Mechanisms Of Pharyngeal Collapse In Obstructive Sleep Apnoea Defined By Optical Coherence Tomography
Funder
National Health and Medical Research Council
Funding Amount
$476,764.00
Summary
Obstructive sleep apnoea is characterised by intermittent collapse of the upper airway (throat) resulting in episodes of decreased blood oxygen levels, increased blood pressure and sleep disruption. Obstructive sleep apnoea is common, affecting 5% of middle-aged adults, and is associated with worsening health, increased motor vehicle accidents and increased risk of heart disease. However the mechanisms responsible for obstructive sleep apnoea are not well understood. One reason for this lack of ....Obstructive sleep apnoea is characterised by intermittent collapse of the upper airway (throat) resulting in episodes of decreased blood oxygen levels, increased blood pressure and sleep disruption. Obstructive sleep apnoea is common, affecting 5% of middle-aged adults, and is associated with worsening health, increased motor vehicle accidents and increased risk of heart disease. However the mechanisms responsible for obstructive sleep apnoea are not well understood. One reason for this lack of understanding is that current diagnostic techniques can not accurately measure changes in the size and shape of the upper airway during sleep. Such information is vital for the accurate diagnosis and treatment of obstructive sleep apnoea. This project proposes to use a technique called endoscopic optical coherence tomography (eOCT), recently developed by ourselves, to measure the changes in upper airway size and shape in patients with obstructive sleep apnoea during wakefulness and, importantly, during sleep. A prototype of the system has been developed. Preliminary in vivo studies have been performed in the human upper airway and the results from these preliminary trials have been published. To our knowledge, world-wide, this is the only such system capable of making these measurements. The studies proposed in this application will provide a better understanding of the mechanisms underlying obstructive sleep apnoea and may lead to the development of greatly improved and more specific treatments that are tailored to the exact needs of the individual patient.Read moreRead less
Factors Determining Collapsibility Of The Human Upper Airway During Sleep And General Anaesthesia
Funder
National Health and Medical Research Council
Funding Amount
$259,625.00
Summary
Obstructive sleep apnoea (OSA) is common, affecting between 2-4% of middle-aged adults. It is characterised by repetitive partial or complete collapse of the upper airway during sleep. Each episode is accompanied by transient hypoxemia, hypertension and arousal. The repetitive arousals disrupt sleep resulting in excessive daytime tiredness and lethargy, which have major consequences for social well-being and productivity in our community. OSA is an independent risk factor for vascular disease. C ....Obstructive sleep apnoea (OSA) is common, affecting between 2-4% of middle-aged adults. It is characterised by repetitive partial or complete collapse of the upper airway during sleep. Each episode is accompanied by transient hypoxemia, hypertension and arousal. The repetitive arousals disrupt sleep resulting in excessive daytime tiredness and lethargy, which have major consequences for social well-being and productivity in our community. OSA is an independent risk factor for vascular disease. Central to understanding OSA is knowledge of the mechanisms responsible for vulnerability to upper airway collapse. It remains unclear to what extent this vulnerability relates to abnormalities in the underlying structure and passive physical characteristics of the upper airway, versus abnormalities in activity of upper airway muscles. Making this distinction has been problematic because current methods of testing upper airway collapsibility in sleeping humans tend to result in changes in muscle activity and-or sleep state, affecting the measurements. It is, however, possible to suppress upper airway muscle activity and eliminate measurement-related changes in muscle activity and state with general anaesthesia, while maintaining normal spontaneous breathing. We have developed and refined this method and propose to use it in novel investigations to (a) relate the behaviour of the flaccid airway (no muscle activity) under anaesthesia to its behaviour during sleep (when muscle activity is variable but quantifiable), and (b) determine the effect of changes in body habitus (posture and lung volume) on airway collapsibility. These studies will allow examination of the exciting possibility that measurements made under brief general anaesthesia could be used to define propensity to obstruction during sleep. They will also allow examination of the contribution of common changes in body habitus toward vulnerability to upper airway collapse.Read moreRead less
I am an applied respiratory physiologist investigating the pathophysiology of upper airway dysfunction in individuals with sleep-disordered breathing and the application of exercise physiology principles to the development of novel rehabilitation methods
Clinical And Physiological Features Of Obstructive Sleep Apnoea Phenotypes
Funder
National Health and Medical Research Council
Funding Amount
$117,331.00
Summary
Obstructive sleep apnoea has variable causes and clinical effects in different patient groups. My research will quantify the contribution of various physiological processes to the development of upper airway obstruction in different sub-types of sleep apnoea and to determine how this affects clinical presentation. I will be measuring a number of physiological parameters, and finding out how sleep apnoea manifests in terms of symptomatology and adverse health effects.
Mechanisms And Treatment Of Upper Airway Collapse In Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$328,668.00
Summary
Obstructive sleep apnoea (OSA) is characterized by intermittent closure of the upper airway (throat) resulting in episodes of decreased blood oxygen levels, increased blood pressure and disturbed sleep. Repetitive overnight arousals from sleep cause excessive daytime tiredness and lethargy, which have major consequences for social well-being and productivity in our community. OSA is a common condition, affecting as many as 2 to 4% of middle aged adults, and is associated with an increased cardio ....Obstructive sleep apnoea (OSA) is characterized by intermittent closure of the upper airway (throat) resulting in episodes of decreased blood oxygen levels, increased blood pressure and disturbed sleep. Repetitive overnight arousals from sleep cause excessive daytime tiredness and lethargy, which have major consequences for social well-being and productivity in our community. OSA is a common condition, affecting as many as 2 to 4% of middle aged adults, and is associated with an increased cardiovascular risk, however the mechanisms underlying the increased upper airway collapsibility in individuals with OSA are not well understood. The proposed studies represent a series of investigations into fundamental mechanisms of neural and mechanical control of upper airway patency, how these mechanisms act to stabilize the upper airway, and whether these reflex control mechanisms can be manipulated to provide a novel treatment for OSA.Read moreRead less
The Obstructive Sleep Apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA is amongst the commonest chronic disorders of adult males, occurring in 5% of men over the age of 45 years. We will examine how muscles in the throat act to keep the airway open. We will also study how tongue and jaw position influences throat blockage. The throat is lined with fluid which ....The Obstructive Sleep Apnoea syndrome (OSA) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSA is amongst the commonest chronic disorders of adult males, occurring in 5% of men over the age of 45 years. We will examine how muscles in the throat act to keep the airway open. We will also study how tongue and jaw position influences throat blockage. The throat is lined with fluid which may become dry and sticky if, for example, breathing takes place via the mouth rather than the nose. We will study the effects of this throat lining fluid and examine ways in which treatments might help to avoid throat blockage during sleep by keeping the throat lined with non-sticky fluid. These studies will increase our understanding of OSA and help to design better treatments for the condition. People who have OSA also may develop high blood pressure associated with the nervous system response to breathing difficulties during sleep over a long period of time. In the same way as is used in the lie detector test, we will use measurements of the electrical conductivity of the skin to assess this nervous system response during sleep. These studies will help to understand how hypertension develops in OSA and who is likely to be affected. Asthma is a major health problem in Australia affecting around 20% of children and 12% of adults. Asthmatics react to inhaled pollens etc. The nose normally acts as a filter to remove many such particles from the inhaled air. If breathing takes place via the mouth more and larger particles can gain access to the lungs. We will investigate whether asthmatics breathe through their nose only or breathe through the mouth more than normal (particularly during sleep), if treatments can alter this and whether such treatments reduce the occurence of asthma attacks.Read moreRead less
The Role Of Lung Volume In The Pathogenesis And Treatment Of Obstructive Sleep Apnea.
Funder
National Health and Medical Research Council
Funding Amount
$337,691.00
Summary
Obstructive sleep apnea (OSA) is a common disorder of repetitive upper airway collapse during sleep. Reducing the volume of air in the lungs increases airway collapsibility. Lung volume is therefore likely important in OSA but has not been investigated thoroughly. Also, whether raising lung volume during sleep can be used to treat OSA is unknown. The aim of this grant is therefore to investigate the role, and therapeutic potential, of lung volume in OSA.
Novel Therapeutic Phenotyping For Sleep Apnoea - A Paradoxical Role For Sedatives
Funder
National Health and Medical Research Council
Funding Amount
$639,168.00
Summary
Sleeping pill (sedative) use has risen dramatically. Sedatives may worsen a common breathing condition called obstructive sleep apnoea (OSA). Accordingly, their use has been discouraged in OSA. However, recent studies indicate that certain sedatives may actually reduce OSA severity in some patients. By studying the effects of common sedatives on OSA and breathing, this proposal aims to explain these apparent paradoxical responses and ultimately provide a new treatment approach for OSA.
The Role Of Sedatives And Arousal In Obstructive Sleep Apnoea – Pathophysiology And Therapeutic Utility
Funder
National Health and Medical Research Council
Funding Amount
$415,218.00
Summary
Recent studies indicate that certain sleeping pills (sedatives) may actually reduce obstructive sleep apnoea (OSA) severity in some patients. This research aims to determine the: 1) characteristics of patients who are most likely to respond to this novel approach. 2) effects of commonly prescribed sedatives on upper airway function and breathing during sleep. 3) utility for a sedative to yield sustained reductions in OSA severity and daytime sleepiness in the appropriately selected OSA patients.
Respiratory Phenotyping For New Targeted Approaches To Treat Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$631,370.00
Summary
>9% of Australians have obstructive sleep apnoea (OSA). OSA has several causes. Untreated OSA is associated with major health consequences. <50% of OSA patients tolerate the main therapy, continuous positive airway pressure. New treatments are urgently required. This proposal aims to use & develop novel approaches to identify the causes of OSA on a per patient basis, improve current therapies & test if new targeted therapies can be used to treat OSA in appropriately selected patients.