Oxygen is essential for life because it is required for the process of cellular respiration, which is the process by which cells of the body convert nutrients into energy. Oxygen is carried by the hemoglobin in red blood cells via the circulation to all the living cells of the body. Without sufficient oxygen, the cells are unable to meet their energy needs, which can lead to damage or death of the cells. The brain and heart are particularly vulnerable to low levels of oxygen in the body.
Low blood oxygen (called hypoxemia), can be caused by a variety of conditions that affect the lungs. These include COPD, infections (e.g. COVID or influenza, or RSV), blood clots, fluid in the lungs (e.g heart failure).
A pulse oximeter is a device that measures the oxygen saturation of a patient’s blood. It does this by using a sensor that is placed on a a fingertip or skin. The sensor contains two LED lights, one red and one infrared, that shine through the skin and into the pulsating bloodstream. The amount of light absorbed by the blood is then used to calculate the oxygen saturation, or the percentage of hemoglobin molecules in the blood that are carrying oxygen.
Oximeter accuracy may be affected by the amount of melanin, the pigment that gives color to the skin. Melanin can absorb light, and the more melanin there is in the skin, the less light will reach the blood vessels beneath the skin. This might make it more difficult for the oximeter to accurately measure the oxygen saturation of the blood of some patients. Some studies have found that pulse oximeters may not be as accurate in individuals with darker skin tones, specifically in low oxygen conditions. It’s important to note that it’s still possible for dark skinned individuals to use pulse oximeters, but it’s important to also rely on other clinical signs for a more accurate reading, such as oxygen saturation from blood gas analysis, and physical examination in emergency or critical care settings.
Simply put, pulse oximeters appear likely to provide misleading measures of blood oxygen levels to patients of color- indicating that patients are healthier than they actually are and increasing their risk of negative health impacts from diseases like Covid 19, C O P D, Asthma and Pulmonary Fibrosis.
CNN reports about the problem with people of Color be misdiagnosed due to improper measurements from Oximeters
Senators Warren, Booker, Markey, Wyden, and Duckworth Renew Request for FDA to Address Concerns about Dangerous Pulse Oximeter Inaccuracies | U.S. Senator Elizabeth Warren of Massachusetts