Wilderness & Environmental Medicine最新文献

Griffith Pugh, MD (1909-1994), was a pioneer in altitude physiology. During World War II, he developed training protocols in Lebanon to improve soldier performance at altitude and in the cold. In 1951 he was chosen to join the British Everest team as a scientist. In preparation, he developed strategies for success on a training expedition on Cho Oyu in 1952. Results from Cho Oyu led to the use of supplemental oxygen at higher flow rates during ascent than used previously (4 L/min vs 2 L/min) and continued use (at a reduced rate of 2 L/min) during descent, enabling increased performance and improved mental acuity. Oxygen was also used during sleep, leading to improved sleep and warmth. Adequate hydration (∼3 L/day) was also stressed, and a more appealing diet led to improved nutrition and condition of the climbers. Improved hygiene practices and acclimatization protocols were also developed. These strategies contributed to the first successful summiting of Mount Everest in 1953. Pugh was then appointed as the lead scientist for a ground-breaking eight-and-a-half-month research expedition where the team was the first to overwinter at high altitude (5800 m) in the Himalayas. This current work summarizes Pugh's scientific contributions as they relate to success on Mount Everest and in inspiring future altitude research by generations of successful researchers.

Snakebites in unusual anatomical locations may lead to life-threatening consequences. Merrem's hump-nosed viper (Hypnale hypnale) is a medically important snake in Sri Lanka and India that causes many bites and envenomings. Their bites occur almost exclusively on upper and lower limbs and commonly result in local effects, with some patients developing systemic envenoming. No antivenom is available for treating envenoming by H. hypnale. We report an unusual case of H. hypnale bite on the tongue of a 10-month-old infant resulting in rapid local swelling of the tongue and floor of the mouth, requiring prompt intervention to prevent life-threatening upper airway obstruction. Early tracheostomy prevented upper airway obstruction and, along with supportive steroid therapy and antibiotics, led to a complete resolution of the local effects of the infant without permanent disability, despite the unavailability of antivenom.

At the Plaza de Mulas medical tent, located at 4300 m (14,100 ft) along the Normal Route to the 6960 m (22,837 ft) summit of Aconcagua in Argentina, a Korean male in his 50s with no known medical conditions presented with lightheadedness and shortness of breath. He had taken sildenafil and acetazolamide that morning without improvement. Vital signs on arrival were notable for oxygen saturations in the high 60s with basilar crackles on lung auscultation, concerning for high altitude pulmonary edema. The patient was started on oxygen via nasal cannula and given dexamethasone. History was limited secondary to language barriers, but on review of systems the patient noted mild chest pressure. Bedside cardiac echocardiogram was performed, which revealed a septal wall motion abnormality. The patient was therefore given aspirin and clopidogrel and was flown to a lower trailhead, where he was met by local Emergency Medical Services. A 12-lead electrocardiogram revealed an anterior ST-elevation myocardial infarction, and the patient was taken emergently to the catheterization lab in Mendoza and underwent stent placement with a full recovery.

Introduction: Some experts recommend that ambulant hypothermic patients should be rewarmed, fed, and not permitted to exercise for 30 min because of concerns that afterdrop can cause cardiac instability. We investigated the outcome of ambulant hypothermic patients in a case series from mountain rescue teams in Great Britain.

Methods: A questionnaire was used to collect information on a series of adult patients with a clinical diagnosis of mild hypothermia. All patients were alert on the AVPU scale and evacuated by walking from the mountain. The outcome measures were survival or a change in management because of medical deterioration during evacuation.

Results: A series of 108 eligible cases were reported over a 5-year period. When rescuers arrived on the scene, 98 (91%) patients were stationary, and 10 (9%) were still mobile. Thirty-eight (39%) of the stationary cases were walked immediately off the mountain without any on-scene delay. In the remaining 60 (61%) stationary cases, the decision was taken to delay evacuation to provide food, drinks, and additional clothing. In 3 cases, the use of heat packs indicated an intention to actively rewarm. In cases where the on-scene time was reported, 27 (79%) were known to be mobile again within 20 min. All patients survived, and no adverse medical events occurred in all 108 cases.

Conclusions: In this study, no adverse events occurred because of immediate mobilization, suggesting that in these cases, there appears to be minimal risk of early activity.

Prophylactic use of acetazolamide (ACZ) to prevent acute mountain sickness (AMS) is a common practice among high altitude travelers and mountaineers. With its use comes a possible risk of acute kidney injury (AKI). We present a case in which a 56-year-old male hiker in Grand Canyon National Park developed acute exertional rhabdomyolysis and subsequent AKI while taking prophylactic ACZ to prevent AMS. This medication was prescribed despite the hiker encountering only moderate altitude at Grand Canyon with a planned descent within <24 h. The resulting AKI was determined to be the combined result of acute exertional rhabdomyolysis and dehydration/hypovolemia, with the ACZ, a diuretic, as a contributing factor. Medical providers need to recognize the risks/benefits with ACZ use for AMS prophylaxis and avoid prescribing it to individuals whose altitude exposure and activity fall outside the clinical practice guidelines recommended for use.

Research has highlighted the need for training lifeguards in psychosocial skills. Therefore, this study aims to analyze the effectiveness of a short 10-h training program encompassing dimensions associated with emotional management, focus of attention, interpersonal relationships, and lifeguard behavior, and its effects on their psychosocial skills. A total of 64 lifeguards with experience ranging from 1 to 25 years (M = 5.93, SD = 6.07), randomly divided into experimental and control groups, participated in this study. The d2 Test of Attention, the Social Intelligence Test of O'Sullivan and Guilford, and the MSCEIT Emotional Intelligence Test were used to assess psychosocial skills. A multivariate analysis of variance for repeated measures (2 × 3 (Group × Time) MANOVA) was performed to analyze the effects of the training program on psychosocial skills. The results revealed that the experimental group showed statistically significant improvements in focus of attention and emotional intelligence compared to the control group. However, it is worth noting that no statistically significant group interactions were observed for measures of social intelligence. Taken together, these results seem to highlight the importance of including psychosocial content in the general training of lifeguards.

Antarctic expeditions are exceptional challenges for the human body, and medical issues such as nutritional deficiencies, polar anemia, cold injuries, and even death have been reported. We prospectively investigated medical issues encountered by a 33-year-old female adventurer completing the longest solo unsupported one-way polar ski expedition in Antarctica, covering 1484.53 km in 70 days and 16 h from Hercules Inlet to the Ross Ice Shelf, in temperatures estimated from -12 to -50°C and wind speeds of up to 60 mi/h. The adventurer developed a debilitating overuse musculoskeletal neck injury due to poor environmental conditions (ie, poor visibility, wind, and soft snow) while pulling a heavy sled and continuously holding the neck in a flexed position for checking directions on a mounted compass. The adventurer further developed a cold injury on the left calf (polar thigh) that gradually worsened and became ulcerated and more painful throughout the expedition. Potential risk factors included cold ambient temperatures, exposure to windy conditions, and clothing. After the expedition, this injury was treated with a skin graft. Important changes in body mass were observed (ie, reduction of body mass by 26.7% after the expedition) as well as general fatigue, muscle soreness, and sleep deterioration. This case study contributes to the body of knowledge of medical issues during Antarctic expeditions and provides the first scientific account of an adventurer with polar thigh. Further research into this condition is recommended.

We present a case of neurotoxic effects in a pediatric patient after envenomation by a timber rattlesnake (Crotalus horridus) in the Appalachian upstate of South Carolina. Though some members of this species are capable of primarily neurotoxic envenomation, there is heterogeneity in venom composition, and neurotoxic timber rattlesnakes are not endemic to the Appalachian region. However, neurotoxic effects caused by C horridus species lacking typical neurotoxins have been suspected, though not previously confirmed in the medical literature. This case presents a patient who was envenomated by a genotypically confirmed non-neurotoxic C horridus but who nevertheless presented with symptoms consistent with primary neurotoxicity. Neurotoxic effects can be variable in their response to traditional antivenom, though this patient demonstrated rapid response to treatment, representing a novel case in the literature of neurotoxic effects from a snake lacking typical neurotoxins with documented improvement with traditional antivenom.