Saline versus balanced hydroxyethyl starch: does it matter?

A total balanced volume replacement strategy is a new concept for correcting hypovolemia. To fulfill this concept, balanced colloids, for example, balanced hydroxyethyl starch (HES) solutions, are necessary in addition to balanced crystalloids. Conventional HES solutions consist of saline with abnormally high concentrations of sodium (154 mmol/l) and chloride (154 mmol/l).

In animal as well as in human studies, the use of HES dissolved in a plasma-adapted solution showed beneficial effects on acid-base status compared with conventional HES dissolved in saline. As the base excess is an important surrogate marker for identifying patients with malperfused tissues, infusion of considerable amounts of unbalanced HES solutions producing low base excess would possibly result in inappropriate clinical interventions. Balancing the HES preparation was associated with significantly fewer alterations in coagulation; dilution of blood with balanced HES showed significantly fewer negative effects on thrombelastography and platelet aggregation than conventional HES.

Although only a few studies using balanced HES solutions are available at present, it is difficult to argue against using HES preparations that are adapted to plasma instead of HES preparations that contain unphysiologic saline solution. First results are very promising - large clinical trials are necessary to assess the value of a total balanced volume replacement strategy including plasma-adapted HES solutions.