“Common errors associated with improper sample collection and storage are
1. If the sample is left uncapped for a prolonged period, the partial pressure of carbon dioxide in the arterial blood (PaCO2) and the PaO2 may decrease. The PaO2 may increase if the sample PaO2 is less than the partial pressure of oxygen in the room (e.g. venous blood).
2. If the sample is unchilled for a long period, cellular metabolism will continue, the PaO2 will decrease, and the PaCO2 will increase.
3. If the blood is not anticoagulated, the sample will clot in the system and cause an error.”
—Kurt A. Grimm, DVM, MS, PhD, DACVA, DACVCP
From Arterial blood gas analysis and interpretation in anesthetized patients