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.
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.
Pharyngeal Wall Folding: Role In Upper Airway Collapsibility
Funder
National Health and Medical Research Council
Funding Amount
$217,274.00
Summary
In obstructive sleep apnoea (OSA) the throat closes during sleep. In order for the throat to close the surface of the throat has to fold. Mathematical models predict that the more folds present, the more stable a structure will be. This research will examine how folding of the airway surface of the throat is achieved in subjects with and without OSA. It will also develop ways of changing the folding patterns using bench, animal and human studies. This will result in new treatments for OSA.
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
Pressures Exerted On Upper Airway Walls By Surrounding Tissue Structures
Funder
National Health and Medical Research Council
Funding Amount
$426,500.00
Summary
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 effects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect of the pressure in the tissues surrounding the throat on the ability of the throat to stay open a ....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 effects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in 5% of men over the age of 45 years. In the proposed studies we will examine the effect of the pressure in the tissues surrounding the throat on the ability of the throat to stay open and allow breathing. The major outcome of the animal studies is increased knowledge concerning mechanisms whereby collapsing forces are applied to the upper airway. This will give insights into potential factors influencing upper airway collapse during sleep in OSA patients. Of particular importance will be our studies on the effects of jaw position on the pressure exerted on the walls of the throat since the use of an intra-oral device to hold the jaw forward during sleep is one of the treatments used to prevent throat blockage during sleep. The studies in humans will examine, for the first time, the notion that the mass (weight) of the neck has a direct effect on the severity of sleep disordered breathing. If neck mass has a substantive influence on sleep disordered breathing then strategies aimed at reducing neck mass (fat) may provide a new therapeutic approach to the management of OSA patients.Read moreRead less
The Role Of Arousal In The Pathogenesis Of Obstructive Sleep Apnea And Implications For Novel Therapeutic Treatments
Funder
National Health and Medical Research Council
Funding Amount
$297,888.00
Summary
This research forms part of a series of studies aimed at characterizing the relative importance of the various physiological causes (phenotypes) of obstructive sleep apnea (OSA) and has the potential to lead to individually tailored novel therapies according to these traits. Specifically, this proposed research will investigate the role of arousal from sleep (brief awakening) in OSA and explore methods of manipulating the arousal threshold as a new treatment approach for certain OSA patients.
Hydrostatic Pressure Distributions In Peri-pharyngeal Tissues : Impact On Upper Airway Patency
Funder
National Health and Medical Research Council
Funding Amount
$508,935.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our mo ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our model will be the influence of the properties of the tissue that form the walls of the throat. Our goal is to construct a computer model that will be useful in identifying specific features of throat function that make people susceptble to the development of OSAHS. In this manner we hope to provide a tool that can be used to develop new approaches to the treatment and prevention of OSAHS.Read moreRead less
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
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
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