Fluid therapy in the critically ill patient - Beliefs and hard evidence in 2010

Meta-analyses and recent large-scale studies have shown that resuscitation of critically ill patients with either crystalloids or colloids is equally effective. However, such synthetic colloids as gelatines, dextrans or hydroxyethyl starch (HES) are associated with inherent risks. These include impairment of coagulation, renal failure and, in the case of HES, uptake into tissue with long-term adverse effects on morbidity and mortality in susceptible patients. Adverse effects of colloids are dose-related and become evident only after a certain latency period. It has been suggested that a new HES 130/0.4 has fewer adverse effects than older products; however, no data are yet available for critically ill patients, and current evidence would seem to indicate a comparable risk profile. The assumption that the volume of crystalloid needs to be at least three to four times that of colloid to achieve comparable volume effects is no longer tenable. In critically ill patients less than twice the crystalloid fluid volume achieved adequate resuscitation with comparable outcomes. This fact considerably undermines the notion that colloid is superior to crystalloid. Current best evidence shows that crystalloid solutions and albumin can be considered generally safe. In patients with brain injury, however, albumin is associated with increased mortality. To date there are no data from outcome-related clinical trials showing that balanced crystalloid or balanced HES solutions have fewer clinically relevant adverse effects than saline-based products. Since the use of synthetic colloids in volume therapy does not result in improved clinical outcomes, and adverse effects are increasingly being reported, their administration to critically ill patients should be questioned. A reconsideration of their indication and cumulative dose limitation based on data from clinical studies of adequate duration is urgently needed.