Pulse Oximetry Accuracy and Skin Pigmentation in Congenital Heart Disease: A Prospective Observational Study

Garrett Burnett, MD

Garrett Burnett, MD

Garrett Burnett, MD
Assistant Professor of Anesthesiology, Perioperative & Pain Medicine, Icahn School of Medicine at Mount Sinai

Dr. Burnett’s project is entitled “Pulse Oximetry Accuracy and Skin Pigmentation in Congenital Heart Disease: A Prospective Observational Study.”

Background: Pulse oximetry (SpO2) has been an essential perioperative monitor for noninvasively estimating arterial oxygen saturation (SaO2). The incorporation of pulse oximetry into routine care has coincided with a significant reduction in anesthesia-related fatalities.1 Recent retrospective studies have demonstrated discrepancies between measured pulse oximeter values and measured arterial oxygen saturation in patients self-identifying as Black or Hispanic.2 These findings have demonstrated elevated rates of occult hypoxemia (i.e., SpO2 ≥92% despite SaO2≤88%) in non-White patients and linked occult hypoxemia to increased mortality and changes in treatment.3-5 These previous retrospective studies have utilized self-identified race/ethnicity as a surrogate marker for skin pigmentation, but this may not be an accurate metric for skin pigmentation because a wide variety of skin pigmentations can be observed within a given racial or ethnic group. While several small prospective studies have investigated this discrepancy outside the clinical setting, all have utilized color-matching techniques (i.e., Fitzpatrick Scale) to quantify skin pigmentation.6 Color-matching represents a more objective measure of skin pigmentation when compared to self-identified race/ethnicity, but its utility is limited by factors such as ambient lighting and variability in practitioner interpretation. Further, commonly used color-matching techniques (i.e., Fitzpatrick scale) were not developed to evaluate skin pigmentation. Color spectrophotometry (CS) represents an objective method for skin pigmentation measurement and overcomes the limitations of color-matching.7 It is imperative that the relationship between pulse oximeter accuracy and CS-measured skin pigmentation be determined in order to improve equity in pulse oximeter function across all patients.

Aims: This study aims to evaluate the relationship between pulse oximeter accuracy and CS-measured skin pigmentation in pediatric patients with congenital heart disease having cardiac surgery. Accuracy will be tested using United States Food & Drug Administration guidelines (Accuracy Root Mean Square, Mean Bias, and Bland-Altman analysis). As a secondary aim, the correlation between pulse oximetry accuracy with CS-measured skin pigmentation, self-reported race/ethnicity, and measures using Fitzpatrick scale will be assessed. As a final secondary aim, we will evaluate the relationship of occult hypoxemia undetected by pulse oximetry with CS-measured skin pigmentation.

Implications: This project addresses the APSF’s priority on Clinical Deterioration by working to improve a commonly utilized perioperative monitor for patients of all races and ethnicities. Pulse oximetry is utilized for all patients throughout the perioperative period. Inaccuracies in pulse oximetry may have impacts on patient outcomes and treatments. Determining the relationship between pulse oximetry and CS-measured skin pigmentation works towards the goal of making pulse oximetry equitable for all patients. Results from this study will potentially improve pulse oximeter accuracy in the congenital heart disease population and inform future studies evaluating this relationship in the more general population as a whole.

REFERENCES

  1. Kiani J. How pulse oximetry influenced medicine and how its evolutiion will influence medicine. APSF Article Between Issues. June 2021. https://www.apsf.org/article/how-pulse-oximetry-influenced-medicine-and-how-its-evolution-will-influence-medicine/ Accessed November 30, 2023.
  2. Burnett GW, Stannard B, Wax DB, et al. Self-reported race/ethnicity and intraoperative occult hypoxemia: a retrospective cohort study. Anesthesiology. 2022;136:688–696. PMID: 35231085.
  3. Henry NR, Hanson AC, Schulte PJ, et al. Disparities in hypoxemia detection by pulse oximetry across self-identified racial groups and associations with clinical outcomes. Crit Care Med. 2022;50:204–211. PMID: 35100193.
  4. Wong AKI, Charpignon M, Kim H, et al. Analysis of discrepancies between pulse oximetry and arterial oxygen saturation measurements by race and ethnicity and association with organ dysfunction and mortality. JAMA Netw Open. 2021;4. PMID: 34730820.
  5. Fawzy A, Wu TD, Wang K, et al. Racial and ethnic discrepancy in pulse oximetry and delayed identification of treatment eligibility among patients with COVID-19. JAMA Intern Med. 2022;182:730–738. PMID: 35639368.
  6. Foglia EE, Whyte RK, Chaudhary A, et al. The effect of skin pigmentation on the accuracy of pulse oximetry in infants with hypoxemia. J Pediatr. 2017;182:375–377.e2. PMID: 27939107.
  7. Ly BCK, Dyer EB, Feig JL, et al. Research techniques made simple: cutaneous colorimetry: a reliable techique for objective skin color measurement. J Invest Dermatol. 2020;140(1):3-12.e1. doi 10.1016/j.jid.2019.11.003.

Funding: $149,999 (January 1, 2024–December 31, 2025). The grant was designated as the APSF/Medtronic Research Award.