Pulse Oximetry and Arterial Saturation Difference in Pediatric COVID-19 Patients: Retrospective Analysis by Race*

Abstract

Objectives: 

Pulse oximetry (Spo₂) may overestimate arterial oxygen saturation (Sao₂) in blood laboratory testing. This study aimed to assess Spo₂–Sao₂ difference in relation to race (i.e., patient self-reporting as Black or White), occult hypoxemia, and length of stay (LOS) in pediatric patients with COVID-19.

Design: 

Single-center retrospective study in pediatric COVID-19 patients. We used multivariable linear regressions to examine the association between race and oximetry measurements and between occult hypoxemia and LOS. Oximetry bias was defined using Spo₂ and Sao₂ data according to approved comparisons. Occult hypoxemia was defined as Spo₂ greater than 92% and Sao₂ less than 88%.

Setting: 

Quaternary pediatric hospital.

Patients: 

Pediatric COVID-19 patients admitted to Texas Children’s Hospital between May 2020 and December 2021.

Interventions: 

None.

Measurements and Main Results: 

There were 2713 patients with complete physiological data in the analysis. Of the total, 61% were Black, and 39% were White. Oximetry bias was greater in Black compared with White patients (p < 0.001), and this bias increased as the oxygen saturations decreased (p < 0.001). Black and White patients had a 12% and 4% prevalence of occult hypoxemia, respectively (p < 0.001). LOS was not associated with oximetry bias or occult hypoxemia once controlled for the level of support (intensive care, respiratory, circulatory).

Conclusions: 

We found an oximetry bias in the measurement of Spo₂ with respect to Sao₂ in symptomatic hospitalized pediatric patients with the diagnosis of COVID-19. Furthermore, race is related to an increased oximetry bias. However, we did not find a relationship between oximetry bias and the LOS in the hospital in this cohort of patients.