EFFECT OF VASOPRESSORS ON FLUID CHALLENGE PERSISTENCE AN OBSERVATIONAL STUDY IN PATIENTS UNDERGOING LAPAROTOMY.

The hemodynamic effect of the fluid challenge administration (FC) depends on different variables related to the interplay between cardiac function and vascular tone response. In this context, the effect of adding a vasopressor to keep the arterial pressure between predefined ranges may impact on the persistence of stroke volume (SV) changes after FC administration. In fact, both the effect on arterial elastance and venous return may increase the persistence of SV increase, which is know to drop to baseline pre-FC values within fw minutes after FC administration. This single-centre observational study, in elective patients scheduled for elective laparotomy, hypothesizes that intraoperative norepinephrine infusion would prolong the effect of FC administration.