The American journal of medicine
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Stress-related mucosal damage of the upper gastrointestinal tract occurs in the majority of critically ill patients. The more severe the underlying disease, the greater the chance that mucosal damage and subsequent bleeding will develop. Clinical outcome is determined by the type and severity of the underlying illness; however, cases with severe gastric damage, as diagnosed by endoscopic examination or by bleeding, have the poorest prognoses. ⋯ Vigorous acid suppression with prolonged periods of pH control may be necessary to treat stress-related mucosal damage and to prevent bleeding. Treatment modalities in current use include antacids, cimetidine, and other histamine (H2)-receptor antagonists, and, more recently, sucralfate. Current evidence indicates that antacids, given hourly and titrated to a present pH goal, or primed continuous infusion of cimetidine are the most efficacious regimens in maintaining intragastric pH control.
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During the last 15 years, there has been a dramatic decline in the incidence of bleeding from stress-related mucosal damage. This decrease probably relates to an increased understanding of those mechanisms responsible for the pathogenesis of stress-related mucosal damage and the application of this knowledge to prophylaxis and treatment. ⋯ The nearly routine use of prophylactic antacid and/or histamine (H2)-receptor antagonist therapy to adequately buffer intragastric acidity is another factor that has minimized the development of stress-related damage. As continued understanding of the mechanisms responsible for stress damage is obtained and therapy applied appropriately, this disease should become a disorder of only historical interest in years to come.
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Randomized Controlled Trial Comparative Study Clinical Trial
A randomized trial of dexamethasone and acetazolamide for acute mountain sickness prophylaxis.
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). ⋯ 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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Visual and auditory neurotoxicity was previously documented in 42 of 89 patients with transfusion-dependent anemia who were receiving iron chelation therapy with daily subcutaneous deferoxamine. Twenty-two patients in the affected group had abnormal audiograms with deficits mostly in the high frequency range of 4,000 to 8,000 Hz and in the hearing threshold levels of 30 to 100 decibels. When deferoxamine therapy was discontinued and serial studies were performed, audiograms in seven cases reverted to normal or near normal within two to three weeks, and nine of 13 patients with symptoms became asymptomatic. ⋯ Moderate abnormalities require a reduction of deferoxamine to 25 mg/kg per dose with careful monitoring. In those with symptoms of hearing loss, the drug should be stopped for four weeks, and when the audiogram is stable or improved, therapy should be restarted at 10 to 25 mg/kg per dose. Serial audiograms should be performed every six months in those without problems and more frequently in young patients with normal serum ferritin values and in those with auditory dysfunction.