*Agnieszka Dmowska-Koroblewska, Michał Michalik, Adrianna Podbielska-Kubera, Włodzimierz Jakub Siemianowski
Drug-induced sleep endoscopy in assessing airway patency – own experiences
Badanie endoskopowe drożności dróg oddechowych w czasie snu farmakologicznego – wstępne wyniki
Department of Otolaryngology, MML Medical Center, Warsaw
Head of Department: Michał Michalik, MD, PhD
Streszczenie
Wstęp. Zespół obturacyjnego bezdechu sennego należy do zaburzeń oddychania w czasie snu. Brak poprawy stanu zdrowia po wcześniej wykonanych zabiegach laryngologicznych stanowi wskazanie do badania endoskopowego w czasie snu indukowanego (DISE– ang. drug-induced sleep endoscopy). DISE dostarcza istotnych informacji na temat czynnościowej drożności górnych dróg oddechowych.
Materiał i metody. Badania przeprowadzono na grupie pacjentów, u których wcześniejsze leczenie chrapania i bezdechu sennego było nieskuteczne. U pacjentów przeprowadzono endoskopię w czasie snu indukowanego DISE. Do znieczulenia zastosowano propofol podawany w ciągłym wlewie dożylnym, co zapewniło bezpieczeństwo wykonywanej procedury.
Wyniki. Od 2007 do 2017 roku w Centrum Medycznym MML przeprowadzono 3911 zabiegów leczących chrapanie i bezdechy podczas snu. W tym czasie wykonano 176 procedur DISE. Sposoby leczenia przyczynowego określano na podstawie ankiety, tomografii komputerowej z promieniem stożkowym (CBCT – ang. cone beam computed tomography), badania laryngologicznego i DISE. Subiektywną poprawę z ustąpieniem objawów uzyskano u 80% pacjentów. W 70% przypadków chrapanie zmniejszyło się. U pozostałej części pacjentów wymagane było poszukiwanie przyczyn ogólnoustrojowych: kardiologicznych, neurologicznych gastrologicznych lub endokrynologicznych.
Wnioski. W grupie pacjentów Centrum Medycznego MML zastosowanie techniki DISE przyczyniło się do precyzyjnego określenia miejsca wibrowania i zapadania się dróg oddechowych.
Badanie DISE daje powtarzalne pomiary drożności dróg oddechowych na poziomie gardła dolnego. DISE umożliwia efektywną diagnostykę przyczyn zaburzeń snu w sytuacji, gdy inne metody, takie jak tomografia stożkowa czy cefalometria, nie są wystarczające.
Summary
Introduction. Obstructive sleep apnea is a disorder of breathing during sleep. Lack of clinical improvement after previously performed laryngological procedures is an indication for endoscopic examination during drug – induced sleep. Drug-induced sleep endoscopy (DISE) provides important information about functional upper airways patency.
Material and methods. The study was performed in patients in whom other treatment methods had not been effective. DISE was performed in these patients. Continuous intravenous propofol infusion was given as general anesthetic to ensure the safety of the procedure.
Results. From 2007 to 2017, 2897 procedures for snoring and sleep apnea were performed at the MML Medical Center. At this time, 176 DISE examinations were performed.
Causative treatment methods were determined by the means of questionnaire, CBCT, laryngological examination, and DISE examination. Subjective improvement of apnea symptoms was achieved in 80% of patients. In 70% of cases, snoring decreased. The rest of the patients are required to look for systemic causes of cardiological, neurological gastrological, or endocrine origin.
Conclusions. In our patients, the use of the DISE examination enabled to precisely determine the location of the vibration and of the collapse of the respiratory tract. DISE enables to effectively diagnose the cause of sleep disorders when other methods, such as cone beam computed tomography (CBCT) or cephalometry are not sufficient.

Introduction
Obstructive sleep apnea syndrome (OSAS) affects between 2% and 4% of the population, mostly adults (1). About 80-90% of cases of OSAS remain undiagnosed (2). OSAS also occurs in children, in particular children older than 3-6 years of age (1).
Obstructive sleep apnea is characterized by high morbidity and mortality and is considered a public health problem. Clinical signs of OSAS include snoring and restless sleep (2). OSAS can also be associated with poor concentration, morning headache, excessive sleepiness during the day, and reduced intellectual ability (3). OSAS leads to hypoxia and significantly reduces patient’s quality of life (4). Factors such as obesity, allergy, and facial deformities may aggravate the problem (4). One of the most common risk factor for OSAS is obesity (5). The accumulation of excessive amounts of adipose tissue around the neck is of particular importance (6).
Obstructive sleep apnea may result in complications in different systems: vascular (myocardial infarction), neurological (stroke), endocrine (growth disturbance in children), and pulmonary (pulmonary hypertension) (7). Therefore, it is important to diagnose this condition and treat it adequately.
Obstructive sleep apnea is a result of anatomical abnormalities of upper respiratory airways, such as nasal turbinate hypertrophy, nasal polyps, deviated nasal septum, adenoid hypertrophy, tonsillar hypertrophy, dropping of soft palate, especially of the uvula, hypertrophy of the base of the tongue, and a pathology of larynx (8). Apnea is defined as a complete blockage of the airflow through the airways lasting at least 10 seconds (4). The goal of treating obstructive sleep apnea is to maintain the patency of the upper respiratory tract.
The severity of OSAS symptoms varies and is dependent on many factors that are not fully known (9). It has been confirmed that sleeping position has an impact on the incidence and severity of symptoms of sleep apnea. Symptoms in patients with OSAS (frequency of apnea, its duration, and desaturation) are increased when the patient is supine. Changes in the upper respiratory tract that are dependent on position during sleep correspond to a different severity of apnea. The mechanism responsible for an increase in symptoms when lying on the back is not clear. Most likely, it is related to the influence of gravity on the arrangement of individual sections of the upper respiratory tract. In the supine position, the tendency of the airways to collapse is greater. After changing the sleeping position from supine to lateral, the obstruction in the structures such as tongue base and larynx is less common. The assessment of changes of the anatomical elements of the upper respiratory tract depending on the sleep position can be used to plan targeted treatment in patients (9).
The diagnostic of OSAS include laryngological examination, endoscopic examination, polysomnography (PSG), cone beam computed tomography (CBCT), rhinomanometry, and drug-induced sleep endoscopy (DISE).
Polysomnography, first described in 1965 by Gastaut, is used for the diagnosis and assessment of severity of OSAS. Continuous Positive Airway Pressure (CPAP) is considered a golden standard of treatment of OSAS (10).
Lack of improvement after previous laryngological surgical procedures (such as septoplasty, palatoplasty, tonsillotomy, and tonsillectomy) is an indication for DISE (11). This applies to both adult and pediatric patients. DISE should be performed in children who continue to snore and wake up during the night after adenotonsillotomy (11).
In 1991, Croft and Pringle first applied drug-induced sleep endoscopy to examine respiratory tract in sedation (12).
Surgical treatment of obstructive sleep apnea requires knowing the exact location of the obstacle. Only the examination of the upper respiratory tract during in a sleeping patient can provide complete information about the state of health (13). To date, there is no optimal method for determining the location of airway obstruction (3). Unfortunately, most of the techniques used to investigate the location of the obstruction are based on the examination in an awake patient and include static rather than dynamic observation. DISE is a unique examination for assessing the cause of apnea and/or snoring, thanks to the patient’s light sleep caused by a pharmacological agent (10).
The examination is completely safe for the patient and is conducted in the presence of an anesthesiologist in an operating room or in a suitably equipped treatment room. Vital parameters are constantly monitored, and if necessary, the patient can be intubated and connected to a life support machine (14).
Different classification systems, such as VOTE classification system (velum, oropharynx lateral walls, tongue base, epiglottis) and NOHL classification system (nose, oropharynx, hypopharynx, larynx) are used to determine the location and severity of the upper respiratory tract obturation. VOTE classification enables quantitative assessment (3). For every level, the severity of obturation is assessed in a three-level scale: 0 – no obstruction (no vibration); 1 – partial obstruction (vibration); 2 – complete obstruction – collapse of airways. Oropharyngeal obturation is classified as: ap – anteroposterior, l – lateral (fig. 1), or c – circular. Not all the obturation patterns can occur on all the assessed levels (11).

Fig. 1. Lower end of tonsil compressing epiglottis
In the NOHL classification system, obturation grade is assessed on a scale from 0 to 4. Oropharyngeal obturation is classified as: ap – anteroposterior, l – lateral, or c – circular. Laryngeal obstruction is also assessed: on an a (epiglottis) or b (glottis) level, as p – positive, or n – negative (fig. 2, 3) (15).

Fig. 2. Collapse of epiglottis

Fig. 3. Airway obstruction at the level of epiglottis
The majority of researchers use the VOTE system (3).
Material and Methods
The study was retrospective. DISE was performed on patients with obstructive sleep apnea. Before the procedure, patients were asked to complete the questionnaire, consisting of an original questionnaire for diagnosing breathing disorders during sleep (fig. 4), based on Berlin Questionnaire – enabling to assess the relationship between respiratory disturbances during sleep and cardiovascular and respiratory diseases – and Epworth Sleepiness Scale by the British Snoring and Sleep Apnoea Association (fig. 5) – enabling the assessment of daytime sleepiness and probability of falling asleep in everyday situations.



Fig. 4. Original questionnaire for diagnosing breathing disorders during sleep

Fig. 5. Epworth Sleepiness Scale
In some of the patients, as a part of extended diagnostic process, apnea/hypopnea index (AHI) was also determined. AHI describes the severity of sleep apnea and is expressed as a number of apnea and hypopnea episodes per hour of sleep (tab. 1).
Tab. 1. AHI score and severity level of OSAS
AHI | Severity of OSAS |
< 5 | normal |
5-14 | mild OSAS |
15-24 | moderate OSAS |
> 24 | severe OSAS |
For each patient, body mass index (BMI) was also calculated and neck circumference was measured.
In laryngological examination, the following structures were assessed: external nose (symmetry and potential deformations), anterior nares, nasal septum, and inferior nasal conchae. Additionally, soft palate was assessed according to Mallampati classification (tab. 2), and tonsils were evaluated with Pirquet Tonsillar Hypertrophy Grading Scale (tab. 3).
Tab. 2. Mallampati score
Grade | Description |
1. | soft palate, uvula, fauces, pillars visible |
2. | soft palate, uvula, fauces visible |
3. | soft palate, base of uvula visible |
4. | soft palate not visible |
Tab. 3. Pirquet score
Grade | Description |
1. | Tonsils hidden behind tonsillar pillars |
2. | Tonsils extend to pillars |
3. | Tonsils visible beyond pillars |
4. | Tonsils covering 50% of space between pillars |
5. | Tonsils extend to midline |
Patients underwent endoscopic examination and CBCT (fig. 6). The indications for surgical treatment included deviated nasal septum, turbinate hypertrophy, and dropping of the soft palate.

Fig. 6. Airway obstruction at the level of velum and tongue root
Powyżej zamieściliśmy fragment artykułu, do którego możesz uzyskać pełny dostęp.
Mam kod dostępu
- Aby uzyskać płatny dostęp do pełnej treści powyższego artykułu albo wszystkich artykułów (w zależności od wybranej opcji), należy wprowadzić kod.
- Wprowadzając kod, akceptują Państwo treść Regulaminu oraz potwierdzają zapoznanie się z nim.
- Aby kupić kod proszę skorzystać z jednej z poniższych opcji.
Opcja #1
19 zł
Wybieram
- dostęp do tego artykułu
- dostęp na 7 dni
uzyskany kod musi być wprowadzony na stronie artykułu, do którego został wykupiony
Opcja #2
49 zł
Wybieram
- dostęp do tego i pozostałych ponad 7000 artykułów
- dostęp na 30 dni
- najpopularniejsza opcja
Opcja #3
119 zł
Wybieram
- dostęp do tego i pozostałych ponad 7000 artykułów
- dostęp na 90 dni
- oszczędzasz 28 zł
Piśmiennictwo
1. Young T, Finn L: Epidemiological insights into the public health burden of sleep disordered breathing: sex differences in survival among sleep clinical patients. Thorax 1998; 53 suppl. 3: 516-519.
2. Viana Ada C Jr, Thuler LC, Araújo-Melo MH: Drug-induced sleep endoscopy in the identification of obstruction sites in patients with obstructive sleep apnea: a systematic review. Braz J Otorhinolaryngol. 2015; 81: 439-446.
3. Altintaş A, Olgun B, Yegin Y et al.: Interobserver Consistency of Drug-Induced Sleep Endoscopy in Diagnosing Obstructive Sleep Apnea Using a VOTE Classification System. J Craniofac Surg. 2017; 1: 1-10.
4. Hasiec A, Szumowski Ł, Walcza F: Obturacyjny bezdech – senny zabójca. For Med Rodz 2012; 6 (3), 103-114.
5. Schwartz AR, Patil SP, Laffan AM et al.: Obesity and obstructive sleep apnea: pathogenic mechanisms and therapeutic approaches. Proc Am Thor Soc 2008; 5(2); 185-192.
6. Ciuba I: Obturacyjny bezdech senny. Zam St Mat; 2011; 13(1): 109-115.
7. Jagannathan R, Seixas A, St-Jules D et al.: Systems Biology Genetic Approach Identifies Serotonin Pathway as a Possible Target for Obstructive Sleep Apnea: Results from a Literature Search Review. Sleep Disord 2017; 2017: 6768323.
8. Atulkumar Shah J, George A, Chauhan N, Francis S: Obstructive Sleep Apnea.Role of an Otorhinolaryngologist; Indian J Otolaryngol Head Neck Surg 2016; 68(1): 71-74.
9. Lee CH, Kim DK, Kim SY et al.: Changes in Site of Obstruction in Obstructive Sleep Apnea Patients According to Sleep Position: A DISE Study. Laryngoscope 2015; 125: 248-254.
10. Ravesloot MJ, de Vries N: One hundred consecutive patients undergoing drug-induced sleep endoscopy: results and evaluation. Laryngoscope 2011; 121(12): 2710-2716.
11. Kezirian EJ, Hohenhorst W, de Vries N: Drug-induced sleep endoscopy: the VOTE classification. Eur Arch Otorhinolaryngol 2011; 268(8): 1233-1236.
12. Croft CB, Pringle M: Sleep nasendoscopy: a technique of assessment in snoring and obstructive sleep apnoea. Clin Otolaryngol Allied Sci 1991; 16: 504-509.
13. Blumen MB, Latournerie V, Bequignon E et al.: Are the obstruction sites visualized on drug-induced sleep endoscopy reliable? Sleep Breath 2015; 19: 1021-1026.
14. Grochowski T, Kukwa W, Krzeski A et al.: Badanie endoskopowe gardła dolnego we śnie farmakologicznym. Mag Otolar 2014; 50(13): 57-61.
15. Vicini C, De Vito A, Benazzo M et al.: The nose oropharynx hypopharynx and larynx (NOHL) classification: A new system of diagnostic standardized examination for OSAHS patients. Eur Arch Otorhinolaryngol 2012; 269(4): 1297-1300.
16. Roblin G, Williams AR, Whittet H: Target-controlled infusion in sleep endoscopy. Laryngoscope 2001; 111: 175-176.
17. Kotecha BT, Hannan SA, Khalil HM et al.: Sleep nasendoscopy: A 10-year retrospective audit study. Eur Arch Otorhinolaryngol 2007; 264(11): 1361-1367.
18. Ryan C, Borek BS, Erica R at al.: Quantitative Airway Analysis During Drug-Induced Sleep Endoscopy for Evaluation of Sleep Apnea. Laryngoscope 2012; 122(11): 2592-2599.
19. Torre C, Camacho M, Liu SY et al.: Epiglottis collapse in adult obstructive sleep apnea: a systematic review. Laryngoscope 2016; 126(2): 515-523.
20. Yegïn Y, Çelik M, Kaya KH et al.: Comparison of drug-induced sleep endoscopy and Müller’s maneuver in diagnosing obstructive sleep apnea using the VOTE classification system. Braz J Otorhinolaryngol. 2017; 83(4): 445-450.
21. De Vito A, Agnoletti V, Berrettini S et al.: Drug-induced sleep endoscopy: conventional versus target controlled infusion techniques – a randomized controlled study. Eur Arch Otorhinolaryngol 2011; 268: 457-462.
22. Witkowska M, Karwacki Z, Rzaska M et al.: Porównanie docelowej infuzji kontrolowanej i anestezji całkowicie dożylnej z użyciem propofolu i remifentanylu do operacji mikrodyskoidektomii w odcinku lędźwiowym kręgosłupa; Anest Int Ter 2012, 44:(3), 156-163.
23. Lo YL, Ni YL, Wang TY et al.: Bispectral Index in Evaluating Effects of Sedation Depth on Drug-Induced Sleep Endoscopy. JCSM 2015; 11(9): 1011-1020.
24. Myles PS, Leslie K, McNeil J et al.: Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. Lancet 2004; 363(9423): 1757-1763.
25. Safiruddin F, Koutsourelakis I, de Vries N: Analysis of the influence of head rotation during drug-induced sleep endoscopy in obstructive sleep apnea. Laryngoscope 2014; 124: 2195-2199.
26. Carrasco-Llatas M, Agostini-Porras G, Cuesta-González MT, Rodrigo-Sanbartolomè A et al.: Drug-induced sleep endoscopy: a two drug comparison and simultaneous polysomnography. Eur Arch Otorhinolaryngol 2014; 271(1): 181-187.
27. Dijemeni E, Kotecha B: Drug-Induced Sedation Endoscopy (DISE) DATA FUSION system: clinical feasibility study. Eur Arch Otorhinolaryngol 2017; 1: 1-14.
28. Vroegop AV, Vanderveken OM, Wouters K et al.: Observer variation in drug-induced sleep endoscopy: experienced versus nonexperienced ear, nose, and throat surgeons. Sleep 2013; 36(6): 947-953.