[Dos and don'ts for crystalloids in intensive care medicine. Can too much water be bad?]

Notwithstanding the use of colloids, crystalloids have a firm position in today's intensive care: In addition to the substitution as a basic requirement of the human organism or drug carriers, they are primarily used for volume replacement. A common complication is the development of interstitial edema, which is due to the composition of these solutions and the permeability of the glycocalyx.With the large variety available on the market, bicarbonate-based precursor isotonic-balanced full electrolyte solutions have become established in the meantime. The use of 0.9% saline solution is regarded as obsolete. With low cost and a good safety profile, a few relevant aspects, e.g., the risk of hypervolemia and electrolyte imbalance, must be taken into account in the use of crystalloids.