In high-risk patients, it is now recommended to guide the intraoperative volume replacement via the stroke volume.

Today, the most commonly used technique for estimating the stroke volume is the arterial waveform analysis in the radial artery. This technique has the disadvantage of being invasive and increasing the time dedicated to anesthesia during the surgery.

The future is the non-invasive monitoring of stroke volume. Thus, Edwards Life Science has developed a continuous monitoring technology and non-invasive arterial pressure, cardiac output and stroke volume using a digital sensor (ClearSight®). The continuous monitoring of blood pressure by this technique was validated in cardiothoracic surgery but studies about monitoring cardiac output or stroke volume are inconclusive and contradictory.

The objective of this study is to compare the use of non-invasive monitoring of stroke volume by Clearsight® with the arterial waveform analysis in the radial artery by Pulsioflex® in major surgery.

Inclusion Criteria:

• Patients scheduled to undergo major surgery
• Patients monitored by a Pulsioflex® device

Exclusion Criteria:

• Patients with heart rhythm disorder
• Patients with Raynaud's disease or vasculitis
• Emergency surgery
• Significant edema fingers