Shedding light on venoarterial PCO₂ gradient

Abstract

As an expression on Fick’s principle, the reduction in cardiac output is associated with a parallel increase in both mixed venoarterial CO₂ content diference (C_mv-aCO₂) and arterial-mixed venous oxygen content diference (C_a-mvO₂). Nevertheless, disproportioned elevations in C_mv-aCO₂ compared to those of C_a-mvO₂ ensue when the anaerobic threshold is reached. Tis results from anaerobic CO₂ production, secondary to the bufering of anaerobically generated protons by bicarbonate.