Crystalloids versus colloids during acute normovolemic anemia: the quest continues

The optimal kind of fluid for fluid resuscitation during acute, severe hemorrhage is still discussed controversially. Of particular interest in this context is the choice of colloids versus crystalloids and their effect on the critical hemoglobin level. In a previous issue of Critical Care, Pape and colleagues describe the effect of four different volume replacement options on the critical hemoglobin concentration, and show marked differences for the different treatments. Even though some important pathophysiological issues remain unsolved, the current manuscript adds interesting evidence to an ongoing quest.