Videoendoscopic evaluation of swallowing using normal saline in NICU infants

Videoendoscopic evaluation (VE) of swallowing involves inserting a small flexible endoscope transnasally to allow direct observation of pharyngeal and laryngeal structures and swallowing functions. In our neonatal intensive care unit (NICU) VE is performed in infants suspected of severe swallowing dysfunction, using normal saline (NS) with the aim of minimizing the detrimental effect of aspiration on respiration caused by VE. This retrospective study was conducted to evaluate the usefulness of VE using NS in NICU infants.

We enrolled 28 infants who demonstrated clinical signs of swallowing dysfunction or who were ready to start oral feeding. Swallowing evaluations were completed using flexible fiberoptic laryngobronchoscopy (FLB). While observing the pharyngeal and laryngeal cavity with FLB, NS was gradually increased by 1 mL and injected up to a maximum of 3 mL, and the swallowing reflex, tracheal aspiration, and pharyngeal residue were observed.

Median gestational age was 37 weeks 6 days, median birthweight 2,539 g, and median age at first examination was 107.5 days. Abnormalities in VE were observed in 20 cases, most of which were upper airway lesions. Most of these upper airway abnormalities were pharyngeal lesions. In two pharyngeal lesion cases, swallowing function improved using positive airway pressure.

Infants with pharyngeal lesions demonstrated abnormal VE findings. Furthermore, positive airway pressure improved swallowing in some cases, suggesting that narrowing of the pharyngeal cavity may affect swallowing function. In addition, results suggest that VE using NS is a safe and useful method for evaluating swallowing function and determining countermeasures in NICU infants.