Outcomes
RENAL
The primary outcome of the study was to assess the agreement between quadriceps and flank oxygen saturation values and invasive somatic reference values. Somatic reference values were calculated as follows:
Somatic reference (%) = 0.7 × iliac vein oxygen saturation (%) + 0.3 × arterial oxygen saturation (SaOAdditionally, we evaluated the agreement between flank oxygen saturation values and invasive renal reference values. Renal reference values were calculated as follows:
Renal reference (%) = 0.7 × renal vein oxygen saturation (%) + 0.3 × SaOFor the calculation of invasive reference values a 70:30 venous-to-arterial ratio was assumed, similar to the algorithm of cerebral oximetry [