Role of PCO2 and pH measurements sampled from the right atrial cavity via the central venous catheter in open heart surgery

ABSTRACT

CO2 and W produced in tissus come into venous blood. Can PCO2 and pH sampled from the right atrial blood via a central venous catether approriately replace the arterial PCO2 and pH in open hear surgery? Objectives: To evaluate the correlation and the agreement of PCO2 and of pH between the arterial and venous right atrial blood. Methods: Cross-over study with matched comparision, calculation of paired t test, coefficient of correlation r (Pearson), agreement (Bland-Altman). Results: Arterial-venous right atrial PC02 gradient-5.68 (+/-2.44), r = 0.92 and narrow agreement. Arterial-venous right atrial pH gradient 0.04 (+/-0.02), r = 0.94 and narrow agreement. Conclusion: PCO2 and pH of the right atrial blood can safely replace the arterial PCO2 and pH in cardiac anesthesia and intensive care.