Diaphragm Ultrasound İn Children With OSAS

This prospective observational study is designed to evaluate perioperative diaphragmatic function using ultrasonography in pediatric patients undergoing elective surgery under general anesthesia. The study will be conducted in children aged 1-12 years who are followed at the Department of Otolaryngology of Istanbul University Istanbul Faculty of Medicine and are scheduled for surgery based on clinical indications.

A total of 60 children will be enrolled in the study in accordance with predefined inclusion and exclusion criteria. Participants will be classified into two groups based on the results of the parent-completed Pediatric Sleep Questionnaire (PSQ) administered preoperatively. A PSQ total score of ≥0.33 (at least 8 "yes" responses out of 22 items) will be considered indicative of suspected obstructive sleep apnea, and children scheduled for adenotonsillectomy will form the study group. Children with a PSQ total score of \<0.33 and no clinical findings suggestive of obstructive sleep apnea who are scheduled for elective non-airway-related otolaryngologic surgeries will be included in the control group.

All patients will receive standardized perioperative anesthesia and surgical care. Diaphragmatic ultrasonographic assessments will be performed in the supine position during spontaneous breathing preoperatively and postoperatively. Diaphragmatic thickness will be assessed using a 4-15 MHz linear transducer placed perpendicular to the chest wall at the 7th-9th intercostal space along the right anterior axillary line; thickness will be measured at end-inspiration and end-expiration, and the diaphragmatic thickening fraction will be calculated. Diaphragmatic excursion will be evaluated using a 1-6 MHz convex transducer positioned in the right anterior subcostal region between the midclavicular and anterior axillary lines, and craniocaudal excursion will be recorded during quiet and deep breathing.

The primary objective of this study is to evaluate diaphragmatic function by comparing diaphragmatic thickening fraction between children with suspected obstructive sleep apnea and a control group. Secondary objectives include the assessment of diaphragmatic excursion, the evaluation of associations between diaphragmatic ultrasonography parameters and perioperative respiratory variables, and the assessment of postoperative recovery characteristics. In this context, the study aims to investigate the role of diaphragmatic ultrasonography as a noninvasive perioperative assessment tool for the evaluation of respiratory function and perioperative respiratory findings in children with suspected obstructive sleep apnea undergoing surgery.

• Diaphragmatic Thickness at End-Inspiration (mm) [Time frame: Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.]
• Perioperative Respiratory and Recovery Parameters [Time frame: During surgery and for the duration of postoperative recovery.]
• Diaphragmatic Thickness at End-Expiration (mm) [Time frame: Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.]
• Diaphragmatic Excursion During Quiet Breathing (mm) [Time frame: Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.]
• Diaphragmatic Excursion During Deep Breathing (mm) [Time frame: Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.]
• Diaphragmatic Excursion Ratio (Quiet Breathing / Deep Breathing) [Time frame: Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.]