View clinical trials related to Apnea.
Filter by:In obstructive sleep apnea (OSA), the upper airway recurrently closes during sleep. The mechanisms that lead to airway closure are not completely understood. Some studies have shown that there is progressive narrowing of the pharyngeal airway across breaths during expiration (Progressive Expiratory Narrowing, PEN) preceding an obstructive apnea. The investigators will assess the viscoelastic properties of the pharyngeal airway and its role in PEN.
The objective of this study is to determine the effect of dexmedetomidine infusion on the Apnea / Hypopnea Index (AHI) of individuals with previously documented obstructive sleep apnea. We hypothesize that dexmedetomidine infusion may reduce the AHI in patients with obstructive sleep apnea (OSA).
In obstructive sleep apnea, the upper airway recurrently closes during sleep. The mechanisms that lead to airway closure are not completely understood. While the airway of some people narrows and airflow decreases during inspiration due to increasing inspiratory effort, others maintain constant airflow throughout inspiration. Airway neuromuscular reflexes may protect against airway narrowing that occurs due to increasing inspiratory effort. To test this hypothesis, the investigators will initially measure airway neuromuscular reflex and inspiratory flow and then attenuate neuromuscular reflex through topical pharyngeal anesthesia to observe the effects on inspiratory flow.
40% of patients with Sleep Disorder Breathing (SDB) appearing during the acute phase of stroke show a respiratory pattern characterized by central apnoeas and/or periodic breathing. Clinical studies conducted in patients with hearth failure and central apnoeas have demonstrated the pathogenetic central role of hypersensitivity of central and peripheral chemoreceptors in association with baroreflex hypersensitivity, expression of hyperactivity of sympathetic nervous system. The joint study of chemoreflexes and baroreflexes in patients with central apneas during the acute and subacute phase of ischemic stroke represents, to our knowledge, a novelty in literature, that should supply useful elements to clarify the pathogenesis and the clinical and prognostic significance of these disorders. Investigators expect a difference in the analysis of the baroreflexes and chemoreflexes in patients with ischemic stroke/transient ischemic attack (TIA) and central apnoeas than patients with ischemic stroke not accompanied by respiratory problems and compared with healthy controls.
It is often clinically impossible to differentiate children with an isolated snoring from those with OSA. The diagnosis of OSA is currently based on nocturnal, laboratory-based polysomnography. This expensive examination is poorly accessible due to appointments delays at hospital. Our study is designed to compare the characteristics of a home polysomnography versus standard polysomnography for the diagnosis of pediatric OSA.
The purpose of this study is determine safety and efficiency of mechanical ventilation in children with two different types of single use laryngeal masks (Ambu AuraOnce vs. LMA Supreme). The main interest is leakage pressure of oropharynx and stomach. The null hypothesis is that leakage pressures of Ambu AuraOnce and LMA Supreme are equivalent. The alternative hypothesis is that there is a difference in leakage pressure.
The central aim of this research project is to determine how the ever-growing problem of obesity in the western world contributes to the pathophysiology of obstructive sleep apnea (OSA). To complete this aim, the investigators will determine the impact of obesity on the mechanisms underlying OSA. This will be achieved by making physiological measurements of 4 physiological traits known to cause OSA as well as the patients sleep apnea severity, before and after weight-loss surgery (i.e. bariatric surgery).
Specific aim: To test the effects of nasal expiratory positive airway pressure (EPAP) therapy on sleep apnea severity among patients with recent ischemic stroke. Hypothesis 1: Ischemic stroke patients with sleep apnea will have less severe sleep apnea, as measured by the apnea-hypopnea index (AHI), with nasal EPAP therapy compared with a control night. Hypothesis 2: Ischemic stroke patients will have higher mean levels of oxygen saturation with nasal EPAP therapy compared with a control night.
Supine positioning was reported to increase upper airway collapsibility, apnea frequency and duration. Positional therapy, designed to minimize supine sleep, was reported to be beneficial in the general sleep apnea population. As supine sleep is very common in stroke patients, positional therapy might also have therapeutic effects. Given differences between stroke patients with sleep apnea and the general sleep apnea patient, such as rolling ability, body mass index and daytime sleepiness, positional therapy results in the general population may not be applicable to the stroke patient. The effects of positional therapy in ischemic stroke patients with OSA have not been well-investigated. We therefore performed a pilot randomized, controlled, cross-over study to test the following hypotheses: (1) positional therapy reduces the amount of nocturnal supine positioning in patients with subacute ischemic stroke, and (2) severity of sleep apnea improves, as reflected by apnea-hypopnea index (AHI), during positional therapy. The tolerability of positional therapy over a 3-month period in patients with ischemic stroke was also evaluated.
study Hypothesis: We hypothesize that CPAP could effectively improve the endothelial dysfunction by anti-inflammatory effect in patients of OSA,and compare to the effect of statin.