Is it necessary to transport arterial blood samples on ice for pH and gas analysis?

We evaluated whether arterial blood samples for pH and blood gas analysis need to be transported on ice. We found that although the changes in pH, pCO2 and pO2 were greater in samples kept at room temperature versus those kept on ice, the difference was probably not of clinical significance until the period of time after arterial puncture exceeded 20 minutes. We recommend that arterial blood samples do not need to be kept on ice if the analysis for pH and gases is performed within 20 minutes of blood being drawn.