At what level is the pediatric airway narrowest?

From the Guidelines

The pediatric airway is narrowest at the subglottis, as stated in the study published in Pediatrics in 2015 1. This anatomical feature is critical in understanding the management of pediatric airway emergencies, as it explains why conditions like croup or foreign body aspiration can lead to significant airway obstruction. The subglottis is the narrowest portion of the pediatric airway, and this narrowing can be exacerbated by conditions such as infantile hemangiomas, which can cause biphasic stridor and barky cough in affected infants 1. Key points to consider in pediatric airway management include:

• The subglottis is the narrowest portion of the pediatric airway, making it a critical consideration in airway management 1
• Conditions like croup or foreign body aspiration can cause significant airway obstruction due to the narrow diameter of the pediatric airway 1
• Selecting the appropriate endotracheal tube size is crucial in pediatric airway management, and anatomical differences between children and adults must be taken into account. The study published in Pediatrics in 2015 1 provides valuable insights into the diagnosis and management of infantile hemangiomas in the pediatric airway, highlighting the importance of considering the subglottis as the narrowest portion of the airway.

From the Research

Location of the Narrowest Portion of the Pediatric Airway

• The pediatric airway is a complex structure, and its narrowest portion has been a subject of debate among researchers.
• According to a study published in 2018 2, the functionally-narrowest portion of the pediatric upper airway is located in the subcricoid region.
• However, other studies suggest that the narrowest portion of the pediatric airway may be at or just below the glottic opening 3, or at the glottis 4.
• A review of historic and recent investigations of the anatomy of the pediatric larynx found that in vivo observations suggest that the narrowest portion of the airway is more proximal than the cricoid cartilage, while in vitro studies confirm that the nondistensible and circular or near circular cricoid outlet is the narrowest level 5.
• Another study published in 2020 found that the transverse diameter of the inlet of the cricoid cartilage is the smallest diameter of the cricoid cartilage, and that the "funnel shape" of the cricoid cartilage remains unchanged during development 6.

Key Findings

• The narrowest portion of the pediatric airway is a matter of debate, with different studies suggesting different locations.
• The subcricoid region, glottic opening, and glottis have all been identified as potential narrowest portions of the pediatric airway.
• The shape of the pediatric cricoid cartilage is also a subject of controversy, with some studies suggesting that it is elliptical in shape, while others describe it as circular or near circular.
• The development of the cricoid cartilage and its implications for the use of endotracheal tubes in the pediatric population are important considerations for clinicians 6.