Targeting oxygen delivery in the postoperative period has been shown to reduce hospital length of stay and complications 1. Using a near-infrared spectroscopy device such as the Inspectra™ 325 allows the measurement of tissue oxygen saturation (STO₂) noninvasively as well as a rudimentary measure of blood flow beneath the probe. It is plausible, then, that changes in oxygen delivery (DO₂) during postoperative optimisation may be reflected in changes in STO₂ and provide a noninvasive surrogate of DO₂.

All adult patients admitted to the ICU after surgery who underwent protocolised haemodynamic optimisation were included. All patients had STO₂ recorded over the thenar eminence using an Inspectra™ 325 for the first 8 hours of their stay.

We found a significant correlation between the changes in STO₂ and oxygen delivery index (DO2I) over the first 8 hours of intensive care stay (n = 40, correlation coefficient of 0.947, P = 0.0001, Figure 1). We classified patients who achieved DO₂I > 600 ml/min/m² as responders. These responders had higher STO₂ values by 3 hours of optimisation, a change that remained significant throughout the duration of the study (Figure 2).