Severity of disease Sepsis-related Organ Failure Assessment (SOFA score) was calculated at the time of each measurement to asses the level of organ dysfunction. Dobutamine, norepinephrine requirement represented the dose of drug during the Sto2 measurement. Used of levosimendan is reported if patient received the drug less then a week before inclusion in the study. Use of intra-aortic balloon pump during ICU stay is reported.