Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight patients with mild-to-moderate chronic obstructive pulmonary disease (COPD) and average resting Pao2 of 66 mm Hg were studied clinically and physiologically at sea level and after ascent to 1,920 m. At sea level the patients were symptomatic but not disabled. After ascent the patients had only mild symptoms of fatigue and insomnia, and one had severe headache during exercise on the first day. Funduscopic changes were not observed, nor did cardiac or pulmonary findings change. Resting sea level Pao2 dropped to 51.5 mm Hg within three hours of ascent, and the Paco2 fell from 37.8 to 33.9 mm Hg. Over the next three days, the Pao2 increased to 54.5 mm Hg as hyperventilation continued. At exercise, sea level Pao2 dropped from a mean value of 63 to 46.8 mm Hg at altitude. Pulse rates at rest or exercise did not change. Normal values for 2,3-diphosphoglycerate (2,3-DPG) did not change after ascent at 16 and 42 hours. We believe aircraft flight or travel to moderate altitudes for this type of COPD patient is safe. Preexisting hypoxemia resulting from disease may facilitate the adaptation of patients to severe hypoxia and may prevent symptoms similar to acute mountain sickness.
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PMID:Short-term adaptation to moderate altitude. Patients with chronic obstructive pulmonary disease. 68 52

Altitude sickness is a clinical syndrome that occurs with abrupt ascents to altitudes of 3000 metres and above. Symptoms include headache, malaise, fatigue, dizziness, anorexia, nausea and vomiting, and oliguria. At higher altitudes more severe illness resulting from pulmonary oedema or cerebral oedema can occur.
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PMID:Altitude sickness. 232 86

A clinical syndrome identical to the chronic mountain sickness of the Andes occurs commonly in Lhasa, Tibet. It affects, almost exclusively, the immigrant Han population and develops after an average of 15 years' residence at high altitude. The early symptoms are attributable to polycythaemia--headache, dizziness, loss of memory and fatigue being prominent. In the later stages of the disease, dyspnoea and peripheral oedema develop. Haemodynamic investigations show pulmonary hypertension with a normal cardiac output and dilatation of the right ventricle in the long-established case. Respiratory gas studies provide evidence of alveolar underventilation and ventilation: perfusion inhomogeneity. Both clinical and investigatory data suggest that the earlier stages of the disease are dominated by polycythaemia, while cardiopulmonary involvement increases with the duration of the disease. The disease is rare in women and uncommon in Tibetans. Cigarette smoking appears to be a contributory factor.
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PMID:Chronic mountain sickness in Tibet. 251 94

The incidence of acute mountain sickness was determined by questionnaire in 454 individuals who attended week-long continuing medical education programs at ski resorts in the Rocky Mountains with base elevations of about 2000 m. As a control group, 96 individuals who attended continuing medical education programs at sea level in San Francisco completed similar questionnaires. Study subjects were classified as having acute mountain sickness when they reported three or more of the five possible cardinal symptoms: headache, insomnia, dyspnea, anorexia, and fatigue. Only symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. Acute mountain sickness-like symptoms occurred in 25% of subjects at 2000 m compared with 5% of subjects at sea level. The incidence of acute mountain sickness at 2000 m was greatest among subjects who had come from lower altitudes. Half of the subjects with symptoms took medication. The duration of symptoms was short, with 90% of all symptoms that were reported occurring in the first 72 hours. Acute mountain sickness is common at intermediate altitudes, and it is frequently severe enough to prompt self-medication.
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PMID:Incidence of acute mountain sickness at intermediate altitude. 291 Nov 69

To test the value of dexamethasone acetate for ameliorating acute mountain sickness (AMS), we conducted a double-blind, randomized study that compared the effects of 4 mg of dexamethasone acetate or a placebo (given every six hours for six doses beginning at the time of exposure) at 2700 and 2050 m. Study subjects, who were recruited from health professionals who attended continuing medical education programs at ski resorts in the Rocky Mountains, were classified as having AMS when they reported three or more of the five usual symptoms (headache, insomnia, dyspnea, anorexia, and/or fatigue) on a single day. All symptoms with an intensity of at least grade 2 (moderate) out of 5 were analyzed. At 2700 m, there was a 50% decrease in the mean AMS symptom score in the dexamethasone group (0.94 +/- 1.11 vs 1.84 +/- 1.44 [mean +/- SD]) and the incidence of AMS was 20% of that in the control group (3/38 vs 14/35). At 2050 m, there was no difference between dexamethasone and a placebo in the mean AMS symptom score (1.52 +/- 1.50 vs 1.24 +/- 1.33) and the incidence of AMS (5/25 vs 4/25). Dexamethasone ameliorates the usual symptoms of AMS at 2700 m but not at 2050 m.
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PMID:Effects of dexamethasone on the incidence of acute mountain sickness at two intermediate altitudes. 291 Nov 70

Behavioral, physiologic and exertional fatigue is differently defined, though symptoms are similar. The beneficial effect of amantadine on fatiguability in multiple sclerosis is accompanied by neuropeptide and lactate changes in the circulation. Exercise sometimes overwhelms temperature regulating mechanisms and may be associated with heat stroke. Endogenous opioids are markedly increased in the circulation during heat stroke and the use of specific opioid antagonists therapeutically has been proposed for heat stroke. Sympathetic activity changes in endurance trained subjects and vasoconstrictor responses are markedly attenuated. Similar changes occur in parasympathetic function which can be abnormal in up to 90% of endurance trained subjects. Hormonal secretion during prolonged exertion is altered and the normal signals (inhibiting or activating feedback mechanisms) are different in endurance trained subjects. Altitude, associated with acute mountain sickness, is also accompanied by an increase in cranial bloodflow. Circadian and temporal variation in autonomic function are manifest by changes in mast cell numbers and 5-HT containing nerve fibers in temple skin of patients with cluster headache. The remission rate induced by vagal stimulation in subjects with intractable hiccups is also affected by circadian hormonal or neurogenic influences.
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PMID:The autonomic nervous system and fatigue. 296 78

Forty-seven climbers participated in a double-blind, randomized trial comparing acetazolamide 250 mg, dexamethasone 4 mg, and placebo every eight hours as prophylaxis for acute mountain sickness during rapid, active ascent of Mount Rainier (elevation 4,392 m). Forty-two subjects (89.4 percent) achieved the summit in an average of 34.5 hours after leaving sea level. At the summit or high point attained above base camp, the group taking dexamethasone reported less headache, tiredness, dizziness, nausea, clumsiness, and a greater sense of feeling refreshed (p less than or equal to 0.05). In addition, they reported fewer problems of runny nose and feeling cold, symptoms unrelated to acute mountain sickness. The acetazolamide group differed significantly (p less than or equal to 0.05) from other groups at low elevations (1,300 to 1,600 m), in that they experienced more feelings of nausea and tiredness, and they were less refreshed. These drug side effects probably obscured the previously established prophylactic effects of acetazolamide for acute mountain sickness. Separate analysis of an acetazolamide subgroup that did not experience side effects at low elevations revealed a prophylactic effect of acetazolamide similar in magnitude to the dexamethasone effect but lacking the euphoric effects of dexamethasone. This study demonstrates that prophylaxis with dexamethasone can reduce the symptoms associated with acute mountain sickness during active ascent and that acetazolamide can cause side effects that may limit its effectiveness as prophylaxis against the disease.
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PMID:A randomized trial of dexamethasone and acetazolamide for acute mountain sickness prophylaxis. 333 64

The purpose of this investigation was to determine if the hyperventilatory response to fatiguing isometric exercise at sea level could predict resting ventilation and acute mountain sickness (AMS) at 4300 m altitude. Exercise consisted of four successive endurance handgrips held to complete fatigue at 40% of maximum isometric handgrip strength (MHS). There was no relationship between the magnitude or pattern of exercise-induced hyperventilation at sea level and the severity of AMS later at altitude. Sea level hyperventilatory response was not predictive of resting ventilation at altitude. Altitude exposure progressively increased both the incidence and magnitude of the hyperventilatory response to exercise and prolonged it for 60-90 s into the recovery period, providing support for the "central command" theory of ventilatory control during isometric exercise. MHS was significantly increased at altitude--by 11% on day 2 and 16% on day 6. Endurance times to fatigue were reduced, but not always significantly so. A follow-up study involving more practice at sea level demonstrated MHS to be significantly increased throughout an entire 18-d stay at 4300 m and for 3, but not 5, days after descent. Significant changes in endurance could not be demonstrated. Neither AMS nor changes in body weight or circulating norepinephrine levels can account for the temporal pattern of increased grip strength, but the respiratory alkalosis occurring at altitude appears to be a likely mechanism.
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PMID:Respiratory response and muscle function during isometric handgrip exercise at high altitude. 381 31

During three expeditions to high altitude the Birmingham Medical Research Expeditionary Society has studied the effects of the ascents on its members. The severity of acute mountain sickness (AMS) produced was assessed by three methods, interview, self assessment and peer review. Physical examination was unhelpful. The results of the three methods were closely correlated. Clinical interview permitted allowances to be made for individual factors such as fatigue. There was no tendency for self assessment to indicate effects consistently more or less than the other methods. Peer review revealed a wide spread of opinions but the large number of observers allowed the derivation of plausible mean values. Correlation of AMS with arterial pH and PaCO2 showed little relationship but correlation with PaO2 was good, particularly for self assessment. As all the methods are subjective a combination of techniques is recommended for future expeditions.
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PMID:The clinical assessment of acute mountain sickness. 397 47

A resident living at Lake Tahoe, Calif, at an elevation of 2,000 meters, had fatigue, edema, and erythrocythemia. Hematocrit was 63 percent, and arterial blood gas values revealed hypoxemia and respiratory acidosis. Results of pulmonary function tests, sleep study, and thyroid function all were normal. Erythrocytosis, cor pulmonale, and respiratory acidosis resolved after the patient moved to sea level. This patient suffered from chronic mountain sickness. Her symptoms resolved with relief of hypoxia.
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PMID:Chronic mountain sickness at an elevation of 2,000 meters. 636 45


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