ABG's and O2

[Helper330]

Ok today i had a patient on a vent. Day two of being in a coma, he was found in his appartment by a neighbor, and sent to the ER. Today I was looking at his ABG's pH 7.38, CO2 40, O2 239, and HCO3 22. My question is why is the O2 so high everything that i look up talks about O2 being normal or low, so why is it high?

[Double-Helix, BSN, RN]

Most likely because he is receiving a high concentration of oxygen on the vent. He needs to be hyper-oxygenated to provide adequate oxygen flow to his tissues, but his blood still has normal O2 carrying capacity.

The normal ABG ranges that you'll have in your lab book refer to patients who are breathing spontaneously 21% O2, or room air. But your patient is probably receiving at least 50% or higher FiO2 on the vent, which is going to make the PaO2 shoot up.

[ckh23, BSN, RN]

To piggyback onto Ashley, you have to know what your vent settings are and what the patient is doing on the vent. As an example, if the patient's vent is set on 100% FiO2 and his body is not in a hyper dynamic state and the tissue is adequately oxygentated, it will not need the o2 and it will stay in the blood stream.