Episode 110: Pulse Ox in Dark-skinned People.
Learn about the most recent findings in pulse oximeters in dark-skinned people. Bahar and Arianna explain the new recommendations by FDA regarding this topic.
Written by Bahar Hamidi, MS4; and Arianna Crediford, MS4. American University of the Caribbean (AUC). Comments by Hector Arreaza, MD.
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Bahar: When I first saw this news breakout on CNN I was stunned! A cohort study just published (7/11/22) in JAMA called “Assessment of Racial and Ethnic Differences in Oxygen Supplementation Among Patients in the Intensive Care Unit” revealed that Asian, Black, and Hispanic patients received less supplemental oxygen than White patients, because of the differences in pulse oximeter performance, which may contribute to known race and ethnicity–based disparities in care. I cannot believe this discovery has not been given the attention it deserves earlier. I believe maybe COVID had a lot to do with it; as checking the pulse ox deciphered the patients’ treatment plan. Let’s think about it for a moment, how important is the pulse ox accuracy?
Arianna: Well, we know that insufficient administration of supplemental oxygen can make changes in the initiation and management of noninvasive verse invasive mechanical ventilation. The study mentions some other important points like pulse oximeter performance disparities playing a role in decision-making regarding fluid management, specialty service consultation, and even intensive care unit (ICU) admission.
Bahar: It states, “artificially high SpO2 readings in the emergency department could also affect the perceived need for cardiology service admission for heart failure management, possibly explaining the finding that Black and Hispanic patients were less likely than White patients to be admitted to a cardiology service.”
Arianna: So how you may ask the study really put this to the test? The large cohort study had 3,069 patients in the intensive care unit, so what they did was they took the average hemoglobin oxygen saturation for each patient and tracked how much supplemental oxygen was given to the patients and lo and behold, the data revealed that Asian, Black, and Hispanic patients had a higher adjusted time-weighted average pulse oximetry reading and were administered significantly less supplemental oxygen compared with White patients even with adjusting for potential confounders.
Bahar: And what is the solution you may ask? Well, the FDA issued a new draft guidance that recommends companies making medical products submit a “race and ethnicity diversity plan” to the agency early in their development of products, and that a plan should include enrolling diverse groups of people into their clinical trials as of April 2022. As a reminder, it's been a year since CDC declared racism a public health threat.
Arianna: Rutendo Jakachira is a Ph.D. student in Brown University's Department of Physics. She is studying racial disparities in pulse oximetry. She stated that COVID-19 likely helped uncover the suspected pulse oximeter limitations in dark-skinned people. Kimani Toussaint is a professor and senior associate dean in the School of Engineering at Brown University. Jakachira, Toussaint, and their colleagues from Engineering at Brown University are developing non-invasive methods to make pulse oximeters more accurate in blood oxygen readings for people with dark skin tones.
Bahar: Toussaint stated that they are “trying to mitigate the skin tone issues by doing something interesting with the light, but it’s a significant challenge and this really highlights the need to have diversity and inclusion.”
Pulse oximeters work by sending beams of light through the fingertips to measure blood oxygen levels, they are actually measuring how much oxygen has been absorbed by hemoglobin. Melanin is the brown pigment that gives color to our skin, hair, and eyes. It turns out that both hemoglobin and melanin absorb light at similar wavelengths and it can be challenging to separate their contributions to the detected level of oxygen.
Arianna: Toussaint explains that melanin will overlap with the absorption properties of the hemoglobin in your blood, which can lead to inaccurate pulse oximeter readings because people have different amounts of melanin.
Bahar: Jakachira and Toussaint are trying to cancel out the effect of melanin on how pulse oximeters measure blood oxygen levels. The result of this work would be a contribution that can be applied to other similar-based technologies that measure levels of substances through the skin, but they could not share additional details of their proceedings as the research team is currently completing a patent application. Now what is also shocking is that there have actually been prior studies that have shown differences of several percentage points in SpO2 for a given hemoglobin oxygen saturation between Black and White patients, but in the past, the clinical significance of these findings was discounted and downplayed.
Arianna: I think this study and discovery urges further studies in different regions and not just at one institution or geographic location. The article encourages further exploration of specific factors within a racial and ethnic group that could put some patients at particularly high risk of oxygenation disparities, including skin tone, degree of desaturation, exposure to specific oxygen delivery devices, comorbidities, and other sociodemographic factors.
Bahar: Some other studies they hope will be performed are:
-Differences in oxygen supplementation in patients receiving invasive or noninvasive positive pressure ventilation and a potential association of vasopressors and inotropes AND Clinical decisions other than oxygen delivery that may be affected by pulse oximeter performance discrepancies.
Arianna: So we can definitely say that some groundwork has been done but further research is needed to confirm these findings and explore other clinical factors associated with treatment disparities.
Bahar: It is great to stay in the loop and know what health care providers should look out for, I hope this podcast will raise awareness of the matter and hopefully we come up with a more accurate Pulse Ox prototype that will be fit for all ethnicities and skin tones.
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Conclusion: Now we conclude episode number 110 “Pulse Ox in Dark-skinned People.” Today we learned that pulse oximeters are being adjusted to become more accurate in different shades of skin. We are working together to make medicine a better science for all. “Not everything that is faced can be changed, but nothing can be changed until it is faced,” said James Baldwin. This week we thank Hector Arreaza, Bahar Hamidi, Arianna Crediford, Valeri Civelli, and Ariana Lundquist. Audio by Adrianne Silva.
Even without trying, every night, you go to bed being a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. If you have any feedback, contact us by email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. See you next week!
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References:
- Gottlieb ER, Ziegler J, Morley K, Rush B, Celi LA. Assessment of Racial and Ethnic Differences in Oxygen Supplementation Among Patients in the Intensive Care Unit. JAMA Intern Med. Published online July 11, 2022. doi:10.1001/jamainternmed.2022.2587. https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2794196
- Howard, Jacqueline, Scientists are searching for solutions after studies show pulse oximeters don't work as well for people of color, CNN Health, Published on July 11, 2022. https://www.cnn.com/2022/07/11/health/pulse-oximeters-dark-skin-study/index.html
- Royalty-free music used for this episode: Good Vibes Alt Mix by Videvo, downloaded on May 06, 2022 from https://www.videvo.net/royalty-free-music-track/good-vibes-alt-mix/1017292/
