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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breathing is a complex act requiring the coordinated activity of multiple groups of muscles. Thoracic and abdominal respiratory muscles expand and contract the lungs, whereas pharyngeal and laryngeal respiratory muscles maintain upper airway patency and regulate upper airway resistance. An appreciation of the importance of the latter muscle group in maintaining ventilatory homeostasis and in the pathophysiology of sleep apnea has led to extensive studies examining the neural regulation of pharyngeal dilator muscles. The present review examines the role of heterogeneity in motoneuron and muscle properties in determining the diversity in the electrical and mechanical behaviors of thoracic compared with pharyngeal muscle groups. Specifically, phrenic and hypoglossal motoneuron electrophysiological properties influence whether and the extent to which these neurons will fire in response to a given synaptic input arising from chemo- and mechanoreceptors and from respiratory and nonrespiratory pattern generators. Furthermore, thoracic and pharyngeal muscle properties determine the mechanical response to motoneuronal activity, including the speed of contraction, relationships between motoneuron firing frequency and force production, and whether force is maintained during repetitive activation. Heterogeneity in the functional capabilities of these motoneurons and muscles is in turn determined by diversity of their structural and biochemical properties. Thus, intrinsic properties of respiratory motoneurons and muscles act in concert with neuronal drives in defining the complex electrical and mechanical behavior of pharyngeal and thoracic respiratory motor systems.
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PMID:Intrinsic properties of pharyngeal and diaphragmatic respiratory motoneurons and muscles. 140 39

Some children who snore heavily, have been shown to have periods of apnoea which, if frequent, are known as the obstructive sleep apnoea syndrome (OSA). Twenty patients with OSA, who presented to the Department of Thoracic Medicine, Royal Children's Hospital, Melbourne, over a three-year period, were reviewed. The findings indicated that OSA is more common than is generally supposed and that it can present with a wide range of symptoms. It is important that an early diagnosis of this syndrome is made, to prevent major complications and to allow appropriate therapy.
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PMID:Snoring in children: is it pathological? 404 46

Obstructive sleep apnoea may present with a wide range of symptoms resulting in a variety of referral pathways. A multidisciplinary approach to examination and diagnosis helps to determine the most appropriate treatment plan for each individual. The subject is seen by each member of the team, appropriate investigations undertaken and a further meeting arranged at which all opinions are discussed. A reasoned treatment regime is produced, taking into consideration the patient's wishes and overall medical condition. This paper describes the team approach currently employed in the Department of Thoracic Medicine at The Prince Charles Hospital, Brisbane, Australia. The thoracic physician and ENT surgeon work in close collaboration with their dental colleagues: an orthodontist, prosthodontist and a maxillofacial surgeon. An outline of the examination and investigations made by each is described and the multidisciplinary approach is illustrated by a description of the management of five subjects with suspected obstructive sleep apnoea.
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PMID:The importance of a multidisciplinary approach to the assessment of patients with obstructive sleep apnoea. 885 Jan 65

The development of inexpensive tools for diagnosing sleep apnea syndrome (SAS) is a result of the high prevalence of this condition and of the high cost of polysomnograms (PS). MESAM IV is a portable device that records changes in oxygen saturation (SO2), heart rate (HR) and snoring (S). Readings can be automatic or manual, the latter in function of an events index (EI), with a graph of the three variables generated. We carried out a simultaneous study of 51 subjects suspected of having SAS who were referred to the sleep unit by the pneumology outpatient clinic. PS was interpreted manually at 30-sec intervals as recommended by the American Thoracic Society. An apnea/hypoapnea index (AHI) > or = 10/hour of sleep was used as the cutoff point for SAS. Thirty-two (63%) subjects were found to have SAS as indicated by PS. The rate of agreement between AHI and automatic analysis of SO2, HR and S was only moderate (intra-group correlation coefficients -ICC- of 0.50, 0.40, and 0.53, respectively) and was inferior to manual analysis with EI (ICC of 0.77). Assessment of diagnostic efficacy of automatic analysis in terms of sensitivity (SEN), specificity (SPE), positive predictive value (PPV) and negative predictive value (NPV) yielded the following results: SO2 (SEN 94%, SPE 26%, PPV 68% and NPV 71%), HR (SEN 59%, SPE 58%, PPV 70%, NPV 46%); S (SEN 84%, SPE 26%, PPV 66%, NPV 50%). Manual analysis (EI) gave more valid results (SEN 100%, SPE 84%, PPV 91%, NPV 100%). If patients with chronic obstructive lung disease are excluded, however, the results for automatic analysis improve: SEN 100%, SPE 91%, PPV 96%, NPV 100%. These results show that MESAM IV is of great help in diagnosing SAS, allowing better screening for identifying candidates for PS.
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PMID:[Validity of a portable recording system (MESAM IV) for the diagnosis of sleep apnea syndrome]. 795 34

Obstructive sleep apnoea may present with a wide range of symptoms resulting in a variety of referral pathways. A multidisciplinary approach to examination and diagnosis helps to determine the most appropriate treatment plan for each individual. The subject is seen by each member of the team, appropriate investigations undertaken and a further meeting arranged at which all opinions are discussed. A reasoned treatment regime is produced, taking into consideration the patient's wishes and overall medical condition. This paper describes the team approach currently employed in the Department of Thoracic Medicine at The Prince Charles Hospital, Brisbane, Australia. The thoracic physician and ENT surgeon work in close collaboration with their dental colleagues: an orthodontist, prosthodontist and a maxillofacial surgeon. An outline of the examination and investigations made by each is described and the multidisciplinary approach is illustrated by a description of the management of five subjects with suspected obstructive sleep apnoea.
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PMID:The importance of a multidisciplinary approach to the assessment of patients with obstructive sleep apnoea. 747 33

The 24-hour properties of sleepiness affect behavior by reducing performance and increasing the likelihood of accidents. This is important to pulmonary physicians who diagnose and treat sleep apnea, because diagnoses of sleep apnea and narcolepsy are associated with as much as a sevenfold increase in the risk of having a motor vehicle accident. Human abilities throughout the 24-hour day have noticeable ups and downs and are probably causally linked to the same control mechanisms that produce the early morning and midafternoon peaks in the tendency to fall asleep. An important characteristic of this pattern is that increased sleep tendency, regardless of how the increase comes about, does not alter the timing of the peaks. In California, and perhaps other states, current laws can be interpreted as requiring clinicians to report all patients with conditions such as sleep apnea and narcolepsy to the county health officer. Although this policy is at variance with recommendations of the American Thoracic Society, attorneys have advised that, in California, a policy of uniformly reporting all patients with disorders of excessive somnolence is proper. Because ignorance of the law is not a valid defense, it is important for physicians to be aware of all state laws relevant to their patients who may be impaired by sleepiness.
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PMID:Sleepiness and human behavior. 936 90

The objectives of this study were to evaluate the reliability and accuracy of a new impedance cardiograph device, the Physio Flow, at rest and during a steady-state dynamic leg exercise (work intensity ranging from 10 to 50 W) performed in the supine position. We compared cardiac output determined simultaneously by two methods, the Physio Flow (QcPF) and the direct Fick (QcFick) methods. Forty patients referred for right cardiac catheterisation, 14 with sleep apnoea syndrome and 26 with chronic obstructive pulmonary disease, took part in this study. The subjects' oxygen consumption values ranged from 0.14 to 1.19 l x min(-1). The mean difference between the two methods (QcFick - QcPF) was 0.04 l x min(-1) at rest and 0.29 l x min(-1) during exercise. The limits of agreement, defined as mean difference +/- 2SD, were -1.34, +1.41 l x min(-1)] at rest and -2.34, +2.92 l x min(-1) during exercise. The difference between the two methods exceeded 20% in only 2.5% of the cases at rest, and 9.3% of the cases during exercise. Thoracic hyperinflation did not alter QcPF. We conclude that the Physio Flow provides a clinically acceptable and non-invasive evaluation of cardiac output under these conditions. This new impedance cardiograph device deserves further study using other populations and situations.
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PMID:A new impedance cardiograph device for the non-invasive evaluation of cardiac output at rest and during exercise: comparison with the "direct" Fick method. 1095 74

There is growing interest in using portable monitoring for investigating patients with suspected sleep apnea. Research studies typically report portable monitoring results in comparison with the results of sleep laboratory-based polysomnography. A systematic review of this research has recently been completed by a joint working group of the American College of Chest Physicians, the American Thoracic Society, and the American Academy of Sleep Medicine. The methods for comparing the results of portable monitors and polysomnography include product-moment correlation, intraclass correlation, mean differences/limits of agreement, sensitivity, specificity, and likelihood ratios. Each approach has advantages and limitations, which are highlighted in this review.
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PMID:Measuring agreement between diagnostic devices. 1455 92

The symptoms and characteristics of sleep apnoea syndrome--excessive daytime sleepiness, loud snoring, restless and non-restorative sleep--are so impressive that it is difficult to understand why its recognition was delayed until the 1970s. The Centennial book of the American Thoracic Society credited Sidney Burwell for the discovery of Obstructive Sleep Apnoea Syndrome. This is only one of the many mistakes and misattributions regarding the history of sleep apnoea syndrome. The earliest descriptions of patients who presumably suffered from sleep apnoea were made in the 19th century. The term "Pickwickian" in connection with sleepy patients was introduced in 1889. The first electrophysiological sleep recordings of Pickwickian patients and the understanding of the syndrome as disordered breathing in sleep, were made during the late 1950s and 1960s. Its recognition as a public health problem was facilitated by Young et al.'s [Young T, Palta M, Dempsey J, et al. The occurrence of sleep-disordered breathing among middle-aged adults. N Engl J Med 1993;328:1230-5] seminal paper documenting the prevalence of the syndrome in the general population, and by the accumulated evidence that the syndrome is a major cardiovascular risk factor. Bibliometric analysis of the literature on sleep apnoea reveals that future research will focus on the long-term outcomes of the syndrome, on the effects of treatment, and on the underlying mechanisms linking it with cardiovascular morbidity.
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PMID:Who was the first to use the term Pickwickian in connection with sleepy patients? History of sleep apnoea syndrome. 1820 61

Thoracic insufficiency syndrome (TIS) is a collection of chest and spine malformations that results in progressively restrictive pulmonary mechanics and an inability of the thorax to adequately support lung growth. Many children with TIS are too young to perform standard pulmonary function tests, yet need functional assessments of their restrictive thoracic disease. We report on the sleep architecture and frequency of sleep-related breathing abnormalities in 11 children with TIS who underwent overnight polysomnography from retrospective chart review. Ten of 11 (92%) had sleep disordered breathing as defined by currently accepted criteria of apnea-hypopnea index (AHI) >2 events/hr. The median AHI was 4.3 events/hr, with obstructive hypopneas (median 3.7 events/hr) accounting for 75% of abnormalities. Respiratory events occurred most frequently during REM sleep (median REM-AHI 17.3 events/hr), and were associated with oxyhemoglobin desaturation, and rarely carbon dioxide retention. Sleep disordered breathing with hypoxemia appears to be a common but under recognized problem among children with TIS. Polysomnogram may have a role as a non-invasive screening tool used in conjunction with other functional respiratory assessments in children with TIS, and warrants further study in a prospective manner.
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PMID:Sleep-disordered breathing in children with thoracic insufficiency syndrome. 2042 54


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