Pulse oximeters are useful medical devices that can measure the percentage of blood that is saturated with oxygen. These devices are extremely common in pre-hospital care due to their small size and portability. Larger variants are also frequently used in hospitals and clinics. Pulse oximeters have been used by medical professionals for several decades. More recently, these handy devices have started being made available to the general public.
Many companies have begun selling pulse oximeters for home use. These home pulse oximeters are available in many formats ranging from sports watches with built-in pulse oximeters, to stand-alone units. The benefit of having these handy devices available to the public is that people are able to monitor their own blood oxygen saturation at home. This is something that can be useful for people who suffer from respiratory conditions as well as for athletes. In some cases it can even help monitoring Covid-19 symptoms. However, behind this benefit hides several limitations that the majority of nonprofessional consumers will be completely oblivious to.
Limmitations of home pulse oximetry:
The first issue with home pulse oximetry is accuracy. A very large percentage of pulse oximeters that are sold for home use are not approved by any regulatory organizations. As such, the accuracy of their measurements can be very poor. When compared with models that are certified for hospital and pre-hospital use, these pulse oximeters may display wildly different and inaccurate results. A study conducted on 6 inexpensive pulse oximeter models demonstrated that of the six models tested, 4 were inaccurate by over 6%. For comparison, the safe range for blood oxygen readings is generally between 95% and 100% (a 5% range).
Another limitation of all pulse oximeters is that correctly interpreting their results requires a certain degree of medical training and knowledge. Pulse oximeters don’t directly measure the oxygen in the blood. Instead, they measure the percentage of blood that is saturated. They can’t tell you if your blood is saturated with oxygen, or something else. This can be particularly life-threatening if a person’s blood is saturated with carbon monoxide (CO). Since carbon monoxide bonds with blood even better than oxygen, it can block oxygen from being circulated in the bloodstream. If that person were to take a pulse oximeter reading, it would likely show 100% which would give the person false comfort. Instead of getting the help they need, they would become more and more hypoxic (oxygen-deficient) and could pass out or die.
Healthcare professionals are trained to consider the possibility of blood being saturated with other substances, but many consumers don’t even know that such a thing is possible. For these reasons, pulse oximeter use by the general public has the potential to be hazardous.