Improving the validity of peripheral venous blood gas analysis as an estimate of arterial blood gas by correcting the venous values with SvO₂.

Background: Peripheral venous blood gas (pVBG) analysis in replacement of arterial blood gas (ABG) is limited by the unpredictable differences between arterial and venous values, especially for PCO2 and pH (ΔPCO2 and ΔpH).

Objectives: We hypothesized that, using the theoretical relationship linking SvO2 and blood flow, we could diminish the effect of local circulatory conditions on ΔPCO2 and ΔpH and thereby increase pVBG validity.

Methods: This was a prospective cross-sectional study performed in emergency patients requiring a blood gas analysis in which ABG and pVBG were performed simultaneously.