Depth-dependent changes of obstruction patterns under increasing sedation during drug-induced sedation endoscopy: results of a German monocentric clinical trial

The Repeatability of Pharyngeal Opening Pressure Under Drug-Induced Sleep Endoscopy

OBJECTIVE

Pharyngeal opening pressure (PhOP) is a measure of upper airway collapsibility that can be obtained during drug-induced sleep endoscopy (DISE) using a continuous positive airway pressure (CPAP) titration. However, the stability of PhOP over the course of sedation during DISE remains unclear. This study aims to compare repeat measures of PhOP over the course of DISE.

STUDY DESIGN

Single arm prospective study.

SETTING

Single tertiary care institution.

METHODS

Patients had 2 CPAP titrations while undergoing DISE. Collected data included patient demographics, PhOP, patient sedation index (PSI), and duration of and between CPAP titrations. t Tests, test-retest coefficient analysis, and repeated measures correlation were performed.

RESULTS

Twenty-five patients completed the study between 2022 and 2023 with 22 patients having sedation depth (PSI) recording. Most were male (76%), obese (average body mass index: 30.24 kg/m2), with severe obstructive sleep apnea (average apnea-hypopnea index: 39.8 events/hr). Test-retest analysis showed good-excellent correlation between PhOP values (intraclass correlation coefficient = 0.892, P < .0001, n = 25). Average time between CPAP titrations was 15 minutes to 6 seconds. Over that time, PhOP increased by an average of 0.72 cmH2O (P = .06, n = 25) and PSI decreased by 9.5 units (P = .01, n = 22). Repeated measures correlation showed a weak negative correlation between PhOP and PSI (r = -.45, P = .03, n = 22).

CONCLUSION

The results showed repeatability of PhOP values over the course of DISE. When adjusted for sedation depth (PSI), deeper sedation was weakly associated with greater PHOP. However, the magnitude of this change was small and we conclude that PhOP remains relatively stable over the course of DISE (Effects of Lung Volume on Upper Airway Patency During DISE [DISE-Pulm], NCT05350332, clinicaltrials.gov).

Quantitative Measurement of Pharyngeal Dimensions During Drug-induced Sleep Endoscopy for Oral Appliance Outcome

OBJECTIVE

To quantitatively investigate the effect of mandibular advancement devices (MADs) on pharyngeal airway dimensions in a transverse plane as measured during drug-induced sleep endoscopy (DISE).

METHODS

Data from 56 patients, treated with MAD at 75% maximal protrusion and with baseline Apnea-Hypopnea Index ≥10 events/h, were analyzed. For each patient, three snapshots were selected from DISE video footage at baseline, with MAD presence, and during chin lift, resulting in 498 images (168/168/162, baseline/MAD/chin lift). Cross-sectional areas, anteroposterior (AP) and laterolateral (LL) dimensions on both retroglossal and retro-epiglottic levels were measured. To define the effect of MAD and chin lift on pharyngeal dimensions, linear mixed-effect models were built. Associations between MAD treatment response and pharyngeal expansion (MAD/chin lift) were determined.

RESULTS

Significant differences were found between retroglossal cross-sectional areas, AP, and LL dimensions at baseline and with MAD presence. At a retro-epiglottic level, only LL dimensions differed significantly with MAD presence compared to baseline, with significant relation of LL expansion ratio to treatment response (p = 0.0176). After adjusting the response definition for the sleeping position, greater retroglossal expansion ratios were seen in responders (1.32 ± 0.48) compared to non-responders (1.11 ± 0.32) (p = 0.0441). No significant association was found between response and pharyngeal expansion by chin lift.

CONCLUSION

Our observations highlight the additional value of quantitative pharyngeal airway measurements during DISE with MAD presence in evaluating MAD treatment outcome. These findings demonstrate an increase in retroglossal airway dimensions during DISE, with MAD presence, and more pronounced increase in retroglossal expansion ratios in MAD treatment responders compared to non-responders after sleeping position correction.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3619-3627, 2023.

A Protocol for Propofol-Infusion Drug-Induced Sleep Endoscopy

OBJECTIVE

The objective of this study was to outline a protocol utilizing propofol infusion without an initial bolus during drug-induced sleep endoscopy (DISE). We define normative values for final propofol infusion rate (P^final ) during DISE and sedation depth values at P^final .

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic hospital.

METHODS

A review of patients with obstructive sleep apnea who underwent DISE between 2016 and 2020 was performed. The following patient data were recorded: demographics; DISE procedure details, including P^final , time to P^final , frequency and cadence of infusion rate changes, depth of sedation as measured by Bispectral Index and SedLine values, and hemodynamics; and polysomnography details including apnea-hypopnea index severity and minimum oxygen saturation. A mixed linear model adjusted for age and body mass index was performed for the analysis of effects on P^final . Pearson correlation coefficients determined the strength of association between depth of sedation measured and pattern of collapse on DISE and P^final .

RESULTS

There were 246 patients who met inclusion criteria. P^final resembled a normal distribution (mean ± SD, 156.44 ± 26.69 mcg/kg/min; median, 150 mcg/kg/min). Analysis demonstrated that P^final was influenced by male sex, current smoker status, time to P^final , and number of propofol dose changes (P < .05). Depth of sedation categories measured differently between Bispectral Index and SedLine (55-65 vs 45-55, P < .001). The pattern including severity of collapse on DISE was not associated with P^final (P > .05). No patients required intra- or postoperative respiratory support beyond oxygen via nasal canula.

CONCLUSION

We describe a propofol slow-infusion DISE protocol that demonstrates safe and reproducible outcomes.

Guidelines of the French Society of ENT (SFORL): Drug-induced sleep endoscopy in adult obstructive sleep apnea syndrome

OBJECTIVES

To determine the indications, anesthesiological and surgical procedure and interest of drug-induced sleep endoscopy in the treatment of adult obstructive sleep apnea syndrome.

DESIGN

A redactional committee of 17 experts was set up. Conflicts of interest were disclosed and followed up throughout the process of drawing up the guidelines. The work received no funding from any firm dealing in health products (drugs or devices). The GRADE (Grading of Recommendations Assessment, Development and Evaluation) method was applied to assess the quality of the data on which the guidelines were founded. It was stressed that strong recommendations should not be made on the basis of poor-quality or insufficient data.

METHODS

The committee studied 29 questions on 5 topics: indications and contraindications, anesthetic technique, surgical technique, interpretation and reporting of results, and management guided by results.

RESULTS

Expert review and application of the GRADE method led to 30 guidelines: 10 with high level of evidence (Grade 1+ or 1-), 19 with low level (GRADE 2+ or 2-) and 1 expert opinion.

CONCLUSION

Experts fully agreed on the strong guidelines formalizing the indications and modalities of drug-induced sleep endoscopy for adult obstructive sleep apnea syndrome.

Beyond VOTE: The New Frontier of Drug-Induced Sleep Endoscopy

Alternatives to positive airway pressure therapy, including surgery, represent an important area of research. Specifically, predictors of response to surgical therapy remain underdeveloped. Drug-induced sleep endoscopy (DISE) holds promise as a diagnostic tool to identify patient-specific causes of airway collapse. Herein, we present a novel, standardized approach which combines anatomic and physiologic measurements during DISE. Our DISE platform measures airflow, airway compliance, airway collapsibility, and structural drivers of collapse. Taken together, these inputs provide a comprehensive framework to further inform the surgeon in providing personalized care of the patient with obstructive sleep apnea.

Comparison of Drug-Induced Sleep Endoscopy and Natural Sleep Endoscopy in the Assessment of Upper Airway Pathophysiology During Sleep: Protocol and Study Design

Study Objectives: Obstructive sleep apnea (OSA) is increasingly recognized as a complex and heterogenous disorder. As a result, a "one-size-fits-all" management approach should be avoided. Therefore, evaluation of pathophysiological endotyping in OSA patients is emphasized, with upper airway collapse during sleep as one of the main features. To assess the site(s) and pattern(s) of upper airway collapse, natural sleep endoscopy (NSE) is defined as the gold standard. As NSE is labor-intensive and time-consuming, it is not feasible in routine practice. Instead, drug-induced sleep endoscopy (DISE) is the most frequently used technique and can be considered as the clinical standard. Flow shape and snoring analysis are non-invasive measurement techniques, yet are still evolving. Although DISE is used as the clinical alternative to assess upper airway collapse, associations between DISE and NSE observations, and associated flow and snoring signals, have not been quantified satisfactorily. In the current project we aim to compare upper airway collapse identified in patients with OSA using endoscopic techniques as well as flow shape analysis and analysis of tracheal snoring sounds between natural and drug-induced sleep. Methods: This study is a blinded prospective comparative multicenter cohort study. The study population will consist of adult patients with a recent diagnosis of OSA. Eligible patients will undergo a polysomnography (PSG) with NSE overnight and a DISE within 3 months. During DISE the upper airway is assessed under sedation by an experienced ear, nose, throat (ENT) surgeon using a flexible fiberoptic endoscope in the operating theater. In contrast to DISE, NSE is performed during natural sleep using a pediatric bronchoscope. During research DISE and NSE, the standard set-up is expanded with additional PSG measurements, including gold standard flow and analysis of tracheal snoring sounds. Conclusions: This project will be one of the first studies to formally compare collapse patterns during natural and drug-induced sleep. Moreover, this will be, to the authors' best knowledge, the first comparative research in airflow shape and tracheal snoring sounds analysis between DISE and NSE. These novel and non-invasive diagnostic methods studying upper airway mechanics during sleep will be simultaneously validated against DISE and NSE. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04729478.

Natural sleep endoscopy in obstructive sleep apnea: A systematic review

This study's objective is to systematically review the literature on natural sleep endoscopy (NSE), including the set-up, different scoring systems, visualized collapse patterns during natural sleep, additional measurements, and comparison of upper airway collapse between NSE and drug-induced sleep endoscopy (DISE). A computerized search on Medline, Web of Science and the Cochrane library was conducted, obtaining 39 hits. Ten prospective studies were included in which NSE was performed in adults with obstructive sleep apnea (OSA). This study's findings suggest the soft palate to be the most frequent site of obstruction (58.8 %), followed by the tongue base (43.2 %), lateral walls (29.9 %), and epiglottis (22.4 %), which is in line with previous findings during DISE. Based on this literature review, the authors conclude that at this stage high quality, comparative research between DISE and NSE is missing. To adequately compare findings between OSA patients, endoscopic classification of upper airway collapse should be standardized. Non-invasive predictive tools to determine pharyngeal collapse are currently under investigation and may obviate the need for invasive endoscopy. This review highlights the contribution of NSE in validating such novel diagnostic methods and in studying upper airway mechanics in a research setting, yet larger and adequately powered studies are needed.

Can Bispectral Index Monitoring (EEG) be an Early Predictor of Respiratory Depression under Deep Sedation during Endoscopic Retrograde Cholangiopancreatography?

Objectives:

The more often the endoscopy sedation is performed, the more the risk of adverse events, and therefore, advanced monitoring becomes more and more essential in endoscopy units. The present study aims to evaluate whether the Bispectral Index (BIS) monitoring is an early predictor of respiratory depression and to determine the compliance between commonly used clinical sedation score.

Methods:

This study was approved by the ethics committee. The sample consisted of 60 patients aged 18 to 50 years with an American Society of Anesthesiologists (ASA) physical status of I scheduled for endoscopic retrograde cholangiopancreatography (ERCP). All patients received propofol mediated sedation. Ramsay sedation score (RSS) was used as a clinical sedation score to assess the depth of sedation. Participants were attached to a BIS monitor. Perioperative hemodynamics, BIS values, the mean dose of propofol, procedure duration, apnea, frequency of oxygen desaturation and airway-related interventions, as well as demographic parameters, were recorded. BIS scores were blinded to RSS data.

Results:

The study sample consisted of 60 patients (36 females) aged 18 to 50 years (mean: 36.10±8.02). The mean procedure time and the dose of propofol were 32.70±1.79 min and 287.17±59.66 mg, respectively. The cut-off values for respiratory depression were as follows. At the 15th min of measurement, the BIS score of 60 had 96.2% sensitivity and 42.9% specificity. At the 20th min of measurement, the BIS score of 59.50 had 98.2% sensitivity and 100.0% specificity. At the 25th min of measurement, the BIS score of 59.00 had 98.3% sensitivity and 50.0% specificity. Regression analysis showed that the mean BIS score (p=0.000, 95%CI-0.110-0.043) increased by 0.076 with a unit increase in the RSS.

Conclusion:

BIS was highly correlated with RSS, and therefore, can be used to avoid respiratory depression during sedation.

Depth of sedation during drug induced sedation endoscopy monitored by BiSpectral Index® and Cerebral State Index®

PURPOSE

Drug induced sedation endoscopy (DISE) is performed to investigate patterns and sites of obstruction in patients with sleep-disordered breathing (SDB). During DISE the patients are sedated to obtain a muscular relaxation of the upper airway which mimics the relaxation during natural sleep. Different sleep stages are intended to be simulated by drug induced sedation, and it is helpful to measure the depth of sedation. The BiSpectral Index® (BIS) is often used for this procedure. Besides the BIS, other means of sedation depth monitoring exist in anaesthesiology but have not yet been investigated with respect to DISE. Monitoring of the Cerebral State Index® (CSI) is one of these methods. The aim of the study was to compare the BIS and CSI for sedation depth monitoring during DISE.

METHODS

Sixty patients underwent DISE monitored by the BIS and CSI in parallel. The BIS and CSI values were compared using the Bland-Altman analysis.

RESULTS

The BIS and CSI values differed during the course of sedation during DISE by a mean of - 6.07. At light sedation (BIS 60-80), lower values by 10 scale points of CSI compared with BIS were detectable. At deeper sedation levels (BIS 40-50), the CSI turned to present equal and even higher values compared with the BIS.

CONCLUSION

Sedation depth measurement during DISE can be performed by the BIS or CSI, but the differences should be interpreted carefully as comparable data for sleep stages in natural sleep are available only for BIS.

Comparison of upper airway obstruction during zolpidem-induced sleep and propofol-induced sleep in patients with obstructive sleep apnea: a pilot study

STUDY OBJECTIVES

Drug-induced sleep endoscopy (DISE) using propofol is commonly used to identify the pharyngeal structure involved in collapse among patients with obstructive sleep apnea. DISE has never been compared with zolpidem-induced sleep endoscopy. We hypothesized that propofol at recommended sedation levels does not influence upper airway collapsibility nor the frequency of multilevel pharyngeal collapse as compared with zolpidem-induced sleep.

METHODS

Twenty-one patients with obstructive sleep apnea underwent polysomnography and sleep endoscopy during zolpidem-induced sleep and during DISE with propofol. A propofol target-controlled infusion was titrated to achieve a bispectral index between 50 and 70. Airway collapsibility was estimated and compared in both conditions by peak inspiratory flow and the magnitude of negative effort dependence. Respiratory drive was estimated by the difference between end-expiratory and peak-negative inspiratory pharyngeal pressure (driving pressure). Site and configuration of pharyngeal collapse during zolpidem-induced sleep and DISE with propofol were compared.

RESULTS

The frequency of multilevel collapse during zolpidem-induced sleep was similar to that observed during DISE with propofol (72% vs 86%, respectively; difference: 14%; 95% confidence interval: -12% to 40%; P = .453). The endoscopic classification of pharyngeal collapse during both conditions were similar. Peak inspiratory flow, respiratory drive (effect size: 0.05 and 0.03, respectively), and negative effort dependence (difference: -6%; 95% confidence interval: -16% to 4%) were also similar in both procedures.

CONCLUSIONS

In this pilot study, recommended propofol doses did not significantly increase multilevel pharyngeal collapse or affect upper airway collapsibility and respiratory drive as compared with zolpidem-induced sleep.

CLINICAL TRIAL REGISTRATION

Registry: clinicaltrials.gov; Name: Natural and Drug Sleep Endoscopy; URL: https://clinicaltrials.gov/ct2/show/study/NCT03004014; Identifier: NCT03004014.

Test-retest reliability of drug-induced sleep endoscopy using midazolam

STUDY OBJECTIVES

Drug-induced sleep endoscopy (DISE) has been suggested to be a valuable method for determining the obstruction patterns causing sleep-disordered breathing. However, since DISE is not performed throughout the duration of sleep but for less than 1 hour, the reproducibility and reliability of DISE are questionable. Therefore, we aimed to determine the test-retest reliability of DISE using midazolam.

METHODS

Thirty-four patients diagnosed with obstructive sleep apnea were prospectively included in this study. The patients underwent 2 separate DISE examinations that were performed at different days using the same drug and technique. For a more accurate comparison, the depth of sleep and examination time were identically controlled. VOTE classification was used to classify the obstruction findings, and the findings of upper airway obstruction were compared between the 2 tests.

RESULTS

There were 30 men and four women; the mean age was 45.4 ± 13.1 years. The mean apnea-hypopnea index was 38.3 ± 22.6, and the lowest oxygen saturation was 77.5% ± 12.4%. The lateral wall of the oropharynx, tongue base, and epiglottis showed very good agreement, and the velum showed good agreement between the first and second DISE examinations.

CONCLUSIONS

The reliability of DISE is debatable because it observes only a small portion of the total sleep, but this study suggests that DISE is a reliable test because the findings of 2 separate DISE examinations on different days showed a high concordance rate.

Positional Awake Endoscopy Versus DISE in Assessment of OSA: A Comparative Study

OBJECTIVE

To compare awake endoscopy with Müller's maneuver (MM) during both sitting and supine positions, with drug-induced sleep endoscopy (DISE) as regard determination of different levels, patterns, and degrees of collapse of the upper airway in adult patients with obstructive sleep apnea (OSA).

METHODS

The study included adult patients with OSA symptoms, who had apnea hypopnea index (AHI) > 15. Patients were examined by MM in a sitting position, then during supine position; DISE then followed. Site, pattern, and degree of obstruction were assessed by experienced examiners according to the nose oropharynx hypopharynx and larynx classification.

RESULTS

Eighty-one adult subjects were included. The most common pattern of collapse at the retro-palatal level was the concentric pattern, while the predominant pattern at the hypopharyngeal level was the lateral wall collapse. The analysis of the pattern of collapse of the study group revealed that the individual pattern did not change (for the same patient at the same level) in the majority of patients whatever the maneuver or the position.

CONCLUSION

This study demonstrates the feasibility of positional awake endoscopy for providing valuable surgical information as regard level, pattern, and degree of severity in OSA. The data of positional awake endoscopy were comparable to those gained from DISE with less morbidity and costs. The idea and results of this work provide a useful foundation for future research in this area. Multicenter studies are encouraged to obtain more reliable conclusions and more clear standards aiming at a better surgical planning.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2269-2274, 2020.

Real-Time Identification of Upper Airway Occlusion Using Electrical Impedance Tomography

STUDY OBJECTIVES

Real-time monitoring of upper airway collapse during sleep could be instrumental for studies in biomechanics of obstructive sleep apnea (OSA) and selecting individualized treatment modalities. Although some imaging techniques are used under sedated sleep, none are available during the entire natural sleep process. We hypothesized that electrical impedance tomography (EIT) can be used for noninvasive continuous imaging of the upper airway during natural sleep and quantifying upper airway collapse in terms of its size.

METHODS

After determining surface landmarks to attach the electrodes for monitoring the retroglossal airway, EIT was conducted in 10 healthy participants. As a feasibility test of EIT in detecting upper airway collapse, transient airway closure was induced by the swallowing maneuver. These EIT images were confirmed by simultaneous magnetic resonance imaging (MRI) scans. Subsequently, EIT scans were conducted in 7 healthy participants and 10 patients with OSA under nonsedated sleep to determine whether it could identify upper airway narrowing or collapse. Respiratory events were identified by concurrent polysomnography (PSG).

RESULTS

Swallowing-induced airway closure was identified successfully in all 10 participants on simultaneous EIT and MRI scans. Sizes and positions of the upper airway closures in reconstructed EIT images were well correlated with those in magnetic resonance images. Obstructive hypopnea and apnea were detected successfully by EIT in 10 patients with OSA, and no significant changes in EIT data were observed in 7 healthy participants during concurrent EIT and PSG tests. Additionally, conductivity changes in the airway were greater during obstructive apnea than during hypopnea (64.3% versus 26.3%, respectively; P < .001) compared with those during baseline respiration.

CONCLUSIONS

EIT could be a useful real-time monitoring device for detecting upper airway narrowing or collapse during natural sleep in patients with OSA. Currently, changes in the upper airway size can be estimated with good accuracy, but shape estimation needs future improvements in the EIT image quality.

Dexmedetomidine versus propofol at different sedation depths during drug-induced sleep endoscopy: A randomized trial

OBJECTIVES/HYPOTHESIS

The aim of this study was to compare the effect of dexmedetomidine and propofol on airway dynamics, cardiorespiratory system, and emergence following drug-induced sleep endoscopy (DISE).

STUDY DESIGN

Prospective, randomized, single-blinded study.

METHODS

Sixty patients age 18 to 65 years in American Society of Anesthesiologists physical status groups 1 and 2 scheduled to undergo DISE were randomly allocated to either Group P (N = 30; receiving propofol infusion at 50-150 μg/kg/min) or Group D (N = 30; receiving dexmedetomidine bolus of 1 μg/kg followed by infusion at 0.5-1.0 μg/kg/hr). DISE was done at light sleep and deep sleep. Airway obstruction at tongue base was recorded as primary outcome. Airway obstruction at velum, oropharyngeal lateral wall, and epiglottis level during light and deep sedation, hemodynamic and respiratory parameters, time to attain sufficient sedation, time for emergence from sedation, and any adverse events during DISE with the two study drugs were recorded as secondary outcomes.

RESULTS

There was a greater degree of obstruction at the tongue base level (P = 0.001) and Oropharynx level (P = 0.017) in Group P compared with Group D during deep sedation. Increase in airway obstruction from light to deep sleep was seen with propofol at the oropharynx (P = 0.0185) and tongue base (P = 0.0108) levels. Two patients (6.6%) in Group D and 10 patients (33.3%) in Group P showed oxygen saturation below the minimum oxygen saturation recorded during polysomnography. Time to open eyes to call after stopping sedation was significantly less in Group P (P = 0.005).

CONCLUSIONS

Dexmedetomidine shows a lesser degree of airway collapse and higher oxygen saturation levels at greater sedation depth during DISE. Propofol has a faster onset and emergence from sedation.

LEVEL OF EVIDENCE

1b Laryngoscope, 130:257-262, 2020.

Drug-Induced Sleep Endoscopy in Treatment Options Selection

Drug-induced sleep endoscopy is a safe and practical technique to evaluate the dynamic upper airway collapse during sleep. We review drug-induced sleep endoscopy in adults, including its indications, technique, evaluation of upper airway collapse, and clinical application. Drug-induced sleep endoscopy is useful to improve treatment options selection for patients with obstructive sleep apnea, especially for those who are unable to accept or tolerate continuous positive airway pressure therapy. Owing to a lack of standardization for drug-induced sleep endoscopy, it is difficult to compare the published literature from different sleep centers across the world.

European position paper on drug-induced sleep endoscopy: 2017 Update

BACKGROUND

The first edition of the European position paper (EPP) on drug-induced sleep endoscopy (DISE) was published in 2014 with the aim to standardise the procedure, to provide an in-depth insight into the main aspects of this technique and to have a basis for future research. Since 2014, new studies have been published concerning new sedative agents or new insights into the pattern/levels of the obstruction depending on the depth of sedation. Therefore, an enlarged group of European experts in the field of sleep breathing disorders (SBD), including the most of the first DISE EPP main authors, has decided to publish an update of the European position paper on DISE, in order to include new evidence and to find a common language useful for reporting the findings of this endoscopic evaluation in adult population affected by SBD.

METHODS

The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centres in order to provide an update regarding the standardisation of the DISE procedure and an in-depth insight into the main aspects of this technique.

RESULTS

After the first European Position Consensus Meeting on DISE and its update, consensus was confirmed for indications, required preliminary examinations, where to perform DISE, technical equipment required, staffing, local anaesthesia, nasal decongestion, other medications, patient positioning, basics and special diagnostic manoeuvres, drugs and observation windows. So far, no consensus could be reached on a scoring and classification system. However, regarding this aim, the idea of an essential classification, such as VOTE with the possibility of its graded implementation of information and descriptions, seems to be the best way to reach a universal consensus on DISE classification at this stage. A common DISE language is mandatory, and attempts to come to a generally accepted system should be pursued.

Drug-Induced Sleep Computed Tomography-Directed Upper Airway Surgery for Obstructive Sleep Apnea: A Pilot Study

OBJECTIVE

A surgical response to upper airway (UA) surgery for obstructive sleep apnea (OSA) depends on adequate correction of collapsible sites in the UA. This pilot study aimed to examine the surgical response to UA surgery directed by drug-induced sleep computed tomography (DI-SCT) for OSA.

STUDY DESIGN

Prospective case series.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

This study recruited 29 OSA patients (median age, 41 years; median body mass index, 26.9 kg/m²) who underwent single-stage DI-SCT-directed UA surgery between October 2012 and September 2014. DI-SCT was performed with propofol for light sedation with a bispectral monitor before and after UA surgery. Nonresponders were defined as those with a reduction in apnea-hypopnea index <50% after 6 months following UA surgery.

RESULTS

DI-SCT showed that 28 (97%) patients had collapses at multiple sites, all of whom underwent multilevel UA surgery accordingly. The apnea-hypopnea index decreased from 53.6 to 26.8 ( P < .001). There were 18 (62%) nonresponders and 11 (38%) responders. Multiple-site collapses could not predict surgical response ( P > .99). The nonresponders had significant improvements in velopharyngeal, oropharyngeal lateral wall, and tongue collapses (all P < .05), whereas the responders had significant improvements in velopharyngeal and oropharyngeal lateral wall collapses (both P ≤ .05).

CONCLUSION

Despite multilevel OSA surgery, residual UA obstruction in nonresponders likely occurs due to multiple mechanisms. DI-SCT may help to elucidate the reasons for a nonresponse.

Drug-induced sleep endoscopy: from obscure technique to diagnostic tool for assessment of obstructive sleep apnea for surgical interventions

PURPOSE OF REVIEW

Provide a practical update on drug-induced sleep endoscopy (DISE) for anesthesia providers, which can also serve as a reference for those preparing to establish a DISE program.

RECENT FINDINGS

New developments in surgical approaches to OSA and the growing global incidence of the condition have stimulated increased interest and demand for drug-induced sleep endoscopy. New techniques include transoral robotic surgery and hypoglossal nerve stimulation. Recent DISE literature has sought to address numerous debates including relevance of DISE findings to those during physiologic sleep and the most appropriate depth and type of sedation for DISE. Propofol and dexmedetomidine have supplanted midazolam as the drugs of choice for DISE. Techniques based on pharmacokinetic models of propofol are superior to empiric dosing with regard to risk of respiratory compromise and the reliability of dexmedetomidine to achieve adequate conditions for a complete DISE exam is questionable.

SUMMARY

The role of DISE in surgical evaluation and planning for treatment of OSA continues to develop. Numerous questions as to the optimal anesthetic approach remain unanswered. Multicenter studies that employ a standardized approach using EEG assessment, pharmacokinetic-pharmacodynamic modelling, and objectively defined clinical endpoints will be helpful. There may be benefit to undertaking DISE studies in non-OSA patients.

A review on drug-induced sedation endoscopy - Technique, grading systems and controversies

Sleep disordered breathing (SDB) comprises a spectrum of disorders, ranging from simple snoring to severe obstructive sleep apnoea (OSA), with a significant burden to health care systems in high income countries. If left untreated, OSA has significant cumulative, long-term health consequences. In the 1990s drug induced sedation endoscopy (DISE) has been developed to become a primary tool in the diagnosis and management of OSA. It allows meticulous endoscopic evaluation of the airway and identifies areas of collapse, thereby informing both on the selection of surgical techniques, where efficacy depends entirely on success at relieving obstruction at a certain level and on the usefulness of conservative measures, such as mandibular advancement splints. This article provides a review of the literature on DISE, covering different grading systems and techniques, explaining different rationales and discussing controversies.

Drug-Induced Sedation Endoscopy (DISE) DATA FUSION system: clinical feasibility study

Drug-induced sleep endoscopy (DISE) is a diagnostic technique for 3D dynamic anatomical visualisation of upper airway obstruction during sedated sleep. There is a lack of standardised procedure and objective measurement associated with information capture, information management, evaluation of DISE findings, treatment planning, and treatment outcomes. The objective of this study is to present clinical feasibility results using a DISE DATA FUSION system for capturing, merging, displaying and storing anatomical data from an endoscopic imaging system and cardiorespiratory data from an anaesthesiological monitoring system simultaneously in real-time during DISE. This prospective cohort study included 20 patients presenting with symptoms of sleep related breathing disorders undergoing drug-induced sedation endoscopy and had volunteered for DISE DATA FUSION system to be used during their DISE assessment. The DISE DATA FUSION system was used to capture, merge, display, and store anatomical changes from an endoscopic imaging system and cardiorespiratory changes from an anaesthesiological monitoring system simultaneously in real time during drug-induced sedation endoscopy assessment. In all 20 patients, anatomical obstructions at different levels of the pharyngeal lumen (soft palate, velum, tonsils, oropharynx lateral wall, base of tongue, and epiglottis) with a different obstruction configuration and severity were captured simultaneously in real time with its associated cardiorespiratory parameters. Furthermore, a composite video consisting of an anatomical image, blood oxygen level, pulse rate, blood pressure, and timestamp was created for every obstructive event. Our system provides a useful and better way of capturing, merging, visualising, and storing anatomical data/physiological data simultaneously during DISE in real time. Furthermore, it enhances the understanding of the impact of the anatomical severity due to the simultaneous display of the cardiovascular parameters at that specific time of anatomical obstruction for optimising surgical decision based on DISE.

Effect of physical stress on drug-induced sleep endoscopy for obstructive sleep apnea

Drug-induced sleep endoscopy (DISE) is a reliable upper airway evaluation tool, widely used to improve surgical results in patients with obstructive sleep apnea (OSA). Several factors, including sleeping position and depth of sedation, affect DISE findings. This study aimed to evaluate the impact of physical stress on DISE findings. Eighty-five patients with OSA underwent two DISE examinations at the same level of sedation. The "first DISE" (control group) was performed after polysomnography, while the "second DISE" (test group) performed immediately after a treadmill stress test. The two groups were compared for changes in degree and configuration of airway obstruction at the levels of the velum, oropharynx, tongue base, and epiglottis. There were several differences in DISE findings between the control and test groups. DISE findings obtained after the stress test revealed significant narrowing of multiple airway structures; upper airway narrowing was observed at the velum (19/48; 39.6%), oropharynx (31/63; 49.2%), and tongue base (9/61; 14.8%). Changes in configuration of upper airway obstruction were observed only at the level of the velum (33/85; 38.8%). Stress exercise test induces changes in the degree and configuration of upper airways narrowing, which causes surgeons to over or underestimate the obstructive pattern, depending on the clinical circumstance. When counseling patients on the likely value of sleep surgery based on DISE findings, stressful physical activity should be included as a contributing factor in treatment planning.

[Drug-induced sedation endoscopy-quo vadis? : Review and outlook]

BACKGROUND

Drug-induced sedation endoscopy (DISE) is a diagnostic procedure which allows evaluation of the collapsibility of the upper airway. According to expert opinion, it is possible to imitate nocturnal collapsibility and perform a realistic investigation of the site of obstruction and vibration. This should enable sufficient and precise therapeutic advice to be given solely on the basis of clinical assessment.

OBJECTIVE

The current publication critically evaluates the present state of development of DISE and its potential indications.

MATERIALS AND METHODS

A PubMed literature research was performed using "sleep" and "endoscopy" or "DISE" as keywords. Relevant publications were evaluated.

RESULTS

The present publication provides a historical summary of the available publications and relates these to other methods for examining obstructive sleep apnea. The present state of DISE in terms of drugs applied, grading systems, and validity is evaluated. Indications for DISE are described and critically discussed on the basis of literature data.

CONCLUSION

DISE provides deep insights into the genesis of obstructions of the upper airway and snoring. Although its value for diagnosis and treatment of sleep-disordered breathing could not yet be demonstrated for all non-CPAP (continuous positive airway pressure) therapies, DISE could identify predictive parameters some methods. Further potential indications for DISE might be predictive examinations for mandibular advancement devices and respiration-synchronous neurostimulation of the hypoglossal nerve. DISE will thus remain a valuable diagnostic tool for obstructive sleep apnea and rhonchopathy.