Objective.—Sleep pattern at high altitude has been studied, mainly with the use of polysomnography. This study aimed to analyze subjective sleep quality at high altitude using the following standardized scales: the Pittsburgh Sleep Quality Index (PSQI) and the Athens Insomnia Scale (AIS-8).

Methods.—Thirty-two members of 2 expeditions—28 males and 4 females (mean age 31 years)—participated in this study conducted in Nepal, Himalayas (Lobuche East, 6119 m above sea level [masl]), Kyrgyzstan, Pamirs (Lenin Peak, 7134 masl), and Poland (sea level). The scales were administered twice, at high altitude (mean altitude 4524 masl) and at sea level.

Results.—Both measures showed a decrease in sleep quality at high altitude (statistical significance, P < .001). Sleep problems affected general sleep quality and sleep induction. Sleep disturbances due to awakenings during the night, temperature-related discomfort, and breathing difficulties were reported. High altitude had no statistically significant effect on sleep duration or daytime dysfunction as measured by PSQI.

Conclusions.—The overall results of PSQI and AIS-8 confirm the data based on the climbers' subjective accounts and polysomnographic results reported in previous studies. The introduction of standardized methods of subjective sleep quality assessment might resolve the problem of being able to perform precise evaluations and research in the field of sleep disturbances at high altitude.

Objective.—To determine the incidence of acute mountain sickness (AMS), the frequency of summiting success, and the factors that affect these in trekkers on Kilimanjaro, one of the world's most summitted high-altitude peaks.

Methods.—The study group comprised 312 trekkers attempting Mt Kilimanjaro summit by the Marango Route. Trekkers ascended over 4 or 5 days along a fixed ascent profile, stopping at 3 huts on ascent (2700 m, 3700 m, and 4700 m) before attempting the summit. Researchers were stationed at each hut for 16 days. Each night we measured heart rate, respiratory rate, blood pressure, oxygen saturation, and Lake Louise Score. We recorded the highest altitude that trekkers reached on the mountain.

Results.—Of 181 complete sets of data, 111 (61%) trekkers reached the summit, and 139 (77%) developed AMS. Physiological results were not related to summit success. The incidence of AMS and summiting success were similar in those on the 4- or 5-day route. Trekkers on the 5-day route who used acetazolamide were less likely to develop AMS and more likely to summit than were those not taking acetazolamide (P  =  <.05); this difference was not present with trekkers on the 4-day route.

Conclusions.—The risk of developing AMS is high on Mt Kilimanjaro. Although taking an extra day to acclimatize with the use of acetazolamide did provide some protection against AMS, ideally trekkers need a more gradual route profile for climbing this mountain.

Objective.—There have been no studies to date exploring the nature of injuries and illness experienced by individuals in a National Park in the southeastern United States. The purpose of this study was to determine the incidence of such illnesses and injuries to visitors in Shenandoah National Park.

Methods.—This study was a retrospective review of the case incident reports from Shenandoah National Park from 2003 to 2007. Data obtained included age, sex, time and date report was received, medical symptoms, trauma type, location of injury, mechanism of injury, level of care, time to patient, time to disposition, disposition type, location, and activity at time of event.

Results.—There were 159 total cases, corresponding to a reported incident rate of 2.7 persons reported injured or ill per 100 000 visitors to Shenandoah National Park. A total of 23.3% of all reported injuries occurred in persons less than 18 years of age. The most common reported adult injury was soft tissue injury, with the most common anatomical location being the distal lower extremity. The most common activity in which adults were involved at the time of the injury was hiking. Of the pediatric trauma cases, the most common mechanism of injury was a fall. Of the adult medical illnesses, the most common complaint was chest pain.

Conclusions.—The pattern of adult and pediatric trauma is consistent among several geographically different National Parks in the United States and represents an injury pattern that all wilderness/outdoor care providers need to be competent to treat. Among adult visitors, the most common medical complaint was chest pain, a complaint more prevalent at Shenandoah National Park compared to other parks. Knowing that trauma injury patterns are relatively similar to those of other parks but that medical illness is more locale specific can help health care providers tailor their resource allotment and health management protocols.

Objective.—Directly experienced health impacts and the perception of health impacts affecting the wider community kayaking in the sea environment were assessed.

Methods.—Four hundred questionnaires were distributed at coastal launch sites in West Wales. One hundred and seventy-eight questionnaires were returned.

Results.—The majority of respondents had not received injuries or developed medical conditions as a result of kayaking in the sea. Among those who had directly encountered health impacts, problems with joints, tendons, and muscles were the most frequently reported injury. When asked what were the most common health impacts in general among those who kayak in the sea, ‘sprains and pulled muscles’ and ‘cuts and abrasions’ were the most frequently cited factors. The rank order of the ‘most common injury or medical condition’ and the ‘most commonly injured part of the body’ varied according to type of boat used and activity undertaken. This variation was evident in relation to direct experience of health impacts and the perception of injuries and medical conditions affecting other kayakers. Most respondents regarded injuries and medical conditions as uncommon and not serious and reported positive health effects from kayaking.

Conclusions.—Health impacts encountered by those kayaking in the sea reflect many of those identified in literature focusing upon other aspects of kayaking. Responses to questions regarding the most common injury or medical condition and the most common injury site vary according to type of boat used and activity undertaken. It is concluded that while there may be common demands placed upon paddlers using a variety of boats and participating in differing activities, it cannot be assumed that they are a homogeneous group. This has implications for the development of incident prevention strategies.

Objective.—To analyze the nature of surfing injuries in Cornwall in order to identify trends and inform clinical management.

Methods.—The details of patients presenting (with injuries sustained while surfboard/bodyboard riding) to the Emergency Department (ED) of the Royal Cornwall Hospital, Truro (UK), from September 2004 until August 2006 were recorded prospectively. The notes were then retrospectively reviewed by a senior ED physician. The records of each visit were scrutinized for date, age, sex, injury type, and injury severity and outcome; in addition, the patient's residential status (Cornish resident or visitor) was recorded.

Results.—A total of 212 patient episodes were collected. Male patients represented 80% of injuries. The average age was 27 years (range, 11–66 years). Nonresident surfers represented 57% (121) of the patients, and 43% (91) of patients were local Cornwall residents. Of the total injuries, 90% (n  =  190) were injuries that were minor/moderate (allowing for discharge after treatment). Lacerations accounted for 38% (n  =  73) of injuries, and bruising and laceration to the head represented 37% (n  = 71) of injuries in this group. Sprains to the neck and back represented 53% (21/40) of all sprains. Fractures of the facial bones represented 6 of the 8 fractures to the head region; the other 2 fractures involved teeth. Fractures to the upper and lower limbs were equally frequent (6 cases of each). Anterior shoulder dislocations accounted for 10% (n  =  19) of injuries not requiring hospital admission. Injuries requiring hospital admission represented 10% (n  =  22). These injuries were a more disparate group, with fractures of the cervical spine and skull accounting for 32% (n  =  7) and fractures of the lower limb 27% (n  =  6) of the total. A total of 77% (n  =  168) of all injuries presented in the summer months (April through September). The greatest number of presentations occurred in August, with 33% (n  =  69) of the total surf-related injuries for the year.

Conclusions.—Surfing injuries were most common in young adult men. Most injuries presenting to the ED were minor/moderate injuries and did not require hospital admission. The overall pattern of injuries was similar to those found in studies from other countries where surfing is popular; however, there was a higher-than-expected incidence of shoulder dislocation. The trends identified in this study could be used to inform education focused on prevention of the most common injuries. Increased use of protective headwear should be considered.

We describe a recent case of presumed redback spider (Latrodectus hasselti) envenomation observed near Noumea in New Caledonia. This is the first local reported case in this archipelago, where L. hasselti is currently considered a native species. We highlight the challenge of providing appropriate analgesia in this situation and believe that the use of specific redback spider antivenom should be considered in New Caledonia.

We report a case of a bather injured by a swordfish in shallow water off the coast of southern Brazil. The victim suffered multiple injuries from the fish's bill, including a puncture wound of his left knee and the tip of the bill remaining as a foreign body. The victim made a full recovery after field management and conservative care. The potential factors leading to this most unusual attack are discussed.

Objective.—To evaluate the effects of a long-distance backpacking trip on body composition, weight, blood lipids, and lipoproteins.

Methods.—Single-subject (male, aged 49 years) study of an experienced backpacker who hiked 118 days on the Appalachian Trail. Outcome measures that were assessed pre-hike and post-hike included body fat (%) by hydrostatic weighing and skinfold assessment, height and weight, body mass index (BMI), circumference measurements (umbilicus, anterior suprailiac, maximum hip, greater trochanter, minimum waist, umbilicus/anterior suprailiac ratio), and blood pressure (systolic and diastolic at rest and peak). Dietary analyses (total kilocalories, protein, carbohydrate, fat, cholesterol, saturated fat, monounsaturated fat, polyunsaturated fat, dietary fiber) were conducted pre-hike, on days 54 through 56, and on days 98 through 100. Blood lipids and lipoproteins (triglycerides, high-density lipoprotein, low-density lipoprotein) were measured pre-hike, on day 89, and post-hike.

Results.—Pre-post differences showed decreases in body weight, from 85.3 kg to 73.9 kg (−11.4 [−13.4%]); percent body fat, hydrostatic weighing, from 25.18 to 14.31 (−10.87 [−43.2%]); percent body fat, skinfolds (7-site), from 23.79 to 11.61 (12.18 [−51.2%]); and BMI, from 29.37 to 25.46 (−3.91 [−13.3%]). Pre-post differences in blood lipid changes over the course of 118 days were as follows: triglycerides (mg·dL⁻¹) fell from 319 to 79 (−240 [−75%]); total cholesterol (mg·dL⁻¹) fell from 276 to 196 (−80 [−29%]); high-density lipoprotein (HDL) (mg·dL⁻¹) rose from 46 to 63 ( 17 [ 37%]); low-density lipoprotein (LDL) (mg·dL⁻¹) fell from 167 to 118 (−49 [−29%]); LDL/HDL ratio fell from 3.63 to 1.87 (−1.76 [−48%]); and total cholesterol/HDL ratio fell from 6.00 to 3.11 (−2.89 [−48%]).

Conclusion.—The physical activity and diet associated with an extended backpacking adventure can considerably reduce and clinically normalize blood lipids and lipoproteins without medication and can very positively affect body composition and weight.

Objective.—Altitude-related cough is a troublesome condition of unknown etiology. Inhaled tussive agents are used to quantify cough, and the citric acid cough threshold has been shown to fall on ascent to altitude. Cough can occur in patients taking angiotensin-converting enzyme inhibitors due to stimulation of airway sensory receptors by increased levels of bradykinin. We hypothesized that increased levels of bradykinin could be responsible for the decrease in citric acid cough threshold on exposure to altitude and a possible etiologic factor in altitude-related cough.

Methods.—Twenty healthy volunteers underwent baseline tests at 700 m before a 2-week stay at 3800 m. Angiotensin-converting enzyme activity and plasma bradykinin were measured at baseline and altitude. Citric acid cough threshold and nocturnal cough frequency were measured at baseline and throughout the 2 weeks at altitude.

Results.—Citric acid cough threshold fell from 3.7 g/dL at baseline to 2.1 g/dL on the second day at 3800 m (geometric mean difference 1.8, 95% CIs 1.0–5.0, P  =  .025) and remained reduced throughout the stay at altitude. Nocturnal cough frequency was unchanged compared to baseline. Plasma bradykinin fell from 0.43 ng/mL at baseline to 0.08 ng/mL at altitude (geometric mean difference 5.7, 95% CIs 2.1–15.5, P  =  .002), but angiotensin-converting enzyme activity was unchanged (mean difference 0.06, 95% CIs –2.7–2.8, P  =  .97). There was no correlation between plasma bradykinin and citric acid cough threshold.

Conclusions.—Increased levels of bradykinin are unlikely to be a significant factor in the increased sensitivity to citric acid seen in hypobaric hypoxia. Further studies are required to elucidate the etiology of altitude-related cough.

Objective.—To determine the incidence of and risk factors for acute mountain sickness (AMS) in native Nepalese children during a pilgrimage trip to Gosaikunda Lake in the Langtang National Park Region of Nepal (elevation 4380 m).

Methods.—A descriptive, noninterventional, cross-sectional study was completed on a group of children during the pilgrimage to Gosaikunda. Participants were interviewed about the symptoms of AMS using the Lake Louise Scoring System.

Results.—Thirty-six children between 3 and 15 years of age were interviewed after a rapid ascent (over 1 to 3 days) from 1950 m to 4380 m. Acute mountain sickness was diagnosed in 17 of 36 (47.2%) children. The sickness was seen in only 5 of 20 (25%) children who took 2 or more days to ascend, compared with 12 of 16 (75%) children who spent only 1 night (reaching the study site at Gosaikunda on the second day) to complete the same ascent (P ≤ .01, odds ratio [OR]  =  9.0, 1.61 < OR < 57.36). No significant correlation was found between the incidence of AMS and gender, previous exposure to high altitude, or concurrent illness.

Conclusions.—Our results indicate that the incidence of AMS in this group of Nepalese children was high and associated with rapidity of ascent. Rapid ascent to high sleeping altitude and increased physical activity were observed as possible risk factors. We suggest organizing educational programs to make children and their parents aware of altitude-related problems and advise gradual ascent to such high-altitude pilgrimage sites.

Objective.—The objective of the study was to assess the level of knowledge regarding snakebite management in doctors likely to treat such bites in the Special Administrative Region of Hong Kong in the People's Republic of China. Key concerns were doctor confidence, consistency of approach, use of anti–snake venom (ASV), and ancillary treatments. Hong Kong hospitals are equipped according to developed country standards, and knowledge therefore becomes the key factor in successful management.

Methods.—A predesigned questionnaire consisting of 29 multiple-choice questions was submitted to physicians likely to treat snakebite victims at all Hong Kong hospitals receiving such patients.

Results.—The key finding identified that only 29% of responding doctors were confident about treating snakebites. In the case of ASV selection between the 2 products available that deal with different species, 66% of doctors either were unsure of which to use or believed the 2 ASVs to be the same. The use of inappropriate clinical endpoints for ASV therapy suggests it is being used unnecessarily.

Conclusions.—There is clear room for improvement in the knowledge base and confidence level of physicians treating snakebites in Hong Kong. Key components of management, such as ASV choice, indications, dosing, and clinical endpoints for administration, were sources of confusion to the participants in this study. The results demonstrate the need for a locally developed and widely distributed snakebite management protocol.

Objective.—Transporting clean drinking water in an easily accessible container is a priority for many outdoor enthusiasts. Two basic hydration systems are commonly used to provide water: the water bottle and the hydration bladder. The authors tested the hypothesis that there were different levels of microbiologic contamination between these 2 systems.

Methods.—Sixty-seven water samples were collected using sterile techniques from outdoor enthusiasts at several outdoor recreational locations. These users were then asked to complete a brief survey that reported demographic information and details of water container use. Water samples were then plated on sheep blood agar, and the colony-forming units were counted after 24 hours of growth. The 2 groups were compared using Student's t test.

Results.—The 2 groups using water bottles or hydration bladders did not show significant differences in container age, duration of outdoor activity, or duration since last cleaning. The groups differed slightly in their composition of hikers/walkers/runners vs cyclists. The water bottle group had a mean colony-forming unit count per 100 mL of 37 (95% CI 26–48), and the hydration bladder had a mean of 27 (95% CI 17–35).

Conclusions.—There was no statistically significant difference between hydration bladders and water bottles in microbial contamination or colonization. Judging from the available data, outdoor enthusiasts should select their water container based on criteria other than the relative exposure to microbes. Additional study is required to replicate this finding in other locations and with improved sample methodology.

Individual psychological responses to heights vary on a continuum from acrophobia to height intolerance, height tolerance, and height enjoyment. This paper reviews the English literature and summarizes the physiologic and psychological factors that generate different responses to heights while standing still in a static or motionless environment. Perceptual cues to height arise from vision. Normal postural sway of 2 cm for peripheral objects within 3 m increases as eye-object distance increases. Postural sway >10 cm can result in a fall. A minimum of 20 minutes of peripheral retinal arc is required to detect motion. Trigonometry dictates that a 20-minute peripheral retinal arch can no longer be achieved in a standing position at an eye-object distance of >20 m. At this distance, visual cues conflict with somatosensory and vestibular inputs, resulting in variable degrees of imbalance. Co-occurring deficits in the visual, vestibular, and somatosensory systems can significantly increase height imbalance. An individual's psychological makeup, influenced by learned and genetic factors, can influence reactions to height imbalance. Enhancing peripheral vision and vestibular, proprioceptive, and haptic functions may improve height imbalance. Psychotherapy may improve the troubling subjective sensations to heights.