Clinical Research Directory

Inclusion Criteria: * Female patients aged 18 years or older. * Scheduled for elective bilateral tubal ligation using the vaginal natural orifice transluminal endoscopic surgery (vNOTES) technique at Yahyali State Hospital. * Requesting permanent contraception and considered surgically eligible for bilateral tubal ligation. * American Society of Anesthesiologists (ASA) physical status I, II, or III. * Scheduled to undergo general anesthesia with endotracheal intubation and controlled mechanical ventilation. * Eligible for the standardized anesthesia and mechanical ventilation protocol. * No clinical condition preventing reliable intraoperative recording of ventilation parameters and respiratory mechanics. * Willing to participate in the study and undergo the planned intraoperative measurements. * Able to provide written informed consent. Exclusion Criteria: * Age younger than 18 years. * Emergency surgery. * Surgery performed using a technique other than vNOTES or conversion to conventional laparoscopy or open surgery. * ASA physical status IV or higher. * Severe chronic pulmonary disease, including severe chronic obstructive pulmonary disease, severe asthma, or interstitial lung disease. * Uncontrolled cardiovascular disease or advanced heart failure. * Body mass index (BMI) ≥35 kg/m². * Pregnancy or suspected pregnancy. * Chest wall deformity or neuromuscular disease that may affect mechanical ventilation parameters. * Missing or unreliable intraoperative measurements. * Refusal to participate or failure to provide written informed consent.