Journal of wilderness medicine最新文献

The major health risks for travelers to developing countries include injuries, malaria, hepatitis A, hepatitis B, rabies, AIDS and travelers’ diarrhea. Most illnesses can be avoided by use of preventive measures including use of seatbelts in cars, hygienic measures and use of effective immunization and chemoprophylaxis. Practitioners of travel medicine need to know the health risks that confront travelers in order to advise which preventive measures should be used. Most available data apply to travelers visiting developing countries.

During a sub-Antarctic expedition, petrol stoves were used for cooking inside tents and snow-holes (snow caves). The carbon monoxide hazard from the use of petrol stoves was assessed by measuring atmospheric levels with direct-reading indicator tubes (Draeger tubes). Levels up to 300 ppm were recorded, higher than previous field experiments have shown. The levels recorded were unlikely to have affected the exercise capacity of expedition members or to have had other serious effects. Direct-reading tubes were a simple and effective means of measurement. One episode of acute serious hazard occurred and is described, but the atmospheric carbon monoxide level was not recorded. It is concluded that the most important hazard from carbon monoxide under mountaineering and exploration conditions is that of acute fatal poisoning.

Six immigrants were studied with cardiac catheterization at Tuotuohe village of Qinghai, China (15400 ft above sea level, barometric pressure 470 torr) to study the pulmonary hemodynamic changes.

The objective was to assess the effectiveness of acetazolamide and the relative speed of response to acetazolamide and methazolamide on blood gases and symptoms of acute mountain sickness (AMS). Thirty-seven subjects suffering from AMS were given 1–1.5 g acetazolamide or 400–500 mg methazolamide in randomized, double-blind trials during three expeditions to high altitude (3200–5486 m). Both drugs improved PaO₂ by 7.7–8.0 mmHg, with a more rapid response at 3 h following methazolamide. Symptom scores improved over 24 h following both drugs, but headaches were induced in 28% of subjects. It was concluded that treatment with acetazolamide and methazolamide improves arterial oxygenation and symptoms of AMS. The differences in time of response between the two drugs were not proven to be clinically important.

The objective of this study was to describe a serious jellyfish envenomation in a scuba diver by an Atlantic Physalia physalis, to review the related literature and to recommend safe diving practices that may reduce the risk of serious jellyfish envenomation in divers. A healthy scuba diving instructor wearing a full wetsuit and gloves but no hood ascended from a night dive and surfaced directly under a large Atlantic Physalia jellyfish. He suffered multiple severe stings to the unprotected areas of his face and neck. He developed acute subjective respiratory distress with hyperventilation, muscle pain and spasms, and impaired consciousness en route to hospital, more than 10 min following envenomation. He recovered quickly in hospital with oxygen, aminophylline and intravenous fluid administration. Delayed recovery of the envenomated skin took several weeks and serology was positive for Physalia venom antibodies. Full protective clothing (e.g. a full, long sleeved wetsuit, plus gloves and hood when appropriate) should be worn by scuba divers on all dives. Ascent routines in diving should include looking directly upwards at the surface with one wetsuited arm outstretched towards the surface throughout the ascent. Removal of tentacles should not be attempted by the diver until he or she has exited from the water.

A high carbohydrate (CHO) diet has previously been shown to lessen the severity of the symptoms of Acute Mountain Sickness (AMS). The aims of this study were to ascertain whether selected military field rations provided adequate nutritional support, and assess the effectiveness of a high CHO food supplement in reducing the severity of the symptoms of AMS at high altitude. An experimental group (n = 32) received field rations plus a CHO food supplement and a control group (n = 35) only received field rations. Food intakes for 15 consecutive days were recorded using a visual estimation technique and 24-h dietary log. Food acceptability was assessed with a 9-point hedonic scale. Daily urine samples and body weights were obtained from all subjects and a 24-h urine sample obtained from a subsample of the combined groups (n = 30) for the first and last two days of the study.

Results show that energy intake decreased for the first three days at altitude, improved on day four and leveled out thereafter. Mean daily energy intakes were 2265 kcal for the supplemented group and 2140 kcal for the control group; body weight losses were 1.71 kg and 1.68 kg. Mean CHO intake was 271 and 244 g per day; 48 and 46% of energy intake. Ration acceptability was generally good and did not decline over time.

It was concluded that rations used at sea level could also be satisfactorily used at altitude, but given an ad libitum dietary regimen and a CHO food supplement, CHO intake was not automatically increased. Supplementation via a beverage component, rather than a food supplement, may therefore be more effective in increasing CHO intake.

Outdoor or wilderness activities are sometimes combined with the ingestion of alcoholic beverages. Despite the feeling of warmth induced by alcohol ingestion, it is widely believed that alcohol actually causes a decrease in body core temperature and increases the risk of hypothermia during cold exposure. However, the literature on the effects of alcohol ingestion on thermoregulation is conflicting. This review summarizes the scientific findings concerning this topic and identifies a number of confounding factors that may explain the conflicting observations. These factors include quantity of alcohol ingested, severity of the cold stress, nutritional state of the individual, composition of the drink, body composition of the individual and alcohol tolerance of the individual. When these factors are considered, it appears that (1) alcohol acts as a poikilothermic agent, causing a reduction in body core temperature during cold exposure, with the magnitude of reduction related to blood alcohol concentration, (2) the severity of cold and the individual's body composition modify the thermoregulatory effects of alcohol, and (3) hypoglycemia greatly exacerbates the reduction in body temperature caused by alcohol ingestion. Furthermore, the primary mechanism by which alcohol ingestion exacerbates the fall in body core temperature during cold exposure appears to be via an impairment of shivering thermogenesis resulting from alcohol-induced hypoglycemia, rather than by increasing heat dissipation via vasodilation as commonly believed.

The eastern massasauga rattlesnake (Sistrurus catenatus), one of the few members of the Crotalidae family indigenous to the Great Lakes region, is considered to be more reclusive and docile than other types of rattlesnake. We report three cases of eastern massasauga rattlesnake envenomation within the Chicagoland area which required therapy with Crotalidae antivenin. Although bites are relatively uncommon, provoked snakes can inflict significant morbidity.