Prognostic significance of central venous-to-arterial carbon dioxide difference during the first 24 hours of septic shock in patients with and without impaired cardiac function

To investigate the prognostic significance of central venous-to-arterial carbon dioxide difference (cv-art CO2 gap) during septic shock in patients with and without impaired cardiac function. We performed a prospective cohort study in 10 French intensive care units. Patients suffering from septic shock were assigned to the impaired cardiac function group (‘cardiac group’, n=123) if they had atrial fibrillation (AF) and/or left ventricular ejection fraction (LVEF) 0.9 kPa; n=19) had a higher day 28 mortality (37% vs. 13%; P=0.042). In the non-cardiac group, a high cv-art CO2 gap was not linked to a higher risk of day 28 death, whatever the threshold value of the cv-art CO2 gap. Patients with septic shock and with AF and/or low LVEF were more prone to a persistent high cv-art CO2 gap, even when initial resuscitation succeeded in normalizing MAP, CVP, and ScvO2. In these patients, a persistent high cv-art CO2 gap at 12 h was significantly associated with higher day 28 mortality.