Effect of Ketamine Infusion on BIS Values

Correlation Between Concentration at the Effector Site of Continuous Infusion of Ketamine (Calculated With DOMINO Pump) and Bispectral Index Values During General Anaesthesia for Breast Surgery

Aim of this trial is to define if Concentration at the effector site (Ce) of Ketamine, during a continuous infusion and calculated with DOMINO model infusion pump are correlated with Bispectral Index BIS values during general anaesthesia for breast surgery.

Correlation between Concentration at the effector site (Ce) of Ketamine and Bispectral Index (BIS) values during general anaesthesia for breast surgery has not been defined yet during a continuous infusion.

Authors want to analyze this correlation during general anaesthesia conducted using Propofol, ketamine and remifentanil. All of these drugs will be delivered with Target-Controlled Infusion pumps (in particular Eleveld for Propofol, Minto for Remifentanil and Domino for Ketamine).

Ketamine will be observationally set at anaesthesiologist's discretion, but only CeK 0.1, 0.2, 0.4 and 0.6 for at least 30 minutes will be considered for analysis.

Inclusion Criteria:

• Undergo general anaesthesia with Targeted Controlled Infusion of Ketamine (Domino model), Propofol (Schnider model) and Remifentanil (Minto model)

Exclusion Criteria:

• Neurological disease
• Psychiatric disease
• Benzodiazepines intake
• Obesity