Hyperoxia: at what level of SpO2 is a patient safe?

E.M.J. Durlinger, A.M.E. Spoelstra, B. Smit, H.J. de Grooth, A.R.J. Girbes, H.M. Oudemans, Y.M. Smulders

Woensdag 20 april 2016

15:30 - 15:40u in Zaal 2.1

Categorie├źn: Parallelsessie

Parallel sessie: Parallelsessie 5: Case reports/research

Purpose: Arterial hyperoxia is associated with adverse outcomes in several categories of critically ill patients, including those with cardiac ischemia, stroke or post-resuscitation. Oxygen status is commonly monitored noninvasively by saturation monitoring (SpO2). However, the risk of hyperoxia above specific SpO2 levels is unknown. The purpose of this study was to investigate whether SpO2 correlates with risk of arterial hyperoxia in critically ill patients, and to determine a threshold value of SpO2 above which the prevalence of arterial hyperoxia distinctly increases.

Design: A prospective observational study in mechanically ventilated patients in the ICU of the VU university medical center in Amsterdam, The Netherlands.

Materials and methods: In 100 patients, we collected 200 arterial blood gases (ABG) and simultaneously registered SpO2 levels, as well as hemodynamic and ventilation parameters, vasoactive medication and clinically assessed peripheral perfusion. Patients under therapeutic hypothermia were excluded.

Results: The risk of arterial hyperoxia, defined either as PaO2 >100mmHg or >125mmHg, was negligible when SpO2 was =95% or =96%, respectively. The majority (89% and 54%, respectively for PaO2>100mmHg and 125mmHg) of ICU patients with SpO2 of 100% had arterial hyperoxia. The association between SpO2 and PaO2 was not markedly influenced by hemodynamic or other clinical variables (pH, pCO2, body temperature, recent blood transfusion).

Conclusions: In critically ill patients, the prevalence of arterial hyperoxia (and therefore the risk of potential adverse affects) increases when SpO2 is >95%. Above this saturation level, supplemental oxygen should be administered with caution in patient susceptible to adverse effects of hyperoxia.