The Steep Price of Racial Color Blindness in Pulse Oximetry Accuracy

By Jacqueline Sergon, Department of Nurse Anesthesia, University of Pittsburgh School of Nursing

As a rapid and non-invasive means of measuring blood oxygenation saturation, the modern-day peripheral pulse oximeter has come to define basic monitoring standards of nursing anesthesia care. Certified registered nurse anesthetists (CRNAs) rely upon pulse oximetry metrics in determining a patient’s oxygenation status, and whether they are a low anesthetic risk, or at greater risk for potential complications such as aspiration pneumonia, or airway obstruction- factors that subsequently influence the anesthesia plan of care.

As CRNAs, and certainly, as SRNAs (student registered nursing anesthetists), we have come to accept as scientific truth, pulse oximetry results as we see them when placed on our patients. However, long-standing research called into question their accuracy as far back as 1990, noting that Black patients were more likely than White patients to have inaccurate pulse oximetry readings (Jubran & Tubin). Additionally, researchers in this study, which examined the reliability of pulse oximetry in ventilator-dependent patients, noted that among White patients, a SpO2 target of 92% reliably predicted adequate oxygen saturation; In Black patients, however, a similar reading equated to significant hypoxemia and thus required a higher SpO2 target of at least 95% (1990). The lack of racial and ethnic diversity was concerning enough for researchers to note this in their published findings, as seen by Kelleher (1987), who stated at the time it was standard practice for dark-skinned patients to be generally excluded from clinical trial subjects.

In subsequent years, these findings remained under-publicized by the medical community and the public as a whole. Consequently, as pulse oximeters became more technologically advanced, they also became more commonplace outside the hospital due to the increased demand for medical supplies in the burgeoning home-healthcare industry. Yet, with the great technological strides being made, there was no commensurate progress on racial diversity on the part of the medical device manufacturers. This can be attributed partly, to a lack of emphasis from the FDA (Food and Drug Administration), which requires manufacturers to have only a minimum of two subjects be of dark skin (FDA, 2013), hence establishing a precedent for a low diversity threshold requirement.

The year 2020 brought forth a seismic cultural shift on two important fronts: the first was the Covid-19 global pandemic, which ushered in a massive upscale in the global demand for peripheral pulse oximeters, as more people were quarantining and self-monitoring in their homes. The other, perhaps not as commonly known, is that the pandemic, and the consequential spike in pulse oximetry demand, also provided an ideal breeding ground for clinical research into the long-held findings of racial inaccuracies in pulse oximetry. It was out of this that the ground-breaking research by Sjoding et al. emerged, in which they examined thousands of hospitalized Covid-19 patients and found that Black patients were three times more likely to have occult hypoxemia associated with inaccurate pulse oximetry readings than White patients (2020). These significant findings were published in the New England Journal of Medicine and have since been widely cited in research studies and news media articles on this topic. Of note, the Anesthesia Patient Safety Foundation (APSF, 2021) cited Sjoding’s research in its clarion call for increased diversification of clinical subjects, as well as increased collaboration amongst stakeholders such as manufacturers, government regulators, and providers in ensuring increased racial diversity of clinical subjects (APSF, 2021). And the FDA cited this research in their official safety bulletin on the limitations of pulse oximetry accuracy and the effects of skin pigmentation (2021).

The underestimation of hypoxemia in pulse ox readings has significant ramifications on clinical progression, prognosis, and patient outcomes with respect to morbidity and mortality rates. In research carried out among Covid-19 and ARDS patients about to be placed on ECMO intervention, data pointed to Black patients having a significantly higher risk of occult hypoxemia compared to White patients (Valbuena, et al., 2021). These findings mirror those of Burnett et al., who similarly found that Black and Hispanic subjects were more dispensed to intraoperative occult hypoxemia than White subjects (2022), as well as that of Henry et al., who found that patients who self-identified as either Black, American Indian or Asian were more likely than White patients to experience occult hypoxemia, and also had greater odds of mortality associated with occult hypoxemia than White patients (2022). Another research study emerging from the Covid-19 pandemic examined the racial and ethnic relational discrepancies between pulse oximetry and arterial oxygen saturation and determined that Black subjects were also more likely to suffer greater organ dysfunction, higher lactate levels, and overall greater mortality than White subjects (Wong et al., 2021). Thus far, research evidence is clear on the impact overestimation of oxygen saturation can have on clinical outcomes on these patients, in masking clinical indicators for Covid-19, pneumonia, or other respiratory disorders.

Racial inaccuracies associated with pulse oximetry use are not just an issue in the U.S. A British study (Crooks, et al., 2022) found that Covid-19 patients of Black, Asian or mixed racial ethnicity had higher oxygen saturation readings than Caucasian patients. The implications of these findings not only highlight the gravity of this issue on a global scale but reiterate the level of multi-party commitment needed to address the need for greater racial and ethnic inclusivity.

In addition to geographic impact, research shows that racial inaccuracies in pulse oximetry apply concomitantly across the entire age spectrum. This is evidenced by research on pulse oximeter accuracy among pre-term infants, which determined that there was a modest but consistent difference in oxygen saturation error between Black and White infants, with the former having higher incidences of occult hypoxemia than the latter (Vesoulis, et al., 2022). These findings serve to illuminate the far-reaching implications to CRNAs as they provide anesthesia care to patients of all age groups; as such, an awareness of these research findings can help influence anesthesia plans for better pediatric outcomes.

Given the research, an overarching theme has clearly emerged of a lack of racial and ethnic diversity in medical device manufacturing and clinical trialing. This has subsequently created a profound ripple effect, across age spectrums, socio-economic strata, and across the globe that is reflected in clinical outcomes. In today’s world, the importance of racial and ethnic diversity and inclusivity is crucial and cannot be over-emphasized, particularly when it comes to devices whose use has potential life or death consequences. As it stands, the current lack of diversity in clinical trials is enabled by a lack of government emphasis on greater diversity and racial inclusivity on the manufacturing level. Therefore, it is incumbent upon not just government regulators and medical device manufacturers to reconsider their policies and practices on racial diversity and inclusivity, but all of us as equally important stakeholders to advocate more aggressively for racial inclusivity and diversity in order to gain better representation not just for ourselves as medical providers and consumers, but for our deserving patients as well.

References:

Crooks, West, J., Morling, J. R., Simmonds, M., Juurlink, I., Briggs, S., Cruickshank, S., Hammond-Pears, S., Shaw, D., Card, T. R., & Fogarty, A. W. Pulse oximeters’ measurements vary across ethnic groups: An observational study in patients with Covid-19 infection. The European Respiratory Journal. (2022); 59. https://doi.org/10.1183/13993003.03246-2021

FDA (2013). Pulse Oximeters – Premarket Notification Submissions [510(k)s]: Guidance for Industry and Food and Drug Administration Staff. Obtained from: https://www.fda.gov/regulatory-information/search-fda-guidance-documents/pulse-oximeters-premarket-notification-submissions-510ks-guidance-industry-and-food-and-drug

FDA (2021). Pulse Oximeter Accuracy and Limitations: FDA Safety Communication. Obtained from: https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication

Feldman, J. APSF Statement on Pulse Oximetry and Skin Tone. APSF Newsletter. (2021) https://www.apsf.org/article/apsf-statement-on-pulse-oximetry-and-skin-tone/

Henry NR., Hanson AC, Schulte PJ, Warner NS, Manento MN, Weister TJ, Warner MA. Disparities in Hypoxemia Detection by Pulse Oximetry Across Self-Identified Racial Groups and Associations With Clinical Outcomes*. Critical Care Medicine. 2022; 50 (2): 204-211. doi: 10.1097/CCM.0000000000005394

Jubran, & Tobin, M. J. Reliability of Pulse Oximetry in Titrating Supplemental Oxygen Therapy in Ventilator-Dependent Patients. Chest, (1990); 97(6): 1420–1425. https://doi.org/10.1378/chest.97.6.1420

Kelleher, J.F. (1989). Pulse oximetry. Journal of Clinical Monitoring (1990); 5(1): 37–62. https://doi.org/10.1007/BF01618369 Sjoding, Dickson, R. P., Iwashyna, T. J., Gay, S. E., & Valley, T. S. (2020). Racial Bias in Pulse Oximetry Measurement. The New England Journal of Medicine, 383(25), 2477–2478. https://doi.org/10.1056/NEJMc2029240

Sjoding, Dickson, R. P., Iwashyna, T. J., Gay, S. E., & Valley, T. S. (2020). Racial Bias in Pulse Oximetry Measurement. The New England Journal of Medicine, 383(25), 2477–2478. https://doi.org/10.1056/NEJMc2029240 Severinghaus, J.W.,& Astrup, P.B. History of blood gas analysis. VI. Oximetry. Journal of Clinical Monitoring (1986); 2, 17-288. https://doi.org/10.1007/BF02851177

Vesoulis, Tims, A., Lodhi, H., Lalos, N., & Whitehead, H. Racial discrepancy in pulse oximeter accuracy in preterm infants. Journal of Perinatology (2022); 42(1), 79–85. https://doi.org/10.1038/s41372-021-01230-3

Wong AI, 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(11):e2131674. doi:10.1001/jamanetworkopen.2021.31674

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Student Column by Jacqueline Sergon, originally published on AANA. View here.

AANA Presents Daniel D. Vigness Federal Political Director Award to PANA

The American Association of Nurse Anesthesiology (AANA) honored Lt. Col. Laura Wiggins, DNP, CRNA, with the Daniel D. Vigness Federal Political Director Award at its Mid-Year Assembly, held in Washington, D.C. on April 2-6. Wiggins, a Certified Registered Nurse Anesthetist (CRNA), is staff CRNA with the University of Pittsburgh Medical Center in Pittsburgh and chief nurse for the critical care transport team in the U.S. Air Force Reserve.

“It is an honor to receive the Federal Political Director Award. Promoting and safeguarding the profession and helping to work towards regulations and legislation that allow CRNAs to practice at their full scope has been both an honor and a privilege,” Wiggins said. “However, all my work could not be accomplished without the support of the Pennsylvania Association of Nurse Anesthetists and my employers. I thank them for providing me with the resources and time to build the relationships that have allowed me to be a successful advocate for all CRNAs.”

Wiggins has been the Federal Political Director (FPD) for the Pennsylvania Association of Nurse Anesthetists (PANA) for the past two years and serves on its Board of Trustees. In 2019 she helped lead more than 180 CRNAs and students enrolled in nurse anesthesiology programs to lobby in Harrisburg on behalf of the profession. She is the former Chief Nurse for the 911th Aeromedical Staging Squadron and former Critical Care Air Transport Team member and has been deployed to support numerous international situations throughout her career.

According to her nominator, Wiggins is a natural leader with a passion for nurse anesthesia. “Whether leading a medical team as the anesthesia director for military operations in Kyrgyzstan, or providing obstetric anesthesia in Pittsburgh, Laura carries herself with a sense of dignity and skill that reflects the best of our profession.”

In addition, she was lauded for her hands-on leadership early in the COVID-19 pandemic. According to her nomination, weeks before Pennsylvania Gov. Tom Wolf even issued a formal stay-at-home order for the commonwealth, the PANA board began researching options to provide personal protective equipment (PPE) to its members. Wiggins relied on her military expertise to review mask options and determine the best fit for PANA to provide to members to keep them safe.

“Laura knew early on how important it was for PANA to not disrupt the supply chain already working on PPE for local hospitals and other facilities around Pennsylvania,” cited her nomination. “Therefore, she spearheaded a discussion with a small 3D printing company in southwestern Pennsylvania. Wiggins began to work with the co-owner of the company to design a 3D-printed mask that would keep our members safe. Laura Wiggins oversaw all of the details, even recruiting a biochemist and an engineer from Stanley Black & Decker to support the cause. After numerous back-and-forth phone calls, texts, virtual calls, and prototype designs, the mask was ready to offer to members as a complimentary benefit. In the initial two hours of sending the e-mail to alert members about the free product offering, PANA received over 400 requests. When completed, PANA shipped over 1,200 PPE masks around the state within four weeks, and this was largely due to the work of Lt. Col Laura Wiggins.”

She is a clinical instructor at the University of Pittsburgh Nurse Anesthesia Program for various courses, including Difficult Airway Course; Regional Anesthesia; and Obstetrics Anesthesia. As a critical care nurse in the Air Force Reserves, Wiggins directly supervises more than 60 medical military personnel while managing all nursing services and flight member activities. In addition, she is an independent contractor with Anesthesiology Services Network, providing anesthesia services for a Level One Trauma Center with 24 operating rooms and diverse areas, including neurosurgery, vascular, thoracic, orthopedics, general, gynecology, pediatrics, trauma, and obstetrics.

Wiggins received her bachelor’s degree in nursing from Pennsylvania State University in State College, and a master’s degree in nursing with a specialization in nurse anesthesia area from Uniformed Services University in Bethesda, Maryland. She earned a Doctor of Nurse Practice degree from the University of Pittsburgh.

As advanced practice nurses, CRNAs are members of one of the most trusted professions according to Gallup. CRNAs provide anesthesia care across all settings and in all patient populations and are the primary anesthesia providers in rural and underserved areas and on the battlefield in forward surgical teams.

During the COVID-19 pandemic, nurse anesthetists across the country have been essential in addressing the deadliest part of the disease in addition to providing top-of-the-line anesthesia care. They have served as experts in airway management, hemodynamic monitoring, management of patients on ventilators, and overall management of critically ill patients.

About the Daniel D. Vigness Federal Political Director Award

The Federal Political Director of the Year Award, established in 2001, was renamed the Daniel D. Vigness Federal Political Director Award in 2013 in tribute and memory of its first winner. It is presented annually to an individual who has made a significant contribution to the advancement of the national healthcare agenda of CRNAs by coordinating grassroots CRNA involvement at the state level or through special contributions to the federal political process.

Pennsylvania SRNA Receives National Accolades

A Pennsylvania nurse anesthesia student received the 2020 AANA Student Excellence Award.

Ryan Wade, a senior at the Allegheny School of Anesthesia/La Roche University, accepted the award during the virtual Annual Congress.

The national award is an annual honor presented to a student in good academic standing who demonstrates outstanding leadership and professionalism, participates in activities that help foster a positive public image of nursing, and engages in activities that support health care.

Wade demonstrated his capacity for leadership and professionalism during his first clinical rotation when he took swift action to help a nurse found unresponsive on the floor. He immediately began CPR and called out for help, remaining calm as he continued providing care. Wade’s actions and competence helped her survive the cardiac arrest, intact cognitively. Her subsequent care uncovered additional complications, and though she later passed away, the family kept in contact with Wade, inviting him to attend her memorial service.

He also maintained academic excellence while being active with PANA. Wade has been an advocate for CRNAs in Pennsylvania by serving on PANA’s Government Relations Committee. He was an active member of the committee for two terms, having participated in numerous events. Wade met with state legislators and committees, including legislative leaders such as former Speaker of the House Mike Turzai and the House Veterans Affairs & Emergency Preparedness Committee. His efforts also extended to the federal level, having met with Vice-President Mike Pence.

"Ryan is a leader among his peers and has consistently exceeded our expectations these past two years,” said PANA Director of State Government Affairs Jessica Poole, DNAP, CRNA. “His drive and enthusiasm is contagious and his wisdom and insight exceeds well beyond his level of training. He represents our profession with tact and professionalism."

Locally, he displayed his professional promise and capabilities of serving the community by serving as a PANA spokesperson to WTAE, a Pittsburgh news channel. During the broadcast, he demonstrated proper use of PPE and informed the public of PANA’s purchase of 3D N-95 masks, intended to support Pennsylvania CRNAs working with COVID-19 patients.

“I envision he will continue in his efforts to privately and publicly represent our profession as a knowledgeable, competent and pre-eminently invested CRNA after graduation,” said Allegheny School of Anesthesia Program Director Deborah Davison, DNAP, MS, CRNA. “I am very proud of his accomplishments and feel confident that he is deserving of this award as recognition for his hard work.”

PANA applauds Ryan Wade’s achievements as an SRNA and congratulates him on this well-deserved national recognition.