Age-based analysis of pediatric upper airway dimensions using computed tomography imaging

Area of Science:

• Pediatric airway anatomy
• Radiology
• Otolaryngology

Background:

• Historical understanding posits a cone-shaped larynx in children.
• Recent research questions this long-held assumption.
• Accurate pediatric airway dimensions are crucial for clinical practice.

Purpose of the Study:

• To evaluate pediatric airway dimensions using computed tomography (CT).
• To determine the dimensional transition between the subglottic area and the cricoid ring in children.
• To challenge the traditional cone-shaped laryngeal model in pediatric patients.

Main Methods:

• Retrospective review of 220 CT scans from children aged 1 month to 10 years.
• Measurements of anteroposterior (AP) and transverse (T) diameters at subglottic and cricoid levels.
• CT scans were acquired during natural sleep or sedation, unrelated to airway symptoms.

Main Results:

• Mean AP and transverse diameters measured at subglottic and cricoid areas.
• AP dimension decreased from subglottis to cricoid; transverse dimension showed significant enlargement (P<0.05).
• Airway dimensions demonstrated linear progression with age (r>0.7).

Conclusions:

• Pediatric airway shape transitions from elliptical (subglottis) to round (cricoid).
• The historically proposed cone shape was not observed in this study.
• The subglottic transverse diameter, the narrowest dimension, is likely the primary site of resistance for endotracheal tube passage.