With its powerful ability to monitoring and support of organs, the survival rate of critically ill patients has been improved significantly by critical care medicine. Critical ill patients centralized in ICU accepted the treatments given by multidisciplinary team as a mode have played a very important role, especially during the rescue of victims in public health emergencies and natural disasters. Changings of the measures of monitoring and support are always along with the development of the critical care medicine. Fluid therapy is the most core measures in ICU, but there is a significant contradiction between positive fluid therapy and patient's impaired organ compensatory ability. The premise of appropriate fluid therapy is continuous and accurate evaluation of the hemodynamic status of critical ill patients. The variation of peak velocity of common carotid artery measured by bedside ultrasound can estimate the volume status of the SICU patients accurately. This method has high feasibility and accuracy and easy to be handled by the residents of ICU. The non-C. difficile associated nosocomial diarrhea even fatal enteritis in ICU can be caused by Klebsiella oxytoca and Clostridium perfringens. Although this kind of incidence occurs in a relatively low rate, it always associates with severe diseases and poor outcome. Analgesia and sedation had become routine measures in ICU. There is still great controversy in some of the sedation protocol, such as sedation level and wake up daily. More and more evidence-based data suggested taking appropriate sedation targeting to individuals, and the protocol should be integrated with the dealing of pain, anxiety and delirium.