Ion-Selective ElectrodesOxygenOxygen ConsumptionReactive Oxygen SpeciesOxygen Inhalation TherapySinglet OxygenOxygen IsotopesHyperbaric OxygenationReproducibility of ResultsPartial PressureTime FactorsAnoxiaOxidation-ReductionHydrogen PeroxideOxidative StressOximetryQuestionnairesWeights and MeasuresAntioxidantsHemoglobinsTreatment OutcomeOxyhemoglobinsProspective StudiesSuperoxide DismutaseAnalysis of VarianceFree RadicalsCarbon DioxideAerobiosisPsychometricsMitochondriaFree Radical ScavengersCatalaseHyperoxiaModels, BiologicalCell HypoxiaNADPH OxidaseSeverity of Illness Index