightened surveillance. NIRS values in at least one injured compartment(s) were > 3% below the uninjured contralateral compartment(s) in all seven patients with ACS. Additional interventional studies are required to validate the use of NIRS for ACS monitoring.