Diaphragm Ultrasound İn Children With OSAS

This is a prospective observational study evaluating perioperative diaphragmatic function by ultrasonography in children aged 1-12 years undergoing elective surgery under general anesthesia. Participants will be classified preoperatively based on the parent-completed Pediatric Sleep Questionnaire (PSQ). Children with suspected obstructive sleep apnea syndrome who are scheduled for adenotonsillectomy will form the study group, while children without clinical findings suggestive of obstructive sleep apnea who are scheduled for elective non-airway-related otolaryngologic surgeries will serve as controls. Diaphragm ultrasound assessments will be performed before and after surgery in the supine position during spontaneous breathing. Measurements will include diaphragmatic thickness at end-inspiration and end-expiration, diaphragmatic thickening fraction, and diaphragmatic excursion during quiet and deep breathing. The primary objective is to compare diaphragmatic excursion and thickening fraction between groups. Secondary objectives include evaluating the association between perioperative respiratory parameters, postoperative recovery, and diaphragm ultrasound measures.