Neonatal Pulse Oximetry Disparities Due to Skin Pigmentation (Neo-PODS)

The goal of this clinical trial is to determine if pulse oximeters show an SaO2-SpO2 discrepancy that correlates with skin pigmentation such that pulse oximetry will overestimate oxygenation in newborns with darker skin. The main questions it aims to answer is if SaO2-SpO2 discrepancy varies with the degree of skin pigmentation among neonates, if gestational age has an influence on SaO2-SpO2 discrepancy, and if packed red blood cell (PRBC) transfusion has an influence on SaO2-SpO2 discrepancy in newborns with various degrees of light and dark skin. Researchers will compare SaO2 and SpO2 values in neonates of various skin pigmentation.

Investigators will use a multicenter prospective cohort approach to measure SpO2 and SaO2 simultaneously in newborns of varying degrees of light and dark skin. The investigators will enroll 163 newborns of varying degrees of light and dark skin to assess the impact of skin pigmentation on the accuracy of pulse oximetry. Data collection will occur during routine blood samples and will involve simultaneous measurement of oxygen saturation by pulse oximetry and additional data extraction from the EHR. The study consists of 4 main components: (1) Skin pigment classification (2) Race and ethnicity classification (3) SpO2 measurement collection (4) EMR data collection (including newborn screen hemoglobin type assessment and transfusion records). After adjusting for SaO2, the SaO2-SpO2 discrepancy will correlate with skin pigmentation such that pulse oximetry will overestimate oxygenation in newborns with darker skin. The distribution of SaO2-SpO2 discrepancy will have more variance in the newborns with darker skin.

During routine arterial blood gas sampling, a coordinator will measure SpO2 from a similar extremity. SpO2 data will be recorded using Masimo Radical-7 oximeters. To minimize ambient light interference or optical cross talk from other SpO2 sensors, all the SpO2 sensors will be fully shielded with cloth wraps provided by Masimo. Each enrolled infant will undergo simultaneous blood gas sampling and SpO2 measurement for each routine blood gas collected. Up to a total of 10 SpO2 measurements will be collected, paired with 10 blood gas samples collected as part of routine care, though We anticipate about 3 paired samples (SaO2 and SpO2) per enrolled infant.

Participant will undergo at most 10 SpO2 measurements paired with at most 10 routine blood gas samples.

Using a prospective cohort of 163 newborns, the investigators will calculate simultaneous SaO2-SpO2 discrepancy and correlate it with a measure of skin pigmentation (melanin index) among neonates with and without hypoxemia.

Determine the influence of gestational age on SaO2-SpO2 discrepancy in newborns with various degrees of light and dark skin.

Premature infants have thinner skin compared to term infants. In this cohort, the investigators will test the hypothesis that SaO2-SpO2 discrepancy increases with gestational age particularly in infants with dark skin. The investigators will calculate the SaO2-SpO2 discrepancy and correlate it with gestational age of infants.

Determine the influence of packed red blood cell (PRBC) transfusion on SaO2-SpO2 discrepancy in newborns with various degrees of light and dark skin.

Many infants in the NICU setting are transfused PRBC with hemoglobin A, which shifts the oxygen-hemoglobin dissociation curve to the right. While the effect of this shift on pulse oximetry is studied, the combined impact of skin pigmentation and transfusion is not known. The investigators will test the hypothesis that PRBC transfusion increases the impact of skin pigmentation on SaO2- SpO2 discrepancy. The investigators will calculate the SaO2-SpO2 discrepancy and correlate it with the skin pigmentation measurement and frequency of PRBC transfusion.

Inclusion Criteria: Newborns postnatal age < 10 days admitted to intensive care unit Presence of arterial catheter or undergoing arterial stick blood gas sampling Exclusion Criteria: Presence of abnormal hemoglobin (including methemoglobin > 3%) - likely to only be known after enrolled and the blood gas is obtained Those in whom SpO2 cannot be measured in the same extremity as the arterial catheter.