By Brenda J. Hoilman, RN |
Many people who have COPD want to know: How do you know when supplemental oxygen is needed? What do my PO2 and O2 Sat. tell me?
There is disagreement among many doctors as to its value and its dangers. There are some basic guidelines............but a basic understanding of the lungs functioning is needed first.
First thing is that most people don't seem to understand the difference between the PO2 reading and the O2 Saturation.
The PO2 measures the amount of dissolved oxygen in the blood. The oxygen saturation is the amount of oxygen actually carried by the hemoglobin.
I don't want to get too complicated here. You just need to know that the two measurements are not the same. I see people with PO2 of 80 thinking it is really bad because they relate it to O2 Sat levels rather than PO2.
Here is a comparison table of PO2
and Equivalent O2 Saturation Levels
O2 Saturation | PO2 |
98% | 100 mmHg |
95% | 80 mmHg |
89% | 60 mmHg |
84% | 50mmHg |
35% | 20mmHg |
I know this is a little confusing.
What it boils down to is that you cannot determine whether you need oxygen
supplementation. A pulmonary doctor, armed with your blood gas information
and your other info can. Do be aware that doctors that are not pulmonary
specialists often don't seem to understand the uses/dangers/guidelines
for the use of oxygen in COPD. It is just a very
special field of understanding.
Brenda J. Hoilman RN
June 1998
On November 28, 1998, shortly after this piece was writen by Brenda, she passed away. She will be missed by the many whom she helped and all those who knew her. |