Abnormal blood carbon dioxide level Elevated pCO2 gap 2025-12-18T15:49:31Z Central venous-arterial carbon dioxide difference (PCO2 gap) can be a marker of cardiac output adequacy in global metabolic conditions that are less affected by the impairment of oxygen extraction capacity. The difference between the venous-to-arterial carbon dioxide saturation (Pv-aCO2) is above the upper limit of normal. Increased pCO2 gap