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.

Orthodontic Management of Adult Sleep Apnea: Clinical Case Reports

Obstructive sleep apnea (OSA) is a serious public health problem that has important impacts on the quality and life expectancy of affected individuals. It is characterized by repetitive upper airway collapse during sleep. OSA requires a multidisciplinary plan of treatment. There is increasing interest in the role of the orthodontist both in screening for adult obstructive sleep apnea and its management. Dental appliances and orthognathic surgery are two strategies that are currently used in the treatment of sleep apnea. This chapter focuses on the orthodontic management of sleep apnea in adults through three clinical cases with varying degrees of severity of sleep apnea. It provides a background on OSA treatment approaches and discusses the potential risks and benefits of each.

A systematic review of anaesthetic agents used in Drug Induced Sedation Endoscopy (DISE) and a description of a new DISE technique

ObjectivesDrug induced sleep endoscopy (DISE) is a standardly used investigation for surgical planning in obstructive sleep apnoea management once conservative treatments have proven inadequate. There are a variety of anaesthetic agents used to obtain sedation necessary for DISE. These agents may have different effect on the upper airway and other parameters important in the diagnosis of the site of collapse during sleep. We aimed to review the commonly agents and evaluate the significance of their impact on the the diagnosis.MethodsA search was conducted through PubMed looking for studies on commonly used anaesthetic agents and their effect on the upper airway and cardiopulmonary parameters. Results: Of the 109 studies yielded by the search, 19 were deemed relevant to the review and met all inclusion criteria. The agents reviewed were: propofol, dexmedetomidine, remifentanil, isoflurane, sevoflurane, midazolam and topical lidocaine. A meta-analysis was not conducted due to the limited number of relevant studies and the heterogeneity of outcomes measured. All agents examined gave some element of airway collapse and impact on cardiopulmonary measures. Most of these effects were shown to be dose-dependent. Of the agents considered dexmedetomidine and propofol gave the most consistently reliable and physiologically safe representations of upper airway collapse seen in OSA patients.ConclusionThere is limited information and no industry standard for the sedative regimen used for DISE. Of the agents reviewed those that caused least cardiopulmonary instability, respiratory depression and exaggerated upper airway collapse were deemed the most appropriate for DISE. The agent that best meet these criteria is dexmedetomidine followed by propofol.

Tracheobronchoplasty and Diaphragmatic Plication under VV ECMO for Combined ECAC and Diaphragmatic Paralysis

The coexistence of expiratory central airway collapse and diaphragmatic paralysis presents a diagnostic and treatment challenge. Both entities are underrecognized causes of dyspnea, cough, sputum production, and orthopnea. Optimal treatment must be individualized and is best achieved by a multidisciplinary team. We present a case of a patient with profound functional impairment from dyspnea and hypoxemia due to expiratory central airway collapse, complicated by bronchiectasis from recurrent respiratory infections, and diaphragmatic paralysis.

Much Ado about Sleep: Current Concepts on Mechanisms and Predisposition to Pediatric Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is a form of sleep-disordered breathing characterized by upper airway collapse during sleep resulting in recurring arousals and desaturations. However, many aspects of this syndrome in children remain unclear. Understanding underlying pathogenic mechanisms of OSA is critical for the development of therapeutic strategies. In this article, we review current concepts surrounding the mechanism, pathogenesis, and predisposing factors of pediatric OSA. Specifically, we discuss the biomechanical properties of the upper airway that contribute to its primary role in OSA pathogenesis and examine the anatomical and neuromuscular factors that predispose to upper airway narrowing and collapsibility.

The Biomechanical Mechanism of Upper Airway Collapse in OSAHS Patients Using Clinical Monitoring Data during Natural Sleep

Obstructive sleep apnea hypopnea syndrome (OSAHS) is a common sleep disorder characterized by repeated pharyngeal collapse with partial or complete obstruction of the upper airway. This study investigates the biomechanics of upper airway collapse of OSASH patients during natural sleep. Computerized tomography (CT) scans and data obtained from a device installed on OSASH patients, which is comprised of micro pressure sensors and temperature sensors, are used to develop a pseudo three-dimensional (3D) finite element (FE) model of the upper airway. With consideration of the gravity effect on the soft palate while patients are in a supine position, a fluid–solid coupling analysis is performed using the FE model for the two respiratory modes, eupnea and apnea. The results of this study show that the FE simulations can provide a satisfactory representation of a patient’s actual respiratory physiological processes during natural sleep. The one-way valve effect of the soft palate is one of the important mechanical factors causing upper airway collapse. The monitoring data and FE simulation results obtained in this study provide a comprehensive understanding of the occurrence of OSAHS and a theoretical basis for the individualized treatment of patients. The study demonstrates that biomechanical simulation is a powerful supplementation to clinical monitoring and evaluation.

Mediastinal Masses, Anesthetic Interventions, and Airway Compression in Adults: A Prospective Observational Study

Background Central airway occlusion is a feared complication of general anesthesia in patients with mediastinal masses. Maintenance of spontaneous ventilation and avoiding neuromuscular blockade are recommended to reduce this risk. Physiologic arguments supporting these recommendations are controversial and direct evidence is lacking. The authors hypothesized that, in adult patients with moderate to severe mediastinal mass–mediated tracheobronchial compression, anesthetic interventions including positive pressure ventilation and neuromuscular blockade could be instituted without compromising central airway patency. Methods Seventeen adult patients with large mediastinal masses requiring general anesthesia underwent awake intubation followed by continuous video bronchoscopy recordings of the compromised portion of the airway during staged induction. Assessments of changes in anterior–posterior airway diameter relative to baseline (awake, spontaneous ventilation) were performed using the following patency scores: unchanged = 0; 25 to 50% larger = +1; more than 50% larger = +2; 25 to 50% smaller = −1; more than 50% smaller = −2. Assessments were made by seven experienced bronchoscopists in side-by-side blinded and scrambled comparisons between (1) baseline awake, spontaneous breathing; (2) anesthetized with spontaneous ventilation; (3) anesthetized with positive pressure ventilation; and (4) anesthetized with positive pressure ventilation and neuromuscular blockade. Tidal volumes, respiratory rate, and inspiratory/expiratory ratio were similar between phases. Results No significant change from baseline was observed in the mean airway patency scores after the induction of general anesthesia (0 [95% CI, 0 to 0]; P = 0.953). The mean airway patency score increased with the addition of positive pressure ventilation (0 [95% CI, 0 to 1]; P = 0.024) and neuromuscular blockade (1 [95% CI, 0 to 1]; P < 0.001). No patient suffered airway collapse or difficult ventilation during any anesthetic phase. Conclusions These observations suggest a need to reassess prevailing assumptions regarding positive pressure ventilation and/or paralysis and mediastinal mass–mediated airway collapse, but do not prove that conventional (nonstaged) inductions are safe for such patients. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New