Wilderness & environmental medicine
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Wilderness Environ Med · Jan 1999
ReviewThe cerebral etiology of high-altitude cerebral edema and acute mountain sickness.
Despite normal cerebral oxygenation and normal global cerebral metabolism, vasogenic edema develops in humans (and sheep) who become moderately ill with AMS/ HACE during 24 hr or more of hypoxic exposure. Hypoxic cerebral vasodilatation appears to be a necessary ingredient but does not per se explain the development of brain edema. In addition to mechanical factors, a number of biochemical mediators might play a role in altering the blood-brain barrier. ⋯ The "tight fit" hypothesis proposes that individual anatomy of the craniospinal axis determines tolerance to mild brain edema and might help explain individual susceptibility; preliminary studies support this notion. Therapy for AMS and HACE is directed to reducing brain volume and stopping the BBB leak (i.e., oxygenation, diuretics, and steroids) before secondary ischemia develops. New therapies directed specifically toward the defect in BBB permeability are likely to be successful.
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Wilderness Environ Med · Jan 1999
Efficacy of Wyeth polyvalent antivenin used in the pretreatment of copperhead envenomation in mice.
Wyeth polyvalent crotalid antivenin is the only commercial antivenin available in the United States to treat North American crotalid envenomations. Wyeth antivenin is made from the serum of horses hyperimmunized with four crotalid venoms (Crotalus adamanteus, Crotalus atrox, Crotalus durrisus terrificus, and Bothrops atrox). Although Wyeth antivenin is believed to be effective against all North American crotalids, its efficacy against Agkistrodon contortrix (copperhead) has never been tested. The purpose of this experiment was to determine the efficacy of Wyeth antivenin in the treatment of copperhead envenomation. ⋯ Wyeth antivenin is effective in treating copperhead envenomation in mice and may therefore be expected to be effective in humans.
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Wilderness Environ Med · Jan 1999
Multicenter StudyRisk factors and patterns of injury in snowmobile crashes.
To evaluate risk factors for snowmobile injury and patterns of injury. ⋯ Snowmobile injuries are related to ethanol use and the high speed attained by the newer generation of snowmobiles. Extremity fractures were a common component of snowmobile injury in this series, and rates of such injuries are similar to rates injuries in motorcycle accidents in states with helmet laws. Efforts at prevention of snowmobile injuries should be targeted at rider education and enforcement of alcohol restrictions.