What is drug-induced sleep endoscopy (DISE) and when is it needed?

The AAO-HNS recommends performing polysomnography (PSG) before DISE (sleep endoscopy) to confirm the presence and severity of OSA (mean consensus score 8.88/9). These two tests serve fundamentally different clinical purposes and are not interchangeable. ^[1]

Polysomnography (PSG) is the gold standard for diagnosing OSA. It answers the question: “Is there OSA, and how severe is it?” PSG quantifies the frequency and severity of respiratory events (AHI), the degree of desaturation, sleep architecture and the positional component. It is performed in a sleep laboratory over a full night without sedation. ^[1]

Drug-induced sleep endoscopy (DISE) is a method for locating the obstruction. It answers the question: “Where exactly does the airway obstruction occur?” DISE is a flexible fiberoptic endoscopy performed under drug-induced sedation with spontaneous breathing, which makes it possible to see sites of upper airway collapse in real time. ^[1]

Key differences

• PSG records physiological parameters (EEG, EOG, EMG, airflow, respiratory effort, pulse oximetry, CO₂) throughout the night and determines the presence, severity and nature of OSA. DISE does not provide these data ^[1]
• DISE shows the specific anatomical sites of obstruction (nasal cavity, nasopharynx, soft palate, lateral oropharyngeal walls, tongue base, epiglottis, supraglottis), which is impossible with PSG. In a series of 22 children with persistent OSA, DISE changed the surgical plan in 73% of cases ^[1]
• DISE is not indicated when the AHI is below 2 events/hour, because a recurring obstructive breathing pattern during sedation is unlikely in these children ^[1]

Indications for DISE (AAO-HNS consensus)

• Children with persistent OSA after adenotonsillectomy — before planning additional surgery (the most common indication; at least 1 site of obstruction was found in 100% of 162 children examined)
• Children with OSA and small palatine tonsils (Brodsky 1–2) — to determine whether tonsillectomy is justified
• Children at high risk of persistent OSA (obesity, Down syndrome, craniofacial anomalies) — at the same time as adenotonsillectomy to identify additional sites of obstruction
• DISE is not indicated for healthy children with adenotonsillar hypertrophy who have no risk factors for persistent OSA ^[1]

DISE findings are assessed using standardized scales (C-P score, Sleep Endoscopy Rating Scale, PedDISE-8), which document the site, pattern and degree of obstruction at each anatomical level. ^[1]

Comparison of PSG and DISE

Practical significance of the differences

PSG and DISE complement each other in the management of children with OSA. PSG is always performed first to confirm the diagnosis and determine severity. DISE is added at the second stage, when the anatomical cause of the obstruction needs to be identified — primarily in persistent OSA after adenotonsillectomy or with an atypical clinical picture (OSA with small tonsils). Surgery planned on the basis of DISE improves PSG parameters and symptoms more than surgery without this information. ^[1]

The new pediatric PedDISE-8 scale assesses 8 anatomical sites (inferior turbinates, adenoids, soft palate, tonsils/lateral pharyngeal walls, lingual tonsil, tongue base, epiglottis, arytenoids) and has shown good inter-rater reliability (ICC 0.67–0.88) and correlation with OSA severity on PSG. ^[8]