140 - Impact of Race and Ethnicity on Oxygen Saturation Index in Infants with Congenital Diaphragmatic Hernia

Poster Number: 140
Publication Number: 140.2199

Background: The oxygen saturation index (OSI) is a metric used to quantify the severity of hypoxic-respiratory failure in neonates, including infants with congenital diaphragmatic hernia (CDH). It is similar to the oxygenation index (OI) but uses oxygen saturation (SpO2) in lieu of pO2 in its formula, and thus removes the dependency on arterial access. High OSI levels have been reported to be associated with an increased likelihood of mortality and need for extracorporeal membrane oxygenation (ECMO) in infants with CDH. Skin color, which can differ in individuals with different race and ethnicity, has been reported to affect the accuracy of pulse oximeters, especially at lower oxygen saturation levels.

Objective: In this study, we sought to determine whether a patient’s race and ethnicity would impact the calculation of OSI values and their prediction of the composite outcomes of mortality and need for ECMO in the CDH population.

Design/Methods: This was a single center retrospective study of 180 infants with CDH admitted to a tertiary-care level 4 NICU from January 2011 to December 2021. Demographic, maternal and birth data, vital sign, ventilator data in the first 120 hours of life (HOL) and post-natal outcomes of need for ECMO and mortality were extracted. OSI was calculated as MAP * FiO2 * 100 / SpO2. Linear regression analysis was used to compare OSI max within 24 HOL among race/ethnicity groups while logistic regression was used for CDH outcomes. Both unadjusted comparisons and comparisons after controlling for CDH severity were examined.

Results: Race/ethnicity frequencies and percentages of the 180 study patients were as follows. White: n=85 (47.2%), Black: n=20 (11.1%), Hispanic: n=55 (30.6%) and Other: n=20 (11.1%). Based on our analyses, we did not find any statistically significant differences in OSI max values obtained within 24 HOL or in the composite outcome of need for ECMO or death. This result was also consistent when the cohort was controlled for CDH severity as shown in Table 1.

Conclusion(s): We report that OSI max within 24 HOL was not affected by patient race or ethnicity in our study. However, given previous literature examining the relationship between skin color and measured SpO2, further studies are indicated to determine whether the use of OSI in place of OI would introduce a racial bias in NICU outcomes.