The climate crisis and environmental pollution are escalating day by day, making the reduction of carbon footprints increasingly important both on an individual and industrial level. Inhalational anesthetic agents are widely used in daily anesthesia practice. However, some of these agents are released into the environment either unchanged or as metabolic by-products. It can take hundreds of years for these substances to be fully eliminated from nature. Therefore, there is a growing interest in identifying alternative anesthetic agents that are fully metabolized, do not produce waste, have a shorter duration of action, and pose less harm to ecosystems.

Recent clinical studies have shown that dexmedetomidine, when administered intraoperatively via infusion without a loading dose and in combination with inhalational agents, provides more stable hemodynamics and results in a shorter postoperative recovery period. Commonly used as a long-term sedative agent in intensive care units, dexmedetomidine has gained popularity in the intraoperative setting due to its stable hemodynamic profile, low incidence of withdrawal symptoms, and faster recovery.

In this study, it is aimed to demonstrate the potential use of dexmedetomidine-whose pharmacodynamic and pharmacokinetic properties are well-known to experienced anesthesiologists-as an alternative to inhalational anesthetic agents for the maintenance of anesthesia, particularly in the geriatric patient population.

Study Design and Setting This prospective, randomized clinical study was conducted at the Department of Anesthesiology and Reanimation, University of Health Sciences, Bakırköy Dr. Sadi Konuk Training and Research Hospital. Patient randomization was performed using a computer-based randomization tool (@randomizer).

Patient Selection A total of 150 patients over the age of 39 who provided informed consent and were scheduled for elective urological procedures at the Urology Department were enrolled in the study. The included surgeries were uretero-renoscopic lithotripsy (URS), transurethral resection of the bladder (TUR-B), percutaneous nephrolithotomy (PCNL), and transurethral resection of the prostate (TUR-P).

Anesthesia Protocol

Upon arrival to the operating room, standard monitoring was applied to all patients. Anesthesia induction and maintenance were carried out according to randomization:

Group DR: Dexmedetomidine + Remifentanil

Group IR: Desflurane + Remifentanil

Intraoperative and Postoperative Data Collection

During surgery, anesthesia depth and hemodynamic parameters were continuously monitored and recorded. At the end of the procedure, the following postoperative data were collected:

Visual Analog Scale (VAS) for pain

Richmond Agitation-Sedation Scale (RASS)

Modified Aldrete Score

The hospital unit/ward to which the patient was transferred

Inclusion Criteria

• Age ≥ 39 years
• Classified as ASA physical status II-IV
• Scheduled for elective endoscopic urological surgery (e.g., URS, TUR-B, PCNL, TUR-P)
• Scheduled for postoperative follow-up in the Post-Anesthesia Care Unit (PACU)
• Ability to provide written informed consent

Exclusion Criteria

• Requirement for conversion to open surgery during the perioperative period
• Patients who decline to participate in the study
• Presence of neuropsychiatric disorders (e.g., dementia, Parkinson's disease, epilepsy, or history of head trauma)
• History of alcohol or substance abuse
• Use of psychoactive medications
• Inability to communicate adequately for any reason