Respiratory illnesses, including conditions such as asthma, Chronic Obstructive Pulmonary Disease (COPD), pneumonia, tuberculosis, and Covid-19, have emerged as significant causes of death and disability worldwide. Contributing risk factors for these respiratory diseases include smoking, exposure to air pollution, and certain chemicals. This article aims to shed light on these risk factors, delve deeper into how pulse oximeters measure oxygen levels in the blood, and discuss the issues surrounding their accuracy.
Table of Contents
Respiratory Illnesses and Risk Factors
According to information provided by the FDA, smoking, air pollution, and age are among the leading risk factors for respiratory illnesses. Smoking, in particular, is a significant contributor to lung diseases as it damages the air passages and the small air sacs (alveoli) found in the lungs. Air pollution, on the other hand, can irritate the airways and cause shortness of breath, coughing, and other respiratory symptoms. Age also plays a part, with older adults more susceptible to respiratory diseases due to a decreased immune function and lung elasticity.
The Role of Pulse Oximeters in Monitoring Oxygen Levels
Pulse oximeters play a crucial role in monitoring the oxygen levels in the blood. They provide a non-invasive method to measure the oxygen saturation level (SpO2), which indicates how much oxygen the blood is carrying. A normal SpO2 reading is typically between 95% and 100%. Readings below 90% are usually considered low and can indicate a medical emergency. However, there have been concerns regarding the accuracy of these devices, especially in individuals with darker skin pigmentation.
Accuracy Issues with Pulse Oximeters
The FDA convened an advisory panel to discuss the concerns that pulse oximeters may provide less accurate readings in people with darker skin pigmentation. This discrepancy can lead to overestimation of oxygen saturation levels, potentially resulting in delayed medical care. The advisory panel discussed recommendations to address this issue, including the need for clinical trials of pulse oximeters to be more inclusive, with a minimum of 24 participants. They suggested using the Monk Skin Tone (MST) scale and the Individual Typology Angle (ITA) at the sensor site for measurements, to ensure accuracy across different skin tones.
Improving the Technology
The FDA advisory panel emphasized the need for improving the technology of pulse oximeters to ensure accurate readings across all skin tones. They also highlighted the need for more diverse clinical trials and encouraged manufacturers to follow stricter requirements, similar to those for prescription-use devices. However, they acknowledged the value of pulse oximeters in saving lives by providing immediate and essential information on a patient’s oxygen level.
The Accuracy of Wearable Devices
Wearable devices like the Apple Watch Series 7 and Garmin Venu 2s, which also measure blood oxygen saturation, have been evaluated for their accuracy. The study findings showed that while these devices show promise for continuous monitoring, their accuracy varies. For instance, the Apple Watch Series 7 had measurements closest to the reference standard, but the Garmin Venu 2s had measurements farthest from it. It is important to consider these limitations for their appropriate use in clinical settings.
In conclusion, while pulse oximeters and wearable devices serve as valuable tools in monitoring SpO2 levels, it is crucial to address the accuracy issues associated with these devices. As we continue to rely on this technology, manufacturers must strive to improve their products and ensure their efficacy across all demographics.
