engleski

Oxygen consumption and CO2 elimination in sepsis

We monitored systemic oxygen consumption (VO2) and CO2 elimination (VCO2) in 20 patients with conventional sepsis criteria during the usual hemodynamic resuscitation procedure. We were led by the assumption that during the conditions of critical oxygen delivery reduction (DO2 crit.) CO2 elimination becomes increased, and that we can recognise this patophysiological phenomenon from the VCO2 and VO2 relationship. We measured VO2 and VCO2 with expiratory gas analysis using the metabolic monitor, and we followed hemodynamics with an invasive technique based on the use of pulmonary arterial Swan-Ganz catheter. The cardiac output was measured by thermodilution, and oxygen transport variables were determined according to the standard procedures and formulas and from in vitro analysis of peripheral arterial and mixed venous blood. During the 6-hour observation period, higher VO2 and VCO2 oscillations individually were found. In the conditions of relatively low VO2, higher VCO2 values were found. The high level of negative linear correlation (Pearson r correlation) was found between cardiac index (CI) and respiratory quotient (RQ), r=0.85, p=0.002. The correlation between oxygen delivery (DO2) and RQ is similar, r=0.733, p=0.01. The high level of positive correlation was found between RQ and vein-arterial CO2 gradient (V-aDCO2), r=0.79, p=0.016. Our preliminary conclusion is that from the findings of relatively low VO2 and raised RQ it is possible to recognise early circulatory instability in patients with sepsis.

circulatory instability; CO2 elimination; hemodynamic resustitation; oxygen consumption

01/0112910