Comparing Eleveld and Minto Models for Remifentanil Target Controlled Infusion During General Anesthesia Using qNOX and ANI Monitoring

What this Trial Is About

Researchers are evaluating two different pharmacokineticpharmacodynamic models used for target-controlled infusion TCI of remifentanil, a commonly used opioid during general anesthesia. The study compares the newer Eleveld model with the widely used Minto model to see if there are differences in the remifentanil effect-site concentrations needed to achieve similar analgesia levels. The assessment focuses on measurements from qNOX and the Analgesia Nociception Index ANI, which monitor the balance of pain signals and analgesic effects during surgery. Additionally, responses to a controlled noxious stimulus called Post-Tetanic Count PTC are analyzed during anesthesia maintenance to explore differences in analgesic responses between the two models. Participants receive general anesthesia with propofol guided by the Eleveld TCI model, combined with remifentanil administered either by the Eleveld or Minto TCI model, as decided by the anesthesiologist. The study observes and compares these two groups during the surgical procedure, focusing on the remifentanil concentrations and nociception monitor values. The Post-Tetanic Count stimulation is applied during anesthesia to test how each model modulates analgesia under a standardized painful input. During the study, researchers continuously monitor remifentanil effect-site concentration, qNOX, and ANI values throughout the surgery. They also assess the participants for postoperative delirium and pain shortly after anesthesia ends, as well as evaluate chronic pain six months following surgery. These measurements help determine if the newer Eleveld model offers advantages over the traditional Minto model in guiding remifentanil dosing and analgesia management. The total participant age range is 18 to 80 years, and the study is observational, tracking outcomes without assigning treatments for research purposes.

Minto and Eleveld Remifentanil Target Controlled Infusion (TCI) Models: a Clinical Comparison