Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0037315 (sleep apnea)
 8,000 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The control system of breathing can be considered as a closed-loop system, consisting of two subsystems: the controlling system and the controlled system. Both subsystems are defined by their input-output relationships. In the controlling system the input is the blood gas value; the output is some parameter of ventilation. The controlled system is characterized by an input of ventilation, and an output of blood gas values. In the closed-loop situation the control of breathing can be influenced by outside "disturbances", threatening to disrupt the regulation of the constancy of the internal environment. When studying the control of breathing, and therefore studying the strengths or defects of this homeostatic system, one has to decide whether one intends to investigate the closed-loop or the open-loop situation, and which defect in a subsystem may be the cause of a disrupted homeostasis. What non-feedback stimuli may be active at the moment of the investigation? How can they be kept constant or eliminated? What possible effects from drugs, beverages, nutrients (possibly consumed hours earlier) may still be present? In particular, the output parameters of the controlling system should be carefully chosen to represent that part of the system that one intends to investigate. Disruptions of the control of breathing may have serious consequences for several categories of patients, e.g. those with chronic obstructive pulmonary disease (COPD), asthma, sleep apnoea, sudden infant death syndrome, several neurological syndromes, and the hyperventilation syndrome. Adequate investigation of the control of breathing in these patients is of great importance for their treatment.
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PMID:Studying the control of breathing in man. 314 Dec 12

Central sleep apnoea (CSA) is a disorder characterised by repetitive episodes of decreased ventilation due to complete or partial reduction in the central neural outflow to the respiratory muscles. Hyperventilation plays a prime role in the pathogenesis of CSA. Chronic heart failure and dwelling at high altitude are classical conditions in which CSA is induced by hyperventilation. Hyperventilation syndrome (HVS) is a prevalent behavioural condition in which minute ventilation exceeds metabolic demands, resulting in haemodynamic and chemical changes that produce characteristic dysphoric symptoms. HVS is frequently caused by anxiety disorders and panic attacks. Until now, medical literature has focussed primarily on daytime symptoms of behavioural hyperventilation. It is currently unknown how this condition may affect sleep. Three cases are reported in which behavioural hyperventilation was associated with occurrence of significant central sleep apnoea, which was not present during normal tidal breathing in steady sleep. Therefore, behavioural hyperventilation should be added to the list of known clinical conditions associated with CSA.
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PMID:Behavioural hyperventilation as a novel clinical condition associated with central sleep apnoea: a report of three cases. 2312 77