The clinical application progress and potential of drug-induced sleep endoscopy in obstructive sleep apnea.

Background and Objective: Obstructive sleep apnoea (OSA) is characterized by nocturnal repetitive upper airway (UA) collapse. For sleep physicians, the recognition of UA collapse characteristics is critical for understanding OSA mechanisms and developing individualized treatment plans. Drug-induced sleep endoscopy (DISE) is an exam during simulated sleep that allows the dynamic assessment of the UA of individuals with OSA. The initial recognition of DISE was to locate the sites of UA obstruction and direct the surgical selection of OSA since it was introduced in the 1990s. After approximately 30 years of studies, based on advances in endoscopic operative techniques and innovative treatments of OSA, DISE had been performed to explore mechanisms and comprehensive treatments related to UA collapse. Methods: This article reviewed contemporary DISE advances, including indications and contraindications, technique of induced sleep, endoscopic operation, UA characteristics classification.Results and Conclusions: Precise selection based on the association between collapse patterns and treatment modalities, such as continuous positive airway pressure, oral appliance, positional therapy, robotic surgery and neurostimulator implanting, is the future research prospect based on DISE.Key messagesDISE provides sleep physicians with valuable information about the upper airway collapse characteristics and dynamic changes during sleep.The studies based on DISE findings improve the selectivity and efficiency of treatment modalities, including classical therapies such as continuous positive airway pressure, oral appliance, positional therapy, and innovative therapies such as neurostimulator implanting and robotic surgery, promote the advancement of OSA precision medicine.

Upper airway collapse characteristics in adult patients with OSA and previous tonsillectomy.

PURPOSE: To analyze upper airway (UA) collapse patterns through drug-induced sleep endoscopy (DISE) in adult patients with obstructive sleep apnea (OSA) who previously underwent tonsillectomy. METHODS: This was a retrospective study on patients with OSA who underwent DISE between June 1, 2013 and July 30, 2017 at Stanford Hospital. Subjects who had prior tonsillectomy history were classified into the tonsil0 group, whereas others were classified into the tonsil1 and tonsil2/3/4 group based on tonsil grade. UA collapse characteristics were recorded and analyzed among groups according to Velum, Oropharynx, Tongue base and Epiglottis (VOTE) classification. RESULTS: A total of 205 individuals were included, 38 in tonsil0 group, 104 in tonsil1 and 63 in tonsil2/3/4. The tonsil0 group had a higher percentage of anterior-posterior (AP) velum (58%) and tongue base (45%) collapse compared with the tonsil2/3/4 group (22%, P = 0.0003 and 22%, P = 0.02, respectively) but less oropharyngeal lateral wall collapses (29% vs 53%, P = 0.02). Most of the tonsil0 group (70%) showed multi-sites collapse pattern, the percentage of combined obstruction in both palatopharyngeal and hypopharyngeal region was higher (50% vs 29%, P = 0.03). The difference of velum complete AP collapse remained significant after adjusting for age and BMI (Odds Ratio = 0.33, 95% CI 0.12-0.86, P = 0.02). No significant differences were found between the tonsil0 and tonsil1 groups. CONCLUSION: Compared with individuals with larger tonsils (grade 2 to 4), those with previous tonsillectomy and OSA were susceptible to the velum AP configuration collapse. Diversity of multi-sites obstruction and combined collapse in both palatopharyngeal and hypopharyngeal level was the main characteristic.

Nocturnal oximetry in the diagnosis of obstructive sleep apnea syndrome in potentially hypoxic patients due to neuromuscular diseases.

INTRODUCTION: Polysomnography is the recommended method for the diagnosis of obstructive sleep apnea (OSA); however, it is expensive, uncomfortable, and inaccessible. Alternative diagnostic methods are necessary, and Nocturnal Oximetry (NO) has proven to be reliable. Nevertheless, there have been doubts about its accuracy in patients with a history of hypoxia. Hence, the objective of this study was to evaluate the performance of NO in patients with neuromuscular diseases (NMD). METHOD: This was a cross-sectional study in patients with NMD suspected of having OSA. We performed a statistical analysis using Spearman's correlation coefficients (SCCs). We used the value of the area under the ROC curve (AUCROC), just as we calculated the sensitivities (Sens) and specificities (Spec) for the chosen variables. RESULTS: The sample comprised 41 patients; 51.2% with muscular dystrophies and 48.8% with motor neuron diseases, with a predominance of men (63.4%). Median age was 42 (19.7-55) years, body mass index (BMI) was 27.9 (23.8-32) kg/m2, forced vital capacity was 67% (54%-76.5%), and maximum inspiratory pressure was-60 cmH2O (-87.5 to -50). The prevalence of OSA was 75.7%. We analyzed and selected the best four oximetric variables with the following performance in identifying the apnea/hypopnea index >5/h, ODI3/2, cutoff>5/h, AUCROC 0.919, Sens 82.3%, Spec 91.7%; ODI3/5, cutoff>11.2/h, AUCROC 0.904, Sens 82.3%, Spec 87.5%; ODI4/5, cutoff>6.02, AUCROC 0.839, Sens 70.6%, Spec 91.6%, and ODI5/5, cutoff>0.87/h, AUCROC 0.870, Sens 94.1%, and Spec 70.8%. CONCLUSION: NO can be used as a diagnostic tool for OSA, even in patients with neuromuscular diseases and potentially hypoxic diseases.

High Tongue Position is a Risk Factor for Upper Airway Concentric Collapse in Obstructive Sleep Apnea: Observation Through Sleep Endoscopy.

PURPOSE: Identification of upper airway (UA) obstruction based on pharyngeal factors is important for obstructive sleep apnea (OSA) evaluation. This study is to assess the association between UA collapse characteristics and Friedman tongue position (FTP) in patients with OSA through drug-induced sleep endoscopy (DISE). PATIENTS AND METHODS: Retrospective study in individuals with OSA who were intolerant to continuous positive airway pressure (CPAP) treatment, submitted to DISE between June 1, 2013, and July 31, 2017. All subjects were classified as having an FTP grade of I to IV, and the velum, oropharynx, tongue base, epiglottis (VOTE) classification was used to analyze the DISE findings. UA collapse characteristics by DISE and FTP grading were compared between groups. The associations between specific DISE findings and FTP were analyzed. RESULTS: In total, 205 patients were assessed. A positive and significant correlation was identified between the presence of retropalatal complete concentric collapse (CCC) and FTP grade, according to the following distributions: I, 17.4%; II, 22.9%; III, 33.7%; and IV, 48.7% (P = 0.014). A logistic regression model revealed that CCC was associated with FTP grade IV. After adjusting for age, sex, body mass index (BMI), and tonsil size (TS), the grade IV individuals had a 4.4-fold higher risk of having CCC than grade I individuals (P = 0.026). Multiple collapse sites and palatopharyngeal or combined (palatopharyngeal and hypopharyngeal) collapse were more prevalent in grade IV individuals. CONCLUSION: OSA patients intolerant to CPAP have a strong positive correlation between the FTP grade and presence of retropalatal CCC. FTP grade IV is an independent risk factor for velum-CCC, controlling for sex, age, BMI, and TS grade.

Insights into Friedman stage II and III OSA patients through drug-induced sleep endoscopy.

BACKGROUND: The Friedman staging is a classic system to predict outcomes of obstructive sleep apnea (OSA) surgery. Increasing stage indicates more severe upper airway (UA) obstruction and worse surgical successful rate. In previous studies, the UA obstruction between stages were usually assessed based on awake examination. Drug-induced sleep endoscopy (DISE) is a new method that can evaluate airway collapse characteristics during sleep. Therefore, we planned to compare Friedman staging and DISE findings and fulfill the knowledge gap on the correlation between awake and sedated UA examination. METHODS: Retrospective case series study that assessed patients with OSA who underwent DISE. Subjects were classified to stage II and stage III groups based on Friedman staging system. UA collapse characteristics based on velum, oropharynx, tongue base, epiglottis (VOTE) classification, including single/multiple obstruction sites, single/combined upper and lower obstruction levels, collapse degree and patterns in different sites, and surgical results among the groups were analyzed. RESULTS: A total of 175 cases were analyzed. No significant differences were found in baseline measurements between groups. Stage III patients (n=102) had a higher proportion (74.5%) with 3 or 4 obstruction sites than stage II (57.5%, n=73). Velum (V) + oropharynx (O) + tongue base (T) was the most common multi-sites combined obstruction pattern with 33% in stage II and 37% in stage III, isolated lower level obstruction was the least with 6% and 4%, respectively. No significant differences were found in obstruction sites and levels. 106 patients underwent surgeries and 33 had post-surgical sleep study, 73.7% and 63.6% response rate were found in stage II and III with no significant difference. CONCLUSIONS: Upper and lower combined obstruction was the main pattern of collapse in both, Friedman stage II and III patients. Patients with OSA and Friedman stage III had more than 2 sites of obstruction than stage II patients.

Otolaryngology during COVID-19: Preventive care and precautionary measures.

Since the outbreak of novel coronavirus disease (COVID-19) in December 2019, it has spread to various regions and countries, forming a global pandemic. Reducing nosocomial infection is a new issue and challenge for all healthcare systems. Otolaryngology is a high-risk specialty as it close contact with upper respiratory tract mucous, secretions, droplets and aerosols during procedures and surgery. Therefore, infection prevention and control measures for this specialty are essential. Literatures on the epidemiology, clinical characteristics and infection control measures of COVID-19 were reviewed, practical knowledge from first-line otolaryngologists in China, the United States, and Brazil were reviewed and collated. It was recommended that otolaryngology professionals should improve screening in suspected patients with relevant nasal and pharyngeal symptoms and signs, suspend non-emergency consultations and examinations in clinics, and rearrange the working procedures in operating rooms. The guidelines of personal protective equipment for swab sampling, endoscopy and surgery were listed. Indications for tracheotomy during the pandemic should be carefully considered to avoid unnecessary airway opening and aerosol-generation; precautions during surgery to reduce the risk of exposure and infection were illustrated. This review aimed to provide recommendations for otolaryngologists to enhance personal protection against COVID-19 and reduce the risk of nosocomial infection.

The Effect of Sedating Agents on Drug-Induced Sleep Endoscopy Findings.

OBJECTIVE: Drug-induced sleep endoscopy (DISE) has gained interest for upper airway evaluation in patients with snoring and obstructive sleep apnea (OSA), and different drugs have been used to induce sedation. Nevertheless, all drugs have presented specific advantages and disadvantages with differential effects on respiratory physiology. This study evaluated and compared the effects of midazolam, propofol and dexmedetomidine on DISE findings, O2 nadir, and bispectral index (BIS) in the same sample of patients. STUDY DESIGN: Case series prospective study. METHODS: Consecutive patients who elected to undergo surgery for OSA treatment and were intolerant to conservative therapies underwent DISE with propofol, dexmedetomidine, and midazolam between July 2015 and July 2016. RESULTS: Fifty-two patients were analyzed, and 43 (82.7%) were men. Agreement among drugs for both degree and patterns of obstruction was excellent at all sites (velum, oropharynx, and epiglottis) except for the tongue base. Dexmedetomidine had the least complete collapse sites and highest O2 nadir and was the only drug for which apnea severity and obstruction levels (upper, lower, or combined) were correlated. The variability among drug treatments for the BIS index was considerable, and propofol had the lowest variability and average value. CONCLUSION: Drug selection had a relevant influence in DISE findings. Compared with dexmedetomidine, midazolam and propofol presented higher incidence of tongue base collapse, lower O2 levels, and lower BIS index values. Propofol resulted in an O2 nadir that most resembled that observed during polysomnography. The BIS index variability differed among drugs, and its use was considered relevant for sedation orientation. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:506-513, 2019.

Digital Health and Sleep-Disordered Breathing: A Systematic Review and Meta-Analysis.

STUDY OBJECTIVES: Sleep disorders in most individuals remain undiagnosed and without treatment. The use of novel tools and mobile technology has the potential to increase access to diagnosis. The objective of this study was to perform a quantitative and qualitative analysis of the available literature evaluating the accuracy of smartphones and portable devices to screen for sleep-disordered breathing (SDB). METHODS: A literature review was performed between February 18, 2017 and March 15, 2017. We included studies evaluating adults with SDB symptoms through the use mobile phones and/or portable devices, using standard polysomnography as a comparison. A qualitative evaluation of studies was performed with the QUADAS-2 rating. A bivariate random-effects meta-analysis was used to obtain the estimated sensitivity and specificity of screening SDB for four groups of devices: bed/mattress-based, contactless, contact with three or more sensors, and contact with fewer than three sensors. For each group, we also reported positive predictive values and negative predictive values for mild, moderate, and severe obstructive sleep apnea (OSA) screening. RESULTS: Of the 22 included studies, 18 were pooled in the meta-analysis. Devices that were bed/mattress-based were found to have the best sensitivity overall (0.921, 95% confidence interval [CI] 0.870, 0.953). The sensitivity of contactless devices to detect mild OSA cases was the highest of all groups (0.976, 95% CI 0.899, 0.995), but provided a high false positive rate (0.487, 95% CI 0.137, 0.851). The remaining groups of devices showed low sensitivity and heterogeneous results. CONCLUSIONS: This study evidenced the limitations and potential use of portable devices in screening patients for SDB. Additional research should evaluate the accuracy of devices when used at home.

The effect of aging on drug-induced sleep endoscopy findings.

OBJECTIVES/HYPOTHESIS: To evaluate the correlation of aging and upper airway collapse characteristics observed by drug-induced sleep endoscopy (DISE), and report the observed differences on obstructive sleep apnea (OSA) subjects, older and younger than 60 years. STUDY DESIGN: Case series. METHODS: This study analyzed the data of 200 OSA patients who underwent DISE between January 1, 2013 and June 30, 2017. The variables sex, body mass index (BMI), Epworth Sleepiness Scale score, tonsil size, modified Mallampati (MM) classification, apnea-hypopnea index (AHI), oxygen desaturation index (ODI), lowest oxygen saturation, and VOTE (velum, oropharynx, tongue base, epiglottis) classification were compared between two groups: <60 and ≥60 years old. RESULTS: Older age had significant correlation with higher AHI, ODI, lower O2 nadir, multisite obstruction, combined upper (palatopharyngeal) + lower (hypopharyngeal) level obstructions, and complete anterior-posterior (AP) velum collapse pattern. Lateral oropharyngeal wall collapse was significantly lower in the older group. Findings remained statistically significant when adjusted for sex, BMI, tonsil size, and MM. CONCLUSIONS: Aging was an independent factor that directly correlated with increased AHI and hypoxemia, multisites, combined levels of obstruction, and complete AP velum collapse pattern. Being older than 60 years had higher of complete AP velum collapse and lower incidence of lateral oropharyngeal wall collapse, regardless of OSA severity and tonsil size. LEVEL OF EVIDENCE: 4 Laryngoscope, 2644-2650, 2018.

Nocturnal Hypoxemia is Associated With Low Testosterone Levels in Overweight Males and Older Men With Normal Weight.

STUDY OBJECTIVES: The relationship among obstructive sleep apnea (OSA), body mass index (BMI), and testosterone levels has long been suggested. Obese men have shown a negative correlation between testosterone level and sleep apnea severity. Yet, little is known about the association between testosterone levels and sleep apnea in men who are not obese. This study evaluated the association between the total testosterone (TT) level and OSA in patients who are not obese. METHODS: A retrospective review of 523 records of patients in whom OSA was diagnosed from 2013-2016 was performed. The study included men with a BMI < 30 kg/m2 and with TT levels measured in a blood sample collected the morning after a sleep study. RESULTS: In all, 153 nonobese men met inclusion criteria, of whom 47 (30.7%) had testosterone levels below the reference values; 44 of these individuals (93.6%) were overweight (P = .029). Reduced testosterone levels showed significant correlations with the oxygen desaturation index, the lowest oxygen saturation < 80% (O2 nadir < 80%), and rapid eye movement (REM) sleep duration, after adjusting for BMI. Among patients with normal weight, only 3 who had O2 nadir < 80% and were older than 50 years presented with a reduced TT level. CONCLUSIONS: In a large population of nonobese men with OSA, we demonstrated that hypoxemia (O2 nadir < 80%) and overweight are associated with reduced testosterone levels. This association was only observed among normal-weight individuals older than 50 years.

Drug-induced sleep endoscopy in the obstructive sleep apnea: comparison between NOHL and VOTE classifications.

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete collapse of the pharynx that result in a decrease in oxyhemoglobin saturation. Nasofibrolaryngoscopy under induced sleep is a promising alternative for identifying sites of upper airway obstruction in patients with OSA. This study aimed to compare the obstruction sites screened by drug-induced sleep endoscopy (DISE) using the Nose oropharynx hypopharynx and larynx (NOHL) and Velum oropharynx tongue base epiglottis (VOTE) classifications. We also determined the relationship between OSA severity and the number of obstruction sites and compared the minimum SaO2 levels between DISE and polysomnography (PSG). This was a prospective study in 45 patients with moderate and severe OSA using DISE with target-controlled infusion of propofol bispectral index (BIS) monitoring. The retropalatal region was the most frequent obstruction site, followed by the retrolingual region. Forty-two percent of patients had obstruction in the epiglottis. Concentrically shaped obstructions were more prevalent in both ratings. The relationship between OSA severity and number of obstruction sites was significant for the VOTE classification. Similar minimum SaO2 values were observed in DISE and PSG. The VOTE classification was more comprehensive in the analysis of the epiglottis and pharynx by DISE and the relationship between OSA severity and number of affected sites was also established by VOTE. The use of BIS associated with DISE is a reliable tool for the assessment of OSA patients.

Drug-induced sleep endoscopy in the identification of obstruction sites in patients with obstructive sleep apnea: a systematic review.

INTRODUCTION: Obstructive sleep apnea syndrome has multifactorial causes. Although indications for surgery are evaluated by well-known diagnostic tests in the awake state, these do not always correlate with satisfactory surgical results. OBJECTIVE: To undertake a systematic review on endoscopy during sleep, as one element of the diagnosis routine, aiming to identify upper airway obstruction sites in adult patients with OSAS. METHODS: By means of electronic databases, a systematic review was performed of studies using drug-induced sleep endoscopy to identify obstruction sites in patients with OSAS. RESULTS: Ten articles were selected that demonstrated the importance of identifying multilevel obstruction, especially in relation to retrolingual and laryngeal collapse in OSAS. CONCLUSION: DISE is an additional method to reveal obstruction sites that have not been detected in awake patients.