Visualizing natural sleep state during nasolaryngoscopy in infants: A feasibility study

Otolaryngology consultation for infant airway obstruction is common, with nasolaryngoscopy being the primary diagnostic tool. However, traditional awake nasolaryngoscopy is often limited by infant crying and brief examinations. A more detailed drug-induced sleep endoscopy requires anesthesia and operating room resources. This study explores Time-Induced Sleep Endoscopy (TISE) as a relatively brief, non-invasive alternative for evaluating sleep-related airway dynamics in infants.

This prospective study enrolled infants under three months of age at UPMC Children's Hospital of Pittsburgh. Hospitalized infants requiring bedside flexible nasolaryngoscopy for airway evaluation were eligible. A flexible nasolaryngoscope was inserted nasally and left in place until the infant fell asleep with a 5-min cut-off. Endoscopic videos were scored for airway obstruction while awake and asleep by two pediatric otolaryngologists using the Sleep Endoscopy Rating Scale. Demographics and time to sleep were recorded. Logistic regression examined factors associated with successful TISE. Inter-rater reliability was assessed using Cohen's Kappa.

Among 19 infants (median post-menstrual age at evaluation: 40.3 weeks, range: 37.1-51.5), TISE was successful in 11 (57.9 %), with an average time to sleep of 3.1 min. Infants younger than three weeks were eight times more likely to fall asleep compared to older infants (OR = 8.00, 95 % CI: 1.00-63.96, p=.048). Compared to awake endoscopy, TISE revealed higher frequency of airway obstruction, particularly for hypopharyngeal obstruction (100 % compared to 18 %, p=.004). Inter-rater reliability was moderate for awake endoscopy (κ = 0.55) and fair for TISE (κ = 0.38).

TISE can allow for visualization of sleep-related airway obstruction in some infants. Further validation is needed for broader use.