The risk of infusing gelatin? Die-hard misconceptions and forgotten (or ignored) truths

Fluid therapy is considered a cornerstone of perioperative and critical care medicine. However, the type of fluids used varies widely among different countries. Synthetic colloids may negatively affect coagulation and are potentially nephrotoxic. "Modern" hydroxyethyl starches (HES) were widely used until recently when their association to mortality and renal replacement therapy risk among critically ill patients brought to restriction by the European Medicines Agency in 2013. Since synthetic colloids are traditionally thought to be much more effective as volume expanders than crystalloids (although their efficacy is probably largely overrated), there is concern that physicians, practically deprived of HES, could be tempted to rely again on "old" gelatins. The aim of this contribution is to warn clinicians that gelatins share all potential adverse effects of other synthetic colloids, and are possibly even more nephrotoxic than HES. Moreover, gelatins have no beneficial effects on outcomes as compared with crystalloids (on the contrary, they might even increase mortality), and are also more expensive. Accordingly, a "return" to gelatins should be strongly discouraged.