Comparison of an optical method to continuously measure blood pressure against an invasive arterial catheter.

The measurement of blood pressure during anesthesia is commonly performed by the inflation of a brachial cuff providing only intermittent blood pressure measurements. In some case, it is required to add a continuous invasive monitoring of blood pressure, via the insertion of an arterial catheter. Unfortunately, the related morbidity is not negligible. To limit the consequences of such a gesture, some developments have been done in the past to allow for continuous non-invasive measurements of blood pressure during anesthesia. Unfortunately, most of these devices are subject to important limitations and constraints of use.

A new system has been designed by CSEM consisting of an optical system fixed on patient's skin, absolutely non-invasive and easy to use. In order to study the reliability of this device, the investigators plan to compare its blood pressure estimates against gold-standard arterial catheter measurements during induction of general anesthesia on:

• 40 patients wearing the optical system at the chest.
• and 40 patients wearing the optical system at the fingertip

Inclusion Criteria:

• patient requiring the placement of an arterial catheter for general anesthesia
• minimum of 18 years
• written consent

Exclusion Criteria:

• minor patient or incapable of discernment
• patient with AIMD
• thoracic surgery