Comparison Between Manual Versus Closed-loop Titration of Propofol and Remifentanil Guided by the qCon and qNox Indexes During Induction and Maintenance of General Anesthesia in Adult Patients: a Multicentre Randomized Controlled Study

Several monitors are currently proposed to evaluate the depth of hypnosis. The Conox monitor differentiates itself from the other brain monitor by calculating two EEG indexes, the qCon and the qNox. The qCon corresponds to the depth of the sedation and the qNox relates to the probability that a nociceptive stimulation triggers a movement of the patient. A controller allowing the automated titration of propofol guided by the qCon and remifentanil guided by the qNox has been developed. In preparation for a large multi-center control trial, this prospective randomized study evaluates the effectiveness of such a closed-loop anesthesia system. Two groups of patients are compared: one arm in which propofol and remifentanil are administered by the anesthesiologist using target-controlled infusion (TCI) systems, and the second arm in which propofol and remifentanil are administered automatically by the combined closed-loop anesthesia system. In both groups, the goal is to maintain qCon between 40 and 60, the recommended range during anesthesia by the manufacturer. It is expected the combined closed-loop anesthesia system group to do similar or better control to maintain the qCon in the desired range.