This study evaluates if dynamic arterial elastance measured before general anesthesia induction can predict the occurrence of hypotension due to general anesthesia induction.

As general anesthetics may be responsible for vasodilation and cardiac depression, arterial hypotension after induction of general anesthesia is a common event and may contribute to an adverse outcome. Dynamic arterial elastance has been proposed as a functional parameter of arterial tone and studies showed that it was able to predict pressure response to fluid administration in fluid-responsive patients and the amount of mean arterial pressure riduction as a conseguence of noradrenaline dose reduction in critically ill patients.

Inclusion Criteria:

• Patients that will be undergone to general anesthesia for surgery
• Patients that need mini-invasive cardiac output monitoring during surgery

Exclusion Criteria:

• Age <18 yo
• Pregnancy
• Arrhythmia
• Severe valvular diseases
• Uncorrectable alterations of arterial signal

Patients undergone to general anesthesia for surgery that need mini-invasive cardiac output monitoring.