Diaphragm Ultrasound İn Children With OSAS

Perioperative Ultrasonographic Assessment Of Diaphragmatic Function İn Pediatric Obstructive Sleep Apnea

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.

Study Overview

• Status: Recruiting
• Conditions: Obstructive Sleep Apnea of Child

Detailed Description

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.

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Demet Altun, Professor; Phone Number: 00905326811767; Email: drdemetaltun@hotmail.com
• Study Contact Backup: Name: Furkan Kelebek, Resident; Phone Number: 00905426140993; Email: furkan.kelebek@istanbul.edu.tr

Study Locations

• Turkey (Türkiye)
  • Fatih
    • Istanbul, Fatih, Turkey (Türkiye), 34093
      • Recruiting
      • Istanbul University, Department of anesthesiology
      • Contact: Furkan Kelebek, Resident; Phone Number: +905426140993; Email: furkan.kelebek@istanbul.edu.tr
      • Contact: Demet Altun, Professor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

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 will be included in this study. Participants will be assessed preoperatively using the Pediatric Sleep Questionnaire (PSQ). Children who answer "yes" to at least 8 of the 22 items and are scheduled to undergo adenotonsillectomy will be assigned to the obstructive sleep apnea syndrome (OSAS) group, whereas children who answer "yes" to fewer than 8 items and are scheduled to undergo elective non-airway-related otolaryngologic surgery will be included in the control group. Only children with ASA physical status I-II who meet the inclusion and exclusion criteria and for whom informed consent has been obtained will be enrolled.

Description

Inclusion Criteria:

• ASA physical status I-II
• Children aged 1 to 12 years
• Scheduled to undergo elective surgery under general anesthesia
• Written informed consent obtained from parents or legal guardians
• Availability of a completed pediatric sleep questionnaire (PSQ)

Exclusion Criteria:

• Patients younger than 1 year or older than 12 years
• Presence of a neuromuscular disease
• Use of medications that may affect neuromuscular function
• Diaphragmatic paralysis
• ASA physical status III-IV
• Refusal to participate in the study or failure to provide informed consent
• Body mass index (BMI) > 35 kg/m²

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Obstructive Sleep Apnea Group; Children with obstructive sleep apnea syndrome, defined by at least 8 "yes" responses out of 22 items on the Pediatric Sleep Questionnaire (PSQ), scheduled for adenotonsillectomy under general anesthesia.
Control Group; Children without obstructive sleep apnea, defined by fewer than 8 "yes" responses out of 22 items on the Pediatric Sleep Questionnaire (PSQ), scheduled for elective non-airway-related otolaryngologic surgeries under general anesthesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragmatic Thickening Fraction (%)	Diaphragmatic thickening fraction will be calculated as (thickness at end-inspiration - thickness at end-expiration) / thickness at end-expiration × 100%, measured by ultrasound. The primary comparison will be between the OSAS group and the control group. Measurements will be assessed before and after surgery.	Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragmatic Thickness at End-Inspiration (mm)	Diaphragmatic thickness at end-inspiration will be measured by ultrasonography. Values will be compared between the OSAS group and the control group, as well as between preoperative and postoperative measurements.	Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.
Perioperative Respiratory and Recovery Parameters	Perioperative respiratory and recovery parameters will be recorded, including oxygen saturation (SpO₂), end-tidal carbon dioxide (EtCO₂) values, Aldrete scores at recovery room admission and discharge, and length of stay in the recovery room. These parameters will be evaluated for associations with diaphragmatic ultrasonography measures and study group (OSAS vs control).	During surgery and for the duration of postoperative recovery.
Diaphragmatic Thickness at End-Expiration (mm)	Diaphragmatic thickness at end-expiration will be measured by ultrasonography. Values will be compared between the OSAS group and the control group, as well as between preoperative and postoperative measurements	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)	Craniocaudal diaphragmatic excursion during quiet tidal breathing will be measured by M-mode ultrasonography. Values will be compared between the OSAS group and the control group, as well as between preoperative and postoperative measurements.	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)	Craniocaudal diaphragmatic excursion during deep breathing will be measured by M-mode ultrasonography. Values will be compared between the OSAS group and the control group, as well as between preoperative and postoperative measurements.	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)	The ratio of diaphragmatic excursion during quiet breathing to diaphragmatic excursion during deep breathing will be calculated. Values will be compared between the OSAS group and the control group, as well as between preoperative and postoperative measurements.	Following premedication and prior to anesthesia induction, and within the first hour after surgery during the postoperative recovery period.

Collaborators and Investigators

• Sponsor: Istanbul University
• Investigators: Principal Investigator: Furkan Kelebek, Resident, Istanbul University; Principal Investigator: Demet Altun, Professor, Istanbul University

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2025
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): August 30, 2026

Study Registration Dates

• First Submitted: January 17, 2026
• First Submitted That Met QC Criteria: January 27, 2026
• First Posted (Actual): February 2, 2026

Study Record Updates

• Last Update Posted (Actual): February 2, 2026
• Last Update Submitted That Met QC Criteria: January 27, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: adenotonsillectomy; diaphragm ultrasound; Pediatric Sleep Questionnaire
• Other Study ID Numbers: 2024/2005

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No