Uniqueness of Pediatric Upper Airway
Previous related pearls:
Uniqueness of Pediatric Lower Airway - Part 1
Uniqueness of Pediatric Lower Airway - Part 2
The frequency of acute respiratory failure is higher in infants and young children than in adults for several reasons. This difference can be explained by defining anatomic compartments and their developmental differences in pediatric patients that influence susceptibility to acute respiratory failure.
The extrathoracic airway (extending from the nose to the subglottic region of the trachea) has significant differences in pediatric versus adult patients include the following:
- Neonates and infants are obligate nasal breathers until the age of 2-6 months because of the proximity of the epiglottis to the nasopharynx. Nasal congestion can lead to clinically significant distress in this age group.
- The small size of the airway is one of the primary differences in infants and children younger than 8 years compared with older patients.
- Infants and young children have a large tongue that fills a small oropharynx.
- Infants and young children have a cephalic larynx. The larynx is opposite vertebrae C3-4 in children versus C6-7 in adults. Larynx cone-shaped: narrowest at subglottic cricoid ring - Softer, more pliable: may be gently flexed or rotated anteriorly
- The epiglottis is larger and more horizontal to the pharyngeal wall in children than in adults. The cephalic larynx and large epiglottis can make laryngoscopy challenging.
- Vocal cords slanted: anterior commissure more inferior
- Infants and young children have a narrow subglottic area. In children, the subglottic area is cone shaped, with the narrowest area at the cricoid ring. A small amount of subglottic edema can lead to clinically significant narrowing, increased airway resistance, and increased work of breathing. Older patients and adults have a cylindrical airway that is narrowest at the glottic opening.
- In slightly older children, adenoidal and tonsillar lymphoid tissue is prominent and can contribute to airway obstruction.
- Upper airway contributes 50% to total airway resistance compared to about 20% in adults.
- Infant head is relatively larger: naturally flexed in supine position. Extension of head may result in tracheal extubation; while flexion may lead to main stem intubation.
