The use of any hemodynamic monitoring technique is to provide reliable and reproducible information on the cardiocirculatory status of a patient in shock. The collected values will enable the intensivist to understand the condition of the patient and to make more informed treatment decisions to optimize the hemodynamic status and improve the prognosis of the patient. Hemodynamic monitoring is required to assess systemic and regional tissue perfusion, and the correction of hemodynamic instability and tissue hypoperfusion is essential to prevent the occurrence of multiple organ failure. In the first part of this thesis, we present the hemodynamic monitoring parameters available to the clinician and their pathophysiological importance.In the second part of this work, we summarize our original clinical research, reviews and comments written during the past six years on several hemodynamic monitoring techniques. Finally, in the third part of this work, we detail our animal research.