Computer-Assisted Analysis of the Impact of Respiratory Quotient on Blood CO2Tension and pH Changes

A computer model for the accurate quantification of blood gas exchange components was used to assess the impact of respiratory quotient (RQ) on venoarterial CO₂tension and pH differences over a large group of patient measurements. The combined use of measured and computer-generated data has shown that, for any given increase in blood CO₂concentration (i.e., when the arterial blood becomes venous), the associated increase in CO₂tension and decrease in pH are inversely related to the RQ, and that this relationship is mediated by the Haldane effect. These results are useful for a thorough understanding of blood gas and metabolic interactions in normal and abnormal states, and for improving the interpretation of changes in venoarterial CO₂tension gradient in clinical monitoring.