Ultrasound assessment of larynx and trachea in the neonatal period-reference values

Ultrasonography is an accessible diagnostic tool that allows noninvasive examination of the larynx and trachea, thereby minimally disturbing patient comfort. Despite the interest of ultrasonographers in these organs, specific normative values for the dimensions of their structures have not been published. This prospective cohort study aimed to establish the normal sizes for the laryngeal and tracheal structures, as assessed using ultrasound, within a neonatal population.

Between 2022 and 2023, experienced sonographers conducted ultrasonographic examinations of the larynx and trachea on 300 healthy newborns of Caucasian descent born between 32 and 42 weeks of gestation. Dimensions of the larynx, thyroid cartilage, vocal folds, glottis, epiglottis, subglottic region, trachea, epiglottis, and infrahyoid muscles were measured.

Normative values were determined for the specific structures of the larynx, trachea, and infrahyoid muscles. The normative sizes for the evaluated structures were determined separately for each sex because of the significant differences observed between the groups.

The results of this study contribute to the advancement of knowledge regarding the structure and function of these organs and may play a crucial role in enhancing the quality of airway management for newborns. The published article serves as a summary of the data obtained from a study registered at ClinicalTrials.gov (identifier NCT05636410).

Question There are no standards for the size of specific parts of the larynx and trachea in the neonatal population on ultrasound examination. Findings The article discusses the ultrasonographic norms for the dimensions of individual laryngeal and tracheal structures, developed based on the studies of 298 neonates. Clinical relevance Knowledge of ultrasound reference values for the size of laryngeal and tracheal structures facilitates the diagnosis of diseases of these organs and allows individualizing the approach to newborns, especially those requiring intensive care.