The major goal of hemodynamic treatment is to reach adequate flow. Near infrared spectroscopy (NIRS) allows non-invasive assessment of skeletal muscle tissue oxygenation during rest and also during vascular occlusion test (VOT). VOT allows estimation of tissue oxygen extraction capability, which could be preserved (i.e. hypovolemic, obstructive and cardiogenic shock) or inappropriate (i.e. sepsis/septic shock). By using ultrasound to estimate cardiac output, arterial hemoglobin oxygen saturation, skeletal muscle NIRS, arterial lactate and hemoglobin, therapeutic goals in critically ill patients with preserved oxygen extraction capability can easily be targeted. Current controversies of NIRS technology and approach to patients with impaired oxygen extraction are discussed as well.
Key words: shock, skeletal muscle, near-infrared spectroscopy, critically ill