Predictability of arterial pH and PCO2 from right atrial blood samples in experimental animal

Arterial and right atrial blood samples were drawn simultaneously under acutely changing acid-base and ventilatory conditions in a series of experiments carried out in nine pigs. The pH, PCO2, bicarbonate concentration and base excess from arterial and right atrial blood are compared. The predictability of the arterial values from the right atrial values is discussed. It is concluded that right atrial blood samples are approximately as informative as arterial blood samples for determining the acid-base status under both normal and acutely changed acid-base and ventilatory conditions.