Dynamic muscle O-2 saturation response is impaired during major non-cardiac surgery despite goal-directed haemodynamic therapy

Background: Near-infrared spectroscopy combined with a vascular occlusion test(VOT) could indicate an impairment of microvascular reactivity (MVR) in septic patients by detecting changes in dynamic variables of muscle O-2 saturation (StO(2)). However, in the perioperative context the consequences of surgical trauma on dynamic variables of muscle StO(2) as indicators of MVR are still unknown. Methods: This study is a sub-analysis of a randomised controlled trial in patients with metastatic primary ovarian cancer undergoing debulking surgery, during which a goal-directed haemodynamic algorithm was applied using oesophageal Doppler. During a 3 min VOT, near-infrared spectroscopy was used to assess dynamic variables arising from changes in muscle StO(2). Results: At the beginning of surgery, values of desaturation and recovery slope were comparable to values obtained in healthy volunteers. During the course of surgery, both desaturation and recovery slope showed a gradual decrease. Concomitantly, the study population underwent a transition to a surgically induced systemic inflammatory response state shown by a gradual increase in norepinephrine administration, heart rate, and interleukin-6, with a peak immediately after the end of surgery. Higher rates of norepinephrine and a higher heart rate were related to a faster decline in StO(2) during vascular occlusion. Conclusions: Using near-infrared spectroscopy combined with a VOT during surgery showed a gradual deterioration of MVR in patients treated with optimal haemodynamic care. The deterioration of MVR was accompanied by the transition to a surgically induced systemic inflammatory response state. (C) 2015 Sociedad Espanola de Anestesiologia, Reanimacion y Terapeutica del Dolor. Published by Elsevier Espana, S.L.U. All rights reserved.