Why would a abg test show a low p02 of 72 ? what would fix this?

A PAO2 of 72 is not considered hypoxic-or low oxygen level. This is different from the oxygen saturation which is above 90%. Increasing the respiratory rate and/or taking deeper breaths would increase your oxygen level. Supplemental oxygen would also increase the levels but an oxygen level you describe would not qualify you for supplemental oxygen. Good luck to you!

The most commonly accepted ranges for PaO2 are 75-100 to 80-100. 72 appears slightly low and without clinical context it is impossible to further comment or speculate, oxygen is usually supplemented per nasal cannula, everything else has to do with addressing the cause of it if indeed suggesting hypoxemia.