See also: Obstructive Sleep Apnea (OSA)
See also: Sleep Apnea Management - Hypoglossal Nerve Stimulation
Content prepared by Evgeniya Molotkova and Dr. Douglas Van Daele (1/13/2025)
Background/General Considerations
Obstructive sleep apnea (OSA) is characterized by a dynamic collapse of the upper aerodigestive tract during sleep. First line treatment is typically continuous positive airway pressure (CPAP) at night; however, CPAP may not be tolerated by all patients, which may contribute to poor compliance. In these cases, other options for therapy may include oral devices, surgical intervention, and upper airway stimulation.
Drug induced sleep endoscopy (DISE) has been established as a useful tool that can help determine patient candidacy for many of these interventions by way of assessing the anatomy and collapsibility of upper airway structures (Cheong et al, 2021). DISE involves visualization of the upper airway with an endoscope during sedation mimicking a sleep state.
Use of DISE in determining candidacy for:
- Mandibular advancement devices (MAD)
- During DISE, the mandible is manually advanced, and if the size of the upper airway increases significantly, then the patient may be a good candidate for this therapy (Cheong et al, 2021)
- Huntley and colleagues found that patients who were assessed with DISE prior to being prescribed a mandibular advancement device had a higher rate of treatment success than patients who were prescribed a mandibular advancement device without being assessed with DISE (Huntley et al, 2018)
- Op de Beeck and colleagues found that certain sites of anatomic collapse on DISE were correlated with increased responsiveness to mandibular advancement devices (Op de Beeck et al, 2019).
- Tongue base collapse was associated with a therapeutic benefit associated with use of MADs
- Complete concentric collapse was associated with treatment deterioration
- Although there have been several studies that investigated the use of DISE in recommending mandibular advancement devices, many of these are retrospective, small, and tended to evaluate participants with less severe OSA (Cheong et al, 2021)
- During DISE, the mandible is manually advanced, and if the size of the upper airway increases significantly, then the patient may be a good candidate for this therapy (Cheong et al, 2021)
- Surgical intervention
- Several studies have investigated the role of DISE in predicting treatment success in a variety of surgical approaches to the treatment of OSA
- Aktas and colleagues found that location of anatomic collapse seen on DISE (upper vs lower airway) correlated with success of tonsillectomy or uvulopalatopharyngoplasty (UPPP)
- Patients who had upper airway collapse on DISE were more likely to have a favorable result compared to those with lower airway obstruction (Aktas et al, 2015)
- Alternatively, Meraj and colleagues found that the results of preoperative DISE did not accurate predict success of transoral robotic surgery for OSA (Meraj et al, 2017)
- Aktas and colleagues found that location of anatomic collapse seen on DISE (upper vs lower airway) correlated with success of tonsillectomy or uvulopalatopharyngoplasty (UPPP)
- There are few large, high-powered studies available that investigate the role of DISE in prognosticating success of soft tissue sleep surgery. A recent meta-analysis by Lisan and colleagues demonstrated that pre-operative assessment with DISE was not associated with a higher surgical success rate or significant change in apnea-hypopnea index (AHI) (Lisan et al, 2023)
- Additional studies are needed to further characterize the role that DISE plays in guiding surgical planning
- Several studies have investigated the role of DISE in predicting treatment success in a variety of surgical approaches to the treatment of OSA
- Upper airway stimulation
- The use of DISE was a mandatory screening measure included in the Stimulation Therapy for Apnea Reduction (STAR) trial that investigated the effectiveness of the Inspire hypoglossal nerve stimulator
- Robust data from this study has indicated that circumferential airway collapse during DISE is highly associated with poor treatment outcomes and remains a contraindication to Inspire placement
- In a retrospective study, Huyett and colleagues found that patients who had complete tongue-related obstruction identified on DISE were more likely to have a better treatment response to upper airway stimulation than those who had complete oropharyngeal lateral wall obstruction on DISE (Huyett et al, 2021)
- The use of DISE was a mandatory screening measure included in the Stimulation Therapy for Apnea Reduction (STAR) trial that investigated the effectiveness of the Inspire hypoglossal nerve stimulator
A major indication for DISE assessment is patients with obstructive sleep apnea that fail or are unable to tolerate CPAP (Charakorn and Kezirian, 2016). This step allows for consideration of other treatments including mandibular advancement devices and sleep surgery, but especially upper airway stimulation. Relative contraindications for DISE include allergies to selected sedative agents, pregnancy, and medical comorbidities that may make administration of anesthetics dangerous. Some investigators also tend to exclude patients with severe OSA (AHI > 70 events per hour) or obesity (Charakorn and Kezirian, 2016)
Charakorn and Kezirian (2016) reported DISE to be a safe procedure in appropriately selected patients. Reported risks include hypoventilation associated with sedation, which may warrant endotracheal intubation in rare cases. These events are rare, but slight desaturations are expected and have been reported to be well-tolerated by patients and can most frequently be managed with bag-valve mask ventilation (Charakorn and Kezirian, 2016).
Anatomy
The VOTE classification is a useful tool that succinctly captures important anatomic considerations in DISE to describe the pattern of airway collapse/obstruction. Pertinent anatomic landmarks include the velum, oropharynx lateral walls, tongue base, and epiglottis (Kezirian et al, 2011). The VOTE classification grades the degree of obstruction at each of these locations from the perspective of different directions (anteroposterior, lateral, and concentric)
- Degree of obstruction:
- 0: No obstruction/no vibration
- 1: Partial obstruction/vibration
- 2: Complete obstruction/collapse
- X: Not visualized
UIHC DISE Protocol for Adult Patients
Pre-procedural Preparation
At the University of Iowa (vetted by senior author Dr. Douglas Van Daele, 12/9/2024), patients are typically assessed with DISE as part of their assessment for hypoglossal nerve stimulator candidacy. Generally, these patients:
- Are at least 18 years of age
- Diagnosed OSA with polysomnography (PSG) or home sleep apnea test (HSAT) with an apnea-hypopnea index (AHI) of ≤ 100
- Cut-off may vary depending on insurance coverage
- Failed or been unable to tolerate CPAP
- Have a BMI ≤ 40
- Cut-off BMI may differ based on insurance coverage
- Not at significant risk for sedation
- Patients with severe sleep apnea are at a higher risk for airway compromise with the administration of sedatives without a secure airway (ASA Practice Guidelines, 2014)
Image quality in DISE is dependent on patient secretion burden. Options for secretion control include:
- Preferred:
- 2-3 sprays of oxymetolazine per nostril (rapid action, timing more flexible)
- Other options:
- 0.2-0.4 mg glycopyrrolate at least 30 minutes prior to procedure
- 0.2 mg atropine at least 30 minutes prior to procedure
Topical anesthetic to the upper aerodigestive tract may minimize patient discomfort following DISE. If utilized, any topical anesthetic spray (with or without decongestant) can be administered 20 minutes prior to DISE.
Nursing Considerations
- Instruments and equipment
- Anesthesiology
- Infusion pump
- Monitoring equipment (ex. pulse oximetry, EKG, blood pressure)
- Bag-valve mask
- Airway emergency cart
- Otolaryngology
- Flexible laryngoscope/pediatric bronchoscope
- Defogging solution/lens cleaning cloths
- Suction
- Anesthesiology
- Positioning
- Preparation and draping
Anesthesia Considerations
Oxygenation
Preoxygenation with either low flow or high flow nasal cannula may prevent desaturations and atelectasis during DISE (Park et al, 2023). Supplemental oxygen during the procedure is not necessarily required, but supplemental oxygen (often via nasal cannula) is frequently utilized at many institutions (Schwartz et al, 2024)(Atkins et al, 2014)(Cho et al, 2015). University of Iowa practice most commonly involves oxygenation during DISE with 6-8 LPM via nasal cannula.
Sedation
The desired level of sedation is less than what is employed for most surgical procedures. Sedation is targeted to recreate snoring and apneic episodes, and sedation should be titrated in over to achieve this middle ground.
- Too little sedation
- No airway collapse at the soft palate or tongue base
- Just enough sedation
- Recreation of apneas and snoring (similar to what is experience during regular sleep)
- Corresponds to Observer Assessment of Alertness/Sedation (OAAS) Score of 2 to 1 (Barakat et al, 2007)
- 0: Does not respond to noxious stimulus
- 1: Does not respond to mild prodding or shaking
- 2: Responds only after mild prodding or shaking
- 3: Responds only after name is spoken loudly, repeatedly, or both
- 4: Lethargic response to name spoken in a normal tone
- 5: Responds readily to name spoken in a normal tone
- Bi-spectral Analysis (BIS) score of 55-70
- BIS is a value derived from EEG (includes beta ratio, SyncFastSlow, Burst Suppression Ratio, and QUAZI parameters) (Barakat et al, 2007)
- Corresponds to Observer Assessment of Alertness/Sedation (OAAS) Score of 2 to 1 (Barakat et al, 2007)
- Recreation of apneas and snoring (similar to what is experience during regular sleep)
- Too much sedation
- Diffuse, multi-level airway collapse
- Accumulation of secretions
- NO response to sternal rub
Patients differ according to amounts of anesthetic agents required. Muscle relaxants are not recommended.
- Propofol is the preferred anesthetic in DISE. Moderate or large boluses are generally not preferred, but a small (20 mg maximum) bolus may be used
- Continuous infusion: propofol should be started at 50-75 mcg/kg/min and increased by 25 mcg/kg/min every 2 minutes until the desired level of sedation is achieved
Procedure
- The patient is positioned supine with their neck in a neutral position.
- A flexible laryngoscope (3.5 mm diameter or less) is inserted in either nostril to assess for signs of nasal obstruction
- Evaluation of the velopharynx should include assessment of both the AP and lateral walls in the same image
- Collapse pattern is assessed over several respiratory cycles (especially during inspiration) using the VOTE tool to determine the dominant pattern and severity of collapse
- The pattern and severity of collapse may evolve over the course of DISE
Desaturations are expected during DISE. Desaturations less than 4% and lasting less than 1 minute should be tolerated (i.e. no intervention necessary).
Postoperative Care
- Transfer to PACU after conclusion
- General diet when patient is alert
- Same day discharge most common
- UIHC hospital-wide protocol for same day surgery for patients with OSA
- Patients at high risk for obstructive sleep apnea (who have a preadmission determined STOP-BANG score 5-8), should use their BIPAP/CPAP when sleeping. Those not fitted with BIPAP/CPAP may need to be admitted overnight if not able to maintain oxygen saturation greater than 92% without oxygen, when resting
- Follow-up
- Results of DISE discussed at next office visit
- Determination of candidacy for Inspire implant
Interpretation of DISE Results
In general, all AP collapse types (at all locations included in the VOTE classification) are eligible for Inspire. Complete concentric collapse is an Inspire contra-indication.
References
Cheong CS, Loke W, Thong MKT, Toh ST, Lee CH. The Emerging Role of Drug-Induced Sleep Endoscopy in the Management of Obstructive Sleep Apnea. Clin Exp Otorhinolaryngol. 2021;14(2):149-158. doi:10.21053/ceo.2020.01704
Huntley C, Cooper J, Stiles M, Grewal R, Boon M. Predicting Success of Oral Appliance Therapy in Treating Obstructive Sleep Apnea Using Drug-Induced Sleep Endoscopy. Journal of Clinical Sleep Medicine 2018; 14:1333-1337.
Op de Beeck S, Dieltjens M, Verbruggen AE, et al. Phenotypic Labelling Using Drug-Induced Sleep Endoscopy Improves Patient Selection for Mandibular Advancement Device Outcome: A Prospective Study. J Clin Sleep Med. 2019;15(8):1089-1099. doi:10.5664/jcsm.7796
Aktas O, Erdur O, Cirik AA, Kayhan FT. The role of drug-induced sleep endoscopy in surgical planning for obstructive sleep apnea syndrome. Eur Arch Otorhinolaryngol. 2015;272(8):2039-2043. doi:10.1007/s00405-014-3162-8
Meraj TS, Muenz DG, Glazer TA, Harvey RS, Spector ME, Hoff PT. Does drug-induced sleep endoscopy predict surgical success in transoral robotic multilevel surgery in obstructive sleep apnea? The Laryngoscope 2017; 127:971-976.
Lisan Q, Baudouin R, Lechien JR, Hans S, Blumen M. Is drug-induced sleep endoscopy associated with better outcomes after soft tissue surgery for sleep apnea? A systematic review and meta-analysis. Clinical Otolaryngology 2023; 48:122-129.
Charakorn N, Kezirian EJ. Drug-Induced Sleep Endoscopy. Otolaryngol Clin North Am 2016; 49:1359-1372.
Kezirian EJ, Hohenhorst W, de Vries N. Drug-induced sleep endoscopy: the VOTE classification. Eur Arch Otorhinolaryngol. 2011;268(8):1233-1236. doi:10.1007/s00405-011-1633-8
Practice Guidelines for the Perioperative Management of Patients with Obstructive Sleep Apnea: An Updated Report by the American Society of Anesthesiologists Task Force on Perioperative Management of Patients with Obstructive Sleep Apnea. Anesthesiology 2014; 120:268-286.
Barakat AR, Sutcliffe N, Schwab M. Effect site concentration during propofol TCI sedation: a comparison of sedation score with two pharmacokinetic models. Anaesthesia 2007; 62:661-666.
Huyett P, Kent DT, D'Agostino MAet al. Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulation Outcomes: A Multicenter Cohort Study. The Laryngoscope 2021; 131:1676-1682.
Park, S., Kim, S.Y. & Kim, H.J. Efficacy of high-flow nasal oxygen during drug-induced sleep endoscopy in patients with obstructive sleep apnea. Sleep Breath 27, 1779–1785 (2023). https://doi.org/10.1007/s11325-023-02785-5
Schwartz, D., Schall, C., Harders, M. et al. Anesthesia for Drug Induced Sleep Endoscopy (DISE). Curr Anesthesiol Rep 14, 469–474 (2024). https://doi.org/10.1007/s40140-024-00632-1
Atkins, J. H., Mandel, J. E., & Rosanova, G. (2014). Safety and efficacy of drug-induced sleep endoscopy using a probability ramp propofol infusion system in patients with severe obstructive sleep apnea. Anesthesia and analgesia, 119(4), 805-810. https://doi.org/10.1213/ANE.0000000000000229
Cho, J.S., Soh, S., Kim, E.J. et al. Comparison of three sedation regimens for drug-induced sleep endoscopy. Sleep Breath 19, 711–717 (2015). https://doi.org/10.1007/s11325-015-1127-9