How to check an Error in ABG ? ABG analysis

Sometimes, clinicians might find ABG result not matching with the patient condition. These results might arise from technical errors in machine and there are certain points which can be used to check the error.

How to Check whether ABG result is Right or has Error?

1. Check patient and ABG correlation
2. Check Lab values: If TCO2- HCO3 > 4meq/L , likely technical error.
3. For pH 7.3 to 7.5, actual bicarb should be

X= 24X PaCO2/HCO3

Y= 80- V

Y should be around last 2 digits after decimal of pH.

V= 30

4. PaO2 –pCo2 relationship: paO2 + PaCO2 should never exceed > 150 mmHg( if not under oxygen.)
5. PaO2-FiO2 relationship.

Also:

And:

If you have any comments, please leave it below.

Dr. Pedchrome

MD Pediatrics and Fellowship Neonatology, he chooses to stay anonymous. He often writes his views online as well as share few important topics for medical students, doctors and specially parents. He does research in pediatrics.