The aim of our study was to study skeletal muscle oxygen kinetics in low flow state due to combined cardiogenic and septic circulatory failure, relate it with central heamodynamic variables and outcome. We hypothesized that basal StO2 could relate to ScvO2, because blood flowing through upper limb muscles importantly contributes to flow through superior vena cava. The second hypothesis was that decrease of skeletal muscle OER and lower muscle oxygen consumption are more pronounced in patients with septic component of circulatory failure due to microcirculatory and metabolic changes seen in sepsis, what results in higher mortality.