Interpretation of venous-to-arterial carbon dioxide difference in the resuscitation of septic shock patients

The evaluation and correction of macrocriculatory and microcirculatory flow play an important role in the resuscitation of circulatory shock (1). The venous-to-arterial carbon dioxide difference [P(v-a)CO2] has gained great attentions in the resuscitation of sepsis. The P(v-a)CO2 is determined by cardiac output and metabolic status, and it has been taken as an indicator of the adequacy of the venous blood ？ow to remove the CO2 produced by the peripheral tissues (2,3)