Pulse pressure variation is a monitoring index that indicates the response to fluid therapy in patients receiving mechanical ventilation, and is used as a reference for patients with unstable hemodynamic conditions. However, it is invasive because it requires arterial puncture to collect it. In a previous study by the investigators, the investigators developed and verified an artificial intelligence model that predicts stroke volume variation, in real time using only the central venous pressure waveform. However, since a large vein such as the jugular vein must be punctured to collect the central venous pressure waveform, it is still invasive, and its clinical utility is low. Therefore, in this study, the investigators collected waveforms from peripheral veins that are less invasive and can be a wide range of applications because all surgical patients have them. The investigators aimed to develop and verify an artificial intelligence model that predicts pulse pressure variation obtained from peripheral venous waveforms .

In this study, the investigators collected waveforms from peripheral veins that are less invasive and can be a wide range of applications because all surgical patients have them. The investigators aimed to develop and verify an artificial intelligence model that predicts pulse pressure variation obtained from peripheral venous waveforms .

Inclusion Criteria:

• Patients who voluntarily agreed and signed the written informed consent form before participating in this study
• Adult aged 19 years or older
• American Society of Anesthesiologists physical class (ASA) 1-3
• Patients scheduled for elective hepatectomy under general anesthesia
• Patients who require arterial pressure monitoring and additional peripheral venous access for routine anesthesia preparation
• Non-smokers with normal pulmonary function

Exclusion Criteria:

• Patients with abnormal findings on electrocardiogram before surgery
• Patients who cannot undergo peripheral venous puncture

Patients scheduled for elective hepatectomy under general anesthesia