Discordance Between Invasive and NonInvasive Oxygen Saturation in Critically Ill COVID-19 Patients

Authors

Thomas H. Fox, LSU Health Sciences Center - New OrleansFollow
William R. Mazalewski, LSU Health Sciences Center - New Orleans
Hai S. Tran, LSU Health Sciences Center - New OrleansFollow
Travis Lindsey, LSU Health Sciences Center - New OrleansFollow
Amita Krishnan, LSU Health Sciences Center - New OrleansFollow
Stephen P. Kantrow, LSU Health Sciences Center - New OrleansFollow
Kyle I. Happel, LSU Health Sciences Center - New OrleansFollow
David R. Janz, LSU Health Sciences Center - New OrleansFollow
Bennett P. Deboisblanc, LSU Health Sciences Center - New OrleansFollow
Matthew R. Lammi, LSU Health Sciences Center - New OrleansFollow

Document Type

Article

Publication Date

7-7-2023

Publication Title

Journal of Intensive Care Medicine

Abstract

Objectives: To investigate discordance in oxy-hemoglobin saturation measured both by pulse oximetry (SpO2) and arterial blood gas (ABG, SaO2) among critically ill coronavirus disease 2019 (COVID-19(+)) patients compared to COVID-19(-) patients. Methods: Paired SpO2 and SaO2 readings were collected retrospectively from consecutive adult admissions to four critical care units in the United States between March and May 2020. The primary outcome was the rate of discordance (|SaO2-SpO2|>4%) in COVID-19(+) versus COVID-19(-) patients. The odds each cohort could have been incorrectly categorized as having a PaO2/FiO2 above or below 150 by their SpO2: Fractional inhaled oxygen ratio (pulse oximetry-derived oxyhemoglobin saturation:fraction of inspired oxygen ratio [SF]) was examined. A multivariate regression analysis assessed confounding by clinical differences between cohorts including pH, body temperature, renal replacement therapy at time of blood draw, and self-identified race. Results: There were 263 patients (173 COVID-19(+)) included. The rate of saturation discordance between SaO2 and SpO2 in COVID-19(+) patients was higher than in COVID-19(-) patients (27.9% vs 16.7%, odds ratio [OR] 1.94, 95% confidence interval [CI]: 1.11 to 2.27). The average difference between SaO2 and SpO2 for COVID-19(+) patients was −1.24% (limits of agreement, −13.6 to 11.1) versus −0.11 [–10.3 to 10.1] for COVID-19(–) patients. COVID-19(+) patients had higher odds (OR: 2.61, 95% CI: 1.14-5.98) of having an SF that misclassified that patient as having a PaO2:FiO2 ratio above or below 150. There was not an association between discordance and the confounders of pH, body temperature, or renal replacement therapy at time of blood draw. After controlling for self-identified race, the association between COVID-19 status and discordance was lost. Conclusions: Pulse oximetry was discordant with ABG more often in critically ill COVID-19(+) than COVID-19(–) patients. However, these findings appear to be driven by racial differences between cohorts.

PubMed ID

37415515

Recommended Citation

Fox, Thomas H.; Mazalewski, William R.; Tran, Hai S.; Lindsey, Travis; Krishnan, Amita; Kantrow, Stephen P.; Happel, Kyle I.; Janz, David R.; Deboisblanc, Bennett P.; and Lammi, Matthew R., "Discordance Between Invasive and NonInvasive Oxygen Saturation in Critically Ill COVID-19 Patients" (2023). School of Medicine Faculty Publications. 1295.
https://digitalscholar.lsuhsc.edu/som_facpubs/1295