Opioid-Free Anesthesia in FESS: A Prospective ERAS Study

This prospective observational study is designed to evaluate perioperative clinical outcomes in patients undergoing elective Functional Endoscopic Sinus Surgery (FESS) under routine clinical care. In accordance with the observational nature of the study, the investigators do not assign or control the anesthetic techniques, drug dosages, or clinical pathways. All perioperative interventions, including the choice between an opioid-free anesthesia (OFA) approach or traditional opioid-based anesthesia, are determined solely by the attending anesthesiologists based on standard institutional protocols and clinical judgment.

Data collection will encompass the entire perioperative period, spanning from the pre-anesthesia assessment until the standard post-operative follow-up intervals.

The clinical tracking workflow consists of the following phases:

• Preoperative Phase: Eligible patients scheduled for elective FESS due to chronic sinusitis are identified during routine pre-anesthesia visits. Baseline demographic characteristics, physical status according to the American Society of Anesthesiologists (ASA) classification, and relevant medical histories are documented.
• Intraoperative Phase: Standard monitoring and depth of anesthesia parameters are recorded in the operating room. Intraoperative hemodynamic data (including heart rate and mean arterial pressure) and parameters related to the surgical field quality are collected at predefined surgical milestones from the initial incision to the completion of the procedure. Total consumption of anesthetic agents and any required vasoactive medications are also logged.
• Postoperative Phase: Following extubation, patients are transferred to the Post-Anesthesia Care Unit (PACU). Early recovery characteristics, including recovery times and discharge scores, are monitored. Within the first 24 hours post-surgery, acute postoperative pain scores and the incidence or severity of postoperative nausea and vomiting (PONV) are tracked at serial clinical intervals.
• Follow-up Phase: Patient-reported outcomes regarding subjective recovery characteristics, such as postoperative sleep quality, are subsequently evaluated during the routine outpatient follow-up visit at one week postoperatively.

Statistical analyses will be performed to evaluate and compare the collected perioperative datasets between patients who received dexmedetomidine-based opioid-free anesthesia and those who received traditional opioid-based regimens under the institutional Enhanced Recovery After Surgery (ERAS) framework. No additional clinical interventions, blood samplings, or changes to standard patient care pathways are introduced due to study participation.

Inclusion criteria

• Patients aged between 18 and 65 years.
• American Society of Anesthesiologists (ASA) physical status I or II.
• Patients scheduled for elective Functional Endoscopic Sinus Surgery (FESS) due to chronic sinusitis.
• Patients whose perioperative care is managed strictly according to institutional Enhanced Recovery After Surgery (ERAS) principles.
• Both female and male patients are eligible for inclusion.

Exclusion criteria

• Known cardiac conduction abnormalities or arrhythmias.
• History of chronic opioid use or opioid dependency.
• Current use of beta-blockers or antiarrhythmic medications.
• Severe hepatic or renal impairment.
• Obesity defined as a Body Mass Index (BMI) greater than 35 kg/m².
• Current use of GLP-1 receptor agonists.
• Documented coagulopathy or bleeding disorders.
• History of prior revision Functional Endoscopic Sinus Surgery (FESS) procedures.
• History of delayed gastric emptying or high risk of pulmonary aspiration.