Uncalibrated Pulse Contour to Assess Fluid Responsiveness in Off Pump Cardiac Surgery

The goal of this observational study is to Compare the performance of uncalibrated pulse wave contour analysis compared with transesophageal echocardiography (TEE) to assess response to a vascular filling test during beating-heart coronary artery bypass surgery, in people over age of 18; hospitalized for scheduled beating heart bypass surgery The aim question is to evaluate the ability of a less invasive cardiac output monitor (uncalibrated pulse wave contour analysis) compared with a reference cardiac output measurement (transesophageal echocardiography) to enable optimization of vascular filling by good assessment of the response to vascular filling in a high-risk perioperative patient population.

As part of hemodynamic monitoring, every patient undergoing beating-heart coronary bypass surgery is fitted with a radial arterial catheter immediately after induction of anesthesia, enabling continuous measurement of blood pressure. Hemodynamic optimization in these patients also involves fitting a transesophageal ultrasound probe to optimize cardiac output using the various therapies available (vascular filling, vasopressors, inotropes).

A specific sensor (FloTrac°, Hemosphere, Edwards°) will be connected to the arterial pressure line to obtain a systolic ejection volume value by analyzing the contour of the uncalibrated pulse wave.

The hemodynamic management of the patient, and the decision to perform a vascular filling test, will be left to the discretion of the practitioner in charge of the patient in the operating room.