Oxygenation Status: The Final Piece

A complete ABG interpretation also includes a comment made on the oxygenation status. This is the easiest part. Hypoxia is graded in stages. Since this low-oxygen reading is coming from arterial blood, instead of hypoxia, it is referred to as hypoxemia (hypoxia in the blood). “Hypox” means low oxygen; “emia” means in the blood.

Hypoxia versus hypoxemia? Don’t get confused here. Both terms essentially mean the same thing. The only difference between these words is where the low oxygen state was read from. Does the patient have low oxygen that is read off of the SpO₂ and clinical picture of the patient? The patient is hypoxic. If you took a sample of arterial blood and tested it and found low oxygen, then you would say the patient has hypoxemia (low oxygen in the blood).

Whatever the PO₂ is, look at where the number falls on the hypoxia description. At the end of your complete ABG interpretation, you add your comment on oxygenation, referring to the following ranges:

Don’t feel you have to memorize the levels. As long as you know the normal levels, and severe is <40 mmHG, then make each stage 20 mmHg above. It is easy to remember, as each stage represents 20 mmHg.

Now, let’s look at what the comments will look like based on what we have learned by looking at three examples:

1. pO2 of 62? Add “with mild hypoxemia” to the end of your ABG interpretation.
2. pO2 of 49? Add “with moderate hypoxemia” to the end of your ABG interpretation.
3. pO2 of 93? Add “with normal oxygenation” to the end of your ABG interpretation.