Evaluation of Consciousness Depth (qCON) and Analgesia Depth (qNOX) Indices in General Anesthesia

Objective: This prospective, single-center, observational clinical study aims to evaluate changes in qCON (hypnotic depth), qNOX (nociception/analgesia depth), EMG, and other parameters in patients undergoing elective cesarean section under general anesthesia, with a focus on the induction and maintenance phases. Background: Primary goals in cesarean anesthesia include maintaining adequate anesthetic depth to prevent awareness and intraoperative recall, preserving uterine tone, and avoiding neonatal respiratory depression. While high inhalation agent concentrations increase uterine relaxation and bleeding risks, opioids administered during the incision-to-delivery interval can cause neonatal respiratory depression. Alternative anesthetic combinations (e.g., ketamine-propofol) are used in practice, but their effects on EEG-derived indices (qCON and qNOX) and potential paradoxical shifts remain poorly defined. Methods: The study will be conducted at Erciyes University Faculty of Medicine Hospital in 140 patients planned for elective cesarean section under general anesthesia (alpha = 0.05, 90% power, effect size = 0.50), including a history of eclampsia, preoperative sedative use, and difficult intubation.

Inclusion Criteria: Pregnant women scheduled for elective cesarean section Aged 18-45 years American Society of Anesthesiologists II-III Patients with an indication for general anesthesia Patients who provided informed consent to participate in the study Exclusion Criteria: Dermatological lesions that may interfere with EEG monitoring Known allergy or hypersensitivity to ketamine, remifentanil, or propofol History or presence of neurological disease (e.g., epilepsy) Body Mass Index (BMI) \> 40 kg/m² Preeclampsia or eclampsia Preoperative sedative or psychotropic medication use Predicted or known difficult tracheal intubation