Effects of Dexmedetomidine Target Controlled Infusion on Patient State Index Values and Electroencephalographic Spectrum During Total Intravenous Anesthesia With Propofol

The effects of Dexmedetomidine administered via Target-Controlled Infusion (TCI, Dyck model) on neuromonitoring during Total Intravenous Anesthesia (TIVA) with Propofol and Remifentanil (TCI, Eleveld model) have not yet been investigated.

The authors aim to systematically evaluate the impact of adding Dexmedetomidine on key neuromonitoring parameters commonly used in clinical anesthesia during the maintenance phase of TIVA-TCI. Specifically, the study will assess:

Patient State Index (PSi) as a measure of the hypnotic state;

Electroencephalographic (EEG) power spectrum, to identify changes in cortical activity patterns associated with Dexmedetomidine administration;

Analgesia Nociception Index (ANI), to evaluate potential modifications in the analgesia-nociception balance;

Pupillometry, to quantify autonomic and pupillary responses to stimuli.

This investigation aims to determine whether the addition of Dexmedetomidine using a TCI approach produces predictable and clinically relevant alterations in neurophysiological monitoring during anesthesia with Propofol and Remifentanil. Ultimately, the study seeks to support more precise drug titration and enhance patient safety.

Inclusion criteria

• Undergo general anaesthesia with Targeted Controlled Infusion of Propofol and Rmifntanil (Eleveld model) and Dexmedetomidine (Dyck model)

Exclusion criteria

• Neurological disease
• Psychiatric disease
• Obesity
• Regional anesthesia performed