Hi, All,

How would you describe a pulse oximeter, and its function, to someone who asked you about this (in the context of Covid, of course).

Thanks!

A little device that checks the oxygenation level of your blood. (Recall your blood gets oxygenated in the lungs and carries oxygen to the rest of your body.)

The result is expressed as a percentage of total capacity. So 98, 99 are great readings. Below 88 (sustained) is considered low enough for supplemental oxygen.

I'd add that pulse oximeters became a thing with COVID because blood oxygen can gradually drop to dangerously low levels without people realizing that it's happening.

This NPR article describes what happens:

https://www.npr.org/sections/g...good-idea-to-buy-one

Says you. I’ve had one since 2008.

I'll never forget the first one I laid eyes on.

It was 1987, and the NICU where Muffin's Sister was treated was using them to track the babies' oxygen levels. Oximeters were attached to the babies' big toes with copious medical tape. Given that their toes were hardly bigger than fat grains of rice, this had to be carefully done, with the foot then being positioned so that the oximeter was being supported by the bed and not the baby's foot or ankle.

It was fascinating when the doctors explained how they worked, and it was obvious how much better control the oximeters gave over oxygen levels. Before, the respiratory therapists would draw a bit of blood from a baby's umbilical line and run tests for CO2 and pH. This could only be done a few times during a shift. (I don't recall if they were able to get O2 from these quick tests.) Based on the results, they would adjust the amount of oxygen coming through the respirator or cannula. With the oximeter, the nurse could monitor the levels constantly and in real time, and the doctor could leave standing orders for what levels prompted a change in O2 levels.

Besides the general life-and-death nature of blood oxygen levels, they are also at the root of the blindness that used to be common with premature babies that was caused by high blood oxygen levels. Muffin's Sister's doctor pioneered a number of treatment protocols, including oximeter usage, and one of the nurses made sure that I knew that that he had never had a baby go blind from retinopathy of prematurity.

Fascinating tidbit about pulseox readings that I learned in EMT class -- they can be very deceiving in the case of carbon monoxide poisoning because the pulseox detects carbon monixide in your blood the same as oxygen. You could have a pulse ox reading of 95% but in reality only 70% of your hemoglobin is attached to oxygen and the rest is attached to carbon monoxide and you'd basically be dead but the pulseox would show you as perfectly healthy. The pulseox is really detecting the percentage of your hemoglobin that is attached to *something* -- most of the time that is oxygen, but if you've been inhaling CO, it will be carbon monoxide...but the pulseox has no way of knowing that and will think you are just peachy.

I learned something today.

Me too!

I've been using one for several years due to post-pneumonia lungs. Also post-op care.

Interesting info!