What is the optimal fluid status in critically ill patients?

shock for three days or more who received higher fl uid volumes had reduced mortality. Th is is an important issue because how much fl uid is enough for critically ill patients has been controversial for a long time. Th e optimal fl uid status should be set according to the prevailing conditions. In contrast to this study, most previous studies have found that a more positive fl uid balance is associated with higher mortality [2,3]. Too much fl uid induces interstitial edema, which results in end organ damage, poor wound healing and nosocomial infection [4]. In order to clarify the correlation between fl uid therapy and mortality, it is necessary to use high or low fl uid volumes as a covariate in a Cox’s proportional hazards model of mortality. As we know, fl uid resuscitation is a critical step to achieve early goal-directed therapy. Whether patients achieved the goal or not should also be included in analysis. Other parameters related to fl uid status, such as central venous pressure level, body composition detected by bioimpedance device, and brain natriuretic peptide level, can be added to the analysis in future studies.