Table 1 .

Inclusion and exclusion criteria

Inclusion criteria	Exclusion criteria
Age ≥ 18 years Elective surgery General anesthesia	ASA physical status > 3 Dyspnea Systolic blood pressure ≥ 180 mmHg Systolic blood pressure < 90 mmHg Decompensated heart failure Elevated pulmonary arterial pressure > 40 mmHg Significant valvular disease Significant carotid stenosis Documented negative fluid balance > 1.000 ml on preceding day Pheochromocytoma SOFA score > 1 Agitation (RASS > 1) IVC non visualized Epidural catheter in use

ASA American Society of Anesthesiology, IVC inferior vena cava, RASS Richmond Agitation Sedation Scale, SOFA Sepsis-related Organ Failure Assessment