Fig. 3From: Prediction of return of spontaneous circulation during cardiopulmonary resuscitation by pulse-wave cerebral tissue oxygen saturation: a retrospective observational studyDifference between TOI and SnO2 measurements. Tissue oxygenation represents hemoglobin oxygenation in all regional vessels. TOI may predominantly reflect venous oxygenation. SnO2 may predominantly represent oxygenation in the hemoglobin transported in blood, and may reflect arterial oxygenation better than TOI. Abbreviations: TOI, total oxygenation index; SnO2, pulse-wave tissue oxygen saturationBack to article page