Upper airway collapse during drug induced sleep endoscopy: head rotation in supine position compared with lateral head and trunk position.

Drug induced sedated sleep endoscopy (DISE) is often employed to determine the site, severity and pattern of obstruction in patients with sleep apnea. DISE is usually performed in supine position. We recently showed that the obstruction pattern is different when DISE is performed in lateral position. In this study, we compared the outcomes of DISE performed in supine position with head rotated, with the outcomes of DISE performed with head and trunk in lateral position. The Prospective study design was used in the present study. Sixty patients with OSA (44 male; mean apnea hypopnea index (AHI) 20.8 ± 17.5 events/h) underwent DISE under propofol sedation. Patients were placed in lateral position, and the upper airway collapse was evaluated. The patients were then placed in supine position with the head rotated to the right side. DISE outcomes were scored using the VOTE classification system. In lateral position, nine patients (15.0%) had a complete antero-posterior (A-P) collapse at the level of the velum, nine had a partial A-P collapse. During head rotation and trunk in supine position, at the level of the velum, four patients (6.7%) had a complete A-P collapse, while two patients (3.3%) had a partial A-P collapse. For all other sites, the patterns of collapse were not significantly different between head rotation and lateral position. During DISE, rotation of the head in supine position, and lateral head and trunk position present similar sites, severity and patterns of upper airway collapse, with the exception of collapse at the level of the velum. Here the severity of A-P collapse is less severe during head rotation than in lateral head and trunk position.

Effect of upper-airway stimulation for obstructive sleep apnoea on airway dimensions.

Upper-airway stimulation (UAS) using a unilateral implantable neurostimulator for the hypoglossal nerve is an effective therapy for obstructive sleep apnoea patients with continuous positive airway pressure intolerance. This study evaluated stimulation effects on retropalatal and retrolingual dimensions during drug-induced sedation compared with wakefulness to assess mechanistic relationships in response to UAS. Patients with an implanted stimulator underwent nasal video endoscopy while awake and/or during drug-induced sedation in the supine position. The cross-sectional area, anterior-posterior and lateral dimensions of the retropalatal and retrolingual regions were measured during baseline and stimulation. 15 patients underwent endoscopy while awake and 12 underwent drug-induced sedation endoscopy. Increased levels of stimulation were associated with increased area of both the retropalatal and retrolingual regions. During wakefulness, a therapeutic level of stimulation increased the retropalatal area by 56.4% (p=0.002) and retrolingual area by 184.1% (p=0.006). During stimulation, the retropalatal area enlarged in the anterior-posterior dimension while retrolingual area enlarged in both anterior-posterior and lateral dimensions. During drug-induced sedation endoscopy, the same stimulation increased the retropalatal area by 180.0% (p=0.002) and retrolingual area by 130.1% (p=0.008). Therapy responders had larger retropalatal enlargement with stimulation than nonresponders. UAS increases both the retropalatal and retrolingual areas. This multilevel enlargement may explain reductions of the apnoea-hypopnoea index in selected patients receiving this therapy.

Analysis of the influence of head rotation during drug-induced sleep endoscopy in obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: Currently, drug-induced sleep endoscopy (DISE) in obstructive sleep apnea (OSA) is predominantly performed in supine position. When positional therapy (avoidance of supine sleeping position in positional OSA (POSA) is implemented as (part of the) treatment, one should assess levels of obstruction in the other sleeping positions. Therefore, the current study examined the influence of difference head positions during DISE in patients with OSA and POSA. STUDY DESIGN: Consecutive prospective study. METHODS: DISE was performed in patients with an apnea hypopnea index at baseline polysomnography greater than 5 events/h. The upper airway was assessed at velum, oropharynx, tongue base, and epiglottis level in supine position. The patients head were then tilted to the left and the right side and the DISE findings were recorded. RESULTS: One hundred consecutive patients were included. In positional apneics (n = 67), lateral position was associated with decreased frequency of complete anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P < 0.01) level-and increased frequency of partial anteroposterior collapse at velum (P < 0.01), tongue base (P < 0.01), and epiglottis (P <0.05) level in comparison with supine position. DISE findings showed no difference between the right and left position, whereas findings after head rotation were significantly different in comparison with the supine position. CONCLUSIONS: Head rotation improves upper airway collapse during DISE in supine position. This improvement of upper airway patency is more predominant in POSA patients.

Surgery for obstructive sleep apnea: sleep endoscopy determinants of outcome.

OBJECTIVES/HYPOTHESIS: Although drug-induced sleep endoscopy is often employed to determine the site of obstruction in patients with obstructive sleep apnea (OSA) who will undergo upper airway surgery, it remains unknown whether its findings are associated with surgical outcome. This study tested the hypothesis that drug-induced sleep endoscopy variables can predict the outcome of upper airway surgery in OSA patients. STUDY DESIGN: Case series retrospective analysis. METHODS: Forty-nine OSA patients (41 male; mean apnea-hypopnea index [AHI] 30.9 ± 18.5 events/hour) underwent propofol-induced sleep endoscopy followed by upper airway surgery (palatal surgery, and/or radiofrequency ablation of the tongue base, and/or hyoid suspension) and subsequently a follow-up polysomnography to assess surgical outcome. RESULTS: Twenty-three patients (47%) were responders, and twenty-nine were nonresponders (53%). Nonresponders had a higher occurrence of complete or partial circumferential collapse at velum and complete antero-posterior collapse at tongue base or epiglottis in comparison with responders. Multivariate logistic regression analysis revealed that among baseline clinical and polysomnographic characteristics (e.g., AHI, body mass index) and sleep endoscopy findings, the presence of complete circumferential collapse at velum, and of complete antero-posterior collapse at tongue base were the only independent predictors of upper airway surgery failure. CONCLUSIONS: Drug-induced sleep endoscopy can be used to predict higher likelihood of response to upper airway surgery in OSA.