Nature du priming de la circulation extracorporelle en chirurgie cardiaque adulte et pédiatrique

During the recent years a new debate occurred because of the introduction of a new generation of hydroxyethyl starches (HES) and of balanced cristalloids, for the composition of the priming for cardiopulmonary bypass in cardiac surgery. Colloids used for fluid therapy belong to two groups: gelatin (modified fluid gelatine – MFG – in France) and hydroxyethyl starch (HES). Isotonic saline is mainly used as a solvent of colloids even though responsible for hyperchloremic acidosis when perfused in large volume. Morbidity due to this metabolic disorder is not largely investigated but does not seem very deleterious. However maintenance of the metabolic and acid-base equilibrium encourages the use of balanced solutions as proposed for some HES colloids. Characteristics of HES 130/0.4-0.42 improve safety profile and are preferred, however deleterious effects of HES on hemostasis with increasing bleeding risk and risk of renal impairment, cornerstone in cardiac surgery, lead to a respect of doses, indications and contra-indications of HES. Discussion is mandatory for the use of the new colloids and crystalloids in the composition of the priming, particularly some non oncotic effect of the synthetic colloids must be elucidated to improve the choice between albumin and other colloids.