Drug-Induced Sleep (Sedation) Endoscopy

Drug-induced sedation (sleep) endoscopy - DISE, is commonly used by sleep surgeons to assess dynamic collapse and/or obstruction of the upper airway. This provides a clinical picture of throat muscles that block airflow during sleep. Upper airway collapsibility is a key contributor to sleep-disordered breathing (SDB), including obstructive sleep apnea (OSA). DISE complements polysomnography (sleep study) to help with treatment planning, particularly with alternative treatments to CPAP.

My preference is to perform DISE with Dexmedetomedine (Precedex), unless Propofol needs to be the primary or sole agent. The Precedex protocol that I use is developed by Dr. Vladimir Nekhendzy, a world expert in anesthesia for the complex airway.

I use the VOTE classification described by Dr. Kezirian and Dr. de Vries when reporting DISE results.

DISE Before and After

Maxillomandibular Advancement (MMA)

BEFORE MMA

AFTER MMA

Fun Fact - Dr. Liu was the first to describe changes in DISE before and after MMA surgery. Most important findings included resolution of concentric collapse of the velum and lateral collapse of the pharyngeal wall. DISE findings were then quickly followed-up with computational fluid dynamics (CFD) airway modeling.

DISE Before and After

weight loss

DISE before and after 45 lbs weight loss

Demands on the pharyngeal part of the sleep airway is greatly decreased with weight loss. While behavior measures and bariatric procedures were the only options in recent past, GLP-1 medications such as Zepbound offer another realistic option.

DISE showing upper airway stimulation

(Inspire) in action

Fun Fact - Dr. Liu was the first to describe the continuation of the original Stanford Sleep Surgery Protocol with upper airway stimulation. He authored the work with the original pioneer of the Protocol (and his surgical mentor), Dr. Robert Riley.

DISE | Frequently Asked Questions

    1. To help decision-making in CPAP-alternative treatments

    2. Evaluate important inclusion/exclusion criteria for procedures (Inspire therapy).

    3. To help patient counseling when airway collapse patterns known to be more/less effective are observed.

    1. The nasal passages are decongested.

    2. Monitors for a sedation procedure are placed.

    3. Intravenous access (IV) is established.

    4. Slow infusion of medication (i.e. Dexmetomidine/Precedex and other agents).

    5. Nasopharyngoscope passed through one of the nasal passages to evaluate the nasopharynx, oropharynx, and hypopharynx.

    6. VOTE classification is used to describe findings.

    7. Maneuvers such as head position, body position, chin lift may be performed.

    8. Adjunctive exams with and without oral appliance and CPAP may also be performed.

    9. Awakened in the sedation room (or operating room), and transferred to recovery.

    1. Medical conditions that makes routine sedation unsafe (i.e. high body-mass index, difficult airway, ASA Class 3 or above).

    2. Known allergies to the sedation (and their reversal agents).

    3. Recent upper airway infection (flu, Covid, persistent cough).

  • Q: When do I stop eating and drinking prior to procedure?

    A: For a morning start, after midnight the day before. OK for sips of water to take medications. However, exact medications to take (and to hold), need to be established with the surgeon.

    Q: When do I know the results of my DISE?

    A: As early as the day after the procedure. While it is possible for me to share results with you right away, I frequently find that right after a sedation procedure, patients may not recall details.

    Q: What is recovery like after the procedure?

    A: There should be minimal discomfort in the nose and throat. Some irritation may be expected. Nasal bleeding after DISE is very rare, but can happen.

    Q: Can I drive home after my DISE?

    A: No. We will not start without a friend of family is present with you upon checking in.

    Q: How well do my DISE findings correlate with my sleep study?

    A: While there are correlations, it is important to note that DISE examines anatomy, while the sleep study reveals physiology. Since both bodies of information are important in decision-making for treatment, I see the 2 exams as “complementary.”

  • In 2015, I wrote a technical piece on DISE intended for professional colleagues. While some nuances have evolved, the process and clinical pearls remain largely the same.

    1. 20g IV.

    2. No premedication.

    3. No supplemental O2.

    4. No Glycopyrrolate unless significant brady or secretions (ask the surgeon).

    5. Dex IV bolus 1.5 mcg/kg over 10 min, started immediately on arrival, while the monitors are being applied.

    6. Can either bolus through the Alaris pump syringe using the bolus duration, or put the bolus in 100 ml bag and use the 60 drops/min microdripper wide open: takes exactly 8.5-10 min to run in. Fast Dex administration, especially above 1 mcg/kg, may result in transient hypertension, apnea or hypoxemia/hypercapnia.

    7. Concomitantly, start Dex at 1.5 mcg/kg/hr, and continue during the procedure. D/c Dex 5 min prior to the end of the exam, or immediately after.

    8. No airway supporting maneuvers unless directed by the surgeon; usually with SpO2 in low 80s. Airway support to start with innocuous chin pull (tag on the mentum) or head turn, which is usually sufficient to open the airway.

    9. Wheel out of the OR when responds to commands.

    10. Postop orders: no meds, except Zofran for possible PONV. Fluid bolus for possible Dex-induced hypotension in PACU. High BP meds as required.

    With this technique, the patients should be reliably asleep in 10-15 min, and responding to commands, maintaining the airway within 3-5 min after the end of procedure.