PICCO, or hemodynamic monitoring, refers to pulse wave indicator continuous cardiac output monitoring, a therapeutic tool for continuous monitoring of major hemodynamic parameters in critically ill patients. PICCO technology replaces the original pulmonary artery catheterization, which utilizes transpulmonary thermodilution and pulse wave contour analysis to achieve continuous measurement of major hemodynamic parameters in critically ill patients for patient hemodynamic monitoring and volume management.PICCO is characterized by simplicity, minimally invasiveness, and high efficiency ratio. PICCO can monitor cardiac output and index of each heart beat, arterial pressure, heart rate, cardiac volume per beat and index, peripheral vascular resistance and index, etc., reflecting the hemodynamic situation, which can assist physicians to make effective clinical treatment decisions.