To better understand pathologies, malformations, and difficulties of pediatric airways, it is helpful to know their embryogenesis and anatomy.
Children are not small adults, and it is important to remind to all anesthesiology providers. The differences are related to functional anatomic structures in the pediatric patient, different availability of equipment adaptable to pediatric airways, and the extremely dynamic nature of pediatric airway problems.
The high oxygen consumption combined with a lower functional residual capacity (FRC) and high closing capacity predispose children to hypoxia. Respiratory pathologies highly contribute to airway narrowing.
Preparation to induction in children is crucial. The experience of being separated from the caretaker could become a stressful experience. The induction is a critical time when difficulties and cardiorespiratory problems may occur. The pediatric anesthesia provider must be flexible and consider all these factors while planning the anesthetic.
Video laryngoscopy provides better views of the glottis compared to direct laryngoscopy, although intubation times may be prolonged. Skill acquisition in elective cases before use in complex difficult airway situations is recommended. Corrective maneuvers in the “Can see, can’t intubate” situation must be learned.
EMBRYOLOGY AND ANATOMY OF THE PEDIATRIC AIRWAY
The respiratory apparatus begins to form at the third gestational week when the laryngotracheal diverticulum (LTD) originates from the ventral wall of anterior primitive intestine. These structures are in communication until esophagotracheal septum separates the airways from the esophagus. The glottis region of larynx develops from the cranial portion of the LTD, while the caudal part forms the tracheal tube and the major bronchi. The supraglottis region will form the larynx and pharynx.
The LTD grows and extends caudally toward the future thoracic cavities, then splits into the two buds of the future main bronchi. The right will create the three bronchial lobes and the left the two lobes. The lobar bronchi form by dichotomous division during the sixth month of gestation and then expand to 23 bronchi by birth.
The respiratory tissue and vascular scaffolding derive from the mesoderm layer. The alveoli expand and form by breathing action, reaching full maturation by 5 to 8 years of age. During this very delicate developing embryologic phase, any pathogenic events may result in severe consequences with airway malformations as well as defects of the esophagus, duodenum, and gastric sac. Anomalies of the esophagotracheal septum may cause esophageal atresia, with or without tracheoesophageal fistula (TEF). Tracheal vascularity abnormalities may result in agenesis or complex tracheal stenosis.
AIRWAY MANAGEMENT IN CHILDREN
Children are not small adults, and it is important to remind to all anesthesia providers that only a few adult airway considerations are transferable to the pediatrics. For instance, the definition of difficult airways, ventilation, and some criteria of intubation may be like the adult difficult airway principles. The differences are related to functional anatomic structures in the pediatric ...