Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242706 (hyperoxia)
 5,219 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Friedreich's Ataxia (F.A.) is a degenerative disease which commonly leads to premature death of cardiorespiratory origin. To explain the early death of these patients, previous investigations have established the existence of 1) a cardiomyopathy in nearly 100% of cases, 2) a restrictive pulmonary syndrome of scoliotic origin and 3) a mild hypoxemia associated with slight respiratory alkalosis and a normal oxyhemoglobin dissociation curve. To further assess the cause of early death in patients with such neuromyopathy, we evaluated, in eleven F.A. patients, the sensitivity of the respiratory centers to hypercapnia, hypoxia, and hyperoxia. Ventilatory (VE, VT, F, VT/Ti) and occlusion pressure (P0.1) responses were taken as indices of the respiratory centers output during progressive hypercapnia (Read's method) and isocarbic hypoxia (Weil's method). We studied 11 Friedreich's Ataxia patients and 11 age, sex, and armspan matched controls. The responses of patients to hypercapnia were significantly greater than controls but their responses to hypoxia were similar to controls. Our study establishes that the respiratory centers are functioning adequately in early Friedreich's Ataxia and do not contribute to cardio-respiratory insufficiency in such neuromyopathy.
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PMID:Regulation of respiration in Friedreich's ataxia. 48 4

Respiratory impairment in patients with Steinert's muscular dystrophy is known to lead to respiratory failure. Both the blunted chemical drive of breathing and the respiratory muscle weakness have been cited in the pathophysiology of premature death in these patients. To further assess the chemical control of breathing in these patients, we measured their respiratory responses to hypoxia (Weil's method), hyperoxia (Dejours' method), and hypercapnia (Read's method). In response to the stimuli from these respiratory centers, minute ventilation (VE), tidal volume (VT), respiratory frequency (F), mean inspiratory flow rate (VT/Ti), and occlusion pressure (P0.1) were measured in 12 patients and in 12 normal persons matched to the patients on the basis of age, sex, and arm span. The patients were similar to the control subjects in occlusion pressure results. However, they differed significantly (P less than 0.01) in ventilatory responses by a lower VE, lower VT, higher F, and lower VT/Ti in response to the hypercapnia and hypoxia tests. The responses of patients and control subjects were similar during the hyperoxia tests. Our study, therefore, established that the chemosensitivity of the respiratory centers, as measured by P0.1, is well preserved in Steinert's myotonic dystrophy, but the output to breathing (VE, VT, F, VT/Ti) is modulated by the impaired respiratory mechanics causing a tachypneic breathing pattern, even in the absence of restricted lung volume.
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PMID:Control and modulation of respiration in Steinert's myotonic dystrophy. 736 35