title: Hyperoxia: At what level of SpO2is a patient safe? A study in mechanically ventilated ICU patients.
abstract: Concerns have been expressed regarding a possible association between arterial hyperoxia and adverse outcomes in critically ill patients. Oxygen status is commonly monitored noninvasively by peripheral saturation monitoring (SpO2). However, the risk of hyperoxia above specific SpO2levels in critically ill patients is unknown. The purpose of this study was to determine a threshold value of SpO2above which the prevalence of arterial hyperoxia distinctly increases.
  
  
  
  This is a cross-sectional study in adult mechanically ventilated intensive care patients in a tertiary referral center. In 100 patients, we collected 200 arterial blood gases (ABG) and simultaneously registered SpO2levels, as well as hemodynamic and ventilation parameters and vasoactive medication. Patients under therapeutic hypothermia were excluded.
  
  
  
  The risk of arterial hyperoxia, defined as PaO2>100mmHg or >125mmHg, was negligible when SpO2was ≤95% or ≤96%, respectively. The majority (89% and 54%, respectively for PaO2>100mmHg and 125mmHg) of ICU patients with SpO2of 100% had arterial hyperoxia. The relation between SpO2 and PaO2was not clearly affected by hemodynamic or other clinical variables (pH, pCO2, body temperature, recent blood transfusion).
  
  
  
  In critically ill patients, the prevalence of arterial hyperoxia increases when SpO2is >95%. Above this saturation level, supplemental oxygen should be administered with caution in patients potentially susceptible to adverse effects of hyperoxia.
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: e.durlinger@nki.nl.
authors.forename: E M J
authors.initials: EMJ
authors.lastname: Durlinger
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: am.spoelstra@vumc.nl.
authors.forename: A M E
authors.initials: AME
authors.lastname: Spoelstra-de Man
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Smit
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: H J
authors.initials: HJ
authors.lastname: de Grooth
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: A R J
authors.initials: ARJ
authors.lastname: Girbes
authors.affiliation: Department of Intensive Care, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: H M
authors.initials: HM
authors.lastname: Oudemans-van Straaten
authors.affiliation: Department of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: y.smulders@vumc.nl.
authors.forename: Y M
authors.initials: YM
authors.lastname: Smulders
mesh_terms: D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D003422:Critical Care; D016638:Critical Illness; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018496:Hyperoxia / Q000175:diagnosis* / Q000517:prevention & control*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D010343:Patient Admission; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
keywords: Critically ill; Hyperoxia; Mechanically ventilated; Pulse oximetry; Saturation