“…11 This concept has been proven to be suitable for electrolyte solutions, but our study showed that it is probably not appropriate for gelatin-containing solutions for the TA B L E 2 Concentrations of osmotically active molecules and measured osmolality after in-vitro dilution of human blood with gelatin (GEL) or albumin (ALB) respectively, presented as mean ± SD Measuring the osmolality by freezing point depression is the gold standard, but, because of the observational study design of the GPS study, this was not possible in the in-vivo part. 5 Therefore, we calculated the osmolality using a modified version of Zander's formula, which showed excellent concordance with measured osmolality. 6 The results of our in-vitro experiment can be explained by simple dilution.…”