**6. Sleep nasendoscopy**

Sleep nasendoscopy (SNE) which is also known as drug induced sedation endoscopy (DISE) was pioneered at our institute.13 The beauty of this technique lies in the fact that it allows a three dimensional visualisation of the upper airway during sleep albeit drug induced. This assessment is carried out in an operating theatre setting with the help of an anaesthetist who provides sedation to the patient and closely monitors the patients cardiovascular and respiratory parameters. The sedative agents commonly used are midazolam or propofol, however in some units both the drugs are used.

Drug induced sleep is different from natural physiological sleep but one could argue that the drug used for sedation has the same effect on the different segments of the pharynx thus it would allow us to compare the proportionate obstruction caused at each anatomical level in a similar manner that may exist in natural sleep.

An audit of 2,485 procedures performed over a period of 10 years at our institute has demonstrated that SNE correlates well with apnoea-hypopnoea index and mean oxygen desaturation.14 We have also demonstrated the usefulness of SNE in predicting treatment success in snorers using MAS.15,16 Similarly, SNE has allowed site specific target selection in surgical patients and improved surgical outcomes in our group of patients undergoing laser assisted palatoplasty with or without tonsillectomy has been reported.17-19

Sleep nasendoscopy assessment of snoring is useful as it provides evaluation of the upper airway in the dynamic mode during sleep. However, numerous controversies and debates have arisen and attempts have been made to address some of these by various authors.

For instance, criticisms made by Marais20, whilst comparing snorers and non-snorers, it was claimed that snoring was produced during SNE in a large number of the non-snorers and was not produced in many of the snorers. This was challenged by Berry *et* al21, demonstrating in their study using target controlled infusion of propofol during SNE that all their snorers and non-snorers responded as expected.

Fig. 6. Silver 'reference' marker indicating the correct position of the Apnea-Graph catheter

Sleep nasendoscopy (SNE) which is also known as drug induced sedation endoscopy (DISE) was pioneered at our institute.13 The beauty of this technique lies in the fact that it allows a three dimensional visualisation of the upper airway during sleep albeit drug induced. This assessment is carried out in an operating theatre setting with the help of an anaesthetist who provides sedation to the patient and closely monitors the patients cardiovascular and respiratory parameters. The sedative agents commonly used are midazolam or propofol,

Drug induced sleep is different from natural physiological sleep but one could argue that the drug used for sedation has the same effect on the different segments of the pharynx thus it would allow us to compare the proportionate obstruction caused at each anatomical level

An audit of 2,485 procedures performed over a period of 10 years at our institute has demonstrated that SNE correlates well with apnoea-hypopnoea index and mean oxygen desaturation.14 We have also demonstrated the usefulness of SNE in predicting treatment success in snorers using MAS.15,16 Similarly, SNE has allowed site specific target selection in surgical patients and improved surgical outcomes in our group of patients undergoing laser

Sleep nasendoscopy assessment of snoring is useful as it provides evaluation of the upper airway in the dynamic mode during sleep. However, numerous controversies and debates have arisen and attempts have been made to address some of these by various authors. For instance, criticisms made by Marais20, whilst comparing snorers and non-snorers, it was claimed that snoring was produced during SNE in a large number of the non-snorers and was not produced in many of the snorers. This was challenged by Berry *et* al21, demonstrating in their study using target controlled infusion of propofol during SNE that

assisted palatoplasty with or without tonsillectomy has been reported.17-19

**6. Sleep nasendoscopy** 

however in some units both the drugs are used.

in a similar manner that may exist in natural sleep.

all their snorers and non-snorers responded as expected.

Similarly, questions and concerns that arose about test-retest reliability and of inter-rater reliability of SNE have been elegantly addressed by studies conducted by Rodriguez-Bruno *et* al22 and Kezirian *et* al23 respectively.

Bispectral index monitoring (BIS) has provided an adjunct to the assessment of sleep nasendoscopy in determining the level of sedation required for snoring assessment.24 BIS (figs. 7 & 8) monitor is a neurophysiological monitoring device which continually analyses a patient's electroencephalogram during sedation and general anaesthesia to assess the level of consciousness and depth of anaesthesia.

Fig. 7. Four sensor BIS electrode attached on patient's forehead

Fig. 8. BIS Monitor reading during Sleep Nasendoscopy

The issue of assessing the patient at the correct moment has not previously been addressed and this indeed is an important point as one has to bear in mind the pharmacology and the pharmacokinetics of the different drugs used during sedation. If the patient is assessed too

Evaluation of the Upper Airway in Patients with Snoring and OSA 73

[6] Sheperd JW Jr, Stanson AW, Sheedy PF, et al. Fast-CT evaluation of the upper airway

[7] Schwab RJ, Gefter WB, Hoffman EA, et al. Dynamic upper airway imaging during

[8] Hara H, Murakami N, Miyauchi Y, Yamashita H. Acoustic analysis of snoring sounds by

[9] Saunders NC, Tassone P, Wood G, Norris A, Harries M, Kotecha B. Is acoustic analysis

[10] Brietzke SE, Mair EA. Acoustic analysis of snoring: can the probability of success be

[11] Tvinnereim M, Mitic S, Hansen RK. Plasmaradiofrequency preceded by pressure

[12] Singh A, Al-Reefy H, Hewitt R, Kotecha B. Evaluation of Apnea-Graph in the diagnosis of sleep-related breathing disorders. Eur Arch Otorhinolaryngol 2008;265:1489-94. [13] Croft CB, Pringle M. Sleep nasendoscopy: a technique of assessment in snoring and

[14] Kotecha BT, Hannan AS, Khalil HMB, Georgalas C, Bailey P. Sleep nasendoscopy: a 10 year retrospective audit study. Eur Arch Otorhinoloaryngol 2007;264:1361-1367. [15] Battagel J, Johal A, Kotecha BT. Sleep nasendoscopy as a predictor of treatment success

[16] Johal A, Hector MP, Battagel J, Kotecha B. Impact of sleep nasendoscopy on the

[17] Kotecha B, Paun S, Leong P, Croft C. Laser assisted uvulopalatoplasty: an objective evaluation of the technique and results. Clin Otolaryngol 1998; 23: 354-359. [18] Iyangkaran T, Kanaglingam J, Rajeswaran R, Georgalas C, Kotecha B. Long-term

[19] Chisholm E, Kotecha B. Oropharyngeal surgery for obstructive sleep apnoea in cPAP

[20] Marais J. The value of sedation nasendoscopy: a comparison between snoring and non-

[21] Berry S, Robin G, Williams A, Watkins A, Whittet HB. Validity of sleep nasendoscopy

[22] Rodriguez-Bruno K, Goldberg AN, McCulloch CE, Kezirian EJ. Test-retest reliability of

[23] Kezirian EJ, White DP, Malhotra A, Ma W, McCulloch CE, Goldberg A (2010) Interrater

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early, the muscle relaxation effect of the drug may be over emphasised and if the patient is assessed too late then important anatomical aspect of the obstructive episodes may be missed. Thus the depth of sedation during which the assessment is conducted should be as close to the levels of depth of natural sleep. Evaluation only occurs as a snap shot of a patients whole sleep cycle. However, combining it with BIS values of patients undergoing natural sleep allows a more accurate assessment of sleep disordered breathing.

Finally, a couple of studies have compared awake assessment with SNE in the same group of patients and advocate that SNE is superior; further highlighting the point that there is muscle tone variation in control of upper airway during wakefulness and that during obstructive episodes in sleep. It appeared that hypopharyngeal or laryngeal obstruction could be missed in up to a third of the patients if the assessment was carried out in the awake state only.25, 26

#### **7. Summary**

In order to attain a successful outcome in treating patients with obstructive upper airway in snorers and OSA it is crucial to evaluate the upper airway dynamics very carefully. Apart from its usefulness in research, imaging has a relatively minor role to play in evaluation except in maxillo-mandibular advancement surgery.

Site specific treatment in these patients is required and therefore techniques that offer localisation of these anatomical obstructive segments would prove useful. In the author's opinion the two techniques that appear to do so are sleep nasendoscopy and the Apnea-Graph. This view has also been supported by a recent evidence based review article on assessment of obstruction level and selection of patients for obstructive sleep apnoea surgery.27

Sleep nasendoscopy appears somewhat superior as it allows visualisation of the upper airway whereas the Apnea-Graph merely looks at the pressure values and relies on correct positioning of the transducers. Out-patient clinical examination of the nose and the oropharynx is of paramount importance as it will help identifying potential nCPAP patients who may fail this form of therapy if there is an obvious anatomical problem.

#### **8. References**


early, the muscle relaxation effect of the drug may be over emphasised and if the patient is assessed too late then important anatomical aspect of the obstructive episodes may be missed. Thus the depth of sedation during which the assessment is conducted should be as close to the levels of depth of natural sleep. Evaluation only occurs as a snap shot of a patients whole sleep cycle. However, combining it with BIS values of patients undergoing

Finally, a couple of studies have compared awake assessment with SNE in the same group of patients and advocate that SNE is superior; further highlighting the point that there is muscle tone variation in control of upper airway during wakefulness and that during obstructive episodes in sleep. It appeared that hypopharyngeal or laryngeal obstruction could be missed in up to a third of the patients if the assessment was carried out in the

In order to attain a successful outcome in treating patients with obstructive upper airway in snorers and OSA it is crucial to evaluate the upper airway dynamics very carefully. Apart from its usefulness in research, imaging has a relatively minor role to play in evaluation

Site specific treatment in these patients is required and therefore techniques that offer localisation of these anatomical obstructive segments would prove useful. In the author's opinion the two techniques that appear to do so are sleep nasendoscopy and the Apnea-Graph. This view has also been supported by a recent evidence based review article on assessment of obstruction level and selection of patients for obstructive sleep apnoea

Sleep nasendoscopy appears somewhat superior as it allows visualisation of the upper airway whereas the Apnea-Graph merely looks at the pressure values and relies on correct positioning of the transducers. Out-patient clinical examination of the nose and the oropharynx is of paramount importance as it will help identifying potential nCPAP patients

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[4] Ritter CT, Trudo FJ, Goldberg AN et al. Quantitative evaluation of the upper airway

[5] Mayer G, Meier-Ewert K. Cepahlometric predictors for orthopaedic mandibular advancement in obstructive sleep apnoea. Eur J Orthod1995;17:35-43

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examination. Sleep 2006;29:1456-62.

natural sleep allows a more accurate assessment of sleep disordered breathing.

awake state only.25, 26

except in maxillo-mandibular advancement surgery.

**7. Summary** 

surgery.27

**8. References** 

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**6** 

*Spain* 

**Upper Airway Resistance Syndrome –** 

*1Division of Respiratory Medicine, Hospital Universitario Rio Hortega,* 

*2Division of Respiratory Medicine, Hospital Universitario Rio Hortega, Valladolid,* 

This paper will review the prevalence, pathophysiology, clinical picture, diagnostic advances, natural history, morbidity and management of upper airway resistance syndrome (UARS). The aim is to improve our knowledge about this disease and help to identify

UARS was initially used to describe a group of patients who were sleepy but did not meet the polysomnography diagnostic criteria of obstructive sleep apnoea syndrome (OSAS) (Guilleminault 1993). The first mention of the term was used about children by Guilleminault (Guilleminault 1982) in 1982 and years later also in women (Guilleminault 1995). Is UARS really a disease?. Twenty-five years after first being described, there is still

Some authors consider it to be part of the spectrum of obstructive disorders affecting the upper airway (Douglas 2000; Jhonson 2008; Cracowski 2001), while others believe that OSAS and UARS are separate entities (Gold 2008; Bao & Guilleminault 2004;Lindberg & Gislason 2000). Normally, it is up to the clinician practitioner to screen for this syndrome. Due to its diagnostic difficulty, currently UARS is significantly under diagnosed and no standard management strategy in place in sleep labs. However, great interest exists in the literature for this entity, and many revisions have been carried out (Exar & Collop 1999; Monserrat & Badia 1999; Bao & Guilleminault 2004; Velamuri 2006; Ramar & Guilleminault 2008; Giblin

Epidemiologic studies estimate that SAHS affects 1–5% of adult men in western countries (Young 2002). Sleep apnoea hypopnoea syndrome is the most common form of sleep

significant controversy among experts as to whether UARS is a specific syndrome.

**1. Introduction** 

patients with UARS.

2009; Guilleminault & de los Reyes 2011).

**2. Background** 

**3. Epidemiology** 

*Departament of Medicine, Universidad de Valladolid,Valladolid* 

*Universitario de Santiago de Compostela, Santiago de Compostela,* 

**A Twenty-Five Years Experience** 

Tomas Ruiz Albi2 and Carlos Zamarrón Sanz3

*3Division of Respiratory Medicine Hospital Clínico* 

Felix del Campo Matías1,

