During general anesthesia, intraoperative hypotension (IOH) is associated with increased morbidity and mortality. Mean arterial pressure (MAP) < 65mmHg is the most common definition of hypotension. In order to reduce IOH, a complex method using machine learning called hypotensive prediction index (HPI) was shown to be superior to changes in MAP (ΔMAP) to predict hypotension (MAP between 65 and 75 excluded). Linear extrapolation of MAP (LepMAP) is also very simple and could be a better approach than ΔMAP. The main objective of the present study was to investigate whether LepMAP could predict IOH during anesthesia 1, 2 or 5 minutes before.

Hypothesis : the area under the ROC curves (ROC Area Under Curves) at 1, 2 and 5 minutes of LepMAP would be superior to ΔMAP

Inclusion Criteria:

• All lobectomy including for another study (VATOFA study) with continuous invasive blood pressure monitoring per arterial line
• All pancreaticoduodenectomy or hepatectomy including for another study (CARBODAV study) with continuous invasive blood pressure monitoring per arterial line
• age 18 or over

Exclusion Criteria:

• complex hemodynamic cases (heart, lung and liver transplantation)
• using extracorporeal membrane oxygenation.
• Patient who object to take part of the study.

all gender minimum age : 18 years old Healthy volunteers are not accepted