Please see Bibliography of References for a list of abstracts, manuscripts and posters.

Other Studies

Skeletal muscle oxygen saturation estimates mixed venous oxygen saturation in patients with severe left heart failure

Podbregar M, Mozina H. Crit Care. 2007;11(Supp 2):S112. Abstract P273.

Introduction: Low cardiac output states such, as left heart failure, are characterized by preserved oxygen extraction ratio compared to severe sepsis. Near-infrared spectroscopy (NIRS) allows non-invasive estimation of skeletal muscle tissue oxygenation (StO₂). Aim of study was to determine relationship between StO₂ and mixed (SvO2) venous oxygen saturation in patients with severe left heart failure with or without additional severe sepsis or septic shock.

Methods: 65 patients with severe left heart failure due to primary heart disease were divided into two groups: Group A- patients without (n=24) and Group B- patients with (n=41) additional severe sepsis/septic shock. Thenar muscle StO₂ was measured using NIRS.

Results: In Group A StO₂ was lower compared to Group B and healthy volunteers (58±13 % vs. 90±7% vs. 84±4% p<0.001). StO₂ was higher in Group B compared to healthy volunteers (p=0.02). In Group A StO₂ correlated with SvO2 (r=0.689, p=0.002), StO₂ overestimated SvO2 (bias: -2.3%, precision: 4.6%). In group A changes of StO₂ correlated to changes of SvO2 (r=0.836, p<0.001; ÄSvO2 = 0.84 x ÄStO₂ -0.67). In Group B important disagreement between these variables was present. Plasma lactate concentrations negatively correlated with StO₂ values only in group A (r=-0.522, p=0.009; Lactate = -0.104 x StO₂ +10.25).

Conclusions: Exact numerical values of StO₂ are not equivalent to those of SvO2. However, for clinical purpose, StO₂ values could be used for fast noninvasive SvO2 estimation; and the trend of StO₂ may be substituted for the trend of SvO2 in severe left heart failure without additional severe sepsis or septic shock.