title: Effect of hyperoxia and vascular occlusion on tissue oxygenation measured by near infra-red spectroscopy (InSpectra™): a volunteer study.
abstract: Standard cardiorespiratory monitoring may fail to detect occult tissue ischaemia. This study assessed whether a near infra-red spectroscopy tissue oxygen saturation monitor (InSpectra™) could detect progressive peripheral tissue ischaemia and whether hyperoxia may confound tissue oxygen saturation measurement. Tissue oxygen and arterial oxygen saturations were measured continuously in 30 healthy volunteers, first during a period of progressive increase in inspired oxygen concentration and subsequently during two periods of low- and high-pressure limb ischaemia. Increasing inspired oxygen concentration was associated with a small increase in mean (SD) tissue oxygen saturation of 5.3 (7.1) %, reaching a plateau between 30% and 40% inspired oxygen. The rate and magnitude of decreases in tissue oxygen saturations were greater during high- than low-pressure ischaemia with a mean (SD) desaturation rate of 3.3 (0.9) vs 1.8 (0.8) %.min(-1) (p<0.01). The dose-related association and lack of confounding by hyperoxia suggest that tissue oxygen saturation monitoring may be a useful adjunct to detect occult ischaemia.
authors.affiliation: Department of Intensive Care Medicine, Queen Alexandra Hospital, Portsmouth, UK.
authors.forename: B
authors.initials: B
authors.lastname: Kyle
authors.forename: E
authors.initials: E
authors.lastname: Litton
authors.forename: K M
authors.initials: KM
authors.lastname: Ho
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002138:Calibration; D004305:Dose-Response Relationship, Drug; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D018496:Hyperoxia / Q000378:metabolism*; D007511:Ischemia / Q000378:metabolism*; D008297:Male; D008991:Monitoring, Physiologic; D010092:Oximetry; D010101:Oxygen Consumption / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared; D014111:Tourniquets
chemical_list: D006454:Hemoglobins