Comparison of Age-Based Formula and Ultrasound-Guided Subglottic Diameter Measurement for Endotracheal Tube Sizing

NCT07586592 | Recruiting

• 1 other identifier: FMASU MD353/2025
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

To compare the accuracy of ultrasound-guided subglottic diameter measurement versus age-based formulas in determining the optimal endotracheal tube (ETT) size in pediatric patients with single ventricle physiology and reducing post-extubation complications.

Conditions

Endotracheal Tube Wrongly Placed During Anesthetic Procedure

Outcome Measures

Primary Outcomes (1)

• Accuracy of ETT size selection

  Accuracy of endotracheal tube size selection measured by the number of ETT attempts required to achieve an appropriate leak test and successful airway placement.

  During endotracheal intubation, immediately after induction of anesthesia and neuromuscular blockade (within 10 minutes after induction)

Secondary Outcomes (3)

• Incidence of post-extubation stridor/croup

  From extubation until 24 hours post-extubation

• Severity of post-extubation croup

  At 30 minutes, 2 hours, and 24 hours after extubation

• Duration of ICU stay related to airway complications

  From ICU admission until ICU discharge, up to 30 days

Study Arms (2)

Age-Based Formula Group

ACTIVE COMPARATOR

In neonates and infants under 1 year, a weight-based sizing is used: * Infants \<1 kg (Preterm): 2.5 mm ETT * Infants 1-2 kg: 3 mm ETT * Infants 2-3 kg (Full Term): 3 - 3.5 mm ETT * Infants \>3 kg (3 months to 1 year): 3.5 - 4 mm ETT In Infants \> 1 year, ETT size will be selected based on the standard formula: Cole's Formula for uncuffed ETT. ETT ID (mm) = (Age/4) + 4.

Other: Cole's Formula

Ultrasound Group

ACTIVE COMPARATOR

During mask ventilation, a trained anesthesiologist will perform transverse subglottic diameter measurement using a high-frequency linear ultrasound probe (7-15 MHz). The patient will be positioned supine with mild neck extension. The probe will be placed transversely just below the thyroid cartilage to identify the subglottic airway at the level of the cricoid cartilage. The measured diameter (in mm) will be recorded and used to determine ETT size from the equation: ETT ID (mm) = Subglottic diameter (mm) × 0.8

Device: Ultrasound

Interventions

Ultrasound DEVICE

Using Ultrasound for accuracy of ETT sizing

Ultrasound Group

Cole's Formula OTHER

Subglottic diameter in mm x 0.8

Age-Based Formula Group

Eligibility Criteria

• Age: 3 Months - 8 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Pediatric patients (3 months to 8 years)
• Patients with single ventricle physiology
• Scheduled for Glenn or Fontan surgery or cardiac catheterization
• Patients with Glenn or Fontan shunt scheduled for surgery

You may not qualify if:

• Refusal of legal guardians
• Emergency surgery
• Patients with tracheostomy tubes
• Recent or active upper respiratory tract infection
• Airway anomalies (e.g. Pierre Robin, Treacher Collins)
• ICU stay due to complications other than that of airway

Sponsors & Collaborators

• Ain Shams University: lead

Study Sites (1)

Ain Shams University

Cairo, Abbasseya, 00202, Egypt

RECRUITING

MeSH Terms

Interventions

Ultrasonography

Intervention Hierarchy (Ancestors)

Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis

Central Study Contacts

Nouran Nemr, M.B.B.Ch, M.Sc.

CONTACT

01008558583; Nourannemr@med.asu.edu.eg

Mohamed Tolba, MD

CONTACT

01156622298

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 22, 2026
• First Posted: May 14, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: May 14, 2026

Record last verified: 2026-05

Locations

EG (1)